# Possible motor for mill



## DavidR8 (Mar 7, 2020)

This came up in my feed today. 






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I’m considering it for my mill. But honestly at this point my understanding of using a VFD for a 3-ph motor is that I can spell VFD. And motor. 

My goal is to have to fuss less with belts on the mill as I’ve discovered that it’s a real pain. 

Currently my mill has a 1hp 1-ph 1740 rpm motor. Speeds range from ~200 rpm to ~2100 rpm. 

Would I be making a mistake by picking one up?


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## ttabbal (Mar 7, 2020)

Looks like a decent motor to me. You may have to build an adapter for mill to mount it up. And perhaps something to adapt to the pulley. 

I leave the belts alone most of the time, but do occasionally have to move them if I want large speed changes. Usually only for really large stuff like the spacer I recently modified. 

I run from about 30hz-120hz. About 50-200% speed. I also have a back gear available that drops a lot of speed.


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## DavidR8 (Mar 7, 2020)

Thanks @ttabbal 
I’ll see if the seller responds. 

Any recommendations for a VFD? Did I spell that correctly? 


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## Ulma Doctor (Mar 7, 2020)

the only thing that may be a problem is the voltage.
the motor runs on 575v 3phase


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## DavidR8 (Mar 7, 2020)

Ulma Doctor said:


> the only thing that may be a problem is the voltage.
> the motor runs on 575v 3phase



What voltage should I be looking for?


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## markba633csi (Mar 7, 2020)

Plus if they are compressor motors the rpm might be higher than 1720


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## Ulma Doctor (Mar 7, 2020)

i believe your low voltage should be 208, 230 or 240v- a 230v motor would suffice

575 is high voltage


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## Ulma Doctor (Mar 7, 2020)

markba633csi said:


> Plus if they are compressor motors the rpm might be higher than 1720


they are 1740 motors


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## BrentH (Mar 7, 2020)

Best case David is 220 to 240 Volts three phase.

50/60 hz is all ok as you are using the VFD


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## DavidR8 (Mar 7, 2020)

Awesome! Thanks gents 


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## ttabbal (Mar 7, 2020)

Oops! I missed the voltage. Yeah, you want 220/230/240 whatever they call it these days.  

Some of them are able to be rewired for low/high, that's how most of mine are. But those are 220/440 generally. 

I use the cheap import VFDs from ebay. They work fine for me, though they are not sealed so you need to put them where swarf, oil, grinding dust, etc can't get in them. On the other hand, I can blow up 4 of them before the expensive sealed ones break even.


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## Ulma Doctor (Mar 7, 2020)

ttabbal said:


> Oops! I missed the voltage. Yeah, you want 220/230/240 whatever they call it these days.
> 
> Some of them are able to be rewired for low/high, that's how most of mine are. But those are 220/440 generally.
> 
> I use the cheap import VFDs from ebay. They work fine for me, though they are not sealed so you need to put them where swarf, oil, grinding dust, etc can't get in them. On the other hand, I can blow up 4 of them before the expensive sealed ones break even.


i have had very good luck with inexpensive drives form Ebay
if they ever should break i'm out 50 or 60 bucks- a high end VFD could be more than $1000


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## machPete99 (Mar 7, 2020)

Try to find a motor with "class f" insulation rating. That will stand up better to a VFD.
Also get one that has the frame size/geometry that you need. There are some NEMA standards here.


			https://www.surpluscenter.com/images/techhelp/nema2.pdf
		



			https://www.baldor.com/Shared/pdf/nema_chart_04.pdf


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## Aaron_W (Mar 7, 2020)

When I started hooking up my VFD I quickly found out that not all 3 phase motors are equal. Some work better with a VFD than others, some are made specifically to work with a VFD and will provide much better variable speed control than those that just tolerate a VFD.

In my case it turns out that the person who converted my mill to 3 ph VFD knew what they were doing and used a Baldor motor specifically made to work with a VFD.

I'm not the one to ask about the technical aspects, as I know just enough to electrocute myself, but we have many here who understand this stuff. If you are going to do the conversion I'd get some specific recommendations for the motor beyond 3 phase, 240v, 1740 rpm.


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## graham-xrf (Mar 7, 2020)

DavidR8 said:


> Thanks @ttabbal
> I’ll see if the seller responds.
> 
> Any recommendations for a VFD? Did I spell that correctly?
> ...


@DavidR8
Hi David.
OK - I get it that for you, the simple 3 letters "VFD" is from another dimension!
If you want the most flexible, energy efficient, totally controllable, full torque regardless revs, power_factor_corrected, automatic soft start, internal safe-torque-off e-STOP safety, with controlled accelerate / decelerate to halt without stripping gears, then you now have loads of low-cost multi-pole (meaning 4 to 8 poles) servo drives available. Every (Jap, Chinese, American, Italian, etc.) outfit is falling over themselves to offer everything including "electronic gearboxes", and "guaranteed safety".

*Will the torque force flop out?*
For example - I have recently being going all weak-knee at something like --> THIS
OK - so when we stop getting distracted, the point was how the machine can deliver a full torque controlled dead stop - zero RPM!
That is what a modern multipole servomotor with encoders can do - and motors don't have to be a DC type.

I have listed only 7 features so far. Now consider what "VFD" used to mean. _Variable Frequency Drive!_ So now let us carefully lead you into what this might mean. I will try to make it meaningful for anyone who glazes over when encountering business buzztalk like "fully integrated solutions for fully parameterized high-bandwidth current-loop stability"! Ditch all that for now.

*Motors? "Induction" motors?* ..
Take the most common motor type. From decades past to the present, it is only now that we are finally getting some really serious motor development, like the 185kW motor in the back end of the Tesla Model S, For the average small(ish) lathe, it is a 3/4 HP or 1HP "squirrel-cage" induction motor. If you use both phases in a USA-type supply (2 x 110V = 220V or so), you can have 2.2 to 2.9kW - i.e. up to about 3HP. They can be artificial 3-phase, or an artificial 2-phase which starts out as single phase, and the "other" phase is made by putting it through a capacitor, often seen as the "extra" cylindrical component hanging on the outside of the motor. If you have an "older" piece of iron that hails from the days before software-controlled everything, then this is very likely what came with your iron.

You can "change the speed" of these by making an electronically generated artificial supply, and "make the frequency less than 60Hz". The motors middle bits, "armatures, rotors" whatever, rely on a magnetic field that "rotates". I skip over what exactly is "induction motor" for now. Suffice to say it is the way the rotating bit manages to become magnetic is by having the field "induced" in it - much like a transformer.
It is simply not enough to just change the frequency, which is already low to start with. The torque force drops off dramatically!

Also note that the spinning bit does not manage to keep up with the rotating fields coming from the coils. There is always a "lag", which gets bigger as you load the motor.

*Speed and Torque*
Now we come to the crucial bit. The power delivered by the motor is Power = Torque x Speed. In this case, "speed" is an angular velocity, which can expressed in terms of RPM using conversion constants e.g. HP = Torque (pound-foot) X RPM/5252. The point is - look what happens if you want to go slow! The power falls to zero!  This is the main disappointment if you have a simplistic "VFD" simply plonked straight onto an old induction motor.

*Better types of VFD.*
Still going with the available VFD's, the better types are still able to drive single phase and three phase induction motors with better delivery of torque at slower speeds. They generate an artificial  3-phase supply, or two phase for use with an old motor, and you ditch the capacitor. This can be had from a single phase source. Be aware that there is a limit to how high a voltage you can wring out of a 110V supply. If you can get across the two phases as most US-type household supplies are done, for 220-240VAC, and connect the artificial 3-phase in a wiring mode known as "delta", you can extract a respectable amount of controlled power. These sort only alter the frequency by a limited amount. They operate the motors with large amounts of "slip", and they alter the energy to the coils using quite complex higher frequency pulsed waveforms. Higher frequency means about 2kHz to about 20kHz, though any carrier below 8KHz squeals to annoyance! Welcome to "variable duty-cycle pulsed-width modulation".

So we have many products, all using the simple moniker "VFD", and we now know that some are more capable than others. If you intend to keep the old induction motor, make sure the VFD you choose will drive it, and try and discover if it will deliver enough torque to take the heavy cut, even though you are turning slow. Some of these get very clever. Unfortunately, too many are simply vague about the detail of what the drives really will do.

If I wanted high torque full speed control, I would try for a modern permanent magnet multi-pole motor with shaft encoder, and programmable servo drive, which might all simply go under the name "speed control", These encoders can count all the pulses from the encoder that might happen in decades of turning. They can be used for _positional_ control. Welcome to CNC.

Modern VFDs are clever enough to get by without an encoder. They can sense the currents in the coils. The torque control is not as tight, or as precise, but it removes an expensive component, and may be all you need for regular non-CNC work.

Forgive that I may have just muddied the waters for you. My background includes designing 2 x 70kW servo drives for a 60HP RAT turbine that could receive and deliver program demanded revs and torque either pumping or being pumped by jet fuel, and return incoming power to the grid instead of dumping it in a heater.  I did not miss the point that the humble induction motor on my *South Bend 9A* needs either a damn smart "VFD", or should be replaced by a modern drive motor. The innards of these things are still very physics-fundamenrtal. Just metal and copper and insulation and (now) powerful magnets. Add bearings and shaft. They do not cost substantially more than the old kit unless you are being offered hype! The real smarts are in the drive controllers, often using high-speed 32-bit internal computing.

*Now try and make it simpler*
1. First decision is whether to play with the full servo motor replacement deal, or whether to find some electronics that will make the old induction motor deliver a reasonable facsimile thereof. If you want to use the induction motor, then pay attention to the detail claims of the drive, especially if it calls itself a "VFD". There are some good ones about, made specifically for traditional induction motors, but quoting "Animal Farm", "some are more equal than others. You know now to check whether it can haul up a high torque at 100RPM. Look for features like "Power Factor Correction" , and "RFI filtering", and the presence of a load dump resistance load for acceleration and braking control.

2. The next thing is to check the power input capabilities. Know your AC mains supply, and what the drive expects. Figure out the power.

3. Take care about the motor capabilities. An AC capacitor on an old 60Hz induction motor may not take kindly to a 12kHz carrier pulse-width modulated drive unless the waveform envelope approximates a traditional 60Hz supply, even if the shape is more "square" than "sine".

It can be a complicated subject, and I get it that you want to see straight to an affordable product that can bolt-on. I think they exist, but I was not going there. I have tried to cut through the jargon, but it still ended up a long posting, for which I apologise.

edit: P.S. Just for curiosity, what are the available voltages in a Canadian-type supply. Do you get 2 phases to a household, so higher energy stuff like cookers etc. can have 220-240V? What motor do you want to get adventurous with?


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## DavidR8 (Mar 7, 2020)

Thanks @graham-xrf for the very fulsome treatise! I’ll have to re-read it several times for my brain to fully absorb all the information. 

To your question. I have access to both 110v and 220v, both single phase. 

The existing motor on my 1980’s mill is a 1hp, 110/220v, single phase. It’s currently wired for 220v. 


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## graham-xrf (Mar 7, 2020)

DavidR8 said:


> Thanks @ttabbal
> I’ll see if the seller responds.
> 
> Any recommendations for a VFD? Did I spell that correctly?
> ...


OK - I should have been paying attention to the earlier posts. I just spotted it. Industrial motors can use higher voltages from industrail 3-phase supplies. It makes sense because if they have a whole factory full of machines, then the higher voltages allows lower current, hence easier switching and less copper.

The voltage from neutral to any phase is is phase-to-phase voltage/√3
In your case V= 575/1.732 = 331.9 VAC. You can immediately see that your domestic supply is nothing like that.

Consider your domestic voltage. It might be 115V (say). So if you have available a 2-phase supply point, you get 230VAC phase-to-phase.
Now discover how many amps you can draw from it. It might be (say) 10 amps.
The power you can have from this supply is Volts x Amps = 2.3kW.
This means 2300/746 = 3.08 HP. Change the numbers to suit your situation.

Now come to what motor is usable. An electronic drive will first change the alternating voltage into a direct current supply "bus" using diode rectifiers or other electronic switching. The highest value this bus can get to is a bit less than voltage times √2.
That might be 115 x 1.414 = 325V
The electronics might be able to make an "artificial" 3-phase voltage out of that much. Disregard for now how it does it. We are here seeking to assess how usefully compatible the motors on offer might be. Compare to a UK scene where the 3-phase feed is 415V, and the house voltage is 235-240VAC

We can go on to consider that a 3phase motor can be operated at a lower voltage, but using higher current, by wiring it connected as "delta" instead of "star" connections, and better suit the drive electronics. Regardless, in all these cases, your supply cannot be compatible with an industrial motor rated 575V without transformer or switch-mode boost. The kit to contrive the suitable voltage is way more expensive than simply using the right motor.


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## graham-xrf (Mar 7, 2020)

DavidR8 said:


> Thanks @graham-xrf for the very fulsome treatise! I’ll have to re-read it several times for my brain to fully absorb all the information.
> 
> To your question. I have access to both 110v and 220v, both single phase.
> 
> ...


Oops - the posts crossed again. OK - 220V. This is easy enough for a 1HP motor. About 3.4 amps.
You get that voltage phase-to-phase.

The 1HP is 746 watts. A 575VAC 3-phase motor works to different rules.
3-phase power - √3 x (Power Factor) x Current x Voltage.

That power factor thing is because motors have magnets and coils in them, which have a property called inductance. This is because energy is stored in the magnetic fields, and it resists changes, so it slows down the rise of a current when charging, and tries to keep it going once established. The net effect is to delay, or lag the current changes behind the voltage. The voltage is a bit out of phase with the current. The value of the power factor in a bit of a worst case condition is usually about 0.86. Often the value is printed on the metal label on the motor.

So go for it! 746watts = √3 x 575V x 0.86 x Current.
Figure that the current needed in that motor = 0.871A. The motor delivers 1HP with only 870 milliamps!.

You can tell right away this is not for you. Electronic drives are clever, and I dare say there are some that might make a 3-phase voltage for anything you like starting with only a car cigarette lighter. BUT.. 746 watts taken from the poor suffering 12V battery does it with 62 amps!

A one horsepower servo drive given 220VAC to start with is easy, and reasonably low cost. This is provided you don't ask it to do it with a 575V motor on the other end. Don't buy a 575V motor for your mill.


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## Cooter Brown (Mar 7, 2020)

Only buy a 3ph motor that can be wired to run on 220v 3ph.


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## Nigel123 (Mar 7, 2020)

When I went to variable speed on my mill drill I installed a 2 hp Dc motor
Not sure how the torque at low speed with a VFD on a 1 hp 3 phase would be
Maybe someone who has done this can verify the performance
My mill will go from 120 to 1500 rpm without changing belts on the pulleys
Have not had to change pulleys since installing 15 years ago
You may have to look at a bigger motor to get low speed torque
I agree changing pulleys for speed control is the pitts


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## Ulma Doctor (Mar 7, 2020)

very simply put,
even old school motors can be run off a vfd effectively.
 just realize that torque and Hp vary by changing the frequency.
even the oldest 3 phase motors i have retrofitted with VFD control have performed in the 30 to 90 Hz envelope without incident.
the problems encountered are generally from trying to work outside the envelope.
heat is the major problem, the design of the fan is for 60Hz operation 
when you go too slow, the fan can't move enough air across the under-excited motor
when you go to fast, the fan can't supply enough air across the over-excited motor
don't get too caught up in all the esoterics of VFD control,
it really is not that difficult once you get a few concepts down
they are not magic boxes


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## Nigel123 (Mar 7, 2020)

How would the torque be at 30Hz at 1 hp on a mill drill would it be enough to mill a 4 inch face mill
Just trying to give Dave an insight to update his mill


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## Ulma Doctor (Mar 7, 2020)

that would depend on DOC
if torque was a concern, you could possibly overspeed the motor in the lower speed belt position


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## Ulma Doctor (Mar 7, 2020)

Nigel123 said:


> How would the torque be at 30Hz at 1 hp on a mill drill would it be enough to mill a 4 inch face mill
> Just trying to give Dave an insight to update his mill


i don't have a VFD on a vertical milling machine, but i have a few lathes that are VFD enhanced, (mainly for single to 3 phase conversion)
i use the frequency control mostly for threading operations, where major torque is not really a concern.
but usually i let the lathes work at 60Hz, and change gears if the work is heavier in nature, or i'm making too drastic of a frequency change.
one lathe i have has an inverter rated motor that i could take to over 200Hz, but i don't see the point for a lathe.

if torque is a concern for larger tooling, provision could be made to increase the size of the drive motor for higher torque and Hp values
instead of 1 hp got to 2 hp and worry not about torque or hp


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## Nigel123 (Mar 7, 2020)

So maybe going to more Hp on the motor would be to Dave's benefit
I don't know if it would it  cost more to to go to more Hp but in the long run
to not change pulley speeds might be worth the cost


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## Ulma Doctor (Mar 7, 2020)

or he could just take lighter cuts
if he plans on production or making money, i'd recommend the larger Hp motor
for hobby and fun, go 1 hp and live with the minor limitations


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## Nigel123 (Mar 7, 2020)

Sorry was replying as you post came in
I agree I use a 2 Hp DC motor on my lathe love the capability of variable speed when threading close quarters and need slow speed
I always use the gearing then fine tune with the variable speed
The mill drill might need a little more power


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## DavidR8 (Mar 8, 2020)

I’d love to have the best of both worlds; low speed with torque and the ability to have higher speeds for aluminum. 
I’m not doing any kind of production but 
I would like to be able to take advantage of the rigidity that the 700 lbs of cast iron seem to be able to provide. 

I have taken deep cuts with it and that’s not likely to be the norm but I also don’t want to be limited to 2 thou passes. 

Seems like two options are open to me: 3ph and VFD or a DC motor and speed control. Or am I totally muddled?


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## ttabbal (Mar 8, 2020)

I think you'll be alright. My Bridgeport came with a 1hp and I've never felt like I was lacking torque. I do move the belts when I want the highest or lowest speed. Most of the time it is in the second to highest pulley speed. The VFD and the back gear give me enough range that I don't need to move the belts much. 

It's the original motor from the 50s I think. It runs well with the VFD, but I don't let it try to run below 30hz. The fan probably doesn't move enough air that low, and it gets grumpy much below that. You can set min and max frequency in the settings, so it's easy to keep it from happening accidentally.


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## DavidR8 (Mar 8, 2020)

Thanks @ttabbal 
I’ll keep my eyes open for a suitable 3ph motor 


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## Joeman77 (Mar 8, 2020)

DavidR8 said:


> Thanks @ttabbal
> I’ll keep my eyes open for a suitable 3ph motor
> 
> 
> Sent from my iPhone using Tapatalk


Since you're probably going to have to make an adapter anyway, if it was me I'd take this opportunity to bump the HP up on the motor a bit, more available power won't hurt at all. 1-1/2 to 2hp 220v, 3 phase 1725rpm motors aren't terribly expensive. Try for an "F" rating in insulation if possible (especially if you're buying new) but that's not a deal breaker by any means. Lots of us are running 50 year old motors on VFD's. 
All that being said a new motor & a shiny new VFD doesn't mean you won't have to change belts, it'll just be much less frequent and will probably for that rare occasion when you're down on the RPM's & up on the DOC trying to hog something crazy! The sky (or your wallet) are the limit. Have fun with this!


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## graham-xrf (Mar 8, 2020)

Nigel123 said:


> When I went to variable speed on my mill drill I installed a 2 hp Dc motor
> Not sure how the torque at low speed with a VFD on a 1 hp 3 phase would be
> Maybe someone who has done this can verify the performance
> My mill will go from 120 to 1500 rpm without changing belts on the pulleys
> ...


@Nigel123 : You may have a really good drive control. It may be using PWM drive electronics, and may have a control response faster than the changes in load can collapse the voltage. It sounds like you have a useful power range there. 120RPM is slow enough for most folk, except those into CNC control who want stuff like automatic tapping with stops and reversals and all the stuff you would be doing manually.
BUT..
A "bigger" motor does not simply deliver more low speed torque. If it is an induction motor, with capacitor, instead of being a 8-pole servo-motor with encoder and permanent neodymium magnets, and a smart servo drive, then all that will happen is "big" motor simply fails to spin up to enough revs to deliver it's "bigger" power.

Go slow with your kit, and note the revs. Then give it a bit of load. Does the speed stay exactly unchanged? One can take this test all the way to stall and trip-out, but in most folks shops, that is _not_ something to be casually trying out.


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## graham-xrf (Mar 8, 2020)

Ulma Doctor said:


> they are not magic boxes


Honestly, when I first encountered them, I thought they were (magic boxes).

I think that despite the name "VFD", the good ones have do more than simply alter the frequency. Changing the frequency alone cannot to the trick. The simple inductance is a frequency dependent thing that evaporates as the revs slow down, and inductance is important to limiting the AC current.

We still call them "VFDs", but now, the actual internal operation of variable speed control in AC motors no longer uses simple AC induction motor speed rotating field in relation to frequency in the traditional way. The currents are switched on an off at kilohertz frequencies, and the energy is varied by controlling the ON time compared to the OFF time in a complex waveform. That these techniques can then, at another level, be used to make bolt-on kit that can usefully work "traditional" motors with "artificial AC" is remarkable, and perhaps it was inevitable.

When these technologies are mated up to servo motors specifically built for this kind of control, then we have a whole new game, like robotic CNC. One can, and I have, also explored going _faster_ than the 50Hz or 60Hz related maximum revs. It works well!

I have to appreciate that there are esoterics, and I can't just casually use the term "VFD control" anymore.


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## Nigel123 (Mar 8, 2020)

When I setup this system VFD were expensive and not without problems
I had a surplus of cheap DC motors and drives
By reading threads on this site VFD's and 3 phase are the way to go just have no machines with them installed
Set up a few on drives before I retired almost 20 years ago wash down was a killer
Set the DC drive with max and min trim pots to get RPM stable when loaded
Yes quick reversing is not an option found that out when I hit the reverse switch by mistake lucky 10 amp fuse blew
If I remember rightly the motor bolted on to the mill with  little trouble maybe had to drill a couple of holes
Just wanted to suggest a slightly bigger motor might be less belt changing not that DC is the way to go


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## ttabbal (Mar 8, 2020)

If you have the gear, nothing wrong with DC from what I can tell. Perhaps permanent magnets attracting swarf, but not a big deal. People use treadmill parts which are usually DC motors with PWM speed controllers for this sort of thing all the time. They are popular with the DIY belt grinder crowd too. I think they have some areas on the torque curve they are better and 3ph has some in different areas. I haven't worked with them much, even though I have one in the garage from a treadmill my brother was trashing. I was going to do a grinder with it, but ran into a perfect 3ph, brand new for a killer price.


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## luxige (Mar 8, 2020)

This is a very educational thread!

David, I highly recommend this 8-part YouTube series, starting here:


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## DavidR8 (Mar 8, 2020)

Thanks @luxige!


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## DavidR8 (Mar 9, 2020)

luxige said:


> This is a very educational thread!
> 
> David, I highly recommend this 8-part YouTube series, starting here:



I watched the video series last night. 
What a great explanation for visual learners like me. 
Thanks to everyone that contributed, I feel like I am much better informed now. 


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## DavidR8 (Mar 10, 2020)

I might have found a decent Canadian source for a new 3-phase motor. 
Conversion might be around $325 all in. 


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## DavidR8 (May 1, 2020)

So the motor supplier had a 'free shipping' sale so I have ordered a 1.5 hp 220v/440v 3 ph motor and a Teco VFD.
Watching Clough42's videos he is using a contacter between the line input and the VFD. I can't make out what model it is though.
Ideally I'd like to end up with fwd, rev and variable speed.

In lieu of the contacter, can I simply install an on/off swith on the incoming line? Not to start or stop the mill as I understand frequent power cycles are hard on the VFD internals, but to power on the VFD at the start of the day and off at end of day?


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## talvare (May 1, 2020)

DavidR8 said:


> In lieu of the contacter, can I simply install an on/off swith on the incoming line? Not to start or stop the mill as I understand frequent power cycles are hard on the VFD internals, but to power on the VFD at the start of the day and off at end of day?



Yes. Really no need for a contactor.

Ted


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## Aaron_W (May 1, 2020)

DavidR8 said:


> So the motor supplier had a 'free shipping' sale so I have ordered a 1.5 hp 220v/440v 3 ph motor and a Teco VFD.
> Watching Clough42's videos he is using a contacter between the line input and the VFD. I can't make out what model it is though.
> Ideally I'd like to end up with fwd, rev and variable speed.
> 
> In lieu of the contacter, can I simply install an on/off swith on the incoming line? Not to start or stop the mill as I understand frequent power cycles are hard on the VFD internals, but to power on the VFD at the start of the day and off at end of day?



You can also use a plug on the VFD, just unplug it when you are done using it.


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## DavidR8 (May 4, 2020)

The VFD arrived today. Very impressive bit of kit. 
Motor should be here Friday. 







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## matthewsx (May 4, 2020)

DavidR8 said:


> The VFD arrived today. Very impressive bit of kit.
> Motor should be here Friday.
> 
> 
> ...



Nice, I see you got the unit with FUN built in....

John


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## DavidR8 (May 4, 2020)

matthewsx said:


> Nice, I see you got the unit with FUN built in....
> 
> John



I didn’t even have to pay extra for that!

I fully expect to use that setting 


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## luxige (May 5, 2020)

Please post up your settings, if you don't mind. I'm going to get around to doing that myself in the next few days.…

Congrats!
(And, err, don't drop a screwdriver in there).


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## DavidR8 (May 5, 2020)

luxige said:


> Please post up your settings, if you don't mind. I'm going to get around to doing that myself in the next few days.…
> 
> Congrats!
> (And, err, don't drop a screwdriver in there).


Will do, not likely going to get at it before next week though


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## macardoso (May 5, 2020)

@DavidR8, I work on VFDs all day long. One word of caution... After unplugging it, the DC bus will be charged up to ~325VDC. This voltage is often exposed to some screw terminals for attaching accessories. 325VDC is quite dangerous. Please give it time to bleed off and verify the voltage with a digital multimeter on the bus is below 50VDC before touching the drive to do any wiring. Some have bleeder circuits to do this within a few seconds, but we also have drives at work that can hold this for 10-15 minutes.

Nice VFD you picked out. I think you will be happy.


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## macardoso (May 5, 2020)

@DavidR8, I skimmed this thread and got the impression you were running the machine on 240VAC 1P. It looks like you purchased a 115VAC input drive. 

My concern is that the drive is going to be putting out 115VAC 3P which is half of the voltage you need for your motor. I would think you needed a 
L510-201-H3-U which is the 240VAC 1P input version of this drive.

I also could have missed something here, but I doubt you are hooking up a 115V 3P motor. Those are very uncommon.


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## DavidR8 (May 5, 2020)

macardoso said:


> @DavidR8, I skimmed this thread and got the impression you were running the machine on 240VAC 1P. It looks like you purchased a 115VAC input drive.
> 
> My concern is that the drive is going to be putting out 115VAC 3P which is half of the voltage you need for your motor. I would think you needed a
> L510-201-H3-U which is the 240VAC 1P input version of this drive.
> ...


I am running on 240 V.
This is the link to the VFD where I bought the VFD and motor. The specs indicate 230V input. 








						TECO-Westinghouse L510-202-H1-U | Teco Westinghouse L510-202-H1-U - AC Drive - 2HP CT Rating 230V 1PH Input 230V 3PH Output Chassis L510 Advanced Micro Drive | eMotors Direct | Canada
					

Teco Westinghouse L510-202-H1-U - AC Drive - 2HP CT Rating 230V 1PH Input 230V 3PH Output Chassis L510 Advanced Micro Drive




					www.emotorsdirect.ca


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## macardoso (May 5, 2020)

DavidR8 said:


> I am running on 240 V.
> This is the link to the VFD where I bought the VFD and motor. The specs indicate 230V input.
> 
> 
> ...




Whoops! My bad, sorry. I was looking on another site and found the "101" model by accident. Read too quickly. Sounds like you have a killer setup.


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## DavidR8 (May 5, 2020)

No worries @macardoso!
Ironically I very nearly bought the single phase output version of that unit till I double checked!


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## DavidR8 (May 8, 2020)

My 3 ph motor arrived today.
1.5 hp 220/440v 3 ph



Set to pulling the motor pulley
Don't have a puller so I had to improvise with some all-thread couplers and 3/8" bolts which I used as jacks to lift the pulley off the shaft.
As I got close to getting it off the shaft I ran out of thread on the fully threaded bolts so I ran them back in and put the shouldered bolts in the other end.



The pulley was so tight I thought I was going to strip the threads. Even after heating it up with my propane torch it was a struggle to make it budge.




Finally got it off. Discovered there was no keyway in the pulley, just a setscrew that seated in the keyway. 

I think I'll be shopping for a new pulley as the bore is 15/16" and the new motor shaft is 7/8. I suppose I could bore it out and make a bushing but I have no means to broach the keyway.


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## DavidR8 (May 9, 2020)

Fitted up the motor. Used the existing holes in the motor mount. Almost like I planned it that way 











Now all I have to do is deal with this 






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## hman (May 9, 2020)

I had a similar problem removing the motor pulley on my own round column mill when I converted to a three phase motor and VFD.  The end of my pulley was closed, because the top sheave had an ID smaller than the motor shaft.  I carefully drilled down the centerline (or as close as I could get to it), then tapped the hole for 5/1/16-18 and used a jacking screw (a length of all-thread and double nuts).  As I recall, the depth (thickness) of the aluminum was longer than the tap, so I had to partially counterbore 5/16" to get the threads all the way through.  You might want to drill and tap your new pulley (or your re-used existing one) in a similar manner.


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## Buffalo21 (May 9, 2020)

I’m very conservative, I have a single phase to 3 phase  VFD conversion on one of my mills. It has the original 5 step pulley system and I change belts and use the VFD in conjunction to obtain the speeds I want. I never go below 30 Hz or go above 60 Hz. The motor is a 2 hp Marathon, according to them, because of the motor age, insulation type, torque requirements and intended use, if I stayed within the 30-60 HZ operating range, the motor should function fine for years. As UD posted, the working parameters of the cooling fan’s operation is extremely important, so far the motor has been going strong for 15+ yrs, without an issue.


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## DavidR8 (May 9, 2020)

hman said:


> I had a similar problem removing the motor pulley on my own round column mill when I converted to a three phase motor and VFD. The end of my pulley was closed, because the top sheave had an ID smaller than the motor shaft. I carefully drilled down the centerline (or as close as I could get to it), then tapped the hole for 5/1/16-18 and used a jacking screw (a length of all-thread and double nuts). As I recall, the depth (thickness) of the aluminum was longer than the tap, so I had to partially counterbore 5/16" to get the threads all the way through. You might want to drill and tap your new pulley (or your re-used existing one) in a similar manner.



Thanks that’s a good idea. 
In hindsight a puller might have been a challenge because the motor shaft doesn’t extend much past the bottom edge of the bottom sheave meaning the threaded part of the puller would have had to be pretty long. 

I’m thinking that I might drill and tap two holes in the top of the pulley. Then get piece of flat bar, drill and tap for 5/16” in the centre with two holes corresponding to the tapped holes in the pulley. 
That way I could just bolt the flat bar to the pulley, screw in the 5/16 rod and pop the pulley off. 


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## DavidR8 (May 9, 2020)

Buffalo21 said:


> I’m very conservative, I have a single phase to 3 phase VFD conversion on one of my mills. It has the original 5 step pulley system and I change belts and use the VFD in conjunction to obtain the speeds I want. I never go below 30 Hz or go above 60 Hz. The motor is a 2 hp Marathon, according to them, because of the motor age, insulation type, torque requirements and intended use, if I stayed within the 30-60 HZ operating range, the motor should function fine for years. As UD posted, the working parameters of the cooling fan’s operation is extremely important, so far the motor has been going strong for 15+ yrs, without an issue.



That sounds like sage advice. 
This is an inverter rated motor which the supplier advised is designed to better deal with changes in frequency. 


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## hman (May 9, 2020)

DavidR8 said:


> Thanks that’s a good idea.
> In hindsight a puller might have been a challenge because the motor shaft doesn’t extend much past the bottom edge of the bottom sheave meaning the threaded part of the puller would have had to be pretty long.


Welcome!  I've always been very hesitant to use a gear puller on an aluminum pulley.  It's just too easy to break the aluminum!


DavidR8 said:


> I’m thinking that I might drill and tap two holes in the top of the pulley. Then get piece of flat bar, drill and tap for 5/16” in the centre with two holes corresponding to the tapped holes in the pulley.
> That way I could just bolt the flat bar to the pulley, screw in the 5/16 rod and pop the pulley off.


I assume your pulley has a through hole.  Mine did not.  Here's a couple photos of mine, drilled & tapped, along with the jacking screw and the two setscrews (90º apart on the pulley) and the key that secured the pulley to the motor shaft.


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## DavidR8 (May 10, 2020)

Spent some time tonight making a bushing to adapt my pulley to the new motor. 
Bored out the pulley to 1.125”
Turned down a piece of aluminum to be a slip fit in the pulley bore. 
Bored the aluminum to .875” to slip over the motor shaft. 
Cut the key way using a 1/8” cutoff blade laid flat in tool holder. 
Finished it up with a file. 
The bushing turned out pretty good I think. I didn’t bore the pulley deep enough as it’s about 1/4” too high. Easy enough to go a bit deeper. 

Bunch of firsts for me tonight , boring, working to a specific dimension and cutting a key way. 





















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## DavidR8 (May 12, 2020)

Small question: I'm working out the wiring for the VFD.
I have no problem with running from the outlet the the VFD. My challenge is what wire to use to run from the VFD to the motor. Yesterday I looked at some 14 ga, three-conductor + ground extension cord and the stuff was easily 5/8"+ thick with all of the insulation and whatnot.
I have 14 ga red, black and white THHN. Can I use the THHN if I put it inside some sort of covering?


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## matthewsx (May 12, 2020)

DavidR8 said:


> Small question: I'm working out the wiring for the VFD.
> I have no problem with running from the outlet the the VFD. My challenge is what wire to use to run from the VFD to the motor. Yesterday I looked at some 14 ga, three-conductor + ground extension cord and the stuff was easily 5/8"+ thick with all of the insulation and whatnot.
> I have 14 ga red, black and white THHN. Can I use the THHN if I put it inside some sort of covering?



Shouldn't be any problem with using the THHN wire, I assume you're thinking of flexible wire-mold? You can also just ground the machine rather than running a ground wire to the motor from the VFD.

john


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## DavidR8 (May 12, 2020)

Thanks John, flexible wire-mold is exactly what I was thinking about... could not remember the name for the life of me!


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## luxige (May 12, 2020)

DavidR8 said:


> Bunch of firsts for me tonight , boring, working to a specific dimension and cutting a key way.



That’s gotta be satisfying!


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## DavidR8 (May 12, 2020)

Yup another bit of education in my journey 


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## DavidR8 (May 15, 2020)

I connected the VFD last night. Used 14 ga THHN VFD to motor with ring terminals. Worked like a charm.
Motor is silky smooth after tweaking some settings on the VFD.
Sady I discovered that something is wrong with my bushing as it has about 30 thou runout wobble.  I think the problem is that the keyway at the bottom of the bushing is not as deep as the top so it's wedging the bottom out slightly. I think that I'm going to try and fix that or remake it before I shell out for a new pulley.


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## matthewsx (May 15, 2020)

Yeah, every time I've tried to use a bushing to adapt a pulley it never seems to come out right. I'm sure it can be done but for my money I'd either buy or make a pulley the right diameter for the motor shaft. 

You don't have anything but time and materials to loose by trying again but don't kick yourself too hard if it still doesn't work. In the long run you'll quickly forget what you had to pay for a new pulley and be super happy about the VFD install. I know that's what happened with me, I couldn't tell you how much I paid for the pulley on my Star lathe but it works great....

John


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## DavidR8 (May 18, 2020)

I had another go at the pulley and bushing today.

I used the 4-jaw so I could dial the pulley in nice and true. I chucked it up, called upon Abom79, popped my indicator into the largest pulley groove and got it under a thou of runout in about two minutes. 
Holy moly! The snout of the pulley was wobbling like a weeble! Somehow, I managed to bore the thing off-centre 

I remeasured the bore depth and decided to go 3/8" deeper so I could get the pulley coplaner with the idler pulley.

Commence making horrible cast iron mess. (Yes @mikey, the lathe was fully protected )

Got it bored correctly this time. Time to make a new bushing.
Still using the 4-jaw I chuck up a length of stock. Dialed it in easy. I'm liking this chuck!
I didn't have to take much off the 1-1/8 aluminum to get a nice, slip fit in the pulley. I made sure to take light cuts to avoid heating up the aluminum and throwing off my test fits. A few passes and all done.

Time to bore. Worked my way up to the biggest bit I have, a 5/8' then back to the boring bar till I hit .0875 bang on. 

I decided to not cut a key way. Instead I sawed a slot and then filed it to fit the key like a glove!

Fitted it up and gave it a test run. Smooth as butter, no wobble, no vibration!

Popped the belt on, and the only thing I can hear is horrible grinding from the idler puller. 

Pull that off and discover that the bearings are completely toast. After only 30 years of service with likely zero maintenance. 

So ordered new bearings. For reference there are two 47mm OD, 20mm ID X 14mm thick bearings.

Was a good way the end the day.
Thanks for reading!


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## FOMOGO (May 18, 2020)

It's always nice when a plan comes together. Well done. Mike


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## DavidR8 (May 26, 2020)

A bit of an update on the motor conversion. 
When I fired everything back up the idler pulley bearings were making an awful racket. 
I removed the pulley and pressed out the bearings. They were open cage and completely full of dirt and grime from 30 years of use. 

Took some measurements and ordered new sealed, lubricated bearings which arrived today. 

Just came in from putting it back together. What a difference the new bearings make. There’s only slightly more noise than from the just the motor alone. Very happy with the result. 


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## Aukai (May 26, 2020)

Jackie Gleason had a saying....And away we go.....


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## Joeman77 (May 26, 2020)

Wow, sounds like you're making excellent progress! I think this is definitely an upgrade that you'll be happy with once the shakedown is over.


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## DavidR8 (May 26, 2020)

I am definitely so far. Now that it doesn't sound like a cement mixer I messed with belt locations and I think I can dial the rpm down to what looks like tapping speed and still have enough torque. Taking it up to about 90 hz definitely give me the rpms I had before. Still have to replace drive and spindle bearings.


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## DavidR8 (May 27, 2020)

More success last night. But only because @mksj came to my rescue with excellent instructions on how to program my VFD so that a DPDT switch would enable forward/stop/reverse.
It took a couple of tries to get the programming right. User error as per normal. But now i have forward and reverse on my mill.
I still have to wire in the frequency control potentiometer  and put it all together properly but this was a big step.
Soon I'll be able to start my knurling tool build so that I can make a tap wrench handle... feels a bit like I'm mining iron ore so that I can build a log cabin.


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## mikey (May 27, 2020)

DavidR8 said:


> ... feels a bit like I'm mining iron ore so that I can build a log cabin.



I like the way you put this, Dave. As hobby guys, we often have to learn a skill or build something so we can make the thing we really want. We're so focused on the thing we want that we fail to realize that the skills and bits of knowledge we gain along the way are far more valuable. No other hobby I know of will expand your knowledge or enable your self-reliance more than this one and it's really nice watching you grow.


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## DavidR8 (Jun 1, 2020)

Thanks @mikey, it certainly is a journey. Definitely agree with you about expanding my knowledge and self-reliance. 

For example today I spent nearly 10 hours in the garage. My goal was to get the rest of the VFD wiring sorted out and hopefully have a go at the drive bearings. 
I have to thank Mark @mksj for giving me the tips I need to get the VFD install done. Thanks Mark!

So I cut leads for the frequency control potentiometer the forward/off/reverse switch, soldered that all up and got it installed in a box. 






I have flex conduit for everything but I didn’t have the correct size adapter for the box. Easy enough to retrofit. In the meantime I zip tied all the wires together for tidiness. 

Still need to make labels for the box. Top is frequency, the switch is reverse to the left, off and forward to the right. 

I noticed grease dripping from the bottom of the spindle so decided to pull it. 

Had to make a pulley to remove the drive pulley. Used a 4” length of 3/8” x 3/4” flat stock. Drilled and tapped a centre hole for a 3/8 bolt and a hole at each end for 3/8 bolts. I also drilled and tapped two 3/8 holes in the top of the pulley. Screwed in the two bolts, applied a bit of tension and the pulley popped right off. 

Long story made only somewhat short, my replacement drive bearings are the wrong size inner bore so I didn’t replace them. 
The previous owner had pumped the lower spindle bearing full of grease and it had liquified. I cleaned up the whole mess, and reassembled it. 

I was planning to do the spindle bearings but discovered that my press doesn’t have the height capacity to press on the new bearings. Seems like another project. 


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## mikey (Jun 1, 2020)

Most machine shops and auto repair shops have a hydraulic or arbor press that can do the spindle bearing swaps for you. Shouldn't cost much, especially if you make the pressing adapters to do the job. Is there another HM member near you that might be able to pitch in?


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## DavidR8 (Jun 1, 2020)

mikey said:


> Most machine shops and auto repair shops have a hydraulic or arbor press that can do the spindle bearing swaps for you. Shouldn't cost much, especially if you make the pressing adapters to do the job. Is there another HM member near you that might be able to pitch in?


The only other local member I know of is @francist and I don't believe he has a press.
I'm going to order the correct size drive bearings so I'll be pulling it all apart again. I should have measured the spindle when I had it out so I could make adapters though I suppose I could extrapolate the measurements from the bearing specs.


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## francist (Jun 1, 2020)

@DavidR8  — ah but I do have a press, although not a big one. Mine is a 10-ton Canuck Tire bench mount version so doesn’t have the throw that a floor press does. Is that what you have, or perhaps more to the point, what is the overall height that you would need to do what you want? I can always go measure based on that.

I also have a 1-ton arbour press but that’s not anywhere near what you want. Lemme know if you want me to check.

-frank


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## DavidR8 (Jun 1, 2020)

francist said:


> @DavidR8 — ah but I do have a press, although not a big one. Mine is a 10-ton Canuck Tire bench mount version so doesn’t have the throw that a floor press does. Is that what you have, or perhaps more to the point, what is the overall height that you would need to do what you want? I can always go measure based on that.
> 
> I also have a 1-ton arbour press but that’s not anywhere near what you want. Lemme know if you want me to check.
> 
> -frank



I have a bench top model. 
I don’t know how much height I actually need. I measuremated the height of the spindle to be about 17”. 
Add some space for pressing bushings and call it 20”. 


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## darkzero (Jun 1, 2020)

DavidR8 said:


> I measuremated the height



Haha, never heard that one before, that's a good one! That will go perfect with my EBI (eye ball indicator), maybemeter, or might gauge.


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## francist (Jun 1, 2020)

Hmmm, maybe not going to do it.

Curiously (as I was doinking around in the dim light with my tape measure after dinner thinking well maybe 14, maybe 14 and a half...) there is a teeny sticker on the top of the frame that says “Maximum Lift Range 0 - 14-3/8”)  That’s clear space between the bottom of the ram and top surface of the supporting blocks, so if you needed to slide a solid brick of something in there that would be the max size. That wouldn’t take into account if there was potential to poke part of, say, a shaft through a hole in the supporting blocks to gain some extra range.

I’m not familiar enough with what the pressee looks like but I’m sure you are. Would be worth a careful evaluation to see if an inch or two could be stolen from somewhere depending on creativity of setup. Might be close.

-frank


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## DavidR8 (Jun 1, 2020)

darkzero said:


> Haha, never heard that one before, that's a good one! That will go perfect with my EBI (eye ball indicator), maybemeter, or might gauge.



You heard it here first! 


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## francist (Jun 1, 2020)

I like maybemeter, got a real nice ring to it....


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## DavidR8 (Jun 2, 2020)

Well colour me embarrassed...
In post 76 above I said this "Long story made only somewhat short, my replacement drive bearings are the wrong size inner bore so I didn’t replace them."

Preparing to order new bearings I look at my receipt to see just what I ordered. Hmm looks like I ordered a pair of sealed 6009Z bearings... what the heck is going on?
Trot on out to the shop, get the bearings out of the drawer and look at the box.
Hmm they are what I ordered. What the heck? Wait why are both boxes unopened?
Why is one of the spindle bearings boxes open?
Oh that's because on Sunday I picked up the spindle bearings instead of the drive bearings so of course they didn't fit...
DavidR8 is a duffus!!!


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## darkzero (Jun 2, 2020)

Haha, good to know I'm not the only one that suffers from CRS (can't remember schmoo) & DHC (don't have a clue) from time to time.

"Don't you love it when a plan comes together?" Yes it was planned, don't tell anyone otherwise. You had planned to take the weekend off & install the bearings during the week.


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## DavidR8 (Jun 2, 2020)

And a cunning plan it was!


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