# Original motor from 1986 gone bad? Busy Bee B-244 lathe, speed is all over the place plus big current draw!



## toysareforboys (Feb 24, 2020)

I was doing a massive production run today and was running her for about 10 hours straight then it started to do weird things. It dropped from full speed down to 1/3 speed, drew way more current (dimmed the lights in my shed) for a few seconds to a minute and then went back to full speed, did that over and over, didn't seem to make any different noises, no smells. Even at full speed the amount of torque/power was way way down from what it normally is. After I finished a few more parts with it running like this (about 10 minutes) it permanently dropped to 1/3 speed or less with almost no torque.

When I went to pull the cover off the back of the motor I noticed the air intake screen was plugged up with delrin shavings, so I might have overheated it. I let it sit for a few hours then fired it up again but only 1/3 speed or less, lots of current draw, no torque. I couldn't get the motor cover off because one of the screws to the cover is on the very bottom and I'll have to unbolt the lathe from the bench to get at it. A project for tomorrow maybe.

If I rotate the chuck by hand I can hear some scratching noises in the motor, it was always silent before, but the chuck/motor rotates easily by hand.

Any suggestions on what to look at/for?

If the motor is cooked I'd like to put a motor on it that I can control the speed of (i.e. run it slow but still have full torque). Currently I only have 120v/60hz/20amp available in my shed but I could run 240v to it if necessary. No idea where to start with that stuff though (controller/motor), suggestions appreciated and if you need more info/measurements from the lathe just let me know.

Luckily I was able to finish the production run I was doing so it's not a panic that it get fixed quick.

Thank you for any help you can provide.

-Jamie M.


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## John O (Feb 24, 2020)

A few years ago I went to Carson electric on Milner ave for help with my motor kicking out the vfd.
The person was very helpful explaining my problem in basic language got me to rewire differently.
Did not need parts and didn't charge for the 20 minutes of his time.


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## toysareforboys (Feb 24, 2020)

John O said:


> A few years ago I went to Carson electric on Milner ave for help with my motor kicking out the vfd.
> The person was very helpful explaining my problem in basic language got me to rewire differently.
> Did not need parts and didn't charge for the 20 minutes of his time.


That'd be a short trip for me. I'll bring it to them and see what they say. Thanks!

-Jamie M.


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## toysareforboys (Feb 24, 2020)

Dropped off the entire lathe to them today. They'll give me a quote on repairing the motor as well as upgrading the lathe to a VFD! Oh baby, can't wait 

-Jamie M.


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## toysareforboys (Mar 3, 2020)

Carson couldn't come up with any motors that would fit (that'd work with a VFD) so I picked up the lathe from them unrepaired to come up with some better motor options myself.

I removed the main drive pulley from the lathe chuck driveshaft and the diameter of the shaft is 30mm or just a hair smaller (0.0064") than 1 3/16" so I ordered a split pulley bushing from McMaster Carr in 1 3/16" size (split pulley bushings compress to squeeze the full circumference of the shaft when you bolt a pulley on them) and it fits like a glove, nice!

For a motor I chose a monster stepper motor. I know, I know, stepper is not the the best choice for "high speed" lathe operation because the power/torque massively drops off at high RPM but I just love stepper motors, how simple they are to control (both speed and direction) as well as how much torque they put out (especially at slow speeds).

I went with a massive NEMA 52 sized closed loop stepper motor with a peak holding torque of 28NM, peak pull-out torque (i.e. torque it produces while spinning) of 25NM and at the maximum speed I'll be running it at (1000rpm motor, 2000rpm chuck) it'll provide 6.25NM at the chuck (12.5NM at the motor). The stepper driver it comes with is also super nice! Single phase AC 120v or 240v and it'll spit out 3 phase at up to 8 amps/2000 watts. Closed loop stepper motors (and drivers) can be pushed at much higher speeds without losing as much torque as open loop steppers and closed loop also have the benefit of much much better efficiency so the motor doesn't heat up as much.











It has a digital readout display (of RPM, steps, current/watts, programming options, etc) and you can put it in "speed hold" mode, so say you set it at 500rpm, if you start to machine something and it starts to slow down the motor it'll keep putting more and more power into the motor to keep it at the exactly same RPM! It can even way over current it for a short duration, sweet : https://www.aliexpress.com/item/33018809499.html (obviously with only 120v/15 amps available to me at the moment I'll have to limit the maximum current to the motor, easy with just one setting)






To bolt it to the lathe I picked up a NEMA 52 L/90 degree mount from the same supplier: https://www.aliexpress.com/item/32770775579.html (I'll make an adapter plate to convert the bolt pattern of the stock motor to NEMA 52)

For a speed/direction controller there are quite a few options:

The first/easiest/cheapest option is a cheap stepper controller from Ebay/Amazon/Aliexpress, i.e. from cheapest to "most expensive":

a) $6.59 CAD shipped (free Amazon Prime next day delivery), 8-24v DC input, nice digital display shows duty cycle percentage (0% to 100%), maximum frequency output of ??? : https://www.amazon.ca/dp/B07WMN8255/






b) $7.89 CAD shipped (free Amazon Prime next day delivery), 8-24v DC input, has high/medium/low range settings for the speed control knob, maximum frequency output of 160khz: https://www.amazon.ca/dp/B07WMN8255/






c) $11.99 CAD shipped (free Amazon Prime next day delivery), 5-12v DC input or 15-160v DC input (WARNING: If using more than 5v on the 5v to 12v input jack you must make sure your stepper motor driver can accept 12v pulse signals or you'll have to use a resistor!), has high/medium/low range settings for the speed control knob, maximum frequency output of 127khz: https://www.amazon.ca/dp/B07WT39T4S/






All three options have enable/disable button (starts and stops the motor INSTANTLY, without soft start/stop adjustability unless your stepper driver has it built in), reverse direction button (don't accidentally press this when running at high speed, hopefully my driver has protection against that) and of course speed control knob (with the latter two options having an adjustable range for the knob).

I went with option c as there were a lot of demo videos and wiring diagrams online for it and you can change one of the parts in it to adjust the frequency range it puts out to tune the speed knob for the perfect setup (i.e. 1000rpm motor rpm/2000rpm chuck RPM at knob 100% and super slow 100rpm motor/200rpm chuck rpm for threading at 1% knob). I ordered a cheap $13 CDN 24v DC power adapter to power the controller: https://www.amazon.ca/gp/product/B083ZT4H5N/

Another neat option I saw for remote RPM display (as well as speed control and a ton of other stuff like soft start, etc.) was this $10 remote programmer for the driver so I ordered it as well: https://www.aliexpress.com/item/4000107828403.html






All of the parts have arrived so far minus the ones from China, motor, driver and remote driver programmer/display:






The big pulley (40 teeth) is for the stepper motor (15/16" shaft) and the small pulley (20 teeth) is for the chuck driveshaft (1 3/16" for 30mm shaft). I got a few belts in different lengths and there is also an adjustable tensioner pulley already on the lathe so I should be able to make one fit.

Hopefully people are alive at the factories in China, no replies to e-mails/my orders so far! 

Now I wait on the slow (fedex express) airplane from China!

-Jamie M.


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## toysareforboys (Mar 9, 2020)

First part arrived from china, woot!






That arrived by DHL, 4 days from China to Canada, not bad!

I got a notice from Fedex about the motor and drive though, that they are short staffed due to corona virus and special decomanition has to be done to every package. Still no tracking number so might be quite a delay 

-Jamie M.


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## toysareforboys (Mar 16, 2020)

Big shipment from China today!!! The motor, motor controller, mount and motor temperature/power consumption display!






The live RPM display arrived as well (not in above pic).

I have everything I need to build it now, just need some time, have a pretty absurd work this week 

-Jamie M.


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## toysareforboys (Mar 16, 2020)

Oh, and I completely forgot! I'm getting 240v 100amp service installed in my shed on Thursday! So nice to have 240v, now I can get a nice welder and plasma cutter 






-Jamie M.


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## toysareforboys (Mar 26, 2020)

Electrical upgrade is complete! Took forever because of this Covid-19 stuff 






Now I gotta work on mounting the new motor to the lathe... wish me luck!

-Jamie M.


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## toysareforboys (Mar 26, 2020)

Absolutely absurd! The stock motor mount studs fit the new stepper mount perfectly!! So lucky 






Looks like the idler pulley/pulley cover door mount plate needs a bit of a trim






All trimmed, fits nice now!






Now for a test fit of the motor...











OMG, SHE FITS! Nice.

I put the pulleys on and bolted them up, but didn't know you can only do that once, without a pulley puller (because of the split bushing), so they didn't get aligned good at all  I'll rent a pulley puller tomorrow and get them off so I can do a nice alignment.

Slow speed demo video (I'll post a high speed one once I get the pulleys aligned):






-Jamie M.


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## John O (Mar 27, 2020)

Looks good, Canadian tire and parts source have borrow a tool. I also have some pullers here (Yonge and Steeles) you  could use.


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## toysareforboys (Mar 27, 2020)

John O said:


> Looks good, Canadian tire and parts source have borrow a tool. I also have some pullers here (Yonge and Steeles) you  could use.


Thanks! I've needed one a few times, figure I'll just purchase this one: https://www.canadiantire.ca/en/pdp/oem-gear-puller-long-2-3-in-jaw-1250064p.html#srp

It says they only have 1 in stock which usually means none, and they close early because of Covid-19, but I'll see if I can get off work early to go there.

Thanks for the offer, if stuff doesn't work out I'll let you know 

-Jamie M.


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## homebrewed (Mar 27, 2020)

You've got the start of a killer ELS there -- no need for a spindle encoder with that setup!


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## toysareforboys (Mar 27, 2020)

homebrewed said:


> You've got the start of a killer ELS there -- no need for a spindle encoder with that setup!


Damn, never knew about ELS, that should make me a threading master! Thanks. That closed loop stepper driver has tons of math stuff in it that it can send digitally to another driver so probably wouldn't even need a raspberry pi or anything, put the ratio I want in the main driver and it'll tell the other one to keep in sync. Neat.

I figured out a flawless way to control the stepper with the stock forward/off/reverse knob! Just feed it 5v instead of 110v and it works great, forward or reverse puts out +5v enable signal and forward does +5v and reverse does 0v on the directional signal, sweet. I'll drill a little hole beside the stock knob for the speed dial then I'll be done with the new electrical setup. If I don't mount the driver in a place where I can read the RPM display on it then I'll install the RPM gauge and all the other power display stuff, want to make sure I don't overheat the stepper motor.

Also, someone on this forum sent me a PM with a better belt direction setup so it completely clears the gears, and it works! I'll post a new video soon. I just pray that belt doesn't stretch ever or I'll have to order a slightly shorter one. *EDIT: With how much tension I had to put on the belt it rubbed itself with the freaky setup so had to back to how I had it set up before and to make sure the belt cleared the gears. If I had a very slightly shorter belt the freaky setup would probably work.*

-Jamie M.


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## toysareforboys (Mar 28, 2020)

I got the pulleys all aligned! Like butter baby!







And I rotated the motor 90 degrees so the cross slide could never hit the encoder/motor, flawless clearance now.






And I did another short slow speed video. Had some fun trying to slow down the chuck/motor, probably impossible without breaking your wrists, lol.






Once I get the electrical all buttoned up and re-assemble everything I'll do a final overview video.

So happy with how this worked out.

-Jamie M.


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## toysareforboys (Mar 29, 2020)

Alright, got the mechanical all buttoned up! Only thing left is the electrical now.

Thanks for everyone that tells me ideas, even over a pm, lol. After I posted the last video someone sent me a message with an idea for a stiff belt tensioner that would only cost $2!! I was ready to go out and buy a welder and bunch of supplies to make one.

Their idea was to swap one of the bolts around in the motor mount (so the threaded end would be sticking out into the pulley area) and use a hose clamp from that bolt to the pulley tensioner. They said my last video showing the close up shot of the pulley tensioner helped them figure out.

I tried it but I wasn't able to get a socket on the bolt head (when it's on the motor side, too little clearance to the motor) so instead I used some 7/16" threaded rod as a bolt and that worked out perfectly. With the hose clamp it's super easy to both adjust the tension as well as to loosen it to remove the belt, love it. I put a mark with marker on the hose clamp so after you loosen it or remove it you can put it back to the exact same tension you had before. Thanks again everyone, my idea $500, their idea only cost me $5 





















I put the pulley cover back on, fit flawless, looks just like stock!











And this pic is just so I can remember what belt I used so I can get some spares or replacement in the future






Now to work on the electrical...

-Jamie M.


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## toysareforboys (Mar 30, 2020)

Oh baby, SHE'S FINISHED! It all came together perfectly! Had a little issue with the RPM gauge, so if you get the same one as me ignore the wiring diagram on the back of the LED display, lol 

The correct wiring is:

Terminal 1 = +12V DC & Brown Sensor wire
Terminal 2 = Ground (DC-) & Blue Sensor wire
Terminal 3 = unused
Terminal 4 = unused
Terminal 5 = Black sensor wire

If you're looking at the BACK of the display with the wires coming out the bottom then terminal 1 is on the left. Do not let terminal 3 and 4 wires short out (they are pre-stripped and tinned) as it will cause the RPM to always read zero. If you're sure you've wired everything correctly but are still getting all zeros on the display try flipping your magnet around as the sensor is magnet polarity sensitive.

Probably the final lathe update video. Thanks everyone for all the support. Time to make some BIG chips.






-Jamie M.


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## toysareforboys (Apr 10, 2020)

Yumm 240v!






All wired up, making chips today! 

-Jamie M.


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## toysareforboys (Apr 11, 2020)

Beautiful thing about being able to run it so slow is that the Delrin and the cutter bit doesn't heat up much. When the Delrin gets hot it gets "sticky" which messes up the surface finish and can grab the bit too. 

I love being able to run it at SUPER fast speed on the light cuts and when it starts to get close to the chuck or the end of the cut I slow it right down so I can stop it right at the perfect spot. Love love love the new setup 






-Jamie M.


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## John O (Apr 11, 2020)

Nice job, where do you get coloured delrin, I just see black and white?


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## toysareforboys (Apr 11, 2020)

John O said:


> Nice job, where do you get coloured delrin, I just see black and white?


I buy all my "Delrin" from here: https://beikelan.en.alibaba.com/pro....html?spm=a2700.icbuShop.82.15.163116ddItJWpU

I always order 45mm diameter (parts I make are maximum 41.4mm diameter) and it works out to $12.36US per meter. I generally buy blue and red but they have yellow and green available as well.












Send them a message with what you want (maximum length of one piece they can ship is 1m) and they will spit you back a quote. If you're not in a hurry ask for cheap/slow shipping, otherwise you'll get it in 4 days by DHL. They do free cutting that's super accurate and straight for free, so if you know you need 45mm x 105mm pieces then you can ask for qty: 20 of those, and usually the shipping is much cheaper than the same weight/quantity in 1m length. Leave a few mm for facing as the cut has a pretty rough finish.

-Jamie M.


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## John O (Apr 12, 2020)

Wow about 1/2 the price from around here. thanks


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## brino (May 3, 2020)

@toysareforboys
Hey just found this thread and read it right thru....

Jamie, Thanks for the great pictures!
They are eclipsed only by your exuberance.

Thanks for sharing this.
-brino


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