# Chris G0704 Build



## ChrisAttebery

Back in October of 2012 I started a G0704 build thread on CNC Zone. The Benchtop Mills forum over there is practically dead so I thought I'd start a thread here.

Chris G0704 Build on CNCZone.com

To catch up the machine has the following:
CNC Fusion Premium Ball Screw kit.
3 x KL-5056D Digital Bipolar Stepper Motor Driver-32 bit DSP Based
3 x NEMA23 570oz/in 5A 3/8” Dual Shaft Stepper Motor (KL23H2100-50-4B)
1 x 48VDC/12.5A Switching CNC Power Supply
Ethernet Smooth Stepper
CNC4PC C35 - QUICK SETUP BREAKOUT BOARD
CNC4PC C6 - Variable Speed Control Board
Manual Oiler
Vista CNC iMach P1A-S pendant
Mach Standard Mill running on Mach3.
Touch plate for MSM automatic tool offset measurement
2" head and column spacers.
ABEC 5 AC spindle bearing upgrade
Home brew fogless mist cooling system
1100W 4500rpm motor. IMHO the bare minimum for a decent CNC conversion.
KBIC-225 DC motor controller

2 speed belt drive. Based on Hoss' design. I wound up turning a pair of Multi V pulleys using a J6 belt. 3:2 high ratio and 1:2 low ratio. With the 1100W motor I wound up with 6750 rpm in high and 2250 rpm in low. The spindle pulley is a light press fit into a 6007 bearing. I turned a bushing to fit that bearing into the head casting. This setup is MUCH quieter than the L belts that I started out with.


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## ChrisAttebery

I made a full enclosure using TNUTZ 1010 rails and brackets. I used 1/4" Lexan for the front panels and sliding door. I just used Coroplast for the back walls. The machine sits on a steel stand that I welded up using 3/16 wall 2x3 and 2x2 tubing.


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## ChrisAttebery

That's basically where the machine was up until last week. On Thursday I was milling a block of steel that was going to run for a few hours. I was running a 1/4" 4 flute carbide end mill at 6000 rpm, .250 DOC x .020" WOC. The machine should have only been using about 1/3 HP but apparently I had abused it for too long and it melted down. It shorted out internally and smoked the KBIC in the process. Of course this happened when I had 6 orders sitting on the bench waiting to be machined over the weekend.

On Friday I ordered a MTRP-002-3BD36 2hp, 3600rpm 3 phase motor and a WEG Electric CFW300 series vector drive from Automation Direct.

I bored my motor pulley to .626 on my lathe. I didn't have any small HSS so I just used a piece of sharpened HRS in a tool block to cut the key slot.


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## ChrisAttebery

I’m in a tight spot since I don’t have a motor for the mill so I can’t machine a new mount. I decided to model the top of the machine in Fusion 360 and see what I could come up with. I realized that if I turn the motor 45 degrees that the bolts will clear the outside of the head. I made a couple plates from 3/16” steel on my drill press to mount to the head and turned a couple spacers out of 1” CRS on the lathe. This will move the motor 1” farther back than the 1100W motor but it will still clear the column but about 1/4”.


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## ChrisAttebery

I received my shipment from Automation Direct yesterday. They shipped everything FedEx Overnight. That was a nice bonus.

I was able to get the VFD wired up to the controller and motor. Programmed the VFD and was able to start the motor from Mach3. I programmed the VFD to give the motor a 4500rpm top speed so that it matches the 1100w motor it's replacing. That way I can reuse all of my G code. 

I got the pulley fitted. The key slot was a PITA and needed to be filed about a dozen times.

Here’s a side by side picture with the new motor and the 1100w motor. It’s roughly twice the size.




Here's the new motor sitting on the head. The belts should be here this afternoon. I need to grab a couple 3/8-16 x 3" SHCS screws from the hardware store.


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## Reddinr

Well done.  Always good to see machine build/conversion/rebuild projects I can selfishly learn from!   I bet you will just feel better not having to baby the motor anymore.   I've been thinking about converting my RF-45 type cnc mill to belt drive so I can get higher RPM and quieter operation.  I just have not gotten up the nerve to tear down a perfectly fairly good machine yet.  For now, for high RPMs I rig a porter-cable router to the head and that has worked OK for some things. 

I have a, now dusty, ethernet smoothstepper that I figured I would implement at the same time.  I need to figure out what kind of bearings to use for the spindle.  I want to keep or improve the spindle run-out I have now but get it as fast as practical.


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## ChrisAttebery

The belts came in so I got the machine put back together. I ran a batch of parts for about an hour. The motor was at 105F, about 20 degrees above ambient. On these parts I use a 3 flute 3/8 end mill at 6750 rpm, .650” DOC and .030” WOC. The finish looks better. It think the old motor was struggling to keep up.


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## ChrisAttebery

Yesterday I took it easy on the first part but after that I went right back to the speeds and feeds I used with the 1100w motor. 

Some observations:
1. The motor is quiet below 3500 rpm. As in with hearing protection it’s hard to hear it. Above 3500 rpm the fan is the dominant sound. It isn’t bad though. It’s kind of a low woosh sound.

2. I set the accel and deccel to 1 second each. I immediately noticed how much quicker the spindle ramps up and down compared the the DC motor setup. No more waiting for the spindle to stop before I change tools.

3. I had some parts that I started with the old motor and the finish seems to be better now. I think the old motor may have been struggling for a while.

4. After an hour of running non stop the motor was only about 25 degrees warmer than ambient. The old motor would have been 70-80 degrees over ambient.

5. Even though I have more power I don’t think I can push the machine any harder. I tried increasing the feed rate on one of my roughing cuts and I could hear the machine start to chatter and vibration levels increase. I think 1.5 cubic inches per minute in aluminum is about the limit for these machines. They just aren’t stiff enough to handle more than that. One exception is drilling. I had limited myself to 1/4” and below with the old motor and high speed belt drive. I should be able to push 3/8”-1/2” drills in the high speed setting now since the motor has constant torque down to 1350 rpm at the spindle.


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## GunsOfNavarone

I gotta ask as I am ready to do something now...
What does it cost to do this kind of conversion? The little I have checked into makes me want to buy a Tormach or..... instead of converting what I have. I assume the ballscrews have completely eliminated the backlash? There is the learning curve as well. I'm jealous! Great work! I really think something like this is more than I want to bite off. The VFD conversion wan't bad on my lathe, but this is FAR more entailed.


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## ChrisAttebery

Someone on the other forum mentioned that he regularly pushes his machine 2x harder than I've been pushing mine (3.4 cu in/min vs 1.5cu in/min). I took a look at my mill this morning. The screws all seem to be tight but I could feel some slop in the table if I grabbed the ends and pushed them in opposite directions.

The Y axis seemed to be the culprit. I was able to tighten it down quite a bit. It was enough that I decided to pull the gibb and take a look at it. There's a wear mark where the very top of the dovetail on the base is touching the gibb. It doesn't look like they are machined on the same angles. After playing with it for a while I got it about as tight as I can without stalling the axis. I think the only cure for this would be to buy a new gibb and grind or scrape it to fit the casting.

The X axis seems OK. I pulled the gibb and there are a few spots over the entire face that are contacting. It's not a lot and it's not very even, but it's better than the Y.  I tightened it down until the screw bottomed out in the casting. That axis seems to be OK though.

I checked Grizzly's web site and the gibbs are available for $8.50 each. I think I'll order a pair and see if I can get a better fit on the machine.

Anyway I'm going to try pushing the MRR a bit harder over the weekend and see how the machine reacts.


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## GunsOfNavarone

I am curious how the new gib shim works out..keep us posted.


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## ChrisAttebery

I ran a test cut using a Best Carbide 3/8" 3F Carbide at 6750rpm, 81IPM (.004" IPT) .75" DOC and .030" WOC (1.5" MRR) and worked my way up to .060" WOC (3.65" MRR) in .005" increments. The machine seemed quite happy at 3.65" MRR. I stand corrected. Apparently my weak spindle motor and sloppy gibbs were giving me the impression that the machine was tearing itself apart.


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## ChrisAttebery

GunsOfNavarone said:


> I gotta ask as I am ready to do something now...
> What does it cost to do this kind of conversion? The little I have checked into makes me want to buy a Tormach or..... instead of converting what I have. I assume the ballscrews have completely eliminated the backlash? There is the learning curve as well. I'm jealous! Great work! I really think something like this is more than I want to bite off. The VFD conversion wan't bad on my lathe, but this is FAR more entailed.



I don't remember what I paid to be honest. The mounts and ball screws were around $1k. Automation Technologies has a conversion kit now. I bought my drives, PS, steppers, etc from them too. The motor and VFD I just bought were $400. 

If I had to guess it'd be around $2k-$2.5k to get one up and running. Oh yeah add in a PC, and software (mach4, Acorn, linuxNC). Add another $400 for the bigger motor. The belt drive you can do for about $100. Maybe $3k to get up and running with a decent machine base. Then you need a bunch of tool holders. I use R8 set screw holders and I have about 20 at the moment. Then plan on ruining a few hundred dollars worth crashing them, burning them up, etc.

You need to ask yourself do you want a machine to make money with or just a machine to play with and upgrade as you go? I have countless hours into my machine. I originally bought mine to make money with. I do enjoy upgrading it from time to time it but most of the time I just want it to work. Even a Tormach isn't going to give you industrial class reliability though. If I had the room I'd buy an old Fadal or VF1 and just make parts.


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## ChrisAttebery

Here’s a short video of the machine cutting 6061 aluminum at 3.65” MRR.


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## ChrisAttebery

A quick update: Since installing the 2hp motor I've been able to double the MRR on every one of my programs that I've run in aluminum to roughly 3" pre minute. I've done this mostly by increasing the WOC. I feel really comfortable with the machine running 81IPM (.004 IPT) with a 3 flute carbide end mill. The other day I was tweaking a program and had the feed override set to 150%. The mill powered right along at 120IPM and 4.5" MRR but the finish suffered a bit.


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## ChrisAttebery

I got the flat parts of the new motor mount machined out of 1/2" 6061 last night. The inner pieces mount to the head and the outer pieces mount to the motor.




I went to make the round threaded spacers I need and realized that my 3/8-16 tap can't cut deep enough.


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## Buffalo21

You need a 3/8”-16 nut tap


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## ChrisAttebery

I was thinking a pulley tap would work, but that nut tap looks like what I need. I'll have to see what the local tool shop has in stock.


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## Buffalo21

ChrisAttebery said:


> I was thinking a pulley tap would work, but that nut tap looks like what I need. I'll have to see what the local tool shop has in stock.




I pulley tap has a long reach, but the overall shank diameter is larger than the tap part


top - a 3/8”-16 pulley tap
Bottom - a 3/8”-16 nut tap


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## ChrisAttebery

Thanks for the info Buffalo21.


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## Buffalo21

Chris,

I find this build and some of the others, very interesting, I see CNC equipment on a daily basis, but have no concept of what it take to make a part. I work with computers, in my business, on a constant basis, We have a locked core of safety procedures and protocols, we can alter some of the operating parameters, the fuels being used and set the combustion fuel/air curves, but the locked core can not be altered. When I first started in this business, I need a VOM, a couple screwdrivers, a few wrenches and sockets and a number of pipe wrenches, now I still have all of them equipment, plus welders, plasma cutters, pipe threaders and now 3 laptops and an iPad.

I basically grew up in my grandfather’s machine shop, where everything was 100% manual, the equipment in my shop ranges in age from 1930s to current, but all of it is still manual. I understand the premise of CNC, but wonder if its a one off, its it quicker/easier to do it manually or spend the time to program it, then wait for the program to run, then if errors, rework. If your doing 150 parts, its another story, so is CNC, based on the scale of the job?? Is it the sense of accomplishment?? Mind over electron??

It looks to me that people buy an inexpensive (relative term) bench mill, then spend 3-4 times what they bought the mill for to convert it to CNC. Maybe my view is somewhat askew to the actual premise or goal of the CNC operator. Spoken by a man who has at least 15 welders (still looking for the perfect one).

All of my questioning aside, the workmanship, design and execution is amazing. The idea of “throwing” a bunch of numbers into a machine, that then carves a part is, truly amazing. Maybe if I understood it better.


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## BGHansen

To me CNC is a game changer even for one-offs.  Naturally depends on the one-off.  Make a bracket from a piece of angle and drill 6 holes, do it manually.  I made a clamp to fit my G0709 lathe's tail stock ram for a DRO.  Manually machined it on a mill with a rotary table.  It came out nice and works great.  But I'd have done the job in a third the time with my Tormach.  

CNC doesn't have the "charm" of old-school craftsmanship, no question.  Our tool makers at the GM Lansing Grand River Assembly Plant tool room all completed an apprentice program of 8000 hours of various disciplines.  They're all over 55, so little to no CNC in that training.  Our local community college is spitting out "CNC Machinists" by the dozen with a less than 1 year program.  They take one class in manual machining using a lathe and mill.

Strip out an M6 thread and need to fix it?  Go to a young "CNC Machinist" and they'll tell you you're screwed (pun intended).  Go to one of the old-timers, they'll probably tell you to drill and tap it for a 1/4"-20.

I admit to still being fascinated by watching the stepper motors do exactly what I told them.  A couple of weeks ago I cut some helical gears on the Tormach using the 4th axis tipped at a 45.  Coordinated moves in the X, Z and A axis that could never be done manually.  The CNC just opens up the possibilities to what you can imagine and turn it into a part in minutes.

Bruce


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## Buffalo21

Bruce,

Thanks for the reply.

Are you programming from start every time?? Or are you modifying an existing program?? Are there “canned” programs, that allow to insert certain segments?? And you program from segment to segment?? How intuitive is the CNC software??, can you import a drawing and have the machine “read” the drawing and duplicate it?? Or is it line after line of G code, you have to input??

Sorry for all the questions, I find the subject incredibly interesting, personally its not something I’d probably ever do, but every I see it, I have more questions.


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## ChrisAttebery

I model everything in Fusion 360 first, then make the CAM files, and then run them on the machine. There's no way I could do it most of it on a manual mill. I probably put 3-4 hours into the design, and 1-2 hours on the CAM, but then those plates took about 5 minutes each on the mill.

On the CAM side there are routines built into Fusion that will do pockets, follow a contour, etc.


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## ChrisAttebery

On the tap, I only needed another 1/2" of thread. I looked for a tap but nobody has one locally. I decided to chuck the tap in the lathe and grind the shank down with a cut off wheel in my Dremel tool. Afterward I realized that the tap is just HSS and I have some good inserts for hard metals. I cleaned up the ground area by taking light cuts at 190 rpm.


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## Buffalo21

ChrisAttebery said:


> On the tap, I only needed another 1/2" of thread. I looked for a tap but nobody has one locally. I decided to chuck the tap in the lathe and grind the shank down with a cut off wheel in my Dremel tool. Afterward I realized that the tap is just HSS and I have some good inserts for hard metals. I cleaned up the ground area by taking light cuts at 190 rpm.



Glad you got it


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## ChrisAttebery

Here's a picture of the entire assembly. I downloaded a step file for the motor from Automation Direct. Everything else I drew from measurements.


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## ChrisAttebery

DONE!


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## BGHansen

Buffalo21 said:


> Bruce,
> 
> Thanks for the reply.
> 
> Are you programming from start every time?? Or are you modifying an existing program?? Are there “canned” programs, that allow to insert certain segments?? And you program from segment to segment?? How intuitive is the CNC software??, can you import a drawing and have the machine “read” the drawing and duplicate it?? Or is it line after line of G code, you have to input??
> 
> Sorry for all the questions, I find the subject incredibly interesting, personally its not something I’d probably ever do, but every I see it, I have more questions.


I'll shoot you a PM so I don't mess with Chris' thread


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## ChrisAttebery

Good news, good news, bad news...

The first good news is that I machined a bunch of parts yesterday morning and the mill is much more satisfying to run now that I've cranked up the metal removal rates.

The other good news is that the new spindle and gibbs showed up a couple weeks ago. I finally got around to installing the new spindle yesterday. It seems to have a bit better runout. I measured it at .0015" TIR roughly 1.25" from the end of the spindle with a 1/4" carbide shank in an R-8 end mill holder.

The bad news is that the ABEC 5 bearings that I installed in May are shot. The lower has a click and the upper feels like it's full of sand. :^( I ordered two sets of the cheap AC bearings from VXB that I had originally used. They should be here by the middle of the week.


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## JimDawson

ChrisAttebery said:


> I ordered two sets of the cheap AC bearings from VXB that I had originally used.



One note on VXB bearings.  I bought a set of bearings for my mill head, not for the spindle, but for the drive area.  The ''grease'' in the bearings looked like a mixture of sand and tar.  It was stiff enough that it actually spun the bearing in the bore.  These were sealed bearings and I didn't catch it when I installed them.

I would wash out the new bearings and apply some good grease when you install them.  https://www.amazon.com/Kluber-Isofl...LEX+NBU+15&qid=1593889295&s=industrial&sr=1-5


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## ChrisAttebery

IIRC the bearings were packed in light oil. I’ve been using the Kluber grease since I built my machine. I’m wondering if I put too much preload on the bearings. I usually tighten them until the spindle only turns a couple revolutions when I spin it by hand.


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## ChrisAttebery

It's been a long time since I've updated this thread. Let's see if we can catch up...

I replaced the AC bearings with Timken tapered bearings and the TIR is slightly higher but I haven't had any more issues with the spindle since.

I managed to crack the moveable jaw on my CDCO 4" mill vise. I replaced it with a Kurt DX4. It's amazing how much nicer it is. The vise feels more solid and a lot more repeatable.







A couple days ago I made a Kydex cover to go over the leadscrew and vise body. I covered the back with stick on magnetic sheet.


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## ChrisAttebery

I made my last cut with Mach3 and the Ethernet Smooth Stepper a couple weeks ago. I made a set of mounts for the VFD and cut a window into the front on my controller enclosure so I could mount the VFD inside.




After that I stripped out the ESS, BOB, and C6 variable speed spindle control boards. I also removed a couple 5V and 12V PSUs that were no longer needed.


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## ChrisAttebery

I bought an Acorn controller and wireless MPG from Centroid in December. I got the Acorn mounted and rewired the entire controller. I have all of the 110V and 220V wired through relays that are tied to the E-stop. The only power that isn't tied to the E-Stop is for the Acorn itself.

I made a few changes to the hardware
1. Replaced the cooling fan in my 48V PSU. It had been making noise for years.
2. Installed a dedicated 24V/2A power supply for the all of the I/O, power relays and case fans.
3. Installed covers and GX-4 connectors on all three stepper motors.
4. Replaced the crappy homing switches with Metrol Precison limit switches on all three axis. These Metrol switches claim 5 micron repeatability.


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## ChrisAttebery

I finished up the controller, moved it back into place, and cleaned up all of the cabling between the machine and controller. I also mounted the NUC and bundled all of the PC wiring on the back of the monitor and got the monitor mounted to the enclosure.

I tuned the stepper ratios to less than .001" error over 5" on all three axis. I also set the backlash compensation for all three axis.

I installed ProbeApp V2 this morning and measured a few of my tools. According to ProbeApp my TLO setter is repeatable to .0001". I *think* that should be good enough.


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## ChrisAttebery

The last big change I wanted to make is to get a 3D touch probe. I was about to order a hobby grade unit but I asked around and someone mentioned that they purchased a used Renishaw probe on eBay and made an adapter for it. I started looking around and found a MP3 probe at a used tool store about 30 miles away. I picked it up last Friday. 

I Saturday I found a thread on CNCzone about using the Renishaw probes on Tormach machines. Someone mentioned that they bought one that was DOA. I decided to test mine out and sure enough it was completely dead. The head measures in MegaOhms no matter which pins I measure against. Welllll $#!+!!!!! I talked to the guy I purchased it from and I'm getting a full refund.

So I started looking for another MP3 on eBay and found a brand new head with the inductive pick up and CAT40 taper for $400 with a warranty. That's more than I wanted to spend but I watched it anyway. I got an offer from the seller on Sunday morning for $300. I countered their offer at $250 and they accepted. So, I should have a working probe on Monday.

Another thing that they mentioned in that thread is that the probe really should be used with a probe interface. It is more accurate and will save wear on the contact points inside the head by shutting off the input voltage to the probe when it senses that the contacts are about to be broken. The MP3 will work with the MI5 and MI8 interface units. The MI8 are cheap. I picked one up for under $100.

On Thursday I received the Renishaw MI8 interface unit and a few goodies from Amazon. I mounted the MI8 in an aluminum amplifier enclosure. On the control side I mounted a GX4 connector to provide 24V, GND, probe detected and probe triggered. On the probe side I mounted a DIN5 connector to provide probe +/-, probe detect and GND. I also mounted a super bright LED on the probe side. I mounted this interface unit under the keyboard tray next to the enclosure door for easy access.


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## ChrisAttebery

I made an R8 adapter for the probe out of an R8 to JT33 arbor and a 4" x .75" disk of aluminum. I pressed the tapered SS insert out of the Renishaw inductive adapter. I bored a pocket for it in my adapter. I used a slip fit and Locktite 609 sleeve retainer to attach it. I wired up a DIN5 connector with probe detect, trigger +/-, and GND. The probe detect signal is tied directly to GND.

The new probe head is supposed to be here on Monday. I can't wait to try it out.


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## ChrisAttebery

So far the most noticeable improvements with the Centroid setup have come from the software and hardware controllers being super reliable. I'm not having to constantly restart Mach3, re-home the machine and re-locate my WCS. When I do home the machine the homing switches are so accurate (.0002") that they basically repeat to one step on the motors. According to the probing software I'm using the cheap tool setter is also repeatable to .0002". So I can hit the E-stop, leave the controller running, come back the next day, re-home the machine and not have to worry that the WCS has moved. I can also run Fusion360 on the same PC that runs the machine so I can make minor changes to the code in between cycles without having to use another PC (usually INSIDE the house). It's been refreshing.


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## ChrisAttebery

When I converted my G0704 CNC mill to Acorn I needed a method of measuring the tool length offsets. I bought a cheap imprt tool setter off eBay. I needed software to use it though. I found that ProbeApp V2 from Swissi was priced right and really well done. After using it to measure my TLOs I decided that I wanted to start using 3D probing. I didn't have the budget for a new Centroid probe so I asked about budget probes. Muzzer was kind enough to point out that Renishaw MP-1 or MP-3 probe heads are available fairly cheap on eBay. I picked up a NIB MP-3 for $250. I also found out that they work best when paired with a Renishaw MI-5 or MI-8 probe interface unit. So I picked up an MI-8 for $90 on eBay. It was really easy to wire into Acorn.

Between ProbeApp, the tool setter, and the Renishaw probe tool and part setups are a lot quicker, easier and more accurate than what I was used to in the past.

Here's a video I put together:


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## ChrisAttebery

Since I upgraded the spindle motor the Achilles Heel on my machine has been the spindle bearings. No matter which bearings I've tried AC or tapered its always had mediocre TIR (.0015" - .003"). Now that I've installed the bigger motor they haven't been lasting very long either. The VXB AC bearings only lasted a month or so. I tried Timken tapered bearings and they were a little better but only lasted a few months. The last set I bought was bad right out of the box. I decided to try NSK HR32005XJ and HR32007XJP5 bearings from eBay. These bearings are much smoother than even the best set of Timkens I've bought. I broke them in for a couple hours yesterday and they were only 30F over ambient. The spindle is much quieter than it's ever been before too. I measured it at 76dB at 6750 rpm. The TIR at the bottom of the spindle taper is .0007".

Right after I purchased these bearings someone pointed me to a thread on CNCZone about better bearings for the G0704. SKF's XQ series bearings have tighter tolerances and higher rated rpms on grease than any of the others I've looked at. Next time I need a set I'll be purchasing these.

SKF 32005XQ Reference speed 11000 rpm, Limiting speed 14000 rpm
SKF 32007XQ Reference speed   8000 rpm, Limiting speed 10000 rpm

Here's a link the thread. It contains a lot of good information:
CNCZone - G0704 Tapered Bearing Upgrade


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## OCD Solutions

That is the one upgrade that I have been avoiding for years now and mostly because of that same thread you linked.
I've stripped out the gears and converted to belt drive and amazingly enough, I'm still on my original bearings....knock on wood!

I work on mostly acetal, UHMW and PVC though so my loads are very small. I know if I start doing more heavy work that a bearing upgrade will be inevitable.


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## ChrisAttebery

I think the stock bearings are fine if you're running stock speeds. I'm running my spindle at 3X stock (6750 rpm). That's what kills the cheap bearings. The loads we're putting on the spindle still aren't that high. These bearings are used as wheel bearings so they have to be able to handle loads a lot higher than we'll ever put on them.


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## OCD Solutions

I can go to 7500 but am typically in the 2500-3500 range.


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## ChrisAttebery

OCD Solutions said:


> I can go to 7500 but am typically in the 2500-3500 range.



Oh, I missed that you had a belt drive.


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## OCD Solutions

I'm pricing out the SKF bearings today. I found both on Amazon for around $60. That seems pretty reasonable.
I have a call in to our SKF rep as well to see if our pricing is any better.


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## ChrisAttebery

If you find them on Amazon please post a link. I’ve searched and found them through Google but couldn’t find them on Amazon’s search engine. 

I also tried to order them from a bearing shop. They told me that it wasn’t stocked by SKF but if I wanted 25 they would make them for me.


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## OCD Solutions

Amazon and eBay are known for selling knock-off bearings so I avoid them for anything critical like this or on my vehicle but here are the links.





__





						SKF 32007 X/Q Tapered Roller Bearings 35x62x18mm Same Day Shipping !!!: Amazon.com: Industrial & Scientific
					

SKF 32007 X/Q Tapered Roller Bearings 35x62x18mm Same Day Shipping !!!: Amazon.com: Industrial & Scientific



					www.amazon.com
				







__





						SKF 32005XQ TAPERED ROLLER BEARING: Amazon.com: Industrial & Scientific
					

SKF 32005XQ TAPERED ROLLER BEARING: Amazon.com: Industrial & Scientific



					www.amazon.com
				




I have a set coming direct from SKF. I don't know the price as we spend so much money with them a year that he just said not to worry about the cost.


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## ChrisAttebery

Hmmm, that's interesting. When I looked for those bearings the 32007 was double the price of the 32005. When I placed my order they called me and said that the 32007XQ wasn't available but they could provide a 32007X at the same price. The X version is lower quality and higher runout. needless to say that I declined.


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## OCD Solutions

If you look at the pics of the 32007, the label on the box only shows an X not an X/Q which may explain the lower price, (and support my apprehension of ordering through Amazon sellers).


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## tkalxx

I'm able to source the 32005 X/Q but like you guys, when I called around for the 32007 X/Q, I was told that only the 32007 X was available...


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## tkalxx

Found a source for the SKF 32007 X/Q. I purchased a set from qualitybearingsonline . com for a suspiciously low price. I paid $45 CAD with shipping. I contacted their sales rep beforehand to verify that the bearings listed are not the X version, and I was reassured that they are the X/Q. Will update when they arrive.


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## tkalxx

Bearing was delivered today and it is in fact an X/Q model. I would recommend purchasing from qualitybearingsonline.


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## ChrisAttebery

tkalxx said:


> Bearing was delivered today and it is in fact an X/Q model. I would recommend purchasing from qualitybearingsonline.



That's great news. Thanks for sharing.


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## macardoso

I replaced the bearings with AC about 8 years ago and did a shoddy job of it. They gave me 5 years of life before I replaced them with the same AC bearings but was much more careful about assembly, grease fill, and preload.

3 years later they are still going strong at 5000rpm spindle speed. No discernable play and 0.0004" TIR at the taper. None of my holders/tooling is accurate enough for me to get a value at the end of a test bar.


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## ChrisAttebery

AC bearings have about 1/3 the load rating of tapered. I used the cheap VXB AC bearings for 8 year or so. I replaced them every year or two ( probably a couple hundred spindle hours). When I went to the 2HP 3PH motor I went through a couple sets of AC bearings in short time. I backed off my MRRs but they still didn't last too long. I looked into getting better AC bearings and they were to expensive IMHO. I wish I had been paying attention when the thread about the better tapered bearings showed up in 2017. I have a friend that has been using a set for 4-5 years and they are still holding up. 

I generally shoot for 2cu in/minute in aluminum at 6750 rpm, 81 IPM, .004 IPT with a Best Carbide 3/8" 3 Flute 1" LOC HSC Aluminum End Mill (601-33750-1).


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## macardoso

ChrisAttebery said:


> AC bearings have about 1/3 the load rating of tapered. I used the cheap VXB AC bearings for 8 year or so. I replaced them every year or two ( probably a couple hundred spindle hours). When I went to the 2HP 3PH motor I went through a couple sets of AC bearings in short time. I backed off my MRRs but they still didn't last too long. I looked into getting better AC bearings and they were to expensive IMHO. I wish I had been paying attention when the thread about the better tapered bearings showed up in 2017. I have a friend that has been using a set for 4-5 years and they are still holding up.
> 
> I generally shoot for 2cu in/minute in aluminum at 6750 rpm, 81 IPM, .004 IPT with a Best Carbide 3/8" 3 Flute 1" LOC HSC Aluminum End Mill (601-33750-1).


Wow. Very nice. My go to recipe is 5000 rpm, 3/8" 3F Alu-Power endmill, 1" deep, 30% (0.1125") radial stepover, 0.004" ipt. I go for high speed "dynamic" toolpaths (everyone has a different name for the same thing) with 300ipm back feedrates. 

I have not had the experience of burning up spindle bearings, but I'd seriously consider the taper roller ones suggested if I need to replace mine.


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## OCD Solutions

I'm in no hurry to upgrade my spindle bearings yet so I took one for the team and ordered one of the 32007 X/Q bearings off Amazon just to see what he actually ships. I received a 32007 X bearing yesterday so I've reached out to see if they can correct it. I've also flagged the ad for incorrect listing information.

I ordered a 32005 X/Q from a different seller and should get that one later today. Anyone wanna guess what actually arrives?


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