# Anyone assembling the Clough42 Electronic Leadscrew system? I have questions...



## luxige (Apr 29, 2020)

I’m sure I’ll have many, many questions, but first and foremost is figuring out how much servo motor I will need.

Here is the open-source project I’m talking about:








						Lathe Electronic Leadscrew
					

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James is driving the combination feed/leadscrew of his Grizzly G0602 benchtop lathe (10x22”, 1hp, 432 lb. shipping weight) using a Nema23 hybrid servo of 282 oz/in, about 2 N-m.

My lathe is 70s vintage, unknown maker, 12x36”, 3hp, about 1500 lb. Obviously I need a bigger servo, but I really have no idea how to go about calculating the torque I need. For now, my only idea has been to search for a CNC conversion kit for a similar lathe and see what they spec.

Picture below shows the condition of the QCGB and the reason I’m planning this conversion:


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## luxige (Apr 29, 2020)

And the next question is what’s a good source of cogged belts and wheels in small sizes?
North America shipper preferred.

I’ll need a small set to drive the encoder from the spindle, and something larger to drive the feed shaft with the servo.


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## RJSakowski (Apr 29, 2020)

luxige said:


> I’m sure I’ll have many, many questions, but first and foremost is figuring out how much servo motor I will need.
> 
> Here is the open-source project I’m talking about:
> 
> ...


You pose a very good question.  There is a long thread on the ELS subject which discusses this. 








						electronic lead screw
					

I'm wondering what is state of the art for electronic lead screws these days and if anyone has advise based on implementing on on an import lathe?




					www.hobby-machinist.com
				




 For my part, I installed the ELS  I have a 602oz-in hybrid stepper on my lead screw with 2:1 gear reduction driving with a 42 volt switching supply @ 8 amps.. My G0602 lead screw has  12 tpi.   I ran some tests where my carriage is lifting a bucket of lead  over a pulley.  The stepper started to lose steps at around 3.5 mm/rev. at the lead screw and a dead weight of 105 lbs. which corresponded to 890 rpm at the stepper. (post #287)

You will find out that torque on a stepper motor drops fairly quickly with increasing speed.  Also, lead screws are very inefficient at transmitting power.  The finer the pitch, the more inefficient it is so although you get more torque multiplication as the pitch becomes finer, the efficiency loss eats up a lot of that gain.  On contrast, my Tormach mill with ball screws uses 600 oz-in steppers with no issues.

I would suggest that you pour yourself a couple of your favorite beverages and start reading the above thread.  If you have any questions after that, we'll try to help.  Rather than continue with this thread, they would probably be best added to the above thread so we can keep all the discussion in one place.


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## RJSakowski (Apr 29, 2020)

luxige said:


> And the next question is what’s a good source of cogged belts and wheels in small sizes?
> North America shipper preferred.
> 
> I’ll need a small set to drive the encoder from the spindle, and something larger to drive the feed shaft with the servo.



You can try here.  http://shop.sdp-si.com/catalog/product/?id=A 6R51M150030 
I bought mine on e-bay and some came from China.  The delivery time was around two ro three weeks (pre COVID 19)  Some parts were sourced stateside and came within a week.  

On your first question, this may be of use.
https://www.daycounter.com/Calculators/Lead-Screw-Force-Torque-Calculator.phtml  The big unknown is how much force do you need at the carriage to make the type of cuts that you want.


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## luxige (Apr 29, 2020)

RJSakowski said:


> You can try here.  http://shop.sdp-si.com/catalog/product/?id=A 6R51M150030
> I bought mine on e-bay and some came from China.  The delivery time was around two ro three weeks (pre COVID 19)  Some parts were sourced stateside and came within a week.
> 
> On your first question, this may be of use.
> https://www.daycounter.com/Calculators/Lead-Screw-Force-Torque-Calculator.phtml  The big unknown is how much force do you need at the carriage to make the type of cuts that you want.



Thanks and thanks again!
I’ll check into the thread you referenced and continue there.

Re: pulleys etc., I did find Polytech Design, looks like quality but a little pricey. However, they are stateside.


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## RJSakowski (Apr 29, 2020)

luxige said:


> Thanks and thanks again!
> I’ll check into the thread you referenced and continue there.
> 
> Re: pulleys etc., I did find Polytechnic Design, looks like quality but a little pricey. However, they are stateside.


That's the reason that I went across the pond for my belts and pulleys.  I couldn't find any flaws in mine FWIW.
encoder pulleys  https://www.ebay.com/itm/401625859109
stepper pulleys  https://www.ebay.com/i/173908654969?ul_noapp=true
encoder belts https://www.ebay.com/itm/142829943316 (I ordered two different lengths as I didn't have a final position for the encoder)
stepper belt https://www.ebay.com/itm/3M-HTD3M-3...83.l10137.c10&nordt=true&rt=nc&orig_cvip=true


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## ttabbal (Apr 29, 2020)

Electronic Lead Screw
					

I'm going to attempt to adapt clough42's ELS to my PM1127. I figure I might as well do it publicly in case it ends up being useful for someone else. I have most of the parts now, and have the electronics and servo running on the bench. The first thing I decided to mess with is the rotary...




					www.hobby-machinist.com
				




My build on a smaller lathe. For yours, you will likely need a bigger servo to not be limited by it. I would probably go about 2x the torque. 

For belts and pulleys, I went with a vendor in China on ebay. The cost was a small fraction of the local sources, and look identical. I ended up buying one from a US source for speed, I couldn't tell the difference. For the smaller size GT2 stuff, Amazon had a decent selection. Not that they would be faster than direct from China these days.


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## kb58 (Apr 29, 2020)

I finished mine about 6 months ago. Yeah the required torque is nearly impossible to calculate due to all the variables. Just guess, really. Pick one maybe twice as strong as what he chose, and you can further increase torque with the gear ratios. As far as where to buy the belts and gears from, I used the place he recommended, which as I recall was on Long Island, NY, can't remember the name though, sorry.


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## luxige (Apr 29, 2020)

RJSakowski said:


> That's the reason that I went across the pond for my belts and pulleys.  I couldn't find any flaws in mine FWIW.
> encoder pulleys  https://www.ebay.com/itm/401625859109
> stepper pulleys  https://www.ebay.com/i/173908654969?ul_noapp=true
> encoder belts https://www.ebay.com/itm/142829943316 (I ordered two different lengths as I didn't have a final position for the encoder)
> stepper belt https://www.ebay.com/itm/3M-HTD3M-3...83.l10137.c10&nordt=true&rt=nc&orig_cvip=true



Again, extremely useful; and again, greatly appreciated!
Now that I see a few pertinent products, I have the right terminology to search on. Although I may just go with the same vendors you did.


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## luxige (Apr 29, 2020)

ttabbal said:


> Electronic Lead Screw
> 
> 
> I'm going to attempt to adapt clough42's ELS to my PM1127. I figure I might as well do it publicly in case it ends up being useful for someone else. I have most of the parts now, and have the electronics and servo running on the bench. The first thing I decided to mess with is the rotary...
> ...



Excellent! That’s a really nice looking installation.
I took a quick run through your thread, and I’ll go back and study it carefully tomorrow. I have some questions that I will post there. TIA


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## RJSakowski (Apr 29, 2020)

One point that I didn't make considering the force available to the carriage is that I can easily stop the stepper driven lead screw from rotating using the carriage crank, which is difficult to do when driving the the lead screw with the gear train.  Assuming all of my 1 hp motor was available to the lead screw, at 890 rpm calculated above, there would be  1130 oz-in of torque or roughly four times what my stepper can put out at that speed.  Now not all of the motor power would be used for that purpose and in real life the lathe motor would just stall so a better choice for me would have been something like a 1,000 oz-in. motor.  But as I stated in the other thread, it is highly unlikely that I would ever want to drive the lathe that hard.


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## luxige (Apr 29, 2020)

kb58 said:


> I finished mine about 6 months ago. Yeah the required torque is nearly impossible to calculate due to all the variables. Just guess, really. Pick one maybe twice as strong as what he chose, and you can further increase torque with the gear ratios. As far as where to buy the belts and gears from, I used the place he recommended, which as I recall was on Long Island, NY, can't remember the name though, sorry.



I just quickly checked out your build thread, looks cool!
Has the 440 in-oz of torque worked out okay in practice? (I had been thinking of going pretty big with something like 1200 in-oz, based on a package from Rocketronics).


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## luxige (Apr 29, 2020)

RJSakowski said:


> One point that I didn't make considering the force available to the carriage is that I can easily stop the stepper driven lead screw from rotating using the carriage crank, which is difficult to do when driving the the lead screw with the gear train.  Assuming all of my 1 hp motor was available to the lead screw, at 890 rpm calculated above, there would be  1130 oz-in of torque or roughly four times what my stepper can put out at that speed.  Now not all of the motor power would be used for that purpose and in real life the lathe motor would just stall so a better choice for me would have been something like a 1,000 oz-in. motor.  But as I stated in the other thread, it is highly unlikely that I would ever want to drive the lathe that hard.



Okay, thanks! I have asked my next question (with more to go) over on the big thread as you suggested. TIA


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## BGHansen (Apr 30, 2020)

luxige said:


> I’m sure I’ll have many, many questions, but first and foremost is figuring out how much servo motor I will need.
> 
> Here is the open-source project I’m talking about:
> 
> ...


Ouch


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## Cletus (Oct 22, 2021)

Well, I'm embarking on this project to upgrade my Grizzly G4000 Lathe to ELS.   Is there still any interest in this out there?


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## ttabbal (Oct 22, 2021)

Cletus said:


> Well, I'm embarking on this project to upgrade my Grizzly G4000 Lathe to ELS.   Is there still any interest in this out there?



I would think so. People seem to be asking about it once in a while. Documenting your build could be very helpful for others.


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## Cletus (Oct 22, 2021)

Great.  I bought all the boards on ebay and just sorting out the belts and pulleys that I will need before going any further.


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## Diaric (Jan 2, 2022)

Cletus said:


> Well, I'm embarking on this project to upgrade my Grizzly G4000 Lathe to ELS.   Is there still any interest in this out there?


Yes, there is.
 I have the same lathe, from a Canadian reseller.  As the reply suggested, a documented build would be fantastic.
 I understood most things computer, back in the XP days, and am now lost in space. When James starts talking over my head, I am lost on what I should get and where I should start. A simple get this, build this, try that would be a fantastic resource. I’ve searched for a simplified how too and haven’t found much.
 I am about to start the planning of a variable speed DC motor, and already see myself duplicating things from Clough42’s build and would hope to avoid this and have it all work together smoothly.


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## Cletus (Jan 2, 2022)

I'm very happy with how mine turned out. Here's the link to my build log:









						G4000 ELS Upgrade
					

Back around 2005, I purchased my Grizzly G4000 Lathe and did quite a few very useful mechanical mods to it, leading to the publication with the help of others, two FREE handbooks "Tricking out the Asian 9 x 20 Lathe" and "Rebuilding The Asian 9 x 20 Lathe". Well, this lathe has served me well...




					www.hobby-machinist.com
				




Any questions I can answer, I'll gladly do so, good luck with it.


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## Diaric (Jan 2, 2022)

Thank you very much. I will read intently and drool


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