# lathe speed setup



## goldenoldie (Dec 6, 2014)

how com no one responds to my posts?


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## Gshepherd (May 16, 2012)

Well I will bite…. Sitting here taking a break at 140am doing some glueups…

So what exactly is our question? Be more Specific….


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## Sawdust2012 (Sep 17, 2013)

I think you may be making the same mistake I did early on. Your questions are posted as comments on your profile page. No one would see them unless they looked at your page.


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## mrg (Mar 10, 2010)

Yes, you posted your first two questions on your home page comments section.

Repost them in the forums section and someone will answer them.

Oh and welcome to Lumberjocks.


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## Wildwood (Jul 22, 2012)

Are you talking about adding a countershaft as seen on this lathe?

http://vintagemachinery.org/photoindex/detail.aspx?id=16622


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## goldenoldie (Dec 6, 2014)

Thanks for responding to my screwup. Let's try again. The setup for my lathe will be similar to Wildwood's reponse. I want the maximum number speeds so I have a 4 step pulley on my motor ,the countershaft, and the headstock. My intent was to mount my motor on the bottom with a hinge for ease of belt moving. How can I move the belt from one step to the other on the upper belt ? Do you just force the belt or is there a better way ? I am using link belt. I am also thinking of putting my motor on a slide of some kind to get more speeds. Please help .


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## Oldtool (May 27, 2012)

You should have a method by which to tension the belt. Just take the tension off to move the belt. Sound feasible?


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## BillWhite (Jul 23, 2007)

You said that you were gonna mount the motor on hinges. Just left the motor, move the belt, done. What's hard about that?
Bill


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## Wildwood (Jul 22, 2012)

If go to link will see many old Delta or Delta-Rockwell lathes without a countershaft. Belts run from headstock to motor, and lift motor to reduce belt tension and move belt along the pulley to adjust speed. 
Unless can find somebody that has their stuff in one bag to help you think will spend a lot of time and money without much to show for it!

If got to have a lathe with a counter shaft post your questions at the discussion forum at Vintage Machinery maybe someone can help you.

http://vintagemachinery.org/photoindex/bytype.aspx

We have no idea which Delta/Rockwell or plain Rockwell lathe you are talking about or measurements. You can only calculate speed by knowing size of pulleys & length of belts and few other things. Adding a counter shaft adds little bit more difficulty.


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## MrUnix (May 18, 2012)

> I am mounting an old big 1 HP GE repulsion induction motor to my old Rockwell lathe. My lathe has a 4 step pulley. My motor has a 4 step pulley. I would like to be able to use all combinations of speed. I will therefore have to have my motor slide. Anyone have a good idea on how to achieve this ?


Wth the stepped pulley on lathe and motor, there is no need to make the motor 'slide'. Lathes used that configuration for decades without problem.. you just 'walk' the belt to the different steps on the pulley. The pullies are arranged so they complement each other, wth the largest step on the outside on one, and the inside on the other. Motor (and lathe) can remain mounted securely in place with that setup. Adding a countershaft will involve quite a bit of work and expense and IMHO is not really necessary.

Cheers,
Brad

PS: To calculate the spindle speed, you only need to know the diameters of the pulley and motor speed.. belt length does not play into the equation. You can use this calculator at the vintagemachinery site to calculate what speeds you will have at the spindle:

http://vintagemachinery.org/math/arborrpm.aspx


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## wormil (Nov 19, 2011)

Forget all that complication with countershafts and switching pulleys, switch the lathe over to variable speed. 
http://thewoodknack.blogspot.com/2014/11/how-to-get-variable-speed-on-cheap.html


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## Wildwood (Jul 22, 2012)

MrUnix, using calculator at vintage machines will get OP in the ball park if he already knows distance between pulleys or distance not changed just changing pulleys. Calculator does not take into account belt slippage or other variations.

If do not have the old belt or distance change and need a new belt can get a SWAG using these calculators.

http://www.engineersedge.com/belt_design/belt_length_pulley_center_dist.htm

http://www.blocklayer.com/Pulley-Belt.aspx


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## MrUnix (May 18, 2012)

> MrUnix, using calculator at vintage machines will get OP in the ball park if he already knows distance between pulleys or distance not changed just changing pulleys. Calculator does not take into account belt slippage or other variations.


Distance between pulleys will not change the speed of the spindle.. the motor can be 1 foot or 10 feet away and it will be the same.. and if you have slippage, then the belt tension is not sufficient and needs to be corrected.

Cheers,
Brad


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## goldenoldie (Dec 6, 2014)

I am trying to slow down my lathe to less than 300 rpm and that will not work if I only use two 4 step pulleys . That will only work with a countershaft setup… Without going to a variable speed motor , I will get the max number of speeds by going to a 4 step pulley on my motor, countershaft and headstock. I will make this work if I can work out the slide for my motor. I am also looking for a belt tension release for changing the speed on the belt from countershaft to headstock.


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## MrUnix (May 18, 2012)

Sounds like you wouldn't really need too much to get it to work.. a couple of stepped pulleys, line shaft and pillow blocks. Wouldn't really have any need to slide the motor either, and speed changes can be done by walking the belt just like you would without the intermediate shaft.

With a pretty standard 2/3/4/5" stepped pulley on the line shaft and motor, you can get the line shaft down to just under 700 rpm (assuming a 1725rpm motor). Steps on my vintage rockwell lathes pulleys are 2.5, 3, 4 and 4.5", so using those, the lowest speed would be just under 400 rpm. Using pulleys on the lathe/shaft, or motor/shaft with a greater differential would get it a bit slower.

Curious as to why you would need to go so slow?

Cheers,
Brad


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## wormil (Nov 19, 2011)

My lathe goes down to about 250 rpm but the only thing I do at that speed is apply finish. Unless you already have a countershaft laying around, my advice is forget about it. I looked into it once and cost + effort just isn't worth it. You can hang a motor and make it slide, that's not too difficult. Mount the motor on a plate (wood or metal) then you'll need an arm (wood or metal) that attaches to a sturdy, smooth metal bar mounted parallel to the axis of your spindle. The tricky part is retro fitting all that to your lathe stand or designing a lathe stand to work with it. When I tell you to forget about it and convert to variable speed, it's because I've been down this road of countershafts and sliding motors and it is just so much easier, cheaper, and faster to use a DC motor.


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## REO (Sep 20, 2012)

|Look at the original atlas metal lathe setup. motor hangs by weight and the counter shaft is hinged to tighten with eccentrics. use the two fours and then two twos then you don't have to slide the motor OR leave the distance from the counter shaft to the motor long so that the belt can run out of parallel.


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## Wildwood (Jul 22, 2012)

MrUnix what you say is true for the motor spindle HP & no load max RPM rating does not change if connected to the headstock with single pulleys but as distance increases between those two point without proper belt efficiency suffers.

If you bought a Rockwell 46-11 new would not have to worry about distance between motor & headstock because predetermined at the factory. Once assembled below the headstock on hinged bracket with step pulleys provided lathe speeds pre-determined. See page 7 of manual below.

Size of step pulleys on motor & headstock spindle and belt will determine actual no-load RPM speed. Scroll down to photo 4 will see 46-111, 4-step headstock pulley, also pulley max diameter: 4 7/16", sheaves diameters 3 9/16", 2 15/16", 2 1/8" , 1 1/2" provided.

http://vintagemachinery.org/photoindex/detail.aspx?ID=6838

If you move the motor to a different location, as seen in many restorations (below or side) you can alter minimum-maximum speed by changing headstock & motor pulleys. Headstock pulley diameter has to stay 4 7/16" unless modify headstock but can change sheave diameters. You can add a bigger motor pulley than OEM, that came with lathe as long as sheave diameters match headstock. If modify headstock cand use bigger step pulley. This will change min-max speed of the lathe.

Changing step pulleys and relocating motor require some math to obtain desired speed change and new belt length. 
Rockwell Manual 46-111, for OEM min-max speed page 7 
http://vintagemachinery.org/pubs/2793/6574.pdf


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## MrUnix (May 18, 2012)

*If you bought a Rockwell 46-11 new would not have to worry about distance between motor & headstock because predetermined at the factory.*

Incorrect.. the stand and motor for that lathe were optional. Many people just bought the lathe and mounted them on their own stands/benches and stuck the motor wherever was convenient. Speed was not changed by doing so. I have the 46-110 (predecessor to the 46-111 in your example, but basically the same machine) and it too did not come stock with a stand or motor and they had to be purchased seperately if desired.

Bottom line is that belt length does not alter the speed of a driven pulley. Even your own link proves that:
http://www.blocklayer.com/Pulley-Belt.aspx

Go there and try changing the distance between centers. The belt length will change, but not the RPMs.

*Changing step pulleys and relocating motor require some math to obtain desired speed change and new belt length. *

Yes, changing pulley diameters will change speed, and the math is dirt simple requiring only the pulley diameters and motor speed like I originally stated.. moving the motor, and belt length due to that move, does not play into the speed equation one bit (formula can be found here: http://www.engineeringtoolbox.com/pulley-diameters-speeds-d_1620.html )

Cheers,
Brad


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## wormil (Nov 19, 2011)

I will add there are a number of online calculators for pulleys, do not trust them without checking the math manually. I found more than one to give incorrect answers.


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## Wildwood (Jul 22, 2012)

Think we are saying the same dang thing! Already talked about different configurations because still have no idea which lathe we are talking about.

Hopefully OP has found his lathe at linked web site and figured out what he must do to get it up & running.

True Dat Rick!


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## exelectrician (Oct 3, 2011)

In the future think about electronic speed controls that could be repurposed from existing consumer products. Like the 115V motor in a Maytag side load washing machine, this is a three phase motor with a wide speed control range that runs off a normal 115V plug. 
However you will need a geek to help you with the adaption, but noting that washing machines can be had for next to nothing when the main control panel dies or the pump fails this is an option well worth trying.
I hope this has got you thinking, and good luck to all who take the leap of faith.


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## goldenoldie (Dec 6, 2014)

Got it done. I installed the countershaft with a 4 step pulley. The lathe and motor each have a 4 step pulley. The motor belt to countershaft is tensioned by the mounting my motor on a hinge. The countershaft is adjustable by also being hinged and has a threaded rod with a big knob for holding the belt in tension. Easy to change belt for a multitude of speeds.


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## wormil (Nov 19, 2011)

I wouldn't mind seeing a pic of the finished setup.


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## goldenoldie (Dec 6, 2014)




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## goldenoldie (Dec 6, 2014)

Here is a second pic.


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## wormil (Nov 19, 2011)

That looks great, good job. Any vibration issues? I tried hanging a motor off the back of my lathe stand and no matter what I tried, it caused too much vibration. But your set up is a little different.


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## goldenoldie (Dec 6, 2014)

Minimal vibration using the awesome link belt. I will also add ballast to the box below for turning burls and such. If I get any vibration I will add a tensioning device to my motor but for now i'm good.


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## UncleCysWoodshop (Dec 17, 2014)

My solution on one of my machines was a 2hp DC motor from a tread mill. Wired a 10k ohm Potentiometer into the wires that went off to the bulky original tread mill control. Now I can go as slow as 40 rpm and as fast as 2800. On one of the other lathes I added a Screw controlled Reeves drive, I posted a blog about it.
http://lumberjocks.com/CyF/blog/47681
I gives me a range from about 400 to 3200.


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