Help building pulley setup to a DC motor

[tschmitt]

I am working on a little project but I could use some guidance on what I am trying to look for. I have it drawn out in my head and on paper but I am not sure on what I need to search for in regards to terminology of the parts. From the drawing you can see what I am trying to go for. The motor will be a DC motor (250-500) watts with a pulley that would vary from 3" to 1" depending on the RPM rating of the motor I pick. I need to adapt it over to a pulley and shaft that will be coupled to a 3" 3 jaw chuck. This will not be turning a heaving load. The 3 jaw chuck with clamp to a shaft that turns the device I am testing. The 3 jaw chuck will turn to a max of 4000 rpms, most likely below 3000 most of the time. The pulleys will most likely be a GT2 style pulley for less chance of slippage. I have a machine shop close by that can make the adapter fit the 3 jaw chuck to whatever size/style shaft I end up using. Motor will be reversible so will spin cw or ccw depending on the situation so that will be a factor on the shaft/pulley style I end up using. Any advice on how to proceed would be greatly appreciated. First time building something like this so I'm having a hard time even starting to find parts for this because I am not well versed in the terminology for the parts I am trying to find.

 

[dogdog]

Your bearing would be pillow block bearing or you roll your own. Something like these,

Amazon.com

But you really can’t select any bearing until you decided on the shaft of your chuck and back plate.

As far as pulleys or gt2 timing gear I think that’s what’s called might be too weak, well at least the one I got from Amazon 1” 3” gets aluminum pulley that is. You might want something else.

This is what I got from Amazon for a sun tracker wannabe project it looks tough but it’s errrrr flimsy not sure if it will do what you wanted. Spinning a 3” chuck at 4000 rpm

Amazon.com

 

[tschmitt]

Your bearing would be pillow block bearing or you roll your own. Something like these,

Amazon.com

But you really can’t select any bearing until you decided on the shaft of your chuck and back plate.

As far as pulleys or gt2 timing gear I think that’s what’s called might be too weak, well at least the one I got from Amazon 1” 3” gets aluminum pulley that is. You might want something else.

This is what I got from Amazon for a sun tracker wannabe project it looks tough but it’s errrrr flimsy not sure if it will do what you wanted. Spinning a 3” chuck at 4000 rpm

Amazon.com

Thank you very much! I will do some research and see what I can come up with.

 

[no704]

Not sure exactly what you are looking to do? But it sure sounds like a cheap Chinese mini lathe?

 

[tschmitt]

Not sure exactly what you are looking to do? But it sure sounds like a cheap Chinese mini lathe?

Its going to be spinning the shaft of a distributor so not a lot of torque required but need to reach RPMs of about 1500-2500 RPMs tops. The space between the motor and pulley set up is going to be pretty tight (less than 6" between shaft to shaft) so the pulleys will be small in diameter, I am guessing 1" size pulleys until I get the motor in and start mocking this up. The motor is a 250w 24v 2600 RPM DC motor that I can reverse as needed.

 

[no704]

Its going to be spinning the shaft of a distributor so not a lot of torque required but need to reach RPMs of about 1500-2500 RPMs tops. The space between the motor and pulley set up is going to be pretty tight (less than 6" between shaft to shaft) so the pulleys will be small in diameter, I am guessing 1" size pulleys until I get the motor in and start mocking this up. The motor is a 250w 24v 2600 RPM DC motor that I can reverse as needed.

Sounds like something that could use more like a. O ring than a timing belt?

 

[tschmitt]

Sounds like something that could use more like a. O ring than a timing belt?

Hmmm, I haven't looked into anything like that. Any recommendations on pulleys/belt/o-ring you would look into given the parameters I laid out? The small pulley sizes are making it a little hard to find something to work given the space.

 

[no704]

I recently bought a micro lathe for a project that would probably be good for this. Was like $250-!$350 on Amazon I think. Would need to rig a speed controller maybe as it is single speed. But it’s a, I think 24v dc motor. Frame of the thing is like 80-20 out of the box. Didn’t work out for what I was trying to use it for but seems like you could use it. Think I even still have the packaging. I’ll give ya a deal on it!

 

[no704]

Can’t remember if I got it on amazon or eBay? Doing this from phone now as I’m on the road this week. I’ll try and find a link to the product. It is the cutest little lathe I have ever seen. And it actually does work!

 

[Firebrick43]

A single bearing, no matter how light the load will not work well. You need two and at least a minimal amount of separation between them.

You will be disappointed in GT2 belts at those speeds.

As far as small belts with small diameter pulleys at those speeds, I would choose a J section polyvee/microvee belt, probably a 6 rib one(6J). They are cheap and smooth and can transmit significant power without crazy tension. Polyflex JB belts are also good for this application but much less common and more expensive generally.

Here is the Gates design manual, page 83 is the microvee section.

https://www.gates.com/content/dam/g...catalogs/light-power-and-precision-manual.pdf

 

[tschmitt]

I single bearing, no matter how light the load will not work well. you need to and at least a minimal amount of seperation between them.

You will be disappointed in GT2 belts at those speeds.

As far as small belts with small diameter pulleys at those speeds, I would choose a J section polyvee/microvee belt, probably a 6 rib one(6J). They are cheap and smooth and can transmit significant power without crazy tension. Polyflex JB belts are also good for this application but much less common and more expensive generally.

Here is the Gates design manual, page 83 is the microvee section.

https://www.gates.com/content/dam/g...catalogs/light-power-and-precision-manual.pdf

Thank you! After researching it I will most likely sandwich two flange style pillow brackets between the 1/4 steel plate I am using for the 8mm shaft. I will do some research on the belt types recommended. Thanks again

 

[tschmitt]

I recently bought a micro lathe for a project that would probably be good for this. Was like $250-!$350 on Amazon I think. Would need to rig a speed controller maybe as it is single speed. But it’s a, I think 24v dc motor. Frame of the thing is like 80-20 out of the box. Didn’t work out for what I was trying to use it for but seems like you could use it. Think I even still have the packaging. I’ll give ya a deal on it!

Thanks for the offer but I already have a motor on the way lol, sounds like a neat little lathe though.

 

[no704]

It’s cute. Highly doubt I’ll ever use it. I’d give it to you for shipping and a couple beers. Has a very cute little 3 jaw Chuck. Sounds almost exactly like what you are trying to build from scratch. Not pushing it on you. I’m always looking to use an off the shelf answer to solve a problem.

 

[tschmitt]

It’s cute. Highly doubt I’ll ever use it. I’d give it to you for shipping and a couple beers. Has a very cute little 3 jaw Chuck. Sounds almost exactly like what you are trying to build from scratch. Not pushing it on you. I’m always looking to use an off the shelf answer to solve a problem.

You're welcome to send me a link to what it is and I'll be happy to look at it, lol never know, I might be able to find a use for it.

 

[no704]

Ya, checked my az and eBay history best I can on a phone. Didn’t find it. Be back on a real computer next week.

 

[tschmitt]

Ya, checked my az and eBay history best I can on a phone. Didn’t find it. Be back on a real computer next week.

Sounds good!

 

[no704]

Don’t get me wrong. It’s a real piece of **** as a lathe goes. Comes with some wood sticks to practice on.
But almost sounds like an out of the box solution for what you need.

 

[tschmitt]

Don’t get me wrong. It’s a real piece of **** as a lathe goes. Comes with some wood sticks to practice on.
But almost sounds like an out of the box solution for what you need.

Lol I'll look it over and see. I've already got most of the parts I need for this build, just a matter of putting it all together now once I get a few more kinks figured out.

 

[whateg01]

A single bearing, no matter how light the load will not work well. You need two and at least a minimal amount of separation between them.

You will be disappointed in GT2 belts at those speeds.

As far as small belts with small diameter pulleys at those speeds, I would choose a J section polyvee/microvee belt, probably a 6 rib one(6J). They are cheap and smooth and can transmit significant power without crazy tension. Polyflex JB belts are also good for this application but much less common and more expensive generally.

Here is the Gates design manual, page 83 is the microvee section.

https://www.gates.com/content/dam/g...catalogs/light-power-and-precision-manual.pdf

Could use a double row ac bearing by itself.

Agree on the micro vee. Any timing belt is going to be noisy.

 

[no704]

 

[tschmitt]

Could use a double row ac bearing by itself.

Agree on the micro vee. Any timing belt is going to be noisy.

Thank you, I'll do some checking on the double row ac bearing setup and see.

 

[no704]

Found it. It’s a **** lathe but seems like what or close to what ur r trying to build from scratch.

 

[tschmitt]

I'll do some checking on the lathe. If I am interested I'll get back to you about it. Thanks again!

 

[Firebrick43]

Could use a double row ac bearing by itself.

Agree on the micro vee. Any timing belt is going to be noisy.

You could, but then you would have a custom housing with some way to trap the outer race, and a custom shaft with shoulder and nut to give proper trap to the inner race. And the bearing itself would still be much more expensive than two pillow block bearings mounted with some distance apart. I am guessing the OP has neither the experience or equipment to machine the housing.

 

[no704]

Couldn’t even build anything for the cost, I would not get out of bed for $150. Already has motor, spindle, belts, pulleys. And

 

[tschmitt]

You could, but then you would have a custom housing with some way to trap the outer race, and a custom shaft with shoulder and nut to give proper trap to the inner race. And the bearing itself would still be much more expensive than two pillow block bearings mounted with some distance apart. I am guessing the OP has neither the experience or equipment to machine the housing.

The two pillow block bearings do seem to be a better fit for what I am trying to accomplish. I like that they have the locking set screw to hold the shaft as well so would make it simpler.

 

[tschmitt]

Couldn’t even build anything for the cost, I would not get out of bed for $150. Already has motor, spindle, belts, pulleys. And

Yup its pretty crazy how cheap they can find a way to make things nowadays lol.

 

[no704]

It’s crazy. It’s actually quite well made for what it is. I think it’s a better jumping off point for your project than starting from scratch? If you want the one I have pm me and it’s yours for shipping plus $50 for me having to actually ship it. Might actually be cheaper to just order one if you have prime.

 

[no704]

Spindle spins very true.

 

[Firebrick43]

Ebay 4PJ pulleys

Here is some 4 rib J section pulleys that are pretty cheap from china. For what ever reason the Metric countries have to bastardize the nomenclature and instead of J section call it PJ section????

 

[FrankLee]

I needed something similar and came up with these. They may inspire some ideas. My chuck was threaded on, so mine is not reversible.

 

[tschmitt]

It’s crazy. It’s actually quite well made for what it is. I think it’s a better jumping off point for your project than starting from scratch? If you want the one I have pm me and it’s yours for shipping plus $50 for me having to actually ship it. Might actually be cheaper to just order one if you have prime.

I am going to pass but thank you for the offer, I appreciate it. Most of my parts will be here in the next day or two.

 

[tschmitt]

Ebay 4PJ pulleys

Here is some 4 rib J section pulleys that are pretty cheap from china. For what ever reason the Metric countries have to bastardize the nomenclature and instead of J section call it PJ section????

Thank you! I saw those as well, lol its annoying when they cross label things sometimes.

 

[tschmitt]

I needed something similar and came up with these. They may inspire some ideas. My chuck was threaded on, so mine is not reversible.

Thank you for the pictures, that was one option I had pictured in my mind as well. The chuck being threaded was the reason I am having my local machine shop build me a custom backing plate so it can be run cw or ccw and attach to whatever size shaft I end up going with. The style lathe chuck that you posted is the one I bought except a 3" version. I like that it has the jaw tightening style with a allen/square headed screw vs the two moveable plates, tends to "lock in" better in my experience.