Not for your project. Do yourself a favor and get 2 flange mount pillow blocks. By mounting them on either side of the top of your base, with the shaft going through them you will get all of the support you will ever need for this. You need to measure your rod and pick the correct size. This link just shows what the pillow blocks look like, you may get a better price on Ebay or Amazon. https://www.surpluscenter.com/Bearings/Cast-Iron-2-Bolt-Flange-Mount-Bearings/

Thank you for the great lead, Shortbus. Apologies for the delay in my reply. Does my sketch conform to your suggestion? Hazy on how to secure motor shaft to rod, I sketched a flange for pole that is mounted to wood, and motor shaft embedded into said wood. Hmmm ordered parts. Will Test and Report Back!

 

I was going to suggest a barbecue rotisserie motor. I can pretty much guarantee there will be couple at Value Village in the tools/autoparts section. The motor you ordered says "intermittent duty"; barbecue motors would be rated for continuous duty.

Good idea!!!

 

Definitely check out the rotisserie idea.

If that doesn't pan out, consider placing the bearings something like the following:



The drive system is just shown for example -- your setup might be quite different.

The greater the distance between the bearings, the more sturdy and stable the shaft will be.

Putting one or two clamps of some kind (even hose clamps) as shown will prevent the shaft from being pulled out. The one at the top is the important one.

You might also look into friction bearings, which should work find for your project and can be quite a bit cheaper if you are very budget sensitive.

Some thought should be given to how the shaft is supported vertically so as to minimum friction there. If the bearing has an inner race, you could secure it there via some suitable means. Also, if the clamp rests against the inner race, that should also do fine. If the shaft is going through the bottom bearing and resting on the stationary box bottom, then you would ideally use a thrust bearing, but making a good, smooth end of the pipe and then setting it on a small, smooth steel plate that is greased should work as well. That depends on how long this sculptor is expected to be on exhibit. If it is for a short term show or occasional exhibits, this should be fine. If it's for a permanent exhibit somewhere, you want something better.

 

View attachment 276522View attachment 276523Thank you for the great lead, Shortbus. Apologies for the delay in my reply. Does my sketch conform to your suggestion? Hazy on how to secure motor shaft to rod, I sketched a flange for pole that is mounted to wood, and motor shaft embedded into said wood. Hmmm ordered parts. Will Test and Report Back!

The sketch is good. But if your shaft is 1/2" water pipe yand you have 1/2" bearings the bearings won't fit. The reason is the pipe is much larger, 1/2" = 0.50" 1/2" pipe is 0.84" diameter. https://www.atc-mechanical.com/tube-pipe-101/tube-pipe-size-overview/

 

Some thought should be given to how the shaft is supported vertically so as to minimum friction there. If the bearing has an inner race, you could secure it there via some suitable means. Also, if the clamp rests against the inner race, that should also do fine. If the shaft is going through the bottom bearing and resting on the stationary box bottom, then you would ideally use a thrust bearing,

The 2 back to back pillow blocks eliminates all of the all of the problems you mentioned above. With plain bearings like you showed you would still need a way to secure the outer races, and get them in line to make the sculpture rotate in a level position. the pillow blocks do that and give a thrust component to the weight of the sculpture.

 

The sketch is good. But if your shaft is 1/2" water pipe yand you have 1/2" bearings the bearings won't fit. The reason is the pipe is much larger, 1/2" = 0.50" 1/2" pipe is 0.84" diameter. https://www.atc-mechanical.com/tube-pipe-101/tube-pipe-size-overview/

Ah thank you. I actually ordered 3/4" but cripes that seems to small as well (0.84 > 0.75). Well, all the info was great because it gave me enough data to conclude - this is over my head XD. Time to stake out and find someone to help fabricate this. I have so many other projects to burn through, I can't "learn" this trade too. Thought making something spin would be "easy." Grateful for the info and compassion (the level of noob shaming on most technical forums is pathetic).

 

Look for 0.875" bore
https://www.grainger.com/product/TRITAN-Radial-Ball-Bearing-0-875-35JC81

You'll need some shim stock around it (five to seven wraps of 0.003")...

https://www.amazon.com/Stainless-St...3646849&sprefix=shim+stock+tape,aps,72&sr=8-2

 

Definitely check out the rotisserie idea.

If that doesn't pan out, consider placing the bearings something like the following:

View attachment 276524

The drive system is just shown for example -- your setup might be quite different.

The greater the distance between the bearings, the more sturdy and stable the shaft will be.

Putting one or two clamps of some kind (even hose clamps) as shown will prevent the shaft from being pulled out. The one at the top is the important one.

You might also look into friction bearings, which should work find for your project and can be quite a bit cheaper if you are very budget sensitive.

Some thought should be given to how the shaft is supported vertically so as to minimum friction there. If the bearing has an inner race, you could secure it there via some suitable means. Also, if the clamp rests against the inner race, that should also do fine. If the shaft is going through the bottom bearing and resting on the stationary box bottom, then you would ideally use a thrust bearing, but making a good, smooth end of the pipe and then setting it on a small, smooth steel plate that is greased should work as well. That depends on how long this sculptor is expected to be on exhibit. If it is for a short term show or occasional exhibits, this should be fine. If it's for a permanent exhibit somewhere, you want something better.

Thanks so so much for posting this! As I stated above, taking into consideration all the info and all I do not know about mechanics I will be outsourcing this project. Bless you all! I'll be posting some other digital / circuit related stuff in the forums soon.

 

I did it!!! Video too big to post. Photo will have to suffice. Motor is slightly uneven, but good enough. Bolted it to box using metal braces. JB welded the wood onto the shaft that pipe flange is screwed onto. Used 15/16" hole on top to serve as some kind of stabilizer. ***If I want to turn this on and off with solid state relay hooked up to arduino do I need to worry about blow back voltage from motor?

 

No , solid state relays are optically isolated, there is no connection to the motor circuit.

 

No , solid state relays are optically isolated, there is no connection to the motor circuit.

Thanks!

 

***Just saw on the specs for motor I ordered it states "

• Duty Intermittent(1 min). Does this mean I must program the motor to turn off every minute to cool?

 

It means you chose the wrong motor. You probably want one rated for continuous operation.

A duty cycle should specify a ratio, i.e. one minute per hour, or one minute out of ten.

 

***Just saw on the specs for motor I ordered it states "

• Duty Intermittent(1 min). Does this mean I must program the motor to turn off every minute to cool?

That would work, or, you could use your Arduino's PWM output to run at a slower speed and turn a bit, stop, turn a bit, stop. Etc.

 

That would work, or, you could use your Arduino's PWM output to run at a slower speed and turn a bit, stop, turn a bit, stop. Etc.

Thanks!

 

Well, it seems due to the weight imbalance and length of pole from motor shaft I may need to invest in a pillow flange or two. The pole gets stuck around the plywood hole, and the pipe starts to unthread from the flange attached to motor shaft. Will continue to post my progress, to help others with similar mechanical issues, if nothing else.

 

Certainly the BBQ rotating spit drive motor is far more suited to the application than a 135RPM gearmotor of questionable quality that has an intermittent duty rating. Consider that the speed you mentioned, 2 RPM, will require a 65:1 turn-down, which will not be within the ability of that motor.So the arm would be spinning probably faster than 15 RPM, at which speed any unbalance will have the effect of making it sway. The grill motor will be much closer to the speed that you want. For the bearing where the shaft passes through the platform you can use a piece of high-density polyethylene material (UHMW PE) with a hole drilled in it that is a close but not snug fit for the shaft. No need for a precision higher speed bearing in this application.
To couple that shaft, which looks like steel re-enforcement rod (REBAR), you can simply grind the last bit of the end to a square shape that fits into the square opening of the grill motor. If you do not have a grinder, a file will work but take much longer.

 

Certainly the BBQ rotating spit drive motor is far more suited to the application than a 135RPM gearmotor of questionable quality that has an intermittent duty rating. Consider that the speed you mentioned, 2 RPM, will require a 65:1 turn-down, which will not be within the ability of that motor.So the arm would be spinning probably faster than 15 RPM, at which speed any unbalance will have the effect of making it sway. The grill motor will be much closer to the speed that you want. For the bearing where the shaft passes through the platform you can use a piece of high-density polyethylene material (UHMW PE) with a hole drilled in it that is a close but not snug fit for the shaft. No need for a precision higher speed bearing in this application.
To couple that shaft, which looks like steel re-enforcement rod (REBAR), you can simply grind the last bit of the end to a square shape that fits into the square opening of the grill motor. If you do not have a grinder, a file will work but take much longer.

Hi MisterBill! Thanks so much for the reply. I will take all this info into consideration. A couple things:
0) Great tip about using the acrylic block (is 1" thickness enough?) instead of pillow flange. That said, I've already ordered x2 1" bore pillow blocks. I'm thinking to just wrap the pipe in tape to make up for the wider diameter inside the block.
1) I'm using a 1/2" hollow steel pipe that I believe would prove impossible to couple with the BBQ motor (where there is a will there is a way, to be sure)
2) I'm not adverse to the intermittent duty cycle. Although I don't know the specs which is reckless, I will have the motor computer controlled with an SSR, so it can be on/off over time. Much to play with there (controlled via Arduino + sensors, music, pushbuttons etc)

 

OK, and first, the bearing material would not be acrylic, but rather polyethylene, which is a more slippery material, like those white plastic cutting boards that eventually get scratched up and discarded.
Did not realize the arm was half inch pipe, in the photo it looks like Rebar. Attaching may be even easier. The BBQ rotators usually include the square spit rod, often about 5/16 square or so. A length of that material extended into the half inch pipe will be fairly stable, especially if you drill holes in the pipe for set screws which can be quarter-20 bolts threaded into holes that you drill and tap. Or use self tapping bolts and 3/16 holes for the self tapping bolts to thread. Cheaper than setscrews and you can use a bigger wrench to turn them.

 

OK, and first, the bearing material would not be acrylic, but rather polyethylene, which is a more slippery material, like those white plastic cutting boards that eventually get scratched up and discarded.
Did not realize the arm was half inch pipe, in the photo it looks like Rebar. Attaching may be even easier. The BBQ rotators usually include the square spit rod, often about 5/16 square or so. A length of that material extended into the half inch pipe will be fairly stable, especially if you drill holes in the pipe for set screws which can be quarter-20 bolts threaded into holes that you drill and tap. Or use self tapping bolts and 3/16 holes for the self tapping bolts to thread. Cheaper than setscrews and you can use a bigger wrench to turn them.

Brilliant, thank you so much. Flanges arriving Wednesday. I will order a sheet of 1/2" thick polyethylene (is that sufficient sizing?) as well. Its much simpler to install than the blocks, thats for sure.