Kook needs help with motor size?

Thread Starter

Mark Rountree

Joined May 9, 2017
51
So,as you can see, it's a series of rollers, I need one powerful motor to run these roller in a series of forward reverse motions. This is to be in sequence with one or maybe two steppers to run a lead screw to push the finished product off the machine when it's finished. (Linear actuator like). Firstly a motor will feed the material ( 250mm wide sheetmetal ) into a guillotine 55 mm at a time, then the next motor will run another screw to pull the guilotine down. Next another motor will push the material into the rollers.
After the rolling has finished and the 80mm diameter 55mm high sheetmetal cylinder is finished, then a robotic arm will take the part and pack it.
Phew. Hope that makes sense,
Mark
Ps, cheers for the replies so far
 

MrChips

Joined Oct 2, 2009
30,714
So,as you can see, it's a series of rollers, I need one powerful motor to run these roller in a series of forward reverse motions. This is to be in sequence with one or maybe two steppers to run a lead screw to push the finished product off the machine when it's finished. (Linear actuator like). Firstly a motor will feed the material ( 250mm wide sheetmetal ) into a guillotine 55 mm at a time, then the next motor will run another screw to pull the guilotine down. Next another motor will push the material into the rollers.
After the rolling has finished and the 80mm diameter 55mm high sheetmetal cylinder is finished, then a robotic arm will take the part and pack it.
Phew. Hope that makes sense,
Mark
Ps, cheers for the replies so far
Thanks for elaborating. This gives us a much clearer picture of what you are working on.
It always pays in the long run to start by giving us the big picture so that we start off on the right track.
 

strantor

Joined Oct 3, 2010
6,782
Ok then, thanks for the explanation.
you're using a cordless drill now... according to this, average cordless drill torque is about 1,000 inch-pounds (83ft-lb/112Nm). That's actually a lot higher than I expected.
It's also a lot higher than probably a windshield motor or door lock motor, or anything readily obtainable (cheap) other than the cordless drill you're already using.
I don't know that you actually need that much torque. Does the drill seem quite labored when in use?



EDIT:
As I look online for gearmotors rated to 83 FT-fb, I find they are huge. For a while I wondered how the little drill can outperform these huge motors. I think its because the torque ratings for off-the-shelf gearmotors are given at rated speed. Cordless drill torque is rated at stall. I don't know what that means, other than an off-the-shelf gearmotor is capable of much more torque than the label shows, if you load it all the way to stall; sorry I have no thumb rule to say how much more though
 
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Thread Starter

Mark Rountree

Joined May 9, 2017
51
Ok then, thanks for the explanation.
you're using a cordless drill now... according to this, average cordless drill torque is about 1,000 inch-pounds (83ft-lb/112Nm). That's actually a lot higher than I expected.
It's also a lot higher than probably a windshield motor or door lock motor, or anything readily obtainable (cheap) other than the cordless drill you're already using.
I don't know that you actually need that much torque. Does the drill seem quite labored when in use?



EDIT:
As I look online for gearmotors rated to 83 FT-fb, I find they are huge. For a while I wondered how the little drill can outperform these huge motors. I think its because the torque ratings for off-the-shelf gearmotors are given at rated speed. Cordless drill torque is rated at stall. I don't know what that means, other than an off-the-shelf gearmotor is capable of much more torque than the label shows, if you load it all the way to stall; sorry I have no thumb rule to say how much more though
Aaaannnndddd! Milwaukee wins the torque test.

I'm actually quite sure with the better efficiencies from prototype 2 the torque will be less by a significant margin. It's the motor types to buy and how to control them that I'm thinking about most. I imagine a circuit board like arduino with drivers on it. A laptop to programme the timing, direction and sequence.
Taking into account I have near to no experiance in this, I'm very sorry for the stupid questions.
 

strantor

Joined Oct 3, 2010
6,782
Aaaannnndddd! Milwaukee wins the torque test.

I'm actually quite sure with the better efficiencies from prototype 2 the torque will be less by a significant margin. It's the motor types to buy and how to control them that I'm thinking about most. I imagine a circuit board like arduino with drivers on it. A laptop to programme the timing, direction and sequence.
Taking into account I have near to no experiance in this, I'm very sorry for the stupid questions.
Understood. but in order to make a valid recommendation, need to know the required torque.
Do you have a torque wrench you could test with?

Now it's my turn to ask a stupid question:
If the drill works, why change it? Is it something you're going to sell? If so, I could understand not supplying it with a drill handing off the side.
But, you could control a drill with an arduino if you wanted to.
EDIT: and, if you don't like the looks of the drill you could put the guts in a prettier box.
 

Thread Starter

Mark Rountree

Joined May 9, 2017
51
Really, I just didn't know how accurately I could get a drill motor to behave is my main reason. I basically looked at my 3d printer and thought, that's accurate, I'll use big motors like that and arduino, try learn some coding, and cross my fingers.

I don't have a torque wrench but I did a test with a 300mm spanner on the shaft and it took 10 kg to do the difficult fold.
 

strantor

Joined Oct 3, 2010
6,782
Really, I just didn't know how accurately I could get a drill motor to behave is my main reason. I basically looked at my 3d printer and thought, that's accurate, I'll use big motors like that and arduino, try learn some coding, and cross my fingers.

I don't have a torque wrench but I did a test with a 300mm spanner on the shaft and it took 10 kg to do the difficult fold.
According to the calculator, that's 29N-m, so anything other than a drill would need to meet that at least (at stall).
I don't know how accurately you need to control the drill (or whatever folding motor might be), but if the motor turns a screw to create linear motion to fold the sheet, then you could put a proximity switch to stop it at the proper spot, and that can be "reasonably" accurate. But if you really need precision here, then a servo or stepper is the answer. This stepper gearmotor would be the minimum you could get away with (requires a stepper driver, cannot be powered directly from Arduino)
 

Thread Starter

Mark Rountree

Joined May 9, 2017
51
According to the calculator, that's 29N-m, so anything other than a drill would need to meet that at least (at stall).
I don't know how accurately you need to control the drill (or whatever folding motor might be), but if the motor turns a screw to create linear motion to fold the sheet, then you could put a proximity switch to stop it at the proper spot, and that can be "reasonably" accurate. But if you really need precision here, then a servo or stepper is the answer. This stepper gearmotor would be the minimum you could get away with (requires a stepper driver, cannot be powered directly from Arduino)
Do I need a separate driver for every motor? I do need accuracy and fine adjustment here. Silly question, does a motor at 60 RPM have the same torque as one going at 1000? Physics is very frustrating for me:-(
 

strantor

Joined Oct 3, 2010
6,782
Do I need a separate driver for every motor? I do need accuracy and fine adjustment here.
For every motor that is a stepper motor or servo motor, yes. but stepper drivers are not expensive.
This one should work with the motor I linked to.


Silly question, does a motor at 60 RPM have the same torque as one going at 1000? Physics is very frustrating for me:-(
I'm not sure your question can be answered, worded as is.
If you mean does a single motor have the same torque at 60 and 1000 RPM, even then, hard to answer. Depends on why it's going 60rpm vs 1000rpm. Also depends on what kind of motor, and load.

Basically torque is caused by the load. It takes 30NM to bend your metal. a motor that can sustain 30NM at 1000rpm can do the same at 60 rpm.
Not really sure if that was helpful.
 

Thread Starter

Mark Rountree

Joined May 9, 2017
51
For every motor that is a stepper motor or servo motor, yes. but stepper drivers are not expensive.
This one should work with the motor I linked to.



I'm not sure your question can be answered, worded as is.
If you mean does a single motor have the same torque at 60 and 1000 RPM, even then, hard to answer. Depends on why it's going 60rpm vs 1000rpm. Also depends on what kind of motor, and load.

Basically torque is caused by the load. It takes 30NM to bend your metal. a motor that can sustain 30NM at 1000rpm can do the same at 60 rpm.
Not really sure if that was helpful.
It's all helpful strantor, is that a plc? That's what I think I need, a plc that can drive 5 motors, in sequence, repeating every 5 seconds. I was looking at a nema 43 I think, it was 160$ not geared though. And another 4 23's
 

strantor

Joined Oct 3, 2010
6,782
It's all helpful strantor, is that a plc? That's what I think I need, a plc that can drive 5 motors, in sequence, repeating every 5 seconds. I was looking at a nema 43 I think, it was 160$ not geared though. And another 4 23's
PLC = Programmable Logic Controller.
It's basically an industrial thing similar to Arduino.
It is much more expensive but more reliable and "easier" to program.
If you are going to use a PLC make sure it has at least 5 pulse outputs for driving 5 stepper drives. Not every PLC has this. I am most familiar with Omron PLCs; I can recommend one with pulse outputs if you like.
But I think an Arduino is still possible; not sure why you decided to go with PLC instead.
Either one, Arduino or PLC, is going to require stepper drivers. PLC cannot drive steppers directly
 

MaxHeadRoom

Joined Jul 18, 2013
28,619
There is also a smaller version for a project that does not require a full blown PLC and that is a Smart Relay, there are many Manuf., some are relabeled but all have similar approach.
One of the main strengths of PLC/S.R. is that the screen can display a relay schematic style display that can also indicate the present status of I/O and outputs etc.
Max.
 

strantor

Joined Oct 3, 2010
6,782
There is also a smaller version for a project that does not require a full blown PLC and that is a Smart Relay, there are many Manuf., some are relabeled but all have similar approach.
One of the main strengths of PLC/S.R. is that the screen can display a relay schematic style display that can also indicate the present status of I/O and outputs etc.
Max.
Do any smart relays have pulse/dir outputs for stepper/servo drives?
Closest thing I know is some models of Omron CP1; almost a smart relay, but really an actual PLC.
 
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