callmerob
starting to spend too much on rocks
I really like a dirt road
Member since September 2019
Posts: 143
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Post by callmerob on Jan 29, 2021 18:47:39 GMT -5
Brian, You've got some extrusion? That's great! Almost anything will work if you can position and lock some kind of pivot arm. Add a couple of brackets & springs, and it's done. I looked at hardware store steel Unistrut (square channel tubing, perforated with holes), but decided on 8020 because precut, and aluminum won't rust. I would try those Amazon 12vdc 37mm diameter motors and only 1 power supply because I think it may be sufficient for all 3 motors. Please post pictures if you build anything, even if it's just a pile of parts haha.  |
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callmerob
starting to spend too much on rocks
I really like a dirt road
Member since September 2019
Posts: 143
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Post by callmerob on Jan 29, 2021 19:52:30 GMT -5
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Brian
fully equipped rock polisher
Member since July 2020
Posts: 1,512
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Post by Brian on Jan 29, 2021 20:10:25 GMT -5
Brian, You've got some extrusion? That's great! Almost anything will work if you can position and lock some kind of pivot arm. Add a couple of brackets & springs, and it's done. I looked at hardware store steel Unistrut (square channel tubing, perforated with holes), but decided on 8020 because precut, and aluminum won't rust. I would try those Amazon 12vdc 37mm diameter motors and only 1 power supply because I think it may be sufficient for all 3 motors. Please post pictures if you build anything, even if it's just a pile of parts haha. Will do! This little project may have to sit on the back burner a while since I am in the middle of some home renovations, but once I get some free time back, this will be at the top of the list! I may do some parts acquisition in the meantime, so I may just have a pile of parts to show. |
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callmerob
starting to spend too much on rocks
I really like a dirt road
Member since September 2019
Posts: 143
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Post by callmerob on Jan 30, 2021 14:15:28 GMT -5
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Brian
fully equipped rock polisher
Member since July 2020
Posts: 1,512
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Post by Brian on Jan 30, 2021 14:27:50 GMT -5
That was a fun read! Thanks for sharing the link to that. I love the little saw you made, too! What a great use of parts! Clearly those little motors have served you well! |
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callmerob
starting to spend too much on rocks
I really like a dirt road
Member since September 2019
Posts: 143
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Post by callmerob on Jan 30, 2021 16:08:12 GMT -5
Glad you liked it, Brian. Since I don't have a machine shop anymore, my design&fabrication goals are centered around what I can easily get at the hardware store, Amazon, etc. No lathe or milling machine means I'm down to a hand drill, hacksaw, and a file. But it's all good. I call it the Tinkertoy Method of Mechanical Design. Buy the pieces, drill a few holes, and bolt it together. Kinda like the Erector Set I had as a kid.  I spend a lot of time just thinking about what I want the machine to actually do. Then thinking about how the hardware store can help. Then sketching, scribbling, or hand-drawn or CAD drawing if I need it. A good ruler is essential. Accurately center punch hole locations so the drill starts the hole where it's supposed to be and doesn't wander. Sharp pencil lines are accurate to 0.010", and while not machine tool precision, it's good enough. |
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callmerob
starting to spend too much on rocks
I really like a dirt road
Member since September 2019
Posts: 143
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Post by callmerob on Jan 30, 2021 18:57:34 GMT -5
I worked with similar motors with several robotics teams, They would figure out ways to bust the gear boxes... There are several vendors that sell planetary gear versions, with huge torque ratings. never had students bust a gear box again. Lots of different RPM choices... several vendors, eg www.gobilda.com/yellow-jacket-planetary-gear-motors/#series_5203
put some larger pics up when you get a chance, always thought using some of these on a sphere grinder would be viable... I neglected to acknowledge oregon's contribution of these GoBilda robotics motors. They are really cool. The basic motor #5202 in 12volts / 60rpm is $39. Plus they have affordable accessories like shaft couplings for 6mm shafts, mounting hubs (like to attach a saw blade), motor mount brackets and plates, and small U-channels with holes. All reasonably priced, and definitely NOT toys. One stop shopping. Thank you, oregon. ...And using student-built RC robots to gather pingpong balls is all well and good, but add a saw blade and it's a BattleBot!!! |
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Post by oregon on Jan 30, 2021 19:48:10 GMT -5
They are really cool. The basic motor #5202 in 12volts is $39. Plus they have affordable accessories like shaft couplings for 6mm shafts, mounting hubs (like to attach a saw blade), motor mount brackets and plates, and small U-channels with holes. All reasonably priced, and definitely NOT toys. One stop shopping. ! Planetary gear boxes are just robust. usually 5-10x the torque ratings of an equivalent spur gearbox.
The 117 rpm motor here, closest to the classic xerox sphere machine motor is rated at more than twice the torque that those old GE mina gear motors are. I bet you could drive a hefty tumbler with these as well, DC, so should be pretty straightforward to control speed etc.
Competitive robotics has evolved a lot of nice gear that's able to withstand some abrupt forces/abuse.
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
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Post by NRG on Jan 31, 2021 22:47:20 GMT -5
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
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Post by NRG on Jan 31, 2021 22:54:47 GMT -5
They are really cool. The basic motor #5202 in 12volts is $39. Plus they have affordable accessories like shaft couplings for 6mm shafts, mounting hubs (like to attach a saw blade), motor mount brackets and plates, and small U-channels with holes. All reasonably priced, and definitely NOT toys. One stop shopping. ! Planetary gear boxes are just robust. usually 5-10x the torque ratings of an equivalent spur gearbox.
The 117 rpm motor here, closest to the classic xerox sphere machine motor is rated at more than twice the torque that those old GE mina gear motors are. I bet you could drive a hefty tumbler with these as well, DC, so should be pretty straightforward to control speed etc.
Competitive robotics has evolved a lot of nice gear that's able to withstand some abrupt forces/abuse.
Looks like those are steppers. Does that mean they need a driver? |
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Post by oregon on Jan 31, 2021 23:36:50 GMT -5
Planetary gear boxes are just robust. usually 5-10x the torque ratings of an equivalent spur gearbox.
The 117 rpm motor here, closest to the classic xerox sphere machine motor is rated at more than twice the torque that those old GE mina gear motors are. I bet you could drive a hefty tumbler with these as well, DC, so should be pretty straightforward to control speed etc.
Competitive robotics has evolved a lot of nice gear that's able to withstand some abrupt forces/abuse.
Looks like those are steppers. Does that mean they need a driver? nope, just DC motors, not steppers.
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
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Post by NRG on Feb 1, 2021 11:52:02 GMT -5
oregon thank you These make me wanna have a lathe. Could be easy to make sphere machines with these. Even stout ones for larger balls. Would need to isolate the motor with sheaves and a belt so the lateral forces don't break the bearings of the little motor, couple of bearing blocks and a 5/8" shaft threaded for the core bits. Simple enough. I need to quit my job.
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NRG
fully equipped rock polisher
Member since February 2018
Posts: 1,688
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Post by NRG on Feb 16, 2021 19:02:18 GMT -5
Looks like those are steppers. Does that mean they need a driver? nope, just DC motors, not steppers.
Actually they are steppers. Driver runs at 5V and the page even has a step file for download. That's OK! Maybe even better. |
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Post by oregon on Feb 16, 2021 19:16:23 GMT -5
nope, just DC motors, not steppers.
Actually they are steppers. Driver runs at 5V and the page even has a step file for download. That's OK! Maybe even better. STEP files are CAD representations - use to CAD models, manufacturers have to provide files if they want folks to design with their products. The robotics suppliers generally provide drop ins for most all of the parts they sell.
5V is for the encoder on the rear of the motor, You can use the encoders & PWM to drive the speed of the motors, but you can equally ignore them. These are just brushed DC motors. We haven't worn out brushes with a lot of use, but 24/7 is quite a different use, ymmv.
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