EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: t1d on August 10, 2021, 10:27:11 pm
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- I don't know so much about motors.
- The two types of motors seem to be about the same size.
- I would think the drill motor turns much too slowly, even with the gear box removed.
This would be more DIY-able, if the motor would not have to be rewound. Maybe run up the voltage and limit the current?
I know that rotary tool motors can serve as a dedicated CNC motor substitute, but I kind of want to find a use for these drill motors, other than filling up the land fill.
Thanks for your help.
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While I have no use in mind, I do find it unpleasant to see cordless tools in landfills. First, the battery gives out. Then you discover that a new battery costs as much as a new tool with battery. You take two bad batteries and salvage the good cells so you can make one good battery. But the mechanical surgery leaves a poor tool due to the hardware defects. Then the refurb battery fails.
So you build a mains operated power supply to run the tool, and discover that it's not as powerful as a cheap one.
I have been down these paths several times and at this point will never recommend a battery operated tool. I'd rather have a long extension cord than suddenly discover my battery needs recharging.
Yes the motors can be repurposed but the mechanical details may make it not worth the trouble.
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I have been down these paths several times and at this point will never recommend a battery operated tool. I'd rather have a long extension cord than suddenly discover my battery needs recharging.
I have been down these same exact paths and have come to the same exact conclusion... These discarded motors can be found in the thrift stores for cheap. My interest was more about finding some use for those.
Yes the motors can be repurposed but the mechanical details may make it not worth the trouble.
Without going to the trouble of great detail, what are we generally talking about, for the conversion? If rewinding is required, just say "rewinding" and that can be the end of the discussion. Thanks for your reply and help.
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IDK what I'm talking about but, what are they, brushed DC motors? how do their spec's compare to the 3018 motors? If the drill motor works, and could be mounted properly, won't that be the main hurdle, just getting it mounted correctly ?
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I assume you are trying to use it as a router head and not as the stepper motor. The main issue you will have is the same issue people have when they try to turn a drill press into a mill. the bearings in the motor are not meant for axle loading( I think that's the term for the side to side push). Maybe a mechanical guy can chime in on that.
Most drill motors are slower than what you are looking. A Dremel type motor that can reach that 30,000-18,000 rpm speeds
If you are thinking about building CNC mostly printed cncs are really fun projects. I built one last year.
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IDK what I'm talking about but, what are they, brushed DC motors? how do their spec's compare to the 3018 motors? If the drill motor works, and could be mounted properly, won't that be the main hurdle, just getting it mounted correctly ?
No, getting the motor mounted solid and square would, for me, not be so much of a problem.
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I assume you are trying to use it as a router head and not as the stepper motor. The main issue you will have is the same issue people have when they try to turn a drill press into a mill. the bearings in the motor are not meant for axle loading( I think that's the term for the side to side push). Maybe a mechanical guy can chime in on that.
Most drill motors are slower than what you are looking. A Dremel type motor that can reach that 30,000-18,000 rpm speeds
If you are thinking about building CNC mostly printed cncs are really fun projects. I built one last year.
Ah, I forgot about CNC's using stepper motors. Side loading, too. Good points. I was thinking about using one to just cut PCBs and nothing else. I thought that purpose might be light enough duty that the drill motor might work. No, I don't have a 3D printer...
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You could make a cnc using these motors instead of steppers - if you had a suitable feedback mechanism - but you'd be reinventing the wheel.
Same goes for the side loading, you could take care of that but the parts and effort would add up pretty quick.
Got kids or grandkids in your life? How about using these to make some toys? Make them a powered skateboard or something and use some other form of repurposed (or cheaply acquired) battery to power them.
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Too much play in the shaft.
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I was thinking about using one to just cut PCBs and nothing else. I thought that purpose might be light enough duty that the drill motor might work.
Although the workload isn't too much when cutting pcbs they are actually a little more finicky to cnc than most home projects. I struggle to get the accuracy I need out of the machine I built. when I get into trying to mill the finer pitch stuff like microcontrollers I haven't had much success. mostly because my machine is 1500mm by 1500mm with a Makita router on it. flex in the machine is my issue.
I think you would run into issues with play in the motor for both the router and if used its the stepper. I don't think it would be worth the work to try to make a feedback system to use them like a stepper plus can you eve get the same braking force out of brushless as you can from a stepper ( I have no clue). nema17's can be had for less than the cost of paying yourself minium wage in US and few hours work.
I like the idea of recycling them so here are my ideas for uses of the motor other than a CNC.
-PCB cutting saw(for protoboard I rather cut with snips because dust but these are popular)
-Mini drill press
-high power fume extractor
-RC style robot
-Soldering iron tip polisher(look at a hakko FT700 for ideas)
-allsorts of projects for kids
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These motors probably run quick enough. Even after a 2 stage reduction they still run over 1000rpm.
But the motors themself are of very mediocre quality.
With a bit of searching you find a 400W EUR120 BLDC motor set for CNC with which the ER11 collet is an integrated part of the motor. This would be the way to go to get a decent spindle for the lowest price. Those spindles with a clamped on collet are all garbage. Even when the alignment is good, the motor itself still has a thin and flimsy axle which will lead to vibrations with even small loads.
Such motors are simply not fit for a CNC spindle, and selling them as such is just misleading.
If you want to repurpose such motors, then find another application.
For example, I've used one to electrify my roller blinds. They can be used to automate doors in chicken scoops and other low speed applications.
I do have a 600VA 12V transformer (With bridge and electrolytics) to drive this motor though. These motors can take a lot of current, although with a uC and a control loop you can run these motors from between 5A and 10A (although of course with reduced torque).
Another application for such a motor could be a small circular saw (There are kits for this, with a saw spindle and toothed driving belt)
They can also be used in some kind of robotics application, although the big backlash of the gear train is a serious handicap here.
But, to say it again, These are not a good fit for a CNC spindle.