Not being an engineer, the specifics of the worm gear motors is a mystery to me. I have been digging into the forums to try to identify the specifications necessary for the main motors to see if I can find a non-China based supplier (who will only sell in quantities way above my needs!) for my failures while the store is out of them. Hopefully something on a “usual” site, like Amazon!
I have the following specifications. Can you folks check me on these?
Output shaft - 8mm
Reduction Ratio - 290 to 1
Stall torque - 30kg/cm
Speed - 20rpm
Voltage - 12V
Resolution - 7ppr
What other details would I need to confirm with a vendor to get something that could work on my Maslow?
As another thought: As my motor and encoder is fine, could I just buy gear boxes using these specifications and replace a stripped gear set without replacing the whole thing?
We should have them back in the store in a few days, we’re focusing on getting all the ring kits shipped out today and tomorrow but we’ll try to get them back in the store ASAP
the new boards can support higher than 12v, you don’t want to go to lower
torque, more would be better (but not with the stock controller boards)
final encoder steps (290 gearing 7 encoder4 quad encoder) = ~8000 per rev, you
can go down to ~4000 per rev reasonably, but don’t want to go a lot lower than
that
so the critical things to look for are:
20 rpm
30Kg/cm output
4k pulses/rev of the output shaft
with voltage/current compatible with your motor controller
and output shaft that matches the sprockets you can find.
Gero, do you think an in-country source isn’t possible? Even that link is from Europe. Is it something that is just not in demand otherwise? Or do we have an unusual standard?
you can find the motors on Amazon in every country (it just takes some digging,
but once you have a link in one, you can generally find the same thing in the
others)
The real limiting factor is the motor controller, the one that the maslow kit
ships with is, like everything else with the maslow “just good enough”. this
minimizes cost, but means that when you start upgrading, you find that improving
one part can run into problems unless you upgrade something else.
As such, the exact motors we use are rare, but you could use any worm-drive
motor (or other motor with sufficiant resistance to being back-driven) as long
as you have a controller board to power it and an encoder to read it’s position.
It is so cool that it’s so configurable! And thank you, everyone for helping educate me!
In looking at worm gear motors, I see a large variety of RPMs. It makes sense that a (for instance) 5RPM motor can’t move the router faster, but will a faster motor automatically “slow down” to the speed we are looking for when talked to by the GC? I have been using easel to make my patterns and specify a speed in there of between 20-30 in/min. Does the GC translate this to the motor to tell it how fast to move? Does it recognize a slow motor and is more patient with it getting done with commands or would it time out and throw a “sled not keeping up” error?
When looking at specifications, there are no load, rated load, and stall load torque ratings. Which one needs to be 30 kg.cm? Would a higher torque rating extend the life of the motor? I’ve seen some discussion about how long the motors last before there is gear degradation. Similarly, does leaving the router hanging on the wasteboard reduce the life of the gears? Should I hang or remove the router between uses?
How does the gearing, like 290:1 play into these requirements? Does that only represent motor work to get the gears to move? If the gearing was higher/lower would the GC perceive the difference or does it only look for movement over time?
Again, thank you everyone who is willing to help me learn! You folks are amazing!!
Yes! The speed of motion is set in the gcode file, unless the speed is set faster than the machine can move and then there is a limit. The limit is a setting too so it’s easy to increase if you would like.
GC won’t automatically recognize a slower motor, but you can set the “maximum speed” setting to be lower and then the firmware will not try to move the motor faster than it can move.
When looking at specifications, there are no load, rated load, and stall load
torque ratings. Which one needs to be 30 kg.cm?
the 30kg rating of the existing motor is the stall load
Would a higher torque rating extend the life of the motor?
generally yes
I’ve seen some discussion about how long the motors last before there is gear
degradation.
that’s the quality of the gears, independent of the torque rating
Similarly, does leaving the router hanging on the wasteboard reduce the life
of the gears? Should I hang or remove the router between uses?
it shoudl not matter.
How does the gearing, like 290:1 play into these requirements? Does that only
represent motor work to get the gears to move? If the gearing was
higher/lower would the GC perceive the difference or does it only look for
movement over time?
gc only cares about the final movement, but if the encoder is on the motor, the
encoder resolution gets multiplied by the gear ratio. If the encoder is on the
output shaft, the gear ratio doesn’t matter at all (other than the fact that it
is a factor in the rpm and torque ratings of the motor)
