IDEX printer axis motor sizing question
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I am building a 600x600x200 idex printer with a moving gantry.
Because the gantry is going to be moving on the Y I am trying to keep the weight down.
I am wondering it a pancake stepper would be able to get the job done.
The moving mass of each extruder if going to be close to 500g all inclusive.
That is a 270g Bondtech LGX FF and a 100g mgn12h carriage and a bit extra for brackets.Specifically I am looking at the LDO 42STH20-1004AS "Super Slim" motor.
I will be running a 16T motor pulley to help the give the motor a little more help.
With all the other mass that I am trying to throw around I would love to use a pair of these small motors to minimize the moving mass.Thanks.
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For what its worth, I chuck a 5kg bed around with a single nema 17 at ~3k acceleration on a standard bedslinger with a 400x400mm bed. If its really a concern, use two seperate y motors to move the entire gantry.
Otherwise you should be fine.
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@luke-slaboratory
For moving the gantry itself I do actually have it being moved by 2 separate large steppers.
They are stationary so I don't care about their weight.
But the X axis motors that move the extruders are moving on the gantry so I want to keep their weight to a minimum. -
Right - those X-axis motors are carried by your Y-axis motors, correct? if the Y-axis motors are strong enough and your gantry rigid, going with "big enough" X-axis motors should be more of a concern than saving <5% of the total mass of your Y-gantry, IMHO.
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@jklaus said in IDEX printer axis motor sizing question:
But the X axis motors that move the extruders are moving on the gantry so I want to keep their weight to a minimum.
I'm using a similar (slightly stronger) motor on The Hitchhiker. It drives a 16 teeth pulley through a 5:1 spur gear (BMG extruder parts)
I can reach upto 200mm/s speed with reasonable acceleration. Without a reduction gear i wouldn't expect too much.
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@luke-slaboratory
True, running the numbers in Inventor my whole moving gantry assemble will run right at 11 pounds with everything but the X motors.
The small ones add on about another .6 pounds for both.
While a larger motor with double the torque would be about 1.3 pounds for both.
My Y is driven by 2 motors each with their own driver so throwing around that weight shouldn't be too hard.
And since they aren't moving I always have the option to go even larger on Y if necessary.
My only real concern with the weight is when the Z is getting high I am concerned about possible ringing.
The X axis looks to be 4.4 pounds without motors.
Growing to 5.0 or 5.7 pounds for small or large X motors.
Maybe I am just worrying too much about this and I should go for the large motors.
The connection between the gantry and Y bearing blocks is about as sturdy as I could make it without just being a chunk of aluminum.@o_lampe
That is a pretty interesting setup with a geared moving axis motor.
I haven't seen a setup using a bondtech gear setup to drive an axis before.
That plus something light like an orbiter on top would make a pretty sweet and light direct drive setup. -
@jklaus said in IDEX printer axis motor sizing question:
That plus something light like an orbiter on top would make a pretty sweet and light direct drive setup.
I'm pretty happy with it, although I'd refine the design here and there. ATM I have some backlash in the gears, which causes quality issues.
It works best as 'big nozzle infill extruder'.RRF doesn't have backlash correction for moving axes and I'm also waiting for a way to add an independent mini-Z-axis for mesh leveling.
(hence the dovetail slider)
