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About belts (3GT -> 3mm pitch), what is better, rubber or PU? My motor pulleys have 16T...
by
fma
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Mechanics
I may have a solution...
By making a half turn on the belt between the motor and the static rear idler pulley (on each side), I don't need pulleys with teeth, as belt will be on its back on all idlers pulleys...
What do you think?
by
fma
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Mechanics
"Idlers, either of the inside or outside type, are not recommended and should not be used except for power takeoff or functional use. When an idler is necessary, it should be on the slack side of the belt. Inside idlers must be grooved, unless their diameters are greater than an equivalent 40-groove pulley. Flat idlers must not be crowned (use edge flanges). Idler diameters must exceed the smalle
by
fma
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Mechanics
Looks good to me! If I can get such nice print, I'm happy
What would be the minimum diameter, for a 3mm pitch belt? Where did you find this info?
by
fma
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Mechanics
My concern about teeth was for more for accuracy: on low diameter pulleys, can it lead to position variations, at each tooth?
The original design was working fine, but with a CoreXY config, I can increase the build XY size from 230x230mm to 310x310mm!!!
by
fma
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Mechanics
BTW, do you confirm it is mandatory to have teeth on the passive pulley, for a 3GT (3mm pitch) belt?
by
fma
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Mechanics
Didn't know that both existed in different pitches! Thanks for the info.
About power, I plan to re-build a CoreXY from an old Stratasys mechanic, using Nema23. They used GT3 (3mm pitch) belt, but their design carries the X motor with the extruder, which mean that both X/Y axes are heavy.
Do you think I can use GT2 belt, with the CoreXY design, which is much lighter?
by
fma
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Mechanics
Hi!
I'm looking for GT3 (not GT2!) passive pulleys (bearings) with teeth, for 9mm width belt.
Do you know where I can find that?
Thanks.
by
fma
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Mechanics
Ok, thanks!
by
fma
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Duet
Yes, the servo I plan to use works fine with 3.3V.
Ok, so, I just have to get the signal from the expansion bus of the Duet Wifi, and power up the servo from an external power supply (it can drain up to 2A when stalled)?
by
fma
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Duet
Hi!
Is it possible to connect a servo on the Duet Wifi without one of the expansion boards?
Thanks,
by
fma
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Duet
Quotethe_digital_dentist
Tensile force is tensile force regardless of the belt length.
Yes, but different lengths may require different tensile forces? Never looked at belt specs...
Quote
I haven't seen any convenient device for measuring belt tension, and without specs on it from the manufacturer, the only thing you could do is match tensions. Maybe a small spring-scale could be used. You'd
by
fma
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CoreXY Machines
BTW, any idea of the force (magnitude) needed to have a correct tension on the belts? I guess it depends on the length; let's say 2m for each belt...
Thanks.
by
fma
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CoreXY Machines
Thanks for the info! So, the idea of using only 1 motor is not possible...
Good to know about Bowden length.
by
fma
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General
You can't expect having all nozles at the exact same coordinates. Even if the tool changer is perfect, all heads won't be mounted in the same exact position on each tool. You need to calibrate X/Y, as you need to calibrate Z. And each time you unscrew something for maintenance, you need to re-calibrate again.
That's why I'm looking at a single nozzle head as the Diamond...
by
fma
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General
Yes, but what about X/Y? If one could find an easy way to calibrate...
by
fma
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General
I see. This requires a lot of tuning to perfectly find the relative positions of the nozzles... And each time you disassemble a head, you have to do it again.
by
fma
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General
Yes, I will design the X carriage so I can try this design.
by
fma
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CoreXY Machines
Sorry, I was answering to o_lampe...
dentist, as said, you first have to tension the belt without having it clamped to the X-carriage. Then, once it is tensioned, you clamp it on each side, in this exact position (it requires a simple printed part, clamped on the belt, which can slide on the X-carriage while tensioning, and clamped once done).
Now, I don't know how accurate should be the tensio
by
fma
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CoreXY Machines
Yes, my proposition only works with the same plan configuration...
But I don't see how 2 independent belts can have the same tension, even on a DBolt...
by
fma
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CoreXY Machines
o_lampe, why switching could not work with more than 2 filaments? Ok, it is a little bit more complicated, but possible.
About servo, my idea is to use some sort of cam shaft to disengage the unused filament, by pushing back their respective springs. Using a cam can give string effort without much torque on the servo. Close to what it is done with the Dondolo.
I don't know about the tool change
by
fma
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General
Hi!
I'm thinking to buy a Diamond hotend and use it as a switching color hotend, not mixing (I read that passive mixing is not ideal, because of the toothpaste effect).
In theory, switching only needs 1 motor, as only one filament is used at a time. But in the case of the Diamond, all filaments have to be engaged, to avoid back extruding in unused heads.
My first question is: do unused filamen
by
fma
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General
Hi,
What are the pros and cons of the orientation of the X axis, horizontal vs vertical?
by
fma
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CoreXY Machines
Hi!
I read here that having both belts equally tensioned is mandatory. Looking at this figure:
it appears to me that we can use only one long belt:
- at first, the X-carriage is not attached to the belt; the belt is first tensioned, using motors translation or so;
- then, once this is done, the X-carriage is clamped on both strands of belt. This requires a system so both strands are clamped
by
fma
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CoreXY Machines
Very promising!
Do you plan to sell the hotend alone, or only with the complete Delta printer?
by
fma
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Developers
