10mm belt nema23

[kev20009]

What is the output power of your 36V PSU? How many motors and how long are they? Do you know their voltage and inductance?

I doubt that the steppers are the problem.
You have a 20 tooth pulley with 10 mm pitch? This means you are moving 200 mm with one motor rotation. At 800 mm/sec your motor has 240 RPM which isn't that high.

At high speeds acceleration is important. Unless you are cutting very large parts, you will hardly get to your max speed. Better the acceleration, quicker you'll finish the job with the same feedrate.

thanks for replying again, thought I put belt size, 10mm wide t5 belt so 5mm pitch

psu 36 volt, 300w, 9.5 amps
3 motors, only 2 for x and y axis, 3rd runs table up and down, Size 76mmx56mm


General specifications motors

Step Angle 1.8 Rated Voltage (V) 2.6
Temperature Rise (℃) 80 Max (Max 2 phase on) Rated Current in Sereis (A) 2.0
Ambient Temperature -20～+50 Rated Current in Parallel (A) 4.0
Number of Phase 4 Resistance Per Phase in Series(+/- 10%) 2.2 (Ohm)
Insulation Resistance (MΩ) 100 Min (500VDC) Resistance Per Phase in parallel(+/- 10%) 0.55 (Ohm)
Insulation Class Class B Inductance Per Phase in Series (+/- 20% mH) 7.16
Max.radial force (N) 28 (20mm from the flange) Inductance Per Phase in parallel (+/- 20% mH) 1.79
Max.axial force (N) 10 Unipolar Holding Torque (N.cm) 1.4
Rotor inertia (gcm2) 480 Bipolar Holding Torque (N.cm) 1.89
Mass (Kg) 1.0

hope this helps a little thanks again kev

[Robin Hewitt]

belt size, 10mm wide t5 belt so 5mm pitch

That's what I did, but it was wrong.
I bought T5 belt, tooth width 2.5mm
I bought T5 pulleys, tooth width 3mm
I stared at them in disbelief for 30 seconds then gave up an did something else. Couldn't believe it. What a rip.
If you have better luck let me know so I can resurrect it

[Robin Hewitt]

From the HPC gears website...

Approx. belt flank play backlash are as follows:
T5 - 0.6mm
T10 - 1.1mm
AT5 - 0.2mm
AT10 - 0.4mm
AT20 - 0.8mm

Wonder if I could turn a 5.08mm pitch pulley down a tadge. The 5mm tooth seems a pretty good fit in that.
24t * .08mm / Pi = 0.61mm off the diameter. Might work. Or am I completely getting the sum wrong?

[paulus.v]

Wonder if I could turn a 5.08mm pitch pulley down a tadge. The 5mm tooth seems a pretty good fit in that.
24t * .08mm / Pi = 0.61mm off the diameter. Might work. Or am I completely getting the sum wrong?

It is not that simple to get the pulley tooth size. You have the pitch line, which corresponds to the belt insertion, where the belt bends. From there you calculate the gap between the teeth to correspond to the belt teeth dimension. The teeth on a smaller diameter pulley are narrower than those on a bigger diameter...

If you tension enough the belt you'll have no backlash even with a smooth belt. The teeth are there for timing ... at times

[Robin Hewitt]

It is not that simple to get the pulley tooth size. You have the pitch line, which corresponds to the belt insertion, where the belt bends. From there you calculate the gap between the teeth to correspond to the belt teeth dimension.

But it looks like it might go, a small change in radius gives you 6 times as much off the circumference...

[kev20009]

But it looks like it might go, a small change in radius gives you 6 times as much off the circumference...

got my belt and pulley from cnc4you they match perfect, kev

[Robin Hewitt]

got my belt and pulley from cnc4you they match perfect, kev

Momentary hope, but they have nothing to fit my 15mm wide belt.

I think I might try 3D printing a pulley. Well, why not?

[paulus.v]

You can go with the voltage higher and you will want to do that for better torque at high speeds.
According to the rated inductance you can go up to 32*sqrt(inductance)=43 volt.
Or if you take the rated voltage you have a max. of 20*2.6V=52 volt.

First calc. is more accurate but you have +/-20% inductance accuracy.
Personally I would try with 45-46 volt, but I don't know how would the drives tolerate that voltage. Maybe there are others here with more experience in these drives.
Have you tried wirh the drives set to the maximum amps rating? (SW1, SW2 and SW3 off)

It is possible to be able to improve your speeds in other ways as well. How easy are your axes sliding on their guides? The quality of the belts and pulleys, the weight of the gantry, reducing the inertia of the rotational loads, etc

[kev20009]

You can go with the voltage higher and you will want to do that for better torque at high speeds.
According to the rated torque you can go up to 32*sqrt(inductance)=43 volt.
Or if you take the rated voltage you have a max. of 20*2.6V=52 volt.

First calc. is more accurate but you have +/-20% inductance accuracy.
Personally I would try with 45-46 volt, but I don't know how would the drives tolerate that voltage. Maybe there are others here with more experience in these drives.
Have you tried wirh the drives set to the maximum amps rating? (SW1, SW2 and SW3 off)

It is possible to be able to improve your speeds in other ways as well. How easy are your axes sliding on their guides? The quality of the belts and pulleys, the weight of the gantry, reducing the inertia of the rotational loads, etc

Paul thanks for that advice, I got a 48 volt switching psu that can be turned down so will give it a go,

Axis all run on hirwin rails, will add photo today for you to see,
Thanks again you been big help. Kev

[paulus.v]

The 48V PSU will make a difference. Try with 4.5A but check the motors temperature, if they'll get too warm or hot, reduce the current. Higher current increases only the low speed torque.

Hiwin rails need to be very carefully aligned to have a smooth movement.

https://www.youtube.com/watch?v=AGT5gXpcmBA#t=1m58s