Nema34 - DM860A Driver & Mach3

[Channel]

I took a quick look at the link you suggested, I read it better tonight.

What I knew is that if I increase the resolution too much then I will have problems with the engine torque. In fact, I imagined that 51200 steps / revs could not be used as a value.

My transmission of the X axis is made with:

- M12 screw
- a pulley 20 teeth 5 pitch on the motor axis (I have to check if it is 20 or 15 teeth)
- a 60-tooth pitch 5 tooth pulley on the M12 screw
- two 40-tooth pitch 5 pulleys connected to the ends of the screw
- two 40-tooth pulleys step 5 for "neutral"

I attach photos:


For the Y axis it's all the same except that the screw is an M10.

I attach photos:


For the Z axis I have:

- a pulley 15 teeth step 5 on the drive axle
- a pulley 20 teeth 5 pitch on M10 screw

I attach photos:



The information I miss is:

- How much should you set the driver for? (from what you say 8 could be an optimal value)

- Once the driver has been set how to calculate the "step for" parameter in the motor tuning section of mach3. (My idea is to do the theoretical calculation, and then use the "auto-calibration" tool of mach3 to adjust the value.

For speed / acceleration I thought I would try some values ​​until I found the optimal ones. (unless there is a formula to calculate these two values)

How can I get these values?

Thanks again for the advice and patience XD

[cropwell]

OK, so X and Y are belt drive and are a different problem.

On your Z axis you say M10 screw. Do you mean a piece of threaded rod with the normal coarse pitch of 1.5mm?

If this is so then on your Z axis 200 steps -> 15 (driving pulley)/20 (driven pulley)x 1.5 mm of movement = 1.125mm, so steps per mm is 200 / 1.125 = 225 (note this is steps per millimetre). If you then use microstepping, you will have to multiply that by the factor you set in the driver DIP switches. (other forum members - could you check this as I am tired today, I have done some work and I am not used to it )

I will get to the X and Y later.

A lot of information is here http://www.machsupport.com/wp-conten...all_Config.pdf

[Channel]

Hello,

yes, it is exactly a piece of M10 threaded bar.

So for the Z axis I was able to calculate it like this:

driving-pulley / driven pulley x 1.5mm (threaded bar) the result is divided by 200 (physical steps)
and in this case it would be just like you wrote:

15/20 * 1.5 = 1,125mm 1,125 * 200) 225.

Assuming to set the driver through the dipswitches to 1/4 (400) I have to make 225 * 4 = 900.
Or if set to 1/8 (800) 225 * 8 = 1800

This value is what I have to set in the motor tuning section of mach3 for the right Z axis?

Is this calculation valid even if the pulley on the threaded rod has not been tapped but is held in place by nut-locknut?
I attached a photo for a better clarity:

[cropwell]

Is this calculation valid even if the pulley on the threaded rod has not been tapped but is held in place by nut-locknut?

Only if the pulley does not slip, and that arrangement looks as if it will do so at some time.

You are only using threaded rod on X and Y as axles, so the pitch is irrelevant.

I have yet to get my head round the X and Y axis arrangements, but it looks like the belt attached to the axis will move 200mm per turn of the axle, but you are geared down 3: or 4:1 depending on the number of teeth on your drive pulley. So if you are using 15T drive then your resolution is 4 steps per mm or if 20T 3 steps/mm. So I can see why you are hoping to get some positional accuracy using microstepping to increase your resolution.

I have doubts that this current design will be very accurate. You should also look at some way of fixing your pulleys to the axles other than locking nuts, are there no grubscrew holes on the pulleys ?

[Channel]

Hello,

First of all, thanks for the answers I understood more in these two days than in a month of homemade research.

Let's start with order:

I counted the teeth on the motor pulley (X & Y axis) and is 15 teeth

On the engine pulleys there are two grubscrews and two "footprints" on the shaft, so as to make everything more stable.

As for the pulleys on the threaded bars the nuts and lock nuts that hold everything are stopped with the threadlocker (like the loctite) and also here they should not go anywhere.

As for precision as a first mention the project was bought so I'm pretty sure it should go (unless of my assembly errors)

There is also a video that shows how it works on youtube, and as I said its author is mentioned a couple of times in this forum or Mirko slepko ...

Tomorrow I will try to set the values for the Z axis in order to verify the behavior ...

[Channel]

Hi all!

today I counted the teeth of the pulleys of the Z axis and both result from 20 teeth.

So I applied the formula suggested by cropwell using the value of drivers 8.

(20/20) * 1.5 = 1.5 >> 200 / 1.5 = 133.333 >>> 133.33X 8 = 1066.66

So I set this value in the Z axis.

By moving the axis, however, I noticed that it still moved in an inaccurate way.

So I used the "Auto-tuning" tool from mach3 which calibrated the steps to 533.33 (exactly half)

I have tested some movements such as

- G1 Z10 F400
- G1 Z0 F400
- G1 Z-30 F400
- G0 Z0 F400

And all the movements were performed correctly. (and to be honest, I' am REALLY HAPPY)

The only thing I would like to know because I have this difference between the steps that the machine has calculated and those instead obtained by formula.

I'm pretty sure the driver is at 8 and not at 4 (setting that would justify 533.33 as a step value) but tomorrow I will recheck. XD

As for the X & Y axes, maybe this is the formula?

(engine step * (driven pulley / driving pulley) * driver value) / 50mm

The 50mm value I obtained by making a complete turn to the 60-tooth pulley and measuring the displacement of the trolley.

So the calculation would remain ...
(200 (60/15) x8) / 50 >> (200x4x8) / 50 >>> 6400/50 = 128.

Is this value the one I have to set in the motor tuning section for the X & Y axes?

Thanks all again for your precious help

[Channel]

OK, so X and Y are belt drive and are a different problem.

On your Z axis you say M10 screw. Do you mean a piece of threaded rod with the normal coarse pitch of 1.5mm?

If this is so then on your Z axis 200 steps -> 15 (driving pulley)/20 (driven pulley)x 1.5 mm of movement = 1.125mm, so steps per mm is 200 / 1.125 = 225 (note this is steps per millimetre). If you then use microstepping, you will have to multiply that by the factor you set in the driver DIP switches. (other forum members - could you check this as I am tired today, I have done some work and I am not used to it )

I think you make an error... because the result of 200/1.125 is not 255 but 177,77 ... BUT 200 X 1.125 is 225... so is the calculation or the result wrong?

Anyway I confirm the accuracy of the movements of the Z axis with the values set at 533.33 as described in the previous post ...

[cropwell]

I think you make an error... because the result of 200/1.125 is not 255 but 177,77 ... BUT 200 X 1.125 is 225... so is the calculation or the result wrong?

Anyway I confirm the accuracy of the movements of the Z axis with the values set at 533.33 as described in the previous post ...

It is 200/1.125 but I did say I was tired.