AndyUK's Build - 1.2x1.0m Gantry

[AndyUK]

Y and X axis moving, apologies for the poor videography and mouth breathing; there are still no limit switches so I was trying to manually control and stay near the estop whilst filming, took far too much concentration.

The Y is substantially quieter (smaller single screw and better alignment I guess) and here its setup for 10m/min and 500mm/s^2.

The X still needs some alignment attention, here its running at 8m/min and 500mm/s^2. I think it was slightly crooked because at 10m/min something mechanical was slipping causing it to stall. Once a pulley was tightened and the gantry realigned it seems okay at 10m/min but time shall tell.

It's sounding and seeming okay to me, but I have very little experience to compare against, so comments and concerns appreciated.



Here's a short clip of the slipping I was seeing, after tightening the pulley grubscrew but before realignment:

[JAZZCNC]

Hi Andy, Well done mate it's coming along nicely. Have you checked the steps per is correct because It doesn't look like it's traveling 8 or 10mtr/min to me, thou it's hard to tell from a video? Just use MDI and tell it to move a distance and check it moved the commanded distance. ie: G0 X100 it should move 100mm. Make sure you Zero the axis first and leave enough space to travel.

[AndyUK]

Thanks Dean :)

Interesting to know it doesn't look like 10m/min, I'll try measuring the speed. Haven't verified the steps per yet, I'm merely going off the theory. Steppers are 1.8° per step, 8x microstepping, 10mm pitch screw, set to 160 steps per unit, jogging at 100% (although granted I could be using the UCCNC software incorrectly!)

[JAZZCNC]

Thanks Dean :)

Interesting to know it doesn't look like 10m/min, I'll try measuring the speed. Haven't verified the steps per yet, I'm merely going off the theory. Steppers are 1.8° per step, 8x microstepping, 10mm pitch screw, set to 160 steps per unit, jogging at 100% (although granted I could be using the UCCNC software incorrectly!)

Well that's all correct going by the numbers(provided the MS are correct on drives) so could just be the video but quick measure will verify if it is or not.

[routercnc]

Great work well done !
For comparison my Y axis is sweet running like yours, and my dual screw X axis is much noisier. I think it’s because they are longer and there is much more going on.

The slipping in the second video sounds like classic stepper stalling to me. The stepper torque just falls away with speed so if the mechanicals are good then just drop the speed back.

Well done for getting this far it’s a great achievement !

[JAZZCNC]

For comparison my Y axis is sweet running like yours, and my dual screw X-axis is much noisier. I think it’s because they are longer and there is much more going on.

Yep happens on all machines over a certain length and it's a combo of vibrations through the frame and resonance from the screws. You should hear what a 10 x 5 sounds like in comparison. I'm currently just finishing one that's using rotating nuts and the X-axis still sounds much noiser than the Y-axis. I'll do a video when it's fit to be seen, it's still not fully dressed with wires and pipes hanging out everywhere.

[AndyUK]

The slipping in the second video sounds like classic stepper stalling to me. The stepper torque just falls away with speed so if the mechanicals are good then just drop the speed back.

Well done for getting this far it’s a great achievement !

Thanks :)

I haven't yet tuned the drivers to the steppers, and I've been a bit conservative with the current through them (the water cooling loop which feeds the spindle and the x motors isn't running yet) as I don't want to let them overheat inside the steel box section. Hopefully I'll be able to hit 10m/min reliably when that's done, otherwise I'll live with 7.5.

Today I got the spindle running and the Z axis moving, both seem okay for first use :) Had to swap the spindle rotation direction, and I'm not sure it's hitting the full speed (the VFD says 200 when the dial is at full range, but that might be because I changed the analogue input range for the UB1 which isn't yet in control). Now time to focus on getting those limit switches working before I smash into something!

Jazz, I also quickly verified the steps per using a pair of digital callipers, and the X axis was spot on at 10mm and 50mm. Y axis was 49.95 on a 50mm move which when considering I don't have ultimate faith in the measurement method I'm happy with for now :)

[AndyUK]

Also, having some fun finding an appropriate waste board. Being that its out in the unheated and uninsulated detached garage, I need something thats going to be stable.

I've been canvassing local shop fitters / plastics suppliers / kitchen fitters for some Tufnol 1P/13, Phenolic Sheet, or Trespa Athlon. Looking for approximately 20x800x1000mm - any quotes I get back are in the £300ish range which feels quite dear, is that expensive or about right? Does anyone have any recommended suppliers or alternative materials to look at?

[JAZZCNC]

Also, having some fun finding an appropriate waste board. Being that its out in the unheated and uninsulated detached garage, I need something thats going to be stable.

I've been canvassing local shop fitters / plastics suppliers / kitchen fitters for some Tufnol 1P/13, Phenolic Sheet, or Trespa Athlon. Looking for approximately 20x800x1000mm - any quotes I get back are in the £300ish range which feels quite dear, is that expensive or about right? Does anyone have any recommended suppliers or alternative materials to look at?

You should be able to get a piece of HDPE for a lot less than £300. I've just bought a 10' x 5' x 30mm and it was only £500.

[Dean jeffery]

I use these for HDPE and acetal

https://www.directplastics.co.uk/hdpe-sheet