Hi from a (very) hot Spain

[irving2008]

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For economy reasons, I'm using ordinary threaded rod with ordinary nuts..I know all about backlash but I'm broke!! This means that everything runs a bit slow as it takes approx 17 turns for a 25mm movement.

I have measured it at 'rapid' feed rate to be around 20 inches per minute - not too bad....... but of course when it's 'cutting' (drawing) it's much slower.....also, if I try to speed up the steppers they just seem to stall - don't know why - hope someone can explain......

Is there anything in the Gcode that I can change to speed the cutting up a bit....remember 3 months ago I'd never heard of Gcode!!
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Anything simple I'm doing wrong??

Well done on getting something working...!

OK 17turns for 25mm = 1.5mm pitch threaded rod (M10?)

20ipm = 8.5mm/sec @1.5mm pitch = 5.7revs/sec which assuming 200step motors = 1133steps/sec. which shouldnt max the motor out but depends on drivers. You dont say what controller software but you should be able to increase it there.

The threaded rod/nut combo very high friction so most of your motor torque going into turning the rod not moving the load.

You may find that a brass or Delrin nut will give improvements.

A higher supply voltage (if the drivers can stand it) may give improvement.

What motors, and drivers and power supply voltage?

[gerrymoore]

Thanks for the replies guys!!

First...I'm 58 and keep switching between metric and imperial - I tend to look at the tape measure and take the nearest one!! sorry :-((

Ok......... I'm using Nema 23 type motors from China - supposed to be 1.7nm models.

I'm using a generic driver board with 3 Toshiba TA8435 chips mounted on a large heatsink with two fans cooling it......I'm running in 1/8th step mode...could this be the problem?

Power supply is 27volt 13 amp switch mode type (Chinese).

Mach3 software. I have tried adjusting each motor axis but as soon as I try to get it a bit faster the motors stall....my knowledge of Mach3 is severely lacking:-((

I would like to use my old Toshiba laptop (normal printer port) so I don't have to drag the machine up three flights of stairs in this 100 degree heat but Mach3 doesn't support laptops - anyone out there using a laptop?? if so what (simple) software is available??

Oh...the threaded rod is not too bad friction wise but my 'precision' engineering is a bit rough so I don't think everything is perfectly aligned just yet...but I'm trying!!

The machine is currently in bits as my x axis was too 'wobbly' (technical word) as I tried to cheat and only use one pair of linear bearings....I am redesigning it now for two sets :-0

If this works there may be a picture.........nope thought not!

Anyone tell me how to upload an image??

I'll get back to work on it and advise any progress.....many years ago I built a mini excavator in my garage so I keep telling myself this CNC business should be easier!!!

thanks again............