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Dan73
06-03-2015, 08:10 PM
Hi guys!

I have a crp4896 cnc since 2.5 years,
this machine run with g540 (x,y,z,x-slave) with a USB smoothstepper
and a 47V powersupply

How can I connect a 4th axis ? with the second port of the smoothstepper with a new breakoutboard ?

for some 100mm chuck like this
http://www.ebay.com/itm/CNC-Engraving-Router-Rotational-A-4th-Axis-3-Jaw-100mm-Chuck-65MM-Tailstock-/261583736016

I'll take any suggestion and comments :)

Thanks !

JerryBurks
06-04-2015, 01:20 PM
Can't help with the control aspect of the Smoothstepper but just as a hint: the 6:1 reduction may not be sufficient, depending on the size of the rotated part. E.g. for a 100 mm cylinder the step resolution on the surface is only 0.25mm and for big parts you may run into torque limitations. The very small motor pulley might cause some uneven movement/cogging. But you can spin your work piece really fast :)

FWIW I have an indexer with 50:1 Harmonic Drive reduction and that is still ample fast. Maybe 20:1 would be a good compromise.

Dan73
06-05-2015, 09:32 PM
Thanks Jerry,

does a single laptop with 2 USB cable (can control 2 different breakout boards) and mach3 can control the both cards ?
The second BOB is for the 4th axis in my case

or if someone have a diagram of multi BOB controlled by mach3 ... with or without smoothsteppers ... ?

Acctek CNC
06-06-2015, 04:03 AM
Hi Sir
Good day

1) Sure , you can connect a 4th with your old breakoutboard . you can change each other for x axis and 4th axis , when you use 4th axis , x axis do not move . when you use x axis 4th don't move .
4th axis can use alone driver . when machine working , x y z aixs can move or y z A axis can move .
2) You can also change a new breakoutboard for 4th axis . when machine working , x y z A axis all can move .
Hope to give you some help

Kind regards
Frank

Jinan AccTek Machinery Co., Ltd (http://www.acctekcnc.com)

ger21
06-06-2015, 11:21 AM
Thanks Jerry,

does a single laptop with 2 USB cable (can control 2 different breakout boards) and mach3 can control the both cards ?



A breakout border connects to a parallel port. You need to use a motion controller to use a usb port. Mach3 only allows one motion controller.
However, a usb smoothstepper gives you two parallel ports, and you can use two breakout boards with the smoothstepper.

Dan73
06-06-2015, 11:28 AM
Hi Gerry
Thanks for the answer
this is the answer I expected

"and you can use two breakout boards with the smoothstepper"

:)