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Messages - Davek0974

951
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: October 29, 2016, 11:02:44 AM »
After some thought I reckon the easiest option based on what i have going already is to modify the quill housing and build a better connector arm - this should give more rigidity and still maintain the full Z travel.

In the attached picture, on the left is the existing setup, on the right is my next version - as you can see, in the existing one a lot of twisting moment is placed on the bolt when the arm is pushed down (heavy lines).

In the new version, the twist is converted to an axial pull on the bolt and the force transferred to the quill body via the longer contact face below.

952
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: October 29, 2016, 05:24:39 AM »
Measuring on the existing adaptor from the Z screw to the quill, near the quill, I have well over 0.5mm of flex - thats a bad figure as it equates to backlash at the tool, so doing nothing here is not an option.

So, looking at the options -

Power the quill via the left side of the pinion shaft, this has slop in it so will need some clever way of preloading the quill upwards - this could lead to rapid rack/pinion wear as it will need enough preload to counter cutting forces from pulling the tool downwards.

Power the knee - this is an option but will cost a lot as it needs a ball-screw, servo, drive plus full tear-down to fit it all.

Alter what i have got - looking at the picture below, is there any harm in removing the web of metal circled?? It would mean i can get a bigger connecting arm in there with much more contact below the bolt to resist the down-forces, without losing any Z travel. Means stripping the head again.

953
General Mach Discussion / Re: Plasma Start or Arc OK Counter
« on: October 28, 2016, 09:29:04 AM »
Just looked again, seems the M3 lost a bit of code, this is my m3...

if getuserled(2244)=0 then
SetUserLed(2000,1)
SetUserDro(2000,(GetUserDro(2000)+1))
SetTimer(1)

ActivateSignal(Output1)

Do While Not Isactive(THCON)
   x=x+1
   sleep 1
   if x=3000 then
      msgbox("OK To Move Timed Out")
      Code "M30"
      exit do
   end if
loop
end if

You'll have to edit out the stuff you don't want, I think I have a ARC-OK timer in there as well, you might not want that bit :)

954
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: October 28, 2016, 02:19:29 AM »
This seems a pretty neat way of backlash control - its a brake cable from a motorbike, one end is mounted to the quill and the other has an air cylinder on it with variable pressure.

The guy that fitted it also fitted a very tidy gear reduction system in the aluminium casing on the left, 15:1 ratio, double reduction.

He reports zero backlash and full quill travel :)

I think he had a small air receiver as well to provide a cushion effect.

On cost alone i feel it worth trying a drive from the left of the quill, topper the knee at any speed is going to take some time to save up for and its a big job to fit.

955
General Mach Discussion / Re: Plasma Start or Arc OK Counter
« on: October 27, 2016, 04:11:34 PM »
I have these - arc start counter plus cut time counter.

It was done by adding two DRO's and an LED to the screen,

the m3 macro was edited...
if getuserled(2244)=0 then
SetUserLed(2000,1)
SetUserDro(2000,(GetUserDro(2000)+1))
SetTimer(1)

ActivateSignal(Output1)


And the M5 macro was edited...

DeActivateSignal(Output1)

SetUserLed(2244,0)

DeActivateSignal(Output3)

If GetUserLed(2000)=1 Then
SetUserDro(2001,(GetUserDro(2001) + (GetTimer(1)/1)))
SetUserLed(2000,0)
End
end if

UserDRO2000 counts arc starts and 2001 is the cut time in seconds, both DRO's are persistent.
I also added buttons to zero each DRO
Works well

956
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: October 27, 2016, 01:48:50 PM »
Thanks Rich,

So you had it first on the quill drive and then moved it to the quill direct? I have several good ideas coming in regarding strengthening the joint but all mean losing z travel and i can't do with any less of that.

I am looking at powering the knee instead - the attraction of 15 odd inches of Z axis is appealing but the big drawback is cost, i reckon i'd be looking at £600 at the end of the day with a big ball-screw, servo motor and drive, pulleys, extras etc. Maybe more if it needs a brake for when the power is off.

I'm drawn to splashing about £100 to see if driving the quill is a possibility or not.

957
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: October 27, 2016, 08:52:24 AM »
Anyone have a video or link to some pics of a powered knee mill conversion?

Seems a lot of people rate it but i cant find any proof!  :)

Still deciding which way to go.

958
General Mach Discussion / Re: Bridgeport Knee Mill Conversion?
« on: October 26, 2016, 02:53:18 PM »
Quill drive reduction idea, mk1, pictured.

Gives a 16:1 reduction, takes up little space, relatively easy to build.

Mounts to left side of head onto the 6 screw holes no longer used.

959
General Mach Discussion / Re: Robot part loader for CNC Lathe
« on: October 25, 2016, 06:30:13 AM »
Hiya Hood, Is it possible to expand the CSMIO to that many inputs?

If so then i can heartily recommend the CS_Labs range of controllers to the OP, great units. :)




Edit...

Just looked, max capacity is 192 ins and 96 outs so yes go for a CS_Labs unit :)

That will also offer 6 channels of motion as well.

960
General Mach Discussion / Re: Make tool change not move in X and Y
« on: October 25, 2016, 02:23:49 AM »
Yes the 2010 macros will do this - it should go to wherever yo have "tool change location" set to in the screen set.

I use it too and have heavily modified my macros :)