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Finally... 4th axis

Posted: Fri Mar 07, 2014 10:11 am
by PsyKo
Hello guys,

Just a few words to tell you that I've been able to make and use a 4 axis on the Shapeoko.
First, I apologize for the blurry pictures. They were taken with my old Iphone 3GS...

It still needs some finishing but it works.
Axe4-02-reduced.jpg
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Axe4-01-reduced.jpg
Axe4-01-reduced.jpg (366.33 KiB) Viewed 5752 times
The shaft is a Ø15mm
The aluminium plates were milled using the Shapeoko (I'll probably make new one since those have squaring issues)
I still have to finish it but didn't have enough aluminium :)

The measured runnout is about 0.05mm (or 0.002 in)

I adapted a Ø80mm 4 independent jaws lathe chuck such as this one.
Image

The link between the shaft and the chuck is done by a Delrin plate (milled using the shapeoko and the 4th axis)

I milled my first object. Here is a picture :
Skull_Shapeoko_4axis.jpg
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There is an issue on the left due to misalignement at startup (I forgot to perfectly align the endmill to the center of the shaft)
It's a 20mm skull milled in random wood.

The only issue now is to find a cheap CAM software that can handle it natively.I'm using Cambam, but I have to use tricks to make it work (indexed A axis).

But it's really fun to use :)

Re: Finally... 4th axis

Posted: Fri Mar 07, 2014 10:55 am
by DanMc
Very cool! I've been tossing around a similar idea, but using some 3" aluminum tube I have on hand. Questions; what ratio did you use for the belt? and how did you fasten the delrin to the shaft, set screws? I was actually thinking of trying to mill a chuck out of delrin and use insert nut behind to hold the jaws.

Also you might look at the hobby license for DeskProto, it's not super cheap but is the lowest cost s/w I have found that reliably does 4th and 5th axis.

Re: Finally... 4th axis

Posted: Fri Mar 07, 2014 10:56 am
by kjetilhansen
Looks awesome, congratulations :D

Re: Finally... 4th axis

Posted: Fri Mar 07, 2014 1:07 pm
by PsyKo
Hi,

Thanks folks,

Dan,
I'll take a look at Deskproto. It's 250€ so it's a little bit expensive for now :) It's only a hobby

The ratio is 15:72 (basically 1:4.8)
The delrin is attached to the shaft using M5 holding screws exactly like the one on the pulley of the shapeoko.

I was also thinking of milling the chuck. Then I found one for only 50€ so I saved myself some time...

Re: Finally... 4th axis

Posted: Fri Mar 07, 2014 5:16 pm
by ThatDamnGuy
PsyKo,

Thats awesome nice work! I would love to see a short video of this running and the setup itself if you have the time.

Thanks

Re: Finally... 4th axis

Posted: Fri Mar 07, 2014 5:39 pm
by PsyKo
ThatDamnGuy,

That is possible but now right now. Maybe in 2 weeks from now.
My Shapeoko is not at my place because I don't have enough space.

The setup is quite hasardous for now :) I also have to give my shapeoko a higher Z so the axis can actually pass below the endmill. Right now the spindle is almost at the top of the Z axis rail and the 4th axis shaft is along the Y axis.

Re: Finally... 4th axis

Posted: Sun Mar 09, 2014 12:53 am
by cvoinescu
PsyKo, how is the chuck attached to the shaft?

Re: Finally... 4th axis

Posted: Sun Mar 09, 2014 5:04 pm
by PsyKo
cvoinescu wrote:PsyKo, how is the chuck attached to the shaft?
As mentionned,
The link between the shaft and the chuck is done by a Delrin plate (milled using the shapeoko and the 4th axis)
The delrin is attached to the shaft using M5 holding screws exactly like the one on the pulley of the shapeoko.

Re: Finally... 4th axis

Posted: Mon Mar 10, 2014 11:15 am
by danimal
This gives me hope. I am switching over my controller to linuxCNC driven G540 just so some day I can upgrade to 4 axis. I figure the free 4 axis CAM software is still a little ways out, but it looks like you managed it well. Looks great!

Re: Finally... 4th axis

Posted: Mon Mar 10, 2014 12:01 pm
by PsyKo
The milling process is actually 4 3D profiles done every 90° angle...
Nothing continuous, and I had to insert the rotation manually... It's ok when there is only 4 turns, but for milling a gear for instance, it's more difficult...