old shapeoko 3, fusion 360 circular issues

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WEASEL333
Posts: 11
Joined: Thu Nov 09, 2017 7:47 pm

old shapeoko 3, fusion 360 circular issues

Post by WEASEL333 » Tue Aug 27, 2019 1:16 am

Hello,

I have made a file for cutting out many small holes in plywood in a grid pattern. I used the circular command, all the holes are copies of each other, the depths, tool clearances, and simulations are all good. I have trouble when I export.... standard grbl seems to jam my carbide motion 3,0.368, and the new one made for carbide 3d does the following (after deleting G28 from start and finish)... The first several holes are correct depth, then about 5 holes in the cutter starts higher than before, subsequently the holes get shallower as it goes along. This is driving me mad... can't figure it out. Any ideas gents? Thanks... :idea:
Hard work is it's own rew----- OH HEY, BEER!!! :)

WillAdams
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Re: old shapeoko 3, fusion 360 circular issues

Post by WillAdams » Tue Aug 27, 2019 12:27 pm

Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

hooby2
Posts: 2
Joined: Sat Aug 24, 2019 6:16 pm

Re: old shapeoko 3, fusion 360 circular issues

Post by hooby2 » Tue Aug 27, 2019 3:35 pm

Sounds like the Z-axis missed a few steps - so the subsequent holes are not as deep - in other words, the machine thinks the Z zero that you set at the beginning is now higher than the top of your stock. You can easily confirm that by going to your Z zero at the end of the job- - and it will now be a lot higher than your stock top surface.

When this happens (on the first few holes) you probably heard a "clunk" or two ?

I had this happen several times at first - in my case the Z-axis springs were too strong and the Zaxis missed steps when it tried to get to deeper cuts closer to the stock bottom/wasteboard. I removed one of the two springs and all has been good since. (although I need to get two slightly weaker springs from somewhere - I don't like running the z-axis unbalanced - but it seems fine)

Other causes for this behaviour may be that:
1. your depth of cut or plunge rate is too aggressive,
2. the Z-axis belt is not tight enough,
3. the Z-axis pulley on the stepper motor is slipping,
4. the tool is not firmly in the collet and is pushing up with each cut.

WEASEL333
Posts: 11
Joined: Thu Nov 09, 2017 7:47 pm

Re: old shapeoko 3, fusion 360 circular issues

Post by WEASEL333 » Thu Aug 29, 2019 5:47 pm

Thanks for the replies.. I will try running the job with one spring. checked all screws and tension, seemed good. I have noticed that over the shallower holes that the first carving step starts higher than the stock surface... is this because the router and z axis carriage that holds it are incrementally being pushed higher each time? Belt tension is guitar tight.. tried to hold it and have it skip on either top/bottom pulley or tension bolt to no avail. It makes sense that if I have the same problem over 2 programs that the problem would be analog... it's just hard to track down. It's a difference of about an inch, so I don't think it's the eccentric bolts on the wheels
Hard work is it's own rew----- OH HEY, BEER!!! :)

WillAdams
Posts: 8514
Joined: Mon Apr 09, 2012 6:11 pm
Location: Pennsylvania --- south of the Turnpike, East of US-15
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Re: old shapeoko 3, fusion 360 circular issues

Post by WillAdams » Tue Sep 03, 2019 12:35 pm

Best thing to do is to adjust things so that the machine doesn't have a problem reaching as low as it needs to:

- mount router as low as possible (if using the Carbide 3D adapter insert from underneath)
- add a spoilboard to lift work up so that the machine doesn't struggle

Test feeds and speeds and plunge rate --- if possible use ramping in rather than a direct plunge
Shapeoko 3XL #0006 w/Makita RT0701 Router w/0.125″ and ¼″ Elaire precision collets
Nomad 883 Pro #596 (bamboo)

WEASEL333
Posts: 11
Joined: Thu Nov 09, 2017 7:47 pm

Re: old shapeoko 3, fusion 360 circular issues

Post by WEASEL333 » Tue Sep 10, 2019 2:21 am

Will try a ramping operation... still having the same issue. Painted an alignment mark on top z axis bearing, belt tension is good. all z plate mounting screws are good. Bit is in the collet as far as it will go, with enough room for clearance of tension nut for operation... I just can't figure this one out. Maybe a slower plunge rate and ramping. If it was pushing somewhere due to fast plunge rate, it should show on machine alignment, right? makita adapter is inverted also.. running on a .76" spoil board (thanks Winston for the tutorial) Any other possible problems? Using Fusion 360 with the circular clearing function... plunge 17 in/min, 17,300 rpm spindle 1/4" 4 flute flat. Image
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Hard work is it's own rew----- OH HEY, BEER!!! :)

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