Downtime

[zorlack]

I'm in between shows right now, but I just had some new gear show up. A collet from Precision Bits and some new round-nose bits.

I'm not the kind of person that can have new toys and then wait for an occasion to use them.


42971.jpg

So I carved reddit's alien mascot out of pink foam.

Shot some video just for the heck of it.

-D

[david_gardner]

Watching your video I realized how smooth your prt runs. Mine seems to "slam" at each end of a raster pass with enough force to shake the table. Yours seems to change direction very smoothly.

Any ideas what could be causing my "slamming"?

Care to share your ramp values?

[zorlack]

Hmm... I'm afraid I don't have any magic to share.

I'm using the default values out of the 48x96PRT config file that ships with the Shopbot software.

I was running the bot flat out during this cut. I had the XY speed at 6IPS and the Z speed at 3IPS. There was definitely no slamming...

Are you using more aggressive ramping values?

-D

[david_gardner]

I've tried everything from the default values to Brady's aggressive values and it just bangs back and forth. I don't think the banging is hurting the machine but it is definitely hitting hard enough to leave marks in the workpiece.

[cutitout]

I have a bounce at the end of the raster also but I am on a wooden table and it has had it share of "G" pulling it in all directions.

Was the video run at a faster speed? I am running at 6IPS and it does not look as quick.

what software and post did you use?

Thanks

[zorlack]

David, if you rotate the raster direction by 90 degrees do you get the same shaking?

Eric, Yeah the video is sped way up... I didn't want to bore people by making them watch two hours of machining hehe.

I'd say its probably running the video at 4x to 6x.

[cutitout]

thought it was fast -- to bad I was hoping you had the magic settings for foam cutting speed.

[david_gardner]

Yes, it slams in both directions.

[magic]

change your ramping speed.

[zorlack]

Well, I'm not an expert on these matters, but it brings to mind a few questions:

Does changing the ramping speed have any noticeable affect on tool movement?

Is it possible that the ramping values are being ignored for some reason?

If you used a ridiculously slow ramping value, would the tool obey, and would the slamming stop?