Machine pauses during direction change

[toych]

I have a PRS standard with a spindle.
When cutting a profile or V Carving the tool pauses for about a second when making a directional change. On a profile cut it paused at each corner. If you are not watching the machine you may not even notice it because the part cuts fine other wise.
V-carving was a different matter. The bit paused way to long and burned the material (maple).

Just wondering if anyone has come across this problem themselves.

All setting are factory except for slow corner speed set to 35. I have used this setting for over a year with good results.

Thanks.
Darren

[dengler]

I am having a similar problem. My machine was running fine until last week. Now it takes coffee breaks everytime there is a directional change.

I defragged and ran a disk cleanup on the rip-server and then went in an blew out the dust in both the server and control. This resulted in no change.

The shop that I worked at before had to upgrade the server computer to a faster processor. For there ShopBot to run smother. But that would not be my case now since it worked fine just last week.

Is there any maintenance that can help eliminate the palse. I really need to get the machine back to normal asap.

Thanks,
Daniel

[dengler]

"pause" not palse

[Tim Summerer]

Check your Value->Ramp settings. We had a similar problem- somehow VR got opened and the values set to their minimums. So every time the machine made a direction change it slowed waaay down. Burned wood etc. I'm not at the shop so I can't tell you what our current values are but I think it's about .4

If you have your manual, it has better info on the VR section as well.

[Gary Campbell]

IF you open the [V] [R] settings and hover the mouse over the setting, both the range of settings and the default will display in the info box.

I agree, check the slow corner speeds

[bob_s]

I am having the opposite problem. I am cutting some fancy shaped mortice and tenon joints with a jig that is a poor mans version of Gary's dovetail setup. The bot does a hard shake dance as it cuts some of the little spots between the tenon and the edge of the board. The cuts are clean, but I would rather have it take an extra minute and not put so much stress on the machine. My longer cuts and curves are fast and smooth. I am cutting small areas with a long 1/8 endmill @ 1 ips .1" deep per pass so the cut load is almost zero. The bigger load is from machine inertia.
Should I change the move ramp values for XY , the minimum distance to check, slow corner speed, or do I need to adjust the all of these? I do have fairly aggressive settings to make my 3d work run faster, just not sure where to start backing them out.
any suggestions are appreciated.
Thanks

[Gary Campbell]

Guys...
The Ramp settings are very important to having your machine perform the way you intend it to. The factory settings are a good starting point and are in the middle of the range of adjustments. But they are just that, a starting point.

Brady Watson "wrote the book" on ramping. http://www.shopbotblog.com/index.php/2008/03/a-ramping-the-vr-command-and-how-to-tune-your-tool-for-maximum-performance/ It should be required reading!

I have at least 5 different ramp configurations (so far) that I use depending on the type of cutting that I am doing. I make a custom file (in the 50's) that is similar to this:

' INSTALL V CARVE RAMPS
VR,x.x.x.x.x.x.x.x.x.x.x.x.
PAUSE .5

each VR line is saved from the control software after I make the settings change and have tested them. Then placed in the editor in a new file. There is no substitute for using your cut files and testing different ramp values while air cutting.

[bob_s]

oops just been yelled at by the teacher for not doing my homework, again!

I've been reading Brady's article again - I do like the idea of setting it via a custom file - that will keep me from being lazy and leaving the settings from the last cut when different ones would be better
thanks Gary - you are right - I gotta do the extra bit of work