Long cutting jobs and table shaking

[PhillyCyberJoe]

Hey Folks,
It's been a really long time since I posted here, but still active and checking out the forum every day. I have two questions that I'm hoping someone out there can help me with.

Santa bought me the VectorArt Design and Carve series, which is awesome. It is very easy to model a pretty complex wildlife scene but the cutting job is extremely long on some models. To cut down on some time, I have tried tweaking the speed of the finishing cut and I am now using 150 ipm on the Joe's 2006. The machine handles it well but with 3D models there is a lot of directional changes and at 150ipm the table shakes considerably. My machine has to be on wheels and cannot be bolted to the wall like some others have done. Question #1.....Any ideas about reducing table movement without reducing speed and without bolting to the wall?

Question #2 is regarding splitting up large/long cutting jobs. I will probably utilize "tape splitting" (editing the postp for breaking up into smaller files) in some cases, but wondering what others are doing on this issue. Carving a 3D image is not very forgiving if you stop a job, continue the next day and are even just a few thousands off. For example....does it make sense to peck drill a hole in every job and use that as your reference point for restarting?

Any ideas would be greatly appreciated. BTW...I'm a few days late, but happy new year to all.

Regards,
Joe

[Fatboy]

Joe,
I know exactly what you are talking about with the shaking, I have a set of heavy castors left over from another project but after seeing my 2006 run I have decided to not use them. In fact I have clamped my machine to the permanent bench with sections of 1x4's which has eliminated the shake.

I'd say that the first order of business for you is to get your machine off the wheels and provide a solid connection to the floor (which you say that you can't do).
Another area to look at is the length of your legs, in your case shorter would be better right up to no legs at all. Unless you can make some kind of connections to solid members then you may have to slow the machine down to manage the shaking.

I can't answer #2 but have to commend your relation to the jolly fat man in red. Can you put in a good word for me for next year?

Good Luck and HNY,
Fatboy

[PhillyCyberJoe]

Fatboy,
Thanks for your response. The table that the machine sits on is already kind of low to the ground and generally, the shaking has not been an problem since it's pretty sturdy. The many directional changes and jerky movement of 3D is what is really testing the machine. Maybe I'll just try putting a couple of 4X4's under the cross members of the table to lift the wheels just a bit off the floor.

I would still like to know what others are doing about extremely long cutting times. Where did everybody go?

Thanks again,
Joe

[AJ Negvesky]

I cut at about 120 ipm and to eliminate my table shaking i changed the setting in Mach3 for the acceleration slowed it down and most of the major table movement disappeared.

[PhillyCyberJoe]

Thanks AJ....I appreciate the response. I might have to slow it down just a tad.

Joe

[Phife]

Just turn down your acceleration values for your X and Y.

Ive recently run the Deer Scene Mantel from Vector Arts website. It was the longest job Ive run.

I made 3, each took about 5 hours each to complete. I was using a 3/8" endmill for roughing and a 1/8 Ball mill for Finishing and it turned out great. There a picture of it in my Build thread.

I actually tried to split the job up and ended up ruining a piece. When I tried to restart the job the next day I accidentally Re-referenced the machine and lost the part reference.

I found it worked out just fine running the whole job in a Day.

Good Luck!

[PhillyCyberJoe]

Hey Phife,
Thanks for your response. The mantel is exactly what I want to do and was concerned about all the shaking and the length of the job. I will play around with acceleration as yours and other previous responses has suggested.

You bring up a great point and probably the second part of my original question. I would like to know what others are doing in anticipation of stopping a job that will be continued later. If you know that you are going to do this, what is the best way to account for re-referencing/homing and slight changes in actual machine coordinates? My thought was to include a 1/4" peck drilled hole away from the main design, on every piece. That way I can move the gantry until I am right over it and zero it from there. I'm sure there must be a better way and wondering what others are doing.

Thanks again,
Joe