Sled problem

[rbrown]

I'm doing a 6' x 12" X 5/8" shelf with grooves cut in them and I made a sled 6' 7" x 14" of 3/4 mdf. I built roller supports to in case it flexes (it doesn't) and it is having a hard time measuring the board. It moves to the end of the sled then it moves an inch then back an inch then moves back and forth in smaller and smaller increments until I stop it... So is the sled too heavy or is the brass roller slipping on the mdf or do I have some other problem? Has anyone done something this big and can give me some ideas? It only has a couple of hours of cutting time on the machine so I don't think it is whipped. Thanks, Bob

[badbert]

Couldn't you just add 4" pieces to each end. Or make 1" wide 5/8" thick 6' 8" rails and attach them to the sides. The weight of the sled and the board, is pretty heavy. Also squaring it up in the machine becomes very important. At the very least use masking tape on the bottom of the board or sled where the brass roller contacts. And a few more to add traction.

[aokweld101]

I'm no expert but my thoughts are is if its a .625 thick then its in it's parameters if you support the ends I wouldn't think it would matter about useing a sled.

[bergerud]

I have had the jogging back and forth before and chalked up to software. Rebooted and it stopped. It may not be software, it may be your sled slipping on the belts. Mdf is too smooth. Try some masking or duct tape on the underside for the belts to grip.

[fwharris]

I have had the jogging back and forth before and chalked up to software. Rebooted and it stopped. It may not be software, it may be your sled slipping on the belts. Mdf is too smooth. Try some masking or duct tape on the underside for the belts to grip.

From the conference they talked about the the jogging back and forth thing. What they stated is the machine is calculating/looking for any slop/play in the x gear movement compared to the board tracking system.

I agree that maybe the mdf might be to heavy and slick for this long of a board and when it is at the end it could very possibly be raising the board up and loosing contact with the brass roller. I would go with either a lighter sled material or like stated since the 5/8" board is thick enough just go with that with added width and length...

[liquidguitars]

the jogging back and forth thing. What they stated is the machine is calculating/looking for any slop/play in the x gear movement compared to the board tracking system.

Normal as the board is moving off the brass roller at the end of the board measurement. But any back and forth in the center of the board as it runs is VERY bad and can do damage to the x drive. BTW why would you only use 3.5 on each end of a sled? most of us have documented over 4" or 6" extra is much better.

[Digitalwoodshop]

It is my belief that your rocking back and forth quickly is the result of the board loosing contact with the brass roller. Yes, the machine does the back and forth calculating the GEAR SLOP or LOST MOTION between the X Gear Box and the Actual Board as measured by the brass roller... Or even the board only being held by ONE ROLLER and Lifting...

It is my guess that the board it Drooping at the far end causing the board to be lifted off the brass roller. Yes, you used roller stands but try adjusting it higher.

Masking Tape on the Brass Roller path might be good too...

And since this is a 6 foot board, I would use PLACE on END and add a 4 inch dead area on the right side of Designer... OR even start with a 6 foot 8 inch board and cut off the 4 inches when done. IF the board is only being held by ONE roller when the board is doing it's DANCE then you have found the problem.... A 6 foot 8 inch board and place on end would be the best way to setup this project.

Here is a sample board. 6 Foot 8 inches long and I put 2 four inch boxes on either end and put the artwork between the blocks. Keep in mind the Brass Roller is at the TOP of your SCREEN. and if you are designing the bottom of the board the Brass Roller is on the bottom of the screen and everything is up side down.

AL

[DickB]

It is my guess that the board it Drooping at the far end causing the board to be lifted off the brass roller. Yes, you used roller stands but try adjusting it higher.

I'm with Al on this one as a likely cause. You might think that once you got your rollers adjusted that would be it, but I have found small differences in boards and sleds that have required different setups for the rollers. The machine's rollers as well as the auxiliary rollers should be addressed. BTW I had trouble adjusting the machine's rollers so I use a bit different setup that works well for me:



As you are having difficulty, I would recommend that you try measuring the length of the board before running your project. If you loose contact in the middle of the project it may be difficult to recover. If you can measure the board successfully a couple of times (raising the head between measurements) you should be good to go.

[mtylerfl]

... I use a bit different setup that works well for me:

THAT is a very nice setup! Very, very secure and accurate for long-board projects! Thank you for sharing that idea - it's a great one.

[aokweld101]

I'm looking at DickB set up,.. on your rollers did you buy them or make them, If it is to much to buy them, I could make them myself using aluminum for the rollers and steel for the mount ...and if you bought them... where?