Sled problem

[CNC Carver]

I use these as supports http://www.harborfreight.com/132-lb-...and-68898.html

[fwharris]

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.

LG,

I was just stating what Chris Rawls told us at the conference when the question was asked. He did state that this usually occurs in older machines do to the wear on the gears..

HHHMMM must be someone else on the 3.5" as I do use 4"...

[liquidguitars]

No worries Floyd there are two types of "dancing" one at the end of the measurement that not a issue and one that's bad done in the middle of the board. if that make sense...

HHHMMM must be someone else on the 3.5" as I do use 4"...

I think we know who that is...

[fwharris]

No worries Floyd there are two types of "dancing" one at the end of the measurement that not a issue and one that's bad done in the middle of the board. if that make sense... I think we know who that is...

Oh I know!!!

[badbert]

Ok why would the X-drive go backwards? I agree it is possibly losing the brass roller. But wouldn't it just continue forward? I do understand we are talking two different kinds of back-and-forth. One, when the machine reaches the end of the board it goes back and forth to measure the end. Two, if the board is tapered, or warped, or twisted, the effort needed to move the board becomes excessive and the x-drive stalls and starts a back and forth motion that loops until you stop it. I believe the second is the case here. Just to prove the theory... put the board in without the sled and use measure. Something is causing the increase in effort to move the board.

[fwharris]

Ok why would the X-drive go backwards? I agree it is possibly losing the brass roller. But wouldn't it just continue forward? I do understand we are talking two different kinds of back-and-forth. One, when the machine reaches the end of the board it goes back and forth to measure the end. Two, if the board is tapered, or warped, or twisted, the effort needed to move the board becomes excessive and the x-drive stalls and starts a back and forth motion that loops until you stop it. I believe the second is the case here. Just to prove the theory... put the board in without the sled and use measure. Something is causing the increase in effort to move the board.

From what I got from Chis is that as the board in moving the computer sees the movement of the brass roller and compares it to the X movement. If it finds a difference then it does the jog back and forth to determine the slop in the X gears...

[mcQ]

When you carve a part over about 3 - 4 ft you need to use outfeed tables on each end to support your workpiece. Even though you added 3 1/2" to each end of your sled which keeps the sled under the rollers the length of the board hanging out the ends is prying the compression rollers up and probably causing the sled to loose contact with the tracking roller. Also carving a project this long without support is asking to break the short tables on your machine.

Erwin

[DickB]

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?

I bought them MANY years ago as an accessory to a folding Ryobi Quick Stand. That stand is no longer in production, although Ryobi now sells a totally different stand under the same name. The original accessory included camps to mount a 2x4 under the table, and the rollers slipped onto the 2x4 wherever you wanted them. I built myself a miter saw table with fold-up "wings" and was no longer using the rollers, but they were perfect for the Carvewright.

Harbor Freight has a roller stand on sale right now that could probably be adapted: http://www.harborfreight.com/132-lb-...and-68898.html

[rbrown]

Thanks for the suggestions. My setup is kind of like DickB's except I had a bunch of castor rollers laying around so I put them in pairs on both ends I have eight on each side. Will try the suggestions and let you know... My workshop is 20 mins. away I had to take my step daughter to a college tour and I used the spare car and forgot that my shop keys were on my car key ring so I will try it tomorrow. Don't feel like driving over tonight.

[DickB]

In my experience, long boards (and sleds) are seldom 100% straight. If the rollers are not adjustable to imperfect boards, the rollers may work against you. If they curl upwards towards the ends even a fraction of an inch, the rollers will not support the end of the board when it is fully extended, and the weight may cause the board to lift off the brass roller. So then you need to raise the far rollers slightly. If they curl downwards towards the ends, the brass roller contact may be lost in the middle of the board. Then you need to lower the far rollers a bit.