Spoil board for 25x25 using bed slots

[DenJHill]

Bill Z: you may be referring to sound-deadening board. It's a relatively soft, fibrous material that comes in 4x8 foot sheets. Used under sheetrock to reduce sound transmission through walls. Home improvement stores carry it.

Dennis

[bill z]

Thanks Dennis.

I'll look for it.

[jimily]

If anyone is still working on theirs:
I will say having completed an mdf one and used it a bit that Oak slats is what I would use if I had to do it again. I would still use all the same screws etc but a hardwood instead, and oak is plentiful and cheap. I have run many jobs since making the mdf spoilboard and still don't have a scratch on it. I onion skin and clamp alot, or use jigs. I need to do more screwing down of stuff and not worry about jigs or clamps and really use the spoilboard though I think. I do worry about it swelling too though and hardwood would resist it more.

So yeah I'm onboard with the hardwood spoilboard. But any controllable flat surface is good, at least until it rains.

Have fun!
Jim

[terryz854]

So, I took a look at all the spoil boards in this thread and proceed to make one, or two. First one came out OK but forgot it had to be 25" square and no larger. No problem, trim down. Still had to sand two edges because I didn't have it exactly where it needed to be to have the router bit shave it level. Then, the hold down clamps that came with the machine sure are long. So long that the back side of the router mount caught one and ripped it out of the track. I've had the machine for about three months now it's back to the manuals. As you can see by the attached photos the router mount or router is not exactly level to the tabletop. So I need to research and see what I need to do to level the router so I don't have ridges. This is definitely a learning experience.

[NewAgent45]

I see the tell-tail striping from you surface planning in the picture. This is no surprise. There are several posts on this forum that discuss this. The most recent is http://www.cncsharktalk.com/viewtopic.php?f=7&t=4684 I did not use the tool the bill z though his technique is good. I used a large surface planning bit (1 1/4 dia) and with a large bit the striping is more pronounced. If you examine the striping carefully you can tell which direction you need to go. It also helps it you change the direction of your planning path. I use a pocket toolpath and you can create raster toolpaths at different angles. You can stop the planning run after a few passes add some shims and rerun it this way.

When you are shimming your router you should always loosen the vertical bolts as well as the clamping bolt. This is especially true when the HDPE factory mount is being used. I have replaced my mounting clamp with the one available from Dixie Billet. I recommend placing the shims under the mounting clamp. I think I have 0.025 - 0.030" under the front of my clamp. You may find you have to favor the left or right side. If the spindle is tilted on the X it is possible the gantry is tilted left or right. I recall some on the forum needed to make adjustments to the gantry to correct this.

I keep an assortment of plastic shim stock on hand for this and other shimming applications. This is discussed in more detail in my previous post.

I also want to mention I don't use my spoilboard to cut through anymore. Instead I us a piece of 1/4 MDF cut to size for my cut through projects. I have found this works good. I also use virtual zero with projects that the material might not be uniform. Virtual Zero is working well with the latest controller firmware. You should disable Virtual Zero when surface planning. You want the spoilboard to be "co-planer" to the spindle.

I should also mention that I have made several different clamps to work with my spoilboard my spoilboard is one piece of 3/4 MDF with T-slots cut in it. I also have a variety of different length T-bolts.

Hope this heads you in the right direction.... Rod