ridges on spoilboard when surfacing

[Dan.antes]

When I surface my spoilboard with a 2.5" flycutter in the direction of the X axis I get small ridges from pass to pass. If I change the direction to cut on the Y axis it is a clean surface. I am assuming my Z is slightly out of perpendicular or is it my gantry is not parallel to the table. I tried to manually plumb the the Z carriage but can't seem to make it any better. If I use a 1" cutter the ridge is so small it is barely seen or felt. Any suggestions appreciated. Thanks. Dan

[ger21]

Make sure the spindle power is off, and maybe check with something like a drill press circle cutter, which can give you close to 8" diameter to check. Just a thought.

[MrWild]

Indicaters are the way to go. Problem with your spindle is that is loose. If you have ridges machining in one direction, but not in another, the machining forces are aligning/misaligning your head during the cut. This looseness will affect all cuts even when the head/spindle is trammed while it is off. Once your head is as rigid as you can make it, cut your spoil board with a small diameter cutter to give the most uniform surface you can make. Then tram the head with a indicator so you can make adjustents and SEE what they are doing as you make them You may find that just pushing or pulling on the head makes a huge swing I the indicators reading. In that case, close is all you will be ale to get. As it is a router, and wood, being precise isn't all that important when routing curios. If this is a JGRO you're trying to get precise, well....

[ger21]

Dan has a large, high quality router with a several HP spindle. I doubt the spindle is loose. I'd think his original guess is correct, that the spindle is tilted a bit.

And I think that while some of you guys think woodworking, doesn't need to be precise, I disagree. And I think Dan would disagree as well, when he's doing fancy inlay work.

[Geof]

If you do not have a dial indicator and/or anything to sweep a decent size circle can can true the spindle the tedious way.

Take two cuts to create the step so you know which way to move the spindle after you loosen the mounting bolts.

If the spindle is mounted on a flange you need to estimate how big the step is from the 2.5" dia cutter; let's say it is .010".

Now if the mounting flange is 5" across you have to insert a 0.020" shim on the side where the cutter is cutting too deep. Tighten things down and make another cut.

Just keep on making cuts and adding or removing shims until you are happy.

HINT: Pop/Beer cans make a good source of shim stock; about 0.0025" thick I think they are.

[Switcher]

Originally Posted by Geof If you do not have a dial indicator and/or anything to sweep a decent size circle can can true the spindle the tedious way. Take two cuts to create the step so you know which way to move the spindle after you loosen the mounting bolts. If the spindle is mounted on a flange you need to estimate how big the step is from the 2.5" dia cutter; let's say it is .010". Now if the mounting flange is 5" across you have to insert a 0.020" shim on the side where the cutter is cutting too deep. Tighten things down and make another cut. Just keep on making cuts and adding or removing shims until you are happy. HINT: Pop/Beer cans make a good source of shim stock; about 0.0025" thick I think they are.

Yeah, the more Beer I mean shims you need, the better the table will look!



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[Dan.antes]

I rarely notice any steps in the cut on edges when I am profiling in several steps in 3/4" thick material with a 1/2" or smaller end mill. At times I do see small lines in the edges of harwood from each step. I will have some time tomorrow to try the beer can shim to see if I can get my setup a little closer. I have tried checking the rails down to the table with a micrometer but they seem dead on. I am pretty sure the spindle is tipped ever so slightly on the carriage attached to the vertical rails. I am not quite sure how to shim this but I think I will mount the flycutter and surface a board then put shims on the other side of the cutter at Z0. If I loosen the bolts and nudge the z down a 1-2 thousandths and retiten the bolts, I may get it a little closer. I think a little trial and error is the only way I will be able to make such a small adjustment. I will take a few pictures of the Z setup and the problem and post this week. Thanks for your ideas.

[spoiledbrat]

There are dial indicators available that can mount in your toolholders. This is really the best way to do this.

I found this link while looking for the tool.

http://www.duwaynesplace.com/tramming_mill.html

I might just make a Dial Ind holder like this for my machine.

[timberman]

You will get ridges if you are useing throw away knives on you cutter.if you are like we do the need to be setup perfectly flat.eg sit the cutter head on a sheet of glass when inserting new cutters.
I hope this helps.