Surfacing question

[FJ Baker]

Greetings all,
I am new to the shopbot and surfaced the spoil board on my used PRS Alpha or the first time today. At all of the corners other than the x-0 y-0 corner I got these little triangles at each pass. Has anyone had this problem or might be able to tell me what is wrong?
Thanks
JB

[Brady Watson]

Set your stepover percentage to 15% or 20% when you make your flattening file...or it will do what you show.

Also - check that your spindle is dead square to the table...looks like you've got a few 'steps' from the spindle/router being a little off kilt. You may have to remove the spindle & spindle plate to properly square it up. It's a little bit of a pain, but once you dial it in, it's good forever.

-B

[FJ Baker]

Thanks Brady. I only had it set at 10% for a step over. Also, it has slight lines on all the passes along the x-axis but the ones going along the y-axis are smooth as can be. Is that what you are speaking about concerning the spindle being a bit out of square? Any suggestions were to look for the process of doing this?
JB

[Brady Watson]

Read my post & See if this helps: http://www.talkshopbot.com/forum/showthread.php?t=14893

-B

[FJ Baker]

Thanks for the help!
JB

[knight_toolworks]

I just make a tool in my database for the flattening bit and create a pocketing profile. I have several at different depths so it is fast to setup. I think I have a 50% stepover and I make the rectangle larger then my table so the bit goes past the edges.

[Ajcoholic]

I use a 1 1/4" bit from Dimar to flatten my table. Don't recal what stepover I had, but it left the little triangles (although they were pretty tiny).

A quick swipe with a sharp chisel and in seconds they were gone.

I know... I could have made the stepover smaller, but why let the router run for several more minutes when I can do it "old school" quicker? Blasphemy! ;)

AJC

[michael_schwartz]

A quick swipe with a sharp chisel and in seconds they were gone.

I know... I could have made the stepover smaller, but why let the router run for several more minutes when I can do it "old school" quicker? Blasphemy! ;)

AJC

Its funny you mention that. I used to use a stiff card scraper to remove them before I figured out that I needed to reduce the step over.

[kubotaman]

Another way to make sure your spindle is 90 degrees to the table is to install a long cutter,long shank preferably, and zero a wixey gauge to the table. Stick it on the shank and hopefully it will read 90 degrees. Then turn the shank 90 degrees and take another reading. I used a this piece of paper as a shim to get my spindle right on. Been perfect ever since!!!

[gene]

John,
What size bit are you using to surface the top?

[gene]

The way i dialed my spindle in to be flat with the table was to loosen the nuts holding the spindle so that i could move the spindle with some effort. put the collet wrench in the collet nut . measure the distance from the end of the wrench to the table , very gently rotate the collet with the wrench hanging in the collet nut 180 degrees making sure the wrench does not slip any while you rotate the shaft . and measure the distance after the rotation. get the two measurements as close as possible, do this in the x direction . when you get the measurements to match then do it in the y direction. when you get the y direction measurements to match surface the table and it will tell you if it needs further attention