Re: Linear Motion Parts Source for Hobbyists ?

> Are there any tricks to mounting your "flimsy balsa" prior to

cutting it

> with your CNC router? The reason I ask is that I've got a Sherline

Mill that

> I'm thinking of using to cut out parts for Model Railroad buildings.
>
> -- Jerry

Hi Jerry,

Yes, that can be a problem! The 1st "job" I ran when I finished my
router table was to drill 576 1/8" holes in my "worktable" and added
a few parts to make it a shop vac powered vacuum hold down device. I
subsequently hand tapped about 1/2 of the holes so that I can clamp
down ply and other harder woods with 10/32 machine screws.

I stacked & drilled a few 1/4" "Artboard" (Cardboard/styrofoam
sandwich) to use as a sacrificial underlayment to keep from routing
up my worktable. It works pretty well on the larger balsa parts but
a lot of them have to be "watched" and assisted by hand to keep them
from wandering off as the end of the cut is approached. Since most
wing ribs come in twosies, I take the time to print a drawing of the
layout of the parts on the "virtual worktable" and use that to mark
the locations for 2 or 3 pieces of 2 sided tape on each part so I can
stick 2 pieces of 12" X 12" sheet stock on top of each other and get
2 duplicate parts for each "run". This works OK when the the sheet
thickness is 1/8" or less....I use 1/16" carbide router bits for the
balsa and they have about 5/16 cutting depth.

If I'm doing a constant chord wing, (ribs all alike) I CNC cut a
template from scrap formica and hand cut the ribs with a sharp Exacto
knife. The MaxNC motion kit only gets me about 6-7 ipm safely so I
can hand cut multiples of the same part quicker by hand, as long as
they're not full of lightening holes and other complexities....that's
where the CNC really shines!

HTH
Milton