"Jack Stein" wrote:
If they supplied just the bearings would you have any qualms making
the wheels out of plywood?
For me, NBD, but see below.
If you are going to use plywood as a core, then you want to totally
encapsulate it with epoxy and fiber glass.
The plywood is now totally sealed, and you are no longer dealing with
wood other than as a core material.
If you want to make an 18" wheel, laminate a couple of 19" dia pieces
of 12mm, 4 ply, CDX plywood together with some TiteBond II.
(You can use deck screws as clamps, just sand down the tips when
finished and leave them installed)
When cured, drill a centered thru hole with a hole saw that is 2-3
times the dia of the axle.
(My guess is that 1-1/4 or 1-1/2 would be about right.)
Close the bottom of the hole with masking tape, lay flat on table, and
pour in about 1/2" of micro-balloon thickened fairing putty and let
cure over night.
Next day, remove tape, mix more thickened putty, and fill both sides
proud using a putty knife or equal to apply.
When cured, sand putty smooth on both sides, then apply a layer of
17OZ, double bias glass on top side and let cure.
Next day, glass other side.
When both sides are cured, sand glass with some 60 grit to remove any
drips.and overlaps around outer circle edges.
Center drill a thru hole for the axle.
Notice that you have just drilled thru glass and putty, but the
plywood is still sealed.
Using a router with a 1/2" carbide straight bit and a radius jig, trim
wheel to 18" finish dia.
(Buy a new, low cost carbide blade, use it, then toss it because the
fiberglass will have destroyed it.)
Glass the tread with some 6 oz, glass tape, 2" max width.
Glass 2/3 of wheel at a time.
When cured, rotate wheel and finish.
When cured, sand overlasps smooth, then tape again until you have 3
layers of glass tape.
Trim off excess glass with a sander.
You are now ready to install axle and rubber for tire.
Balance as required.
As I said, straight forward construction, just a PITA to do it.
--
Lew Hodgett
Box 2302
Whittier, CA, 90610-2302
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