Arthur 51 wrote:

To clarify.

[modifying ASCII diagram to work in a fixed pitch font!]

-----------------------------------|
wood for tread |
|
|
|
---------------------|-------------|
6mm mdf | |
---------------------|--------|
---
3/4" nail

The cutter will be a flush trimmer of say 3/8" diameter using
a 1/2" diameter bearing. The bearing will run against the mdf.

OK, I can see what you are doing, but not sure why. Is the MDF just to
increase the hardwood thickness? In the above diagram, where would the
riser meet the tread, at the point the MDF stops?

I would have though a screwing and gluing would be better than a nail in
the above situation.

A more usual layout would be:

------------------------------------\ P
A | |
-------------------------------| |
| B |
C | |
|---| |
---------------------------| D |----/ P

A = 6mm hardwood layer,
B = Hardwood nosing,
C = MDF core,
D = Routed rebate for top of riser
P = Pencil round or chamfer to take the arris off the nosing.


--
Cheers,

John.

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