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NPW_BESPOKE
25-01-2018, 09:10 PM
Hi

I have a stair construction job coming up and want to run the tread and riser housings out on my machine. They are relatively short flights and will fit on my machine bed no problem.

I use vetric V-carve pro as my drawing/machining software and am pretty confident I can draw up the vectors.

I guess my question is more related to the tooling... Stair housing cutters are 'dovetail' in shape (normally 7 degrees?) How would I go about set up as the cutters geometry is wider at the bottom than at the top of the shank.

I also guess this questions extends to any cutters with geometry that is wider at the bottom than at the top and is being plunged passed the material surface?

Just wondering what that meant when it came to toolpathing?

Thanks in advance for any replies

all the best
Nicko

battwell
25-01-2018, 09:31 PM
ive done them- but use straight cutters- and wedge from behind as normal
easiest way is set as single pass (a must with dovetail cutters- and ensuring the plunge is behind the tread- dont want a bigger circle showing)
id set up as a pocket toolpath at depth required . eg 20mm
measure your cutter diameter roughly at 20mm up from bottom with a caliper (or work out with trig if your real fussy)
use that diameter as your tool diameter.
now test the cut on a sample piece. offer up the tread and see the fit- either too tight or too loose .
adjust the toolpath allowance setting + or- to suit and re calculate.
test again- adjust as necessary and your ready to go.
might seem an odd way to do it- but thick timber can be expensive to mess up!

or start - make the pocket smaller by say 3mm. when checking fit - if say too tight by 5mm offset the vector out 2.5mm and just do an inside profile cut to that vector

battwell
25-01-2018, 09:35 PM
ensure in preview that tool enters and exits in correct place- use a lead in/out if required and node edit to move start point to where is best too.

NPW_BESPOKE
27-01-2018, 08:13 PM
Thats great advice thanks

Confirms what I was roughly thinking of as a method... yes lots of testing before I run out of actual material!

cheers for your help I really appreciate it
all the best Nicko