Actual ply thickness?

[Seiken]

Yep, if I'd checked the ply thickness before I'd started I could have made the runners for the plane the right height to work with the ply I already have.
Making up ply the right thickness is a good idea if I can find a source. That said, I have access to a decent thicknesser just up the road - is 4mm thick (x 50mm) thick enough to thickness down to on a machine or does it get tricky being thin? I've only ever used it on larger stock and no idea how it works with thinner pieces.

Yes, you'll be fine, but you'll need a false bed sitting on the bed of the machine. No machine will let the bed get that close otherwise. If you make one of these, you'll need a lip on the trailing edge to prevent the bed being pulled through the thicknesser when the work is fed in.

Check the thicknesser, some will go down to 4mm, the range on mine is specified as
Planing height: 3.2 - 152mm (I've made a few hundred louvre slats 5mm thick no problems without a false bed)

 

[Chris152]

Wiha DialMax arriving Saturday! I have a couple of kids in the house, so plenty of incomplete packs of cards to have a go with tomorrow. If that works, I'm sorted. I think a solid block would be better in the long run tho - I have my bandsaw set up pretty well at the moment (it comes and goes) so I might have a bash at cutting and planing to size by hand once I have something decent to measure it with. If not I'll have a go on my friend's machine - it's an Axminster AT129PT in case anyone knows if that'll thickness down to 4mm? Cheers.

 

[John15]

Bought some ''12''mm ply from Wickes last week for some chair seats. Got it home to find it's a shade under 11mm. It will do the job but I'm annoyed I didn't check at the shop. I guess I would have still bought it...

John

 

[PiratePete]

I had a repair to do on a plywood yacht with hull thickness of 1/2 inch. I ordered some very expensive marine ply at supposedly 12mm which turned out to be just over 11mm.
Ply thickness never seems to be what's quoted.

 

[large red]

I don't have much of an issue with ply changing in size my problem is you never know what your getting 18mm is occasionally 18mm more often it's 16mm sometimes it's 17mm and I have even had 20mm. It's like Forest Gumps chocolates.

 

[Chris152]

Waiting for the rest of the house to raise itself this morning, and knowing how late in the day deliveries come here, I decided to have a go at cutting the 4mm strip from a beech board without the new callipers to measure precisely. Straight from the bandsaw it was annoyingly just under 4mm but I found a sheet of xerox paper underneath raised it to the right height, more or less - to get this into the slot I had to apply a fair bit of pressure, but it went in with no immediate damage.

Fits perfectly both sides.
One thing I've noticed is that you can't have any lateral movement in the packing insert, that results in the stock tilting and planing not square - more non-solid packing will encourage this movement. (Obvious to most I'm sure, but to us learners not so obvious...)