Thread: Cutting the mouth for an infill plane.

G'day Ian. I've just done a search for infills on this site and found your thread about the coffin infill that you made. Lovely! Having seen the she oak, I'm convinced and I'll have a look when I'm out at Trend Timbers next week. I'd like to get the wood for the infill ASAP and let it season a bit more before I start shaping it. Stability is the most important requirement for me, but as this is hopefully to be a bit of a showpiece I'm also looking at appearance and would really prefer an Australian timber. I just love birdseye maple though.
A member of another forum has very generously offered to machine the mouth for me but I'll be making a charitable donation in lieu of payment. I've brushed all the dust off my drawing board, sharpened my pencils and I'm going to make a full size pattern from scrap ply as well.
It's becoming quite a team effort now.

Hi Steve, yeah, it turned out ok, but gave me a few heart-stoping moments along the way. The two main 'blunders were that the left side wall at the toe got a little out of perpendicular (pinched in) during peining, probably because the block I made to clamp it to during hammering didn't match perfectly. It demonstrated how solid double-dovetailed joints are, & there is no way I could straighten it even that tiny amount without applying dangerously excessive force, so I just had to live with it. It complicated fitting the front bun, & lots of careful filing & fitting & re-fitting & the odd expletive was required. I was left with a teeny gap towards the bottom of the left side, so I bedded it in epoxy before riveting. It's not noticeable, & even I don't see it now.

My other blunder involved fitting the lever cap. How to accurately mark out & drill two symmetrically-placed holes on two curved surfaces had me standing on my head more than once! In the event, I got the lever cap pivot holes slightly out of whack, which meant the lever cap had a few thou gap between it & the cap iron on one side. That was fixed by filing the end of the lever cap until it fitted evenly, which took but a few minutes. Again, you can't see it on a cursory inspection, but it annoyed the heck out of me that it was off a bit.

I think it served me right for tackling a curved-sided design as my first project, though it did turn out looking pretty convincing, and is certainly very solid & works as well as I could wish. I have a couple more D/T planes planned in the next few years, and both will be straight-sided, so here's hoping my experience with #1 and a more simple design will make the build will go more smoothly than for my first try.....

Cheers,

Originally Posted by IanW

How to accurately mark out & drill two symmetrically-placed holes on two curved surfaces

I have an idea that someone said they had made a wooden 'shoe' to fit around the plane, marked the central axis and planed the sides square so that it could be drilled on a drill press. (??)
Cheers,
Paul

What I am thinking of doing is using double sided tape to fix the two cheeks together before dovetailing and drilling straight through both at the same time. Quite a few people have mentioned the difficulty of drilling these holes but I haven't seen anyone do it this way. There's probably something I haven't considered here though.
I'm making a full size pattern of the sole to help with the machining of the mouth and throat and the thought occurred to me that I could without too much trouble also make patterns for the sides and while I'm at it, mock up the rest of the plane in scrap wood so I can see how it will look and fit together before I start drilling and bashing away.

Whoever made the old one I have now evidently had the same problem. The lever cap was crooked with a gap showing on one side. I carefully filed them to match and glued some abrasive paper to the back of my diamond plate to smooth the wooden bed for the blade. It's a perfect fit now, but that imbalance has probably been there for a long time. Oddly enough I couldn't detect it when I first tried the plane on arrival and it didn't seem to affect the quality of the cut that I could see.

A quick update to show some progress...the cheeks have been cut out and I'm smoothing them to a fair curve. I used a metal cutting blade in a jigsaw which was a bit slow but I cut both sides in around 20 minutes. Patterns for the sole and cheeks shown.

That sole is a SOLID lump of steel! I wouldn't like to be pushing it all day...but it's not intended for that.

The sole has been machined! The rear angle is 50 degrees and the front is 40 degrees, but I'll still have to file the front of the mouth a bit to open it to suit a 3/16" blade.
Next...cutting the dovetails. I used a jigsaw with a metal cutting blade to cut out the cheeks and I've files them to shape and smoothed them a bit. Also squared the top of the cheeks to the sides. The jigsaw will probably be OK for the brass but the steel will have to be cut with a hacksaw and files with maybe a bit of help from an angle grinder. Then I can make a peining buck and start to join the dovetails.