Infill Design Issue

[Glen C]

There seems to be considerable interest in infills in Canada and the U.S. these days.

One infill design issue that I'm curious about is the need for the beveled plate behind the plane throat. I've always thought this was important, but have heard that it isn't needed if the sole of the infill is 1/4" or thicker.

Here is a photo of the proposed Holtey showing the part I’m referring to.

I'm looking forward to hearing the opinions of the folks on this forum.

 

[bugbear]

One infill design issue that I'm curious about is the need for the beveled plate behind the plane throat. I've always thought this was important, but have heard that it isn't needed if the sole of the infill is 1/4" or thicker.

As a data point, it was present in the Shepherd design, and (IIRC) their design was closely based on original Spiers.

BugBear

 

[Glen C]

As a data point, it was present in the Shepherd design, and (IIRC) their design was closely based on original Spiers.

BugBear

Yes, both the Spiers and Shepherd had this design feature. I'm not sure about other infill makers, but it seems like a good idea.

 

[Ian Dalziel]

Hi Glen,
we call it a frog......

without the addition of the frog in this case the backside of the blade wouldn't reach the sole due to the bevel of the 3/16" blade.

infills are bevel down ...do you see what i mean

Ian

 

[Glen C]

Thanks, Ian.

Sorry ... my original post wasn't very clear.

I believe that proponents of removing the metal frog feel that a wooden infill can support the chipbreaker/iron just as well. In essence, the infill would go right down to the plane sole and replace the support provided by the metal frog.

What do you think?

 

[Ian Dalziel]

Glen,
wood is natural and moves over time.
The frog plays an important role in the fuction of a plane.... any plane....it has got to be flat and even across its width. some infills will use the wood as support others you will see 2 upper buttons. the tripod method. or 3 point support. old planes dont have this but still function very well because they have a frog plate for support that hasnt moved over time.

depending on wood type used... age..... if its old growth or not the extra frog plate just makes it that bit more stable.

hope this helps


Ian

 

[Glen C]

Thanks again, Ian.

I see your point about wood moving. Plus, it would be hard to secure the wooden infill (no matter how stable) as firmly as a metal plate peened to the plane sole.

Is the tripod method you mentioned used on infills? If so, I'm hoping someone can point me to an example.

 

[Ian Dalziel]

here you go

Ian

 

[GEPPETTO]

Hi Ian, excuse me one question...

the adjuster.. are the threads of the main rod the same of the threads of the ring rod? Are they in opposite direction? I thought that the ring which captures the head screw of the capiron would be been free with a sort of rivet :roll: . That is the Norris Adjuster, isn't it?

Cheers
Gabriele

 

[Ian Dalziel]

Geppeto,
original Norris adjusters were similar but the smaller thread was LH.
The larger thread is RH and with one turn of the adjuster it was very coarse movement with a fair bit of backlash.

With this adjuster they are both RH threads the larger is 26tpi BSBrass thread and the smaller is finer...cant remember off hand but i think its a 40tpi if its not then its 32tpi ME thread. When you turn this adjuster it then moves the difference betwen the 2 threads in this case i think about 8 thou at a time...a lot finer with backlash almost eliminated.
I am actually needing to remeasure its movement but its in this region

Ian

 

[GEPPETTO]

Geppeto,
original Norris adjusters were similar but the smaller thread was LH.
The larger thread is RH and with one turn of the adjuster it was very coarse movement with a fair bit of backlash.

With this adjuster they are both RH threads the larger is 26tpi BSBrass thread and the smaller is finer...cant remember off hand but i think its a 40tpi if its not then its 32tpi ME thread. When you turn this adjuster it then moves the difference betwen the 2 threads in this case i think about 8 thou at a time...a lot finer with backlash almost eliminated.
I am actually needing to remeasure its movement but its in this region

Ian

Hi Ian, thanks for the quick answer but... excuse again :roll: if the main threads is 26tpi and the second threads is 32tpi.... would it have to be 32-26= 4tpi at every turn? This only to comprise...Excuse me but I'm not an engineer and the day is going to the end :lol: :roll: ..or.. I knew I eaten too much

Cheers
Gabriele

 

[Nick W]

Gabriele,

What you get is (1/26)" - (1/32)" per turn, which comes out at around 0.0072" per turn (if I've done my sums right 8-[ ).

 

[GEPPETTO]

Gabriele,

What you get is (1/26)" - (1/32)" per turn, which comes out at around 0.0072" per turn (if I've done my sums right 8-[ ).

uuhmm . Right Nick... I don't know what sort of calculation I done . OK. I have understood, now :roll: (repeat..I knew I eaten too much :roll: )

Cheers
Gabriele

 

[Glen C]

Ian ....

In your picture of the infill with the Norris-type adjuster and the two upper buttons, does this plane have a metal frog peened to the base or some other arrangement? (It's a beautiful-looking plane, by the way). Also, is this a common design for Norris and Norris-type infill planes?

Thanks for your help and patience.

Glen

 

[Ian Dalziel]

Glen,
The plane in the photo has a frog plate.
Both pictures are of a Holtey A13 one is in kit form one is built

some norris planes have adjusters some dont....depends on the original purchaser at the time if he wanted an adjuster.
The buttons are not common to norris

Ian

 

[MikeW]

fwiw, neither the Preston I sold nor my unknown-maker infill has this frog piece.

The Preston was a wonderful infill. Never had a movement issue that I could tell. So I think Steve's idea isn't an untried one. But the devil is in the details, including what type of wood and how dry/stable it is that he uses for the infill, aside from build quality issues.

I personally like this Spiers/Holtey method as it would seem to provide a more stable base in the eventuality of any movement. That is, if it were ever to occur. Like I said, my Preston was fine for the years I owned it.

The unknown maker's infill will be restored without an added frog. I'll be using Mahogany that has been in my storehouse for 20 years. I think it's pretty stable by now...

Take care, Mike

 

[Glen C]

Thanks Ian and Mike.

You provided the information that I had hoped for, plus sparked a whole new set of infill plane design questions and issues to pursue. It's an interesting subject.