Slitting saw on BRONZE PLANE MOUTH Need Some Insight on HOW YOU WOULD DO THIS? pics!

Okay so to give you and idea of what I am trying to do I'll start out with what I have, before starting....a sandcast Bronze woodworking plane body. No cores so no undercuts, just sand and a pattern board. From there I start by face milling the bottom of the cast plane. Then I can use the bottom as a plane of reference while I jig it up and use a "Key-slot cutter" or "Slotting saw" from above to put the grooves in the sides and mouth from the inside of the plane (for the the blade). I got a slotting saw the right width and thickness for the blades specs. They only issue is that the Key-Slot cutter/saw obviously cannot go all the way through, you'll max out and the shank will hit going at it from above inside the plane. So you HAVE to finish it by removing quite A LOT of bronze out of the edges of the mouth by hand with a file. (As the saw does go through the middle of the mouth but obviously its radius and shank maxing out prevents the mouth's SIDES from being cut.\

Here are some photos of the plane and how far I've gotten, using the method above, however taking out all the material on the edges of the mouth by hand with a file takes FOREVER. I need to figure out a better way to square up the mouth slot edges (sides) that receives the plane blade through the sole.

IS THERE A BETTER WAY TO DO THIS? WHAT WOULD YOU DO?


Here is a top photo of the plane you can see the work marks from the slotting saw


Here is a straight on photo of the planes mouth from the top of the plane



This is the bottom of the plane, looking at the mouth


Thanks ahead of time guys, I have scoured these forums for ages now and 9 times out of 10 I can find the answer without having to post. First time for everything!Please stay on topic as I need to resolved this issue.

The proper way to do it is by using a broach. That's how GEWA used to make them.

It could be set up on a shaper with a specially made tool. Picture a parting tool being pushed endwise.

a Bridgeport with a Quillnaster attachment could cut the groove but it would be round-bottomed needing to be squared up with a file.

Do you mean like a broach?

I just saw this...that was MY VERY FIRST INSTINCT to think "Broach". I'll have to look around might have to make my own custom one if I plan on making these!

Prof_Bronzini said:

I just saw this...that was MY VERY FIRST INSTINCT to think "Broach". I'll have to look around might have to make my own custom one if I plan on making these!

Click to expand...

Making broaches is a well established business - I don't see a problem having one made. It won't be cheap though. And you'll have to pull it through the initial opening. Depending what you're going to use the planes for, the mouth must be very narrow and the path of the shavings well thought out - they tend to clog badly. The IBEX ones, I mean.

Yep. Make a broach and be done in seconds.

Thanks guys! That's what I was thinking...Broach it is! Could anyone recommend a good place to catch an estimate? I'm expecting to not be happy once I hear the price but hey after I try to make my own and fail I won't mind forking out the cash!!!

Prof_Bronzini said:

Thanks guys! That's what I was thinking...Broach it is! Could anyone recommend a good place to catch an estimate? I'm expecting to not be happy once I hear the price but hey after I try to make my own and fail I won't mind forking out the cash!!!

Click to expand...

Bronze works well with just about every casting method known to mankind.

If the goal is to make "many", not just one or few, I'd first move off sand casting to something that gave a finer finish overall and a closer fit to "final" so there was less metal to be removed. Speaking of fairly economical "investment" casting, eg: lost wax or lost foam, not of precision pre$$ure die ca$ting in metal mold$.

Not only would the broaching process be easier, so, too all other finish machining.

2CW

Maybe the guy who makes lose wax casting using ice instead of wax will chime in here. I agree that a broach for production is best. I do not understand why a really long endmill would not work. Then file or broach the corners.
Bill D

Bill D said:

I do not understand why a really long endmill would not work. Then file or broach the corners.
Bill D

Click to expand...

The entire trick with planes is to have at least the bottom of the mouth perfectly flat where it touches the blade. Often, one glues a piece of paper there , and beds the blade in it with a touch of moisture. The idea is to kill any vibrations of the blade. Wood does that by itself and that's the reason wooden planes feel so smooth sometimes.

Monarchist said:

Bronze works well with just about every casting method known to mankind.

If the goal is to make "many", not just one or few, I'd first move off sand casting to something that gave a finer finish overall and a closer fit to "final" so there was less metal to be removed. Speaking of fairly economical "investment" casting, eg: lost wax or lost foam, not of precision pre$$ure die ca$ting in metal mold$.

Not only would the broaching process be easier, so, too all other finish machining.

2CW

Click to expand...

Hey I do have the wax molds and have done ceramic shell with them in the past but the only problem is all the extra time involved. making waxes, touching them up making a tree burning them out not cracking the shell ect...then the extra materials...ect. With sand aka petrobond I get some VERY good detail consistently with a pattern board as fast as I can ram up a flask which is really convenient. Considering a broach is a pretty fast and simple solution to creating a proper mouth I think I am going to try that route. Thanks for the suggestion though!

I'm searching for custom broach makers seems like its a specialty kind of thing. i'm also going to buy some flat 3/32" thick tool steel and see if I can grind a very primitive broaching pattern out of it, harden it, try it. I want to try it out so I'm going to! hah

AlexO said:

The entire trick with planes is to have at least the bottom of the mouth perfectly flat where it touches the blade. Often, one glues a piece of paper there , and beds the blade in it with a touch of moisture. The idea is to kill any vibrations of the blade. Wood does that by itself and that's the reason wooden planes feel so smooth sometimes.

Click to expand...

Yeah I'd need a 3/32" end mill that has well over an inch of cutting to do in the bronze to get through the whole body of the plans mouth. I thought of that but my brain is telling me that's going to deflect....really badly? Right? .....and that's not going to suffice unfortunately.

Prof_Bronzini said:

Hey I do have the wax molds and have done ceramic shell with them in the past but the only problem is all the extra time involved. making waxes, touching them up making a tree burning them out not cracking the shell ect...then the extra materials...ect. With sand aka petrobond I get some VERY good detail consistently with a pattern board as fast as I can ram up a flask which is really convenient. Considering a broach is a pretty fast and simple solution to creating a proper mouth I think I am going to try that route. Thanks for the suggestion though!

I'm searching for custom broach makers seems like its a specialty kind of thing. i'm also going to buy some flat 3/32" thick tool steel and see if I can grind a very primitive broaching pattern out of it, harden it, try it. I want to try it out so I'm going to! hah

Click to expand...

Meah.. I happen to have both a shaper and a slotter, but still. I have a hard time seeing the benefit of labour-intensive "vanilla" planes, regardless of what they are made of, or how finished. The value-add just doesn't pass through in all that obvious a manner.

Now.. if craftsmanship is the selling "hook"?

See the genuine art-forms - not just functional planes - that one of our PM members has made with Bronze "loops" at the shoe.

I am not trying to rain on anyone's parade, I just want to learn. He already has finished most of the surfaces that the blade will sit on and he needs to finish this opening to the same plane. So I have to ask, how do you ensure that the broach follows that, already established plane, and not get diverted sideways or up by some unequal amounts of metal left by the casting process? Would the broach use that already established plane for guidance? Or what?

I am just trying to understand the process here.

AlexO said:

The proper way to do it is by using a broach. That's how GEWA used to make them.

Click to expand...

Paging Stephen Thomas.....

Im...fairly confused....I don't know what a vanilla plane is or does that refer to fancy planes? I am working on some fairly decorative museum grade pieces. This isn't one of them ;-)


Okay.....


Yes


Yes the broach will only function to widen the narrow slit that the slitting saw was able to make, no metal will need to be removed from top and bottom in my case so a small 3/32" thick slit opening is cut through to the bottom of the plane mouth however wide the circular cutter can manage before the shank hits on the inside (as the circular saw is making a narrower slit on the bottom of the plane as opposed to the inside of the plane due to its circular shape) Anyways the broach will be centered via the small bit of a notch that the the slitting saw was able to passthrough. Then as you press the broach will remove the same amount of metal on each side from that centered point. There needs to be a small amount of wiggle room in my application so the end user can square up the plane blade by hand using lateral adjustment and then lock it in.

Monarchist said:

Meah.. I happen to have both a shaper and a slotter, but still. I have a hard time seeing the benefit of labour-intensive "vanilla" planes, regardless of what they are made of, or how finished. The value-add just doesn't pass through in all that obvious a manner.

Now.. if craftsmanship is the selling "hook"?

See the genuine art-forms - not just functional planes - that one of our PM members has made with Bronze "loops" at the shoe.

Click to expand...

There is a market for horribly over-engineered planes. Infill lignum vitae soles, 1/4" thick blades, powder metallurgy steels, the whole shebang. In my rather vast experience they're all rubbish and the couple of $Ks price makes sure they end up in the hands of people who simply can't tell. A win-win.

When it comes to the small concave/convex/flat "finger planes" as this one here seems to be, I have NEVER seen one where the blade angle was USABLE.

Bit like machine tools : one often wonders who was the ( German ) moron who designed the crap and why.

digger doug said:

Paging Stephen Thomas.....

Click to expand...

This is a most excellent suggestion and one that I was going to post. SMT , the moderator at the woodworking forum here has vast experience building and tuning hand planes! If you post a question there you may get advice from additional members besides Stephen also.
Joe

Prof_Bronzini said:

Im...fairly confused....I don't know what a vanilla plane is or does that refer to fancy planes? I am working on some fairly decorative museum grade pieces. This isn't one of them ;-)

Click to expand...

Clearly not. P'rhaps I should have called it "white bread"?

Yes the broach will only function to widen the narrow slit that the slitting saw was able to make, no metal will need to be removed from top and bottom in my case so a small 3/32" thick slit opening is cut through to the bottom of the plane mouth however wide the circular cutter can manage before the shank hits on the inside (as the circular saw is making a narrower slit on the bottom of the plane as opposed to the inside of the plane due to its circular shape)

Click to expand...

Not sure I grok the choice of slitting saw.

First-time-ever I had that sort of requirement, 1959, tapered hole for the handle of a 250 gram German-pattern toolmaker's "layout" hammer, I was taught - BY the German - to "chain" drill it first, finish with a shaper tool, then files.

Still use it today. 50+ year aged Cherrywood handle now around a hundred years since the tree was cut has needed tightening exactly ONCE since it was made, so...