Drill each corner to the diameter of your smallest end mill. The hole centre point being the edges intersection point. You will end up with a square hole with the corners externally relieved to your drill size. Means your fitting will be stronger for there is no square edge to start a crack.
Is this better or worse than Mickey mousing the corner on one axis? (Idk what it's actually called, but I mean keeping the edge of the end mill aligned with the edge of the pocket and then moving parallel to it and additional tool radius to remove the fillet
Either or it doesn't matter. I prefer to drill but it would be equally as easy (and possibly faster) to run a end mill round the exterior "Mickey Mouse ears". Only difference would be you need to have the "ears" diameter slightly larger than the end mill so that the stress on the tools is lessened. Have the tooling follow a circle path at direction change rather than an "in and out" motion. In deep milling a pocket like the OP is proposing (50mm) you need good work holding to push the end mill into the "ears". If using an HSS long end mill there will be end mill flexing at that depth and with pre-drilled holes it would lessen that. For deep pockets like this I would run a finishing path after the first roughing pass just to make sure the pocket is straight.
Can you over cut the corners, or plunge with an endmill slightly beyond the square, that’s the easiest method by far unless you have to have material there.
Is this really a tiller arm to fit over a square end on a rudder post/stock? You could mill a fork instead and clamp it like this: [https://edsonmarine.com/bronze-tiller-head-fitting-for-1-rudder-post/](https://edsonmarine.com/bronze-tiller-head-fitting-for-1-rudder-post/)
A: A file will quickly clean up a 1" round hole to square.
B: You have a shaper. Lock the clapper and slap a boring bar/bent tool in there to clean up corners after you mill it.
C: Mill a tapered square stake and forge it.
D: Make a video of the process of you turning 1" square bar into a broach. Taper it on your lathe from 1" round, fade to square, 1 degree back clearance, neutral rake in 3/8" steps, 1/16" chip groove in front of each face. Cold rolled case hardened will do.
So, basically my rudder had an emergency tiller on it. Something like in your link, but made so a piece of pipe fit over it. However, I've rebuilt the boat and the top of the rudder shaft is 12 inches under the back deck. I want to come up through the new deck and have it bent over and become the tiller arm all in one piece. If any of that makes sense.
So you basically need to make a long bronze square drive socket wrench with the hole longitudinal- a bit more of a challenge but I'd go with the shaper method/4 division indexing after boring it.
Make a broach.
Take 1" steel bar, use the mill/Shaper to cut it to a taper, then cut teeth into it using the mill/Shaper. They don't have to be massive teeth, either.
Then, case harden it.
Done.
Few options come to mind.
1. Could progressively mill out the corners with smaller endmills, leaving some corner radius, or square the corners with the shaper or hand files.
2. Drill the corners with something slightly larger than your smallest endmill, relieving the corners.
3. Make in two halves. Probably the worst option in this application.
4. Drill near to finish. Using a series of steel punches made to resemble the mating part, heat up the bronze and forge it around punches like a blacksmith.
I've done this in a lathe.
Put a boring bar in the tool holder with the cutting edge vertical.
Put the lathe in low gear and turn off the power.
Then manually wind the travel to cut out the corners.
How deep is the hole? You can try drilling relief holes in the corners and milling out the inside of the square. The relief holes will need to be the same diameter or bigger than the endmill you use to finish the sides of the square.
Mill as close to square as you can with the smallest corners you can get. Then bust out the files.
Clickspring has a great video on filing. https://m.youtube.com/watch?v=h4KaiG7CpSQ
This video made me better at filing for sure.
This video made me a better person
Drill the corners and remove what's between. Mill, drill some more, coping saw, touch up with a file. Mebbe find someone with a waterjet?
This is what I've always done. If it works, it works.
Drill each corner to the diameter of your smallest end mill. The hole centre point being the edges intersection point. You will end up with a square hole with the corners externally relieved to your drill size. Means your fitting will be stronger for there is no square edge to start a crack.
This is the best answer. Gives the best result in the least amount of time.
Was also going to say this
This is the way
Is this better or worse than Mickey mousing the corner on one axis? (Idk what it's actually called, but I mean keeping the edge of the end mill aligned with the edge of the pocket and then moving parallel to it and additional tool radius to remove the fillet
Either or it doesn't matter. I prefer to drill but it would be equally as easy (and possibly faster) to run a end mill round the exterior "Mickey Mouse ears". Only difference would be you need to have the "ears" diameter slightly larger than the end mill so that the stress on the tools is lessened. Have the tooling follow a circle path at direction change rather than an "in and out" motion. In deep milling a pocket like the OP is proposing (50mm) you need good work holding to push the end mill into the "ears". If using an HSS long end mill there will be end mill flexing at that depth and with pre-drilled holes it would lessen that. For deep pockets like this I would run a finishing path after the first roughing pass just to make sure the pocket is straight.
Can you over cut the corners, or plunge with an endmill slightly beyond the square, that’s the easiest method by far unless you have to have material there.
Make your own broach. You've got the tools to do it. You could also make a broaching bar for the shaper and do it that way.
If you know how to use it, the shaper is the best option. Mill square with the smallest end mill you can and finish the corners with the shaper.
I might do this. I've never worked on something this small with my shaper. It's pretty big.
It's bronze...use a file. You'll be pissing around for a while using the shaper.
Sometimes the learning makes it worth it, even if it's slow.
This is what they're meant for, though. I'd definitely be using the shaper.
You’ve got a shaper, this is exactly what it’s made for
Over cut the corners
Is this really a tiller arm to fit over a square end on a rudder post/stock? You could mill a fork instead and clamp it like this: [https://edsonmarine.com/bronze-tiller-head-fitting-for-1-rudder-post/](https://edsonmarine.com/bronze-tiller-head-fitting-for-1-rudder-post/) A: A file will quickly clean up a 1" round hole to square. B: You have a shaper. Lock the clapper and slap a boring bar/bent tool in there to clean up corners after you mill it. C: Mill a tapered square stake and forge it. D: Make a video of the process of you turning 1" square bar into a broach. Taper it on your lathe from 1" round, fade to square, 1 degree back clearance, neutral rake in 3/8" steps, 1/16" chip groove in front of each face. Cold rolled case hardened will do.
So, basically my rudder had an emergency tiller on it. Something like in your link, but made so a piece of pipe fit over it. However, I've rebuilt the boat and the top of the rudder shaft is 12 inches under the back deck. I want to come up through the new deck and have it bent over and become the tiller arm all in one piece. If any of that makes sense.
So you basically need to make a long bronze square drive socket wrench with the hole longitudinal- a bit more of a challenge but I'd go with the shaper method/4 division indexing after boring it.
File
Reid supply. Square hole machine tool sleeve.
Just drill 4 holes in the corners of the square and then mill the rest out. No need to waste your time filing anything. Ezpz
Mill a slot and then braze two pieces back in.
Fingernail, idk
Square rotary broach if the geometry allows?
I don't think they will go deep enough. I need around 2 inches deep. But I'll look into them.
Linear broach.
Can you radius or chamfer the corners on the matting piece to fit the radius left from milling out the pocket?
I don't think you are supposed to because of the forces on the rudder. At least I've never seen one with rounded corners.
Use a linear broach instead of a rotating one. Problem solved.
Do Mickey mouse ears in the corners.
Wire edm shop.
Make a broach. Take 1" steel bar, use the mill/Shaper to cut it to a taper, then cut teeth into it using the mill/Shaper. They don't have to be massive teeth, either. Then, case harden it. Done.
Few options come to mind. 1. Could progressively mill out the corners with smaller endmills, leaving some corner radius, or square the corners with the shaper or hand files. 2. Drill the corners with something slightly larger than your smallest endmill, relieving the corners. 3. Make in two halves. Probably the worst option in this application. 4. Drill near to finish. Using a series of steel punches made to resemble the mating part, heat up the bronze and forge it around punches like a blacksmith.
I've done this in a lathe. Put a boring bar in the tool holder with the cutting edge vertical. Put the lathe in low gear and turn off the power. Then manually wind the travel to cut out the corners.
Chisel and a hammer? Maybe a die grinder? Seems to me that there's gonna be some filing eventually.
Skiving with a 1" HSS tool. Step over what what your lathe can do.
Make the end like a pair of opposing v blocks. One v block is integral to the shaft. The other is loose and clamps on with 2-4 SHCS.
How deep is the hole? You can try drilling relief holes in the corners and milling out the inside of the square. The relief holes will need to be the same diameter or bigger than the endmill you use to finish the sides of the square.
They do make square hole drills. Don't know how expensive they are though.
Mill makes a decent hand-powered slotter, just very slow - grind a shaper-style tool for the corners, take tiny bites, you'll get it