No need for a square hole at all: make the tool 1/2” longer and cross drill for a Tommy bar.
Like this:
Like this:
...... except that the shaper drills very poor holes.No need for a square hole at all: make the tool 1/2” longer and cross drill for a Tommy bar.
Like this:
View attachment 62195
You are not wrong there…...... except that the shaper drills very poor holes.![]()
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I agree - maybe it’s time for you to make rotary broach - just saying
No need for a square hole at all: make the tool 1/2” longer and cross drill for a Tommy bar.
Back when I (and you) was very much younger, Kent-Moore (a division of GM) would sell OEM special tools & manuals to anyone who had the money (pots of it) to buy them.Yes, that method was discussed in post 13 and 14. It's the easiest solution by a very wide margin. 50 bucks isn't bad at all compared to the OEM Volvo tool. I am surprised to see it for sale though.
Back when I (and you) was very much younger, Kent-Moore (a division of GM) would sell OEM special tools & manuals to anyone who had the money (pots of it) to buy them.
Special tools! LOL! Ever been around airplanes? Pretty sure, based on my long contact, that there was some clown in a back room, designing effed up tools, then issuing out the drawings requiring that the guys on the shop floor design their parts around the mangled and welded remains of a half dozen Snap-On wrenches!Early in life, I learned that public libraries got a special deal on hardcover copies of manuals. If you spilled coffee in them you had to pay a very fair price for a new copy and got to keep the old one.
I also learned that the dealers would let you visit their shops and inspect their special tools. That's how I became interested in drafting. I also made a lot of special tools for myself and my friends back in those days.
Further drifting . . .Special tools! LOL! Ever been around airplanes? Pretty sure, based on my long contact, that there was some clown in a back room, designing effed up tools, then issuing out the drawings requiring that the guys on the shop floor design their parts around the mangled and welded remains of a half dozen Snap-On wrenches!
And, while I say that tongue in cheek, I'm not entirely sure I am not wrong!
Gotta say, Public Libraries, and esp., the Inter-Library loan system, were some of the few things that I thought I got my Property Tax dollars, out of!
I frequently got Inter-Library loan books that were out of Reference libraries, from places like Sandia National Laboratories, or NASA, as well as from several University Libraries around the Excited States, and most of those were books that, If you were a Local, you were not allowed out of the building with! Such a GREAT way to preview the books you want to buy, to see if they actually fit the need you think they might!
Only recently Apple started publishing manuals and lending out special tools so anyone can make repairs (have to pay a hefty deposit & shipping costs, and there are penalties if you don't send them back on time). All thanks to the Right to Repair movement.Early in life, I learned that public libraries got a special deal on hardcover copies of manuals. If you spilled coffee in them you had to pay a very fair price for a new copy and got to keep the old one.
I also learned that the dealers would let you visit their shops and inspect their special tools. That's how I became interested in drafting. I also made a lot of special tools for myself and my friends back in those days.
Microfiche. LOL! Very familiar! The parts catalog for one of the aircraft I worked on at the beginning of my career was all on fiche pages. Grumman CS2-F, Tracker, aka, the Stoof.Further drifting . . .
Back when I was consulting I made regular trips to the State Library of Pennsylvania (think of it as a miniature Library of Congress): they had reference material other libraries didn't, but you had to go there to borrow or review. This was back in the 90's, so online resources were limited, although I think you could search their catalog once you were registered. I forget what the topic was but on one visit I had to use a book support and wear white gloves.
I still have my card (and that rom the local Penn State campus), but probably need to get it updated. I also still have the Microfiche that they copied for me and an operating fiche reader.
I have the square 1/4” one
now to fill in, all we need is the 3/8 and 1/2![]()
You drill a round hole, smaller than the square will become.I'll try and get the 1/2. Then all we need is someone to get the 3/8, and we will be a foursome!
We could just ship back and forth as needed!
Question - how does a square broach work? One edge at a time with a wedge, or all 4 corners at once? Or?
All four corners are cut at the same time, as the broach has a series of increasing sized teeth, each taking a larger cut out of the hole.
Smaller than the corners, but not smaller than the flats; for a 1/2" making the hole one drill size, 33/64", 17/32" or 35/64" (even 9/16" would work, it's not an everyday tool) to lower the cutting forces:You drill a round hole, smaller than the square will become.