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Sometimes you need a square hole and can't wait

whateg01

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Had to make some 11mm square holes for carriage bolts for a customer. A little time at the mill and the lathe and the welding bench and this thing worked a treat. A broach would have done the job but no time to wait for one in a size I might never use again.

20250228_220300.jpg

20250228_220316.jpg

The one on the right was the sample part.
20250228_215625.jpg
 
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whateg01

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Saves a lot of filing! You just press that through? Looks like a nice clean hole.
Yeah, drilled a 7/16" hole then pressed it. I was curious how much force it took but every hole I forgot to look at the pressure gauge. I might do another just to look at that. I'm curious if I could have done it in the arbor press.
 

gba2331

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For our HS robotics team, we use sprockets on a hex shaft but I always wondered how they made a hex hole - do you think they could have punched this as well, or is it from an extruded blank that is machined?

IMG_2927.jpegIMG_2928.jpeg
 

Hohn

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For our HS robotics team, we use sprockets on a hex shaft but I always wondered how they made a hex hole - do you think they could have punched this as well, or is it from an extruded blank that is machined?

IMG_2927.jpegIMG_2928.jpeg
You can grind that ID if you have sophisticated enough machines, but typically it's broached.
 

Citation

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For our HS robotics team, we use sprockets on a hex shaft but I always wondered how they made a hex hole - do you think they could have punched this as well, or is it from an extruded blank that is machined?

IMG_2927.jpegIMG_2928.jpeg
I agree with those who suggest broaching. Basic broaches aren't too expensive.
 
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whateg01

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For our HS robotics team, we use sprockets on a hex shaft but I always wondered how they made a hex hole - do you think they could have punched this as well, or is it from an extruded blank that is machined?

IMG_2927.jpegIMG_2928.jpeg
Can't tell what material that is but for robotics, it could be aluminum. If so, it's very possible for it to be an extrusion.
 

gba2331

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Can't tell what material that is but for robotics, it could be aluminum. If so, it's very possible for it to be an extrusion.
That was my thought also, but that leaves a lot of material to be removed to make the gear.
 
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RoninB4

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By my way of thinking, there's no way those work, but they do (once again, no one seems to care what I think). Needs a mill or hell-for-stout DP.
-I had my doubts about them too until I used one, I was delighted for the rest of the day. There's enough info about rotary broaching, including specs, to make one yourself. There's limits but any number of flats between 2-6 are attainable for a reasonably equipped home shop IIRC.

"once again, no one seems to care what I think"
-Maybe but I still read your posts before deciding. :badteeth:
 

Beerhippie

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-I had my doubts about them too until I used one, I was delighted for the rest of the day. There's enough info about rotary broaching, including specs, to make one yourself. There's limits but any number of flats between 2-6 are attainable for a reasonably equipped home shop IIRC.

"once again, no one seems to care what I think"
-Maybe but I still read your posts before deciding. :badteeth:
I've seen videos--maybe This Old Tony?--of folks making them. I don't have the tooling to make or use one, but do have the occasional need for one, which is why I have some small files and a modicum of patience.
 

RoninB4

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I've seen videos--maybe This Old Tony?--of folks making them. I don't have the tooling to make or use one, but do have the occasional need for one, which is why I have some small files and a modicum of patience.
-I did post that a "reasonably equipped" home shop should be able to make one but I guess that I have a rather skewed notion of what "reasonable" is or should be for others. My opinion doesn't always count either.
 

RoninB4

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but do have the occasional need for one, which is why I have some small files and a modicum of patience.
-If the material is shim stock (.025 or less) there's a small, inexpensive, hand held shear for internal hole shapes I could suggest. Won't work for thicker material but for thinner material it's much faster than files and can cut relatively sharp corners from a hole as small as 7/16" IIRC. Thought you (or somebody) might want to know.
 

cannuck

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That guy is going to be hard on quill bearings.
IMHO it is very inappropriate to call this "drilling" as most larger drill presses use Morse taper quills - without a pull-in bolt - so no way to use with side loads. Smaller presses that use a screw-on chuck don't have enough quill rigidity or tight enough fit to cut accurately. You also would need to chuck it up in an indexing boring head. This is a milling operation (and even then you would need a good one). Not to deny, though, this is a ****** brilliant bit of tooling.
 

IndyGarage

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My plasma table is down until I get the pi setup to run it tired of constantly replacing the Dell computers I've been using.
I don't have a table. I just bought a set of templates for round holes, square holes and oval holes - you just mark the location clamp the template on and cut the square.
 

Beerhippie

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I don't have a table. I just bought a set of templates for round holes, square holes and oval holes - you just mark the location clamp the template on and cut the square.
Do you have a link for those? Do they come in different offsets for different drag points?
 

T444e

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Had to make some 11mm square holes for carriage bolts for a customer. A little time at the mill and the lathe and the welding bench and this thing worked a treat. A broach would have done the job but no time to wait for one in a size I might never use again.

20250228_220300.jpg

20250228_220316.jpg

The one on the right was the sample part.
20250228_215625.jpg
I have a project I'm working on and need square holes for a number 10 carriage bolts. I'm using a HSS square blank a that I ground a taper on and slitted the corners to make a broach to use in the arbor press. Proof of concept worked. However, my transfering of hole locations to the steel I need to broach was a failure. I realized to get back on the project and have a better method of hole layout to try.
 
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whateg01

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doo dah, kansas, usa
I have a project I'm working on and need square holes for a number 10 carriage bolts. I'm using a HSS square blank a that I ground a taper on and slitted the corners to make a broach to use in the arbor press. Proof of concept worked. However, my transfering of hole locations to the steel I need to broach was a failure. I realized to get back on the project and have a better method of hole layout to try.
I made the rounds part just a little longer than the thickness of the part so it registers the location. Getting the square punch and die clocked correctly made me a little nervous, but on the one hope where it moved and was way off, it just pinched a thin layer of metal between them so no harm was done.
 
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