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All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Engineering- Research & Development => Topic started by: shorty on May 11, 2017, 10:55:19 PM

Title: Square holes
Post by: shorty on May 11, 2017, 10:55:19 PM
How do you guys make a square hole on the cheap?
Title: Re: Square holes
Post by: dv8eod on May 12, 2017, 12:43:44 AM
In wood or metal?
Wood- drill a hole, chisel it out til square, or use a mortising bit.
Metal- drill a hole, file it out til square.
Title: Re: Square holes
Post by: shorty on May 12, 2017, 05:29:19 PM
Really loud "HAH"

Can't wait for this one. Just made my own broaching tool. Purchasing a Mrod valve tonight.

Someone always told me it's only circles and squares.
Title: Re: Square holes
Post by: Mark Davis on May 12, 2017, 09:06:35 PM
Want to tell us how you made that broaching tool?
I have wild ideas of making a hex broach out of a allen wrench.
Title: Re: Square holes
Post by: Machinist on May 12, 2017, 09:15:08 PM
I make a crude broach and chip away at in in a milling machine.  Chuck the broach up and lock the spindle from turning.  Takes a while but pretty good results. I make the broach smaller than the square desired and work my way around, doing one corner at a time.

What kind of material?  How big and how deep?

Steve
Title: Re: Square holes
Post by: shorty on May 13, 2017, 06:32:09 AM
I made a very crude internal punch broach using a 1/16" HSS turning tool bit. Works good enough for me.
Title: Re: Square holes
Post by: ^^artin on May 15, 2017, 08:14:09 PM
Something like this one ?
https://www.youtube.com/watch?v=MYI1slVGziU (https://www.youtube.com/watch?v=MYI1slVGziU)
Title: Re: Square holes
Post by: Mark Davis on May 16, 2017, 12:42:27 AM
Nice video, now just anneal a hex key...
Thanks Martin
Title: Re: Square holes
Post by: antithesis on September 23, 2019, 09:57:45 PM
Of course I found the party after it was over, house was levelled, and property redeveloped into a mini mall, but this caught my eye..

A place I worked at out of high school had a patent on a system and tooling for boring square and hex holes on a lathe. It was a very imperfect process and many corners needed cleaned on a three ton press, special guides and tooling made, and specialty sharpeners for the straight fluted drills...but it did allow holes of other than round dimension to actually be DRILLED....and holes with bottoms at that.
Title: Re: Square holes
Post by: mobilehomer on September 23, 2019, 11:30:43 PM
For wood - this.
https://www.amazon.com/Breynet-Woodworker-Mortising-Woodworking-Mortise/dp/B079ZQF6TW?ref_=fsclp_pl_dp_1 (https://www.amazon.com/Breynet-Woodworker-Mortising-Woodworking-Mortise/dp/B079ZQF6TW?ref_=fsclp_pl_dp_1)
Title: Re: Square holes
Post by: Motorhead on September 24, 2019, 12:03:46 AM
Where and why do you want / need a square hole ?
Just asking ???
Title: Re: Square holes
Post by: shorty on September 24, 2019, 04:50:48 PM
I was trying it out on a exit port of an Mrod valve as a test to not have to push the seat forward

Round hole at .16" equals .0201 cross section
Square hole at .16"X.16" equals .0256 cross section. Same as .18"  round hole (.0254)


Round hole at .187" equals .0274 cross section
Square hole at .187"X.187" equals .0349 cross section. Same as .21"  round hole (.346)
Title: Re: Square holes
Post by: Motorhead on September 24, 2019, 05:03:15 PM
Thought that might be the case .... just as an FYI, The flow is far more uniform and actually greater in a round over a square hole of equal area.  At best if requiring a square shape have the corners with a HEAVY radius.

 
Title: Re: Square holes
Post by: Piranhaboy on September 24, 2019, 06:13:55 PM
There are also rotary broaches. Work great for making hex head screws. Probably can get them square too.
Title: Re: Square holes
Post by: antithesis on September 24, 2019, 10:35:03 PM
Man I didn't know I had such a knack for raising the dead...now I have to locate the resting place of my ambition😂