# Square holes



## firebird (Sep 14, 2008)

Hi

How do you, sorry, how does one make a square hole. 1/4 inch (6mm) and above I imagine drill a hole then file it out. I'm thinking 1/8 inch (3mm) and below???

Cheers

Rich


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## greenie (Sep 14, 2008)

A broach is the normal method for thick material.
A punch is the easiest for thin material.
The preferred method is governed by the quantity of holes that are required.


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## firebird (Sep 14, 2008)

Hi

I'm planning on making the small wheel handles on steam valves which require square holes. I wont be making that many so expensive tooling is not viable. You can buy them, not all that expensive but I would like to have a go myself.

Cheers

Rich


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## Mcgyver (Sep 14, 2008)

filing works. for a really crisp job, the other method to consider is building it up. take a piece of round brass, mill out a slot at one end then solder a ceiling on it. you now have a square hole. if you carefully cut the slot so it was centre in a piece of round stock, put in a collet and turn the OD. part off, and solder or loctite into a matching hole you;ve made in the hand wheel. I've made square cutting progressive broaches, but it would be a challenge in this size. the other idea is make a single step broach that doesn't cut a full square but cuts four corners into the round bore, it'll work but won't like quite the same as a full square hole.

here's a pic of some home made broaches, sq one is 3/16 iirc


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## 4156df (Sep 14, 2008)

A method that uses the lathe crossfeed and a homemade broaching tool is described on this site:
http://www.modelenginenews.org/. Click "Resources" on the left column, then "How To ?", then "How to Broach Square Holes".
I've not tried this technique, but it looks like it would work.

Dennis


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## firebird (Sep 14, 2008)

Hi

Thanks guys. Some good ideas to work with there.

Cheers

Rich


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## tel (Sep 14, 2008)

The Forzit method works for the occasional job. Drill the round hole, file it out pretty close and then force a HHS toolbit of the appropriate size thru it. Bench vise will do a credible job of this. And for hex holes, a slice of Allen key, cut of square and with a little pilot turned on it will make a very tidy job.


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## Cedge (Sep 14, 2008)

Here's a little tool I've been considering making from a spare bit of tool steel I have laying about.






It comes in 5/16 and 3/16 sizes from MICROMARK.COM

Steve


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## raggle (Sep 14, 2008)

If I may jump in with my first post I would suggest the following. Drill the hole slightly oversize and grind a tiny shaper tool to hold sideways in the toolpost and rack in and out of the hole. Treat each corner as a separate cut, and if you used a 4-jaw when you drilled it a clamp on each jaw in turn provides easy indexing.

Needs a bit of ingenuity to set height and limit of the cut, but I'd think it was repeatable for short production runs. Once you've mastered that you're ready for keyways. I think the method is in Sparey's book "The Amateur's Lathe".

Ray


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## BobWarfield (Sep 15, 2008)

How about a shaper attachment for your lathe to facilitate square holes and keyways?

I've always liked the idea. Here is one such:






It simply uses the compound together with a hand linkage so you can run the tool in and out repeatedly.

Cheers,

BW


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## tel (Sep 15, 2008)

I made one of those years ago Bob. It works fine, but is a bit of a fiddle, as you have to strip the feedscrew out of the topslide to mount it. A better design is a smaller, self-contained one that carries it's own handle and simply clamps down in place of the tool holder. I'll big it out and take a pic at the first opportunity.


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## old-biker-uk (Sep 15, 2008)

Here's some I made earlier (to quote a famous UK kids TV programme)




For the small handwheel I just pushed the broach through in the vice using a couple of short tubes as spacers.
This is the result for a triangular hole, 5/16" sides:-





.
The broach made for this was really too short with insufficient taper so the hole was made by a combination of broach & file.
The hole was for this centre hole divider.





Mark


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## Mcgyver (Sep 15, 2008)

nice work as always Mark, you've got that Victorian flair


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## Circlip (Sep 15, 2008)

So yer mate don't jump down me throat again Rich, If you get a piece of Silver Steel (Drill Rod) and machine it to the size of the square you need, turn a location spigot the same diameter of the root hole in the handwheel onto the end of it, harden and temper and squeeze it through the blank.
 If you imagine the tool that Cedge has posted but using the end that's supposed to fit in the drill chuck as the cutting end, with a slight undercut.
 Regards Ian

 Turn a round peg to create a square hole :big:

 DOH, sorry Tel, mines the English version.


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## firebird (Sep 15, 2008)

Hi

I like that idea Ian. For a one off job that sounds the easiest. For a small run I like McGivers idea of milling a slot, filling in then parting off. When the time comes I'll try both ideas. Making up an attachment for the lathe looks good but I don't think it would get enough use to justify the time it would take to build one, maybe later.

Cheers

Rich


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## tel (Sep 15, 2008)

Mcgyver  said:
			
		

> nice work as always Mark, you've got that Victorian flair



He has, hasn't he. It's beautiful work.


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## steamer (Sep 15, 2008)

I have a keyway slotter that fits on the tool post. I'll try to take a picture.


Dave


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## baldrocker (Sep 15, 2008)

Ummm
How about a square file in a jigsaw.
BR


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## 4156df (Sep 16, 2008)

> nice work as always Mark, you've got that Victorian flair



Beautiful work, Mark. I for one would really like to see a post on how you do your decorative brass turning.

Regards,
Dennis


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## Circlip (Sep 16, 2008)

Rich, you would find more uses for the "Slotter" than you think. Regard it as a mini SHAPER. You also use it when making dial graduations 
 Regards Ian.


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## firebird (Sep 16, 2008)

Hi Ian

I'll look into it. It might be worth making one. A stand alone device might suit me better than one that has to be fitted in the lathe.
Cheers

Rich


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## old-biker-uk (Sep 16, 2008)

Dennis
The hand turning is the easy bit! For the little knurled knobs on the dividers I turn and screw the threaded part and rough out the shape leaving the part to be knurled. (The knurling wheels both spiral & dot were made according to the instructions of Mr Ford  here.






After knurling the knobs are parted off, reversed & held by the threaded end in stub mandrels, finished by hand turning.





Hand turning is one of those things you really just have to have a go at. All you need is a few simple tools & a rest.




I have hand turning rests made for each lathe but they dont have to be anything special, a bar in the top slide tool rest is OK.
You learn more about cutting angles by doing some hand turning than from a shed load of workshop manuals !
Mark


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## tel (Sep 17, 2008)

Hmmmm .... seems I lied, mine doesn't mount on the topslide, it bolts direct to the cross slide. Haven't used it for a few years - Mr.Douglas gets most of that sort of work these days











The mounting arrangement allows for some offsetting for tapered work.


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## Julian (Sep 17, 2008)

Tel

That looks a handy tool and something I have considered building for a while. Thanks for the photos it makes the building of one lool very straight-forward.

Circlip

Thanks for the acknowledgement. It was not my intention to "jump down your throat" but I am very pleased you have understood what I meant and have taken it on-board in your reply to Rich

Many thanks

Julian


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## CrewCab (Sep 17, 2008)

What a brilliant thread ;D .............. Mark :bow: top class stuff mate, if I ever get a little more free time I could well be trying to pick your brain 

I think as with most folk on here we would love to have all the available tooling ............ state of the art Rotary Broach etc, but after all, it's a hobby so it ain't going it's unlikely to happen  ........ I admit to being a gadget freak but to be fair I'm among stiff competition here  ........ so thanks for sharing all the above idea's, they are just great, whether I'll ever make a square punch remains to be seen but, knowing that I can if I want is what matters 8)

Cheers Guys 

CC


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## tel (Sep 17, 2008)

Just to add to the mix, meet Mr.Douglas


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## CrewCab (Sep 17, 2008)

tel  said:
			
		

> Just to add to the mix, meet Mr.Douglas



Hi Doug


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## Julian (Sep 17, 2008)

So tel....how does it fit on the cross-slide.......must be a big lathe!!!!!!!!!!!!!!!!!!!!



Julian.


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## steamer (Sep 17, 2008)

The Pictures as promised.

Mine is based on the ME model only it mounts to the AXA style wedge toolpost. 5 seconds its on, and off.

I am going to rebore the ram and make it 1 1/8 instead of 7/8. This one is a bit wimpy for 5/32 keyways and larger.  But smaller ones are OK in steel.


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## SmoggyTurnip (Sep 18, 2008)

old-biker-uk  said:
			
		

> The hole was for this centre hole divider.



That is a beautiful center hole divider! ... What's a center hole divider???


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## baldrocker (Sep 18, 2008)

Umm ditto
BR


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