[totalhack]

Hey guys I need to make some round parts that are 1 inch in diameter by 1 inch tall and in a perfect world I would like to make 20 at a time on one fixture plate. Material is 12L14 steel.

Can I get some suggestions on ways to hold the material for machining? The best I have come up with so far is a machinable pitbull clamp from Mitee-Bite.

Any input would be greatly appreciated.

[RussMachine]

Are you standing them up, or laying them on their side?

[john robertson]

what machining are you doing to them,more info may help

[SCzEngrgGroup]

At one inch diameter, you could use ER32 collet chucks mounted to a fixture plate to hold them.

Regards,
Ray L.

[totalhack]

I will be standing them up. Most machining will be done on the top side, pocketing, thread milling, and chamfers but I will also need to flip them and mill the bottom side as well. Here is a picture of the finished part. Attachment 232574

Ray, do you have a link for where I might find an collet chuck like the one you are speaking of? Here is a ER32 collet fixture I found on ebay but it is pricey and larger than I would like although they are more versatile and probably more accurate and easier to use. Hmmmm

[john robertson]

I don`t want to sound rude , but you need a lathe

[totalhack]

I don`t want to sound rude , but you need a lathe

Yeah yeah I know but I went with a mill because I could only afford one machine and a mill is more versatile in my opinion. Simply put I can make round parts on my mill but I cannot make square parts on a lathe (at least that I know of).

[Steve Seebold]

Simply put I can make round parts on my mill but I cannot make square parts on a lathe (at least that I know of).

Ah, but you can make square parts on a lathe.

[Hirudin]

Are you willing to make them one at a time? Obviously, your costs will be lower but it'll take a lot longer. Affixing a single 1" rod is going to be a lot easier than affixing 20 at once.

If you have an ER-32 tool holder and a 1" collet (do those exist?) you can clamp the tool holder in a vise with vee blocks. I've done this a few times with an R8 ER-32 tool holder that I shortened* with a band saw - it works well.

For that part I imagine you could do the external thread first and then screw them into a large plate with 20 tapped holes.

* ruined

PS Sorry, I reread your original post and you've already mentioned that you want to make them all at once. All this collet talk confused me. I'm with you, I wouldn't want to spend $2000 to fixture this job either.

[SCzEngrgGroup]

I will be standing them up. Most machining will be done on the top side, pocketing, thread milling, and chamfers but I will also need to flip them and mill the bottom side as well. Here is a picture of the finished part. Attachment 232574

Ray, do you have a link for where I might find an collet chuck like the one you are speaking of? Here is a ER32 collet fixture I found on ebay but it is pricey and larger than I would like although they are more versatile and probably more accurate and easier to use. Hmmmm

You can just use regular TTS ER chucks, mounted to a fixture plate. Given that both ends are threaded, you can also just as easily make them with a very simple fixture using Pitbull clamps or something similar. Machine the external threaded end first, then screw them into threaded holes in the fixture and machine the other end (or vice-versa). No lathe needed - I make parts similar to yours on my mill ALL the time - it's faster and easier than using a lathe, as I can make a dozen or more parts on one fixture, and it's just as accurate if you set it up properly.

Regards,
Ray L.

[philbur]

Here is a ER32 collet fixture I found on ebay but it is pricey and larger than I would like although they are more versatile and probably more accurate and easier to use. Hmmmm

If you think that's pricey you probably would be better off taking up knitting.

Phil

[totalhack]

Are you willing to make them one at a time? Obviously, your costs will be lower but it'll take a lot longer. Affixing a single 1" rod is going to be a lot easier than affixing 20 at once.

If you have an ER-32 tool holder and a 1" collet (do those exist?) you can clamp the tool holder in a vise with vee blocks. I've done this a few times with an R8 ER-32 tool holder that I shortened* with a band saw - it works well.

For that part I imagine you could do the external thread first and then screw them into a large plate with 20 tapped holes.

I currently make them one at a time using my 5C collet fixture but each side is less than 15 minutes so I really can't walk away and do something else so it is not productive enough for me. Honestly I just assumed ER32 would allow for a 1" collet but since you said that I did a QUICK search and it appears that I would need to step up to ER40 to get a 1 inch collet so I guess that er32 option is not an option after all. I have thought about making a fixture plate and screwing the half finished parts into it but then that would require two different fixture plates, one for the top side and one for the bottom. If I use pitbull clamps I can make one fixture plate and just flip the parts. Also I am not sure if my worries are justified or not but I am concerned that if I screw a half finished part into a fixture plate that the forces from milling might cause it to come unscrewed and bomb the cutter.

You can just use regular TTS ER chucks, mounted to a fixture plate. Given that both ends are threaded, you can also just as easily make them with a very simple fixture using Pitbull clamps or something similar. Machine the external threaded end first, then screw them into threaded holes in the fixture and machine the other end (or vice-versa). No lathe needed - I make parts similar to yours on my mill ALL the time - it's faster and easier than using a lathe, as I can make a dozen or more parts on one fixture, and it's just as accurate if you set it up properly.

After my last post I went out to the shop and looked at my TTS ER32 holder and it was indeed threaded on the back side but going off of what Hirudin mentioned it appears I may be hard pressed to find a 1 inch ER32 collet so as of right now I am back to thinking that machinable pitbull clamps are my best option. Again, I am concerned that by screwing the part directly into the fixture plate I would be opening myself up to the spinning force of the cutter unscrewing the part and exploding the cutter and possibly sending a chunk of steel across my shop as a 1.0 caliber bullet. Any tips on how to avoid such a scenario or is it something that I should not be too worried about?

If you think that's pricey you probably would be better off taking up knitting.

LOL ok let me clarify. Not pricey as in too much money but as in 3 times as much as a single pitbull clamp. That being said though since it is a collet fixture it could be used for multiple sized parts down the road and not just a single use setup like a machinable pitbull so in the end the extra price may be worth it. My biggest gripe about that collet fixture was the size of the base. At over 3 inches I would not be able to fit very many on my mill table at any one time. I would really like to do 20 of these parts at a time so I can get away from the machine for a while and do something else. I am a one man show so I need to make maximum use of my time in order to stay on schedule.

[SCzEngrgGroup]

There are many ways to keep a part from spinning due to machining forces. For example, after threading the part into the fixture, you can have a set-screw to lock it in place. Or make the threaded part of the fixture two pieces, with a bolt that lets to clamp the two pieces together once the part is threaded into it. On your part, if you machine the internal-threaded part first, you can use the flats to clamp it to machine the other side. You can also simply be careful to machine it so that the tool forces always tighten, rather than loosen, the threads.

I am surprised you say you're taking 15 minutes to do each side - I would estimate more like 5 minutes total, given that 12L14 machines like butter....

Regards,
Ray L.

[Hirudin]

(Big newbie here)
Would a magnetic chuck allow you to slap them all down and machine them? Or a vacuum fixture? I suppose attaining a faced surface on all the pieces beforehand might be a problem. :/

[SCzEngrgGroup]

(Big newbie here)
Would a magnetic chuck allow you to slap them all down and machine them? Or a vacuum fixture?

Neither would have nearly enough holding force with so little surface area to hold onto.

Regards,
Ray L.

[TurboStep]

As you mentioned that your 5C base is too large maybe you haven't seen these:
33103 - 5C Collet Block Set
Tormach featured them in the following video:
5C Collet Workholding Tips for Mill- Tormach CNC - YouTube
They may not be my first choice but perhaps worth a look.
Step

[hjl4]

A CNC lathe with live tooling and bar feed, can make those in under 4 minutes. Its pretty hard to beat a lathe on anything round. But being that you have a mill, I think the fixture plate suggested by Ray would be the better way to go. It seems more practical, and you can make more then 1 at a time if properly lined up in rows.

[Hirudin]

Those 5C collets and holders look very handy!

Neither would have nearly enough holding force with so little surface area to hold onto.

Ah, darn.

[Bryan Turner]

Super cheap alternative: If your tolerances allow it (loose tolerances), make a set of stacking V-blocks - cut v-shaped grooves out of both sides of a rectangular bar. Then sandwich the lot of them together in a vise (fixed jaw, then row of rounds, then v block, then row of rounds, then v block, etc.. then rounds, then other vise jaw). Theoretically, say 1/8" clearance between parts, a 5" wide, 5" deep vise could hold 4 rows of 5 parts = 20 parts. Would limit your tool to be 1/8" cutter for profile work though. Just make sure they poke up far enough above the vise jaws so you don't mill into them!

--Bryan

[hjl4]

Good thinking Brian. I like that idea. A few minutes making the V-block plates and the greatest advantage, is you can reuse them for other, similar jobs of varying O.D./sizes. Pretty clever .