Expanding mandrels

[specv]

Does anyone use expanding mandrels to hold cylindrical parts from the inside? I am looking for a solution to aa holding problem on a cast part that i need to machine around the whole outside and nee to hold it from the inside.

TIA

[rich]

We turn some chuck jaws and reverse clamping. Works Great.

[Psychomill]

+1 rich

 

I've also used these for small parts and/or multiple parts.

 

ID Xpansion Clamps

 

Click on Products then look for ID Xpansion Clamps

[specv]

the inside of this part is cast at this point in the machining operation, the dia is about 4.5 in.

[CAM-mando]

Is the ID Tapered? (Draft) If so is it in the right direction to use a conical taper lock.

[Chris Rizzo]

Conical taper lock? pleze explain.

 

Upside down cone?

 

Can you get at the part from the topside, or is it closed, like a top-hat.?

[specv]

its closed on the top

and it is sand cast, i dont think its tapered

[Bruce Caulley]

Try mitee bite. If the clamping bore is cast then you might have to skim it true first.

 

Bruce

[Jack Mitchell]

quote:

---

its closed on the top and it is sand cast, i dont think its tapered

---

If it's sand cast then there must be some taper otherwise the center core will not readily separate.

Perhaps an "ID" operation should be added to allow for a concentric mardrel support. Machining would allow for consistancy which is rather difficult even with investment cast.

Just a thought..

 

Regards, Jack

[specv]

I there is not an option to add another op right now. I am going to probe this part for offsets so location is not really a problem this part weighs about 100 lbs. so i want to reduce handling. I actually have some mandrels here but they are not big enough and they do not have a name on them. i will take a picture and see what you guys think.

[Chris Rizzo]

What about softjaws, with a boss carved out of them that protrudes above the top of the vice. They would clamp on the outstroke, vs. the traditional vice clamping direction. Sorta like clamping the id in a 3 jaw.

I've machined alot of rings this way, it's very easy to spring the part though.

[specv]

If i cant find these mandrels then i will have to use a 3 jaw chuck, which will be cheaper for me anyway since i have sacrificial chuck, right now i dont have anywhere to host this picture, photobucket lost my info, so i will have to create a new account.

[specv]

got it

 

 

what i like about this style is that the contact points are knurled. so if anyone knows or has seen any like this let me know.

[McRae]

With a Casting, Why don't you make your own adapter to fit on the mandrel unit pictured above. Use some carbide grippers on 6 Points (3 Top and 3 Bottom).

 

My suggestion anyway. There is an expanding 5C collet style of a tool from Royal Workholding and I think that Hardinge has some as well. 5C may not be robust enough to handle what you need though.

[specv]

if i could do that i would McRae, but this is a picture of another fixture we already use, i was just wondering if anyone has seen anything like this or knows a brand name. I have one brand that i looked at and it was N.A. Woodworth but they didnt have this style.

[McRae]

Found an advertisement in Gear Solutions -

 

www.drewco.com

[somename75]

these might help, look for the ID expansion clamps.

 

http://www.miteebite.com/

 

HTH