DIY trunnion table? Anyone made one for 4th axis?

[SlowRiderr]

Anyone made their own? I threw this design together on Solidworks and it clears the table by .160" at the closest point of near-contact.

My idea is to have it so that it can be quickly removed/installed. My 4th axis chuck is within .001 runout at 12" away (tested with a clamped precision bar in the chuck) so it is very well centered.

[Delw]

I was looking into that way but found a cube to be better for my situations ( my opinion anyhow)

if you run a vice you have to run it horizontal so you really dont have a way to tighten it unless you put a through hole in the tail stock end then a modifed vise handle with extension. theres one made like this I have seen before its around 1500 and will hold a double lock. but then its limited on what you can put in it.

The one thing I dont like about running with a chuck on something that big and heavy is the fixture mayslip when taken heavy cuts, At the very least I would reccomend a 3-5" circle to locate on and cut full dia. pie jaws.

That all being said every application for the use of something like this is different, while it will work for some others it might not.
I personally feel more comfortable with the chuck being gone and bolting directly up to the face plate, to me its more rigid.

I think that fixture you drawn up would work great for mounting a few round parts with collet fixtures on it. mounting any part below centerline would require longer tool holders that would also give off vibration

That is a dam nice solid work job, I like the reflection part, some of you guys can really do some very nice cad work. I suck at it, my 8 year old does a better job with crayons than I can with 3d software.


Not downing your work or Idea at all, as I am going through the same thing, I have one fixture that I am making that has limited use's heck to be honest it would only work on a hand ful of parts, one reason why I am taking so long to build it cause I would like to make it work on lots of different parts that we see. Mine wouldnt work for something like yours would ( which I could use from time to time.) fixtureing is a never ending story, we just never have enough fixtures LOL

Nice job
Delw

[Geof]

Yes do away with the chuck and just bolt directly to the rotary platen for greater rigidity and more room.

To be picky your illustration does not show a trunnion table, or at least what my understanding of a trunnion is; I thought the trunnion was another rotary axis in the center of what your picture shows.

We have several machines equipped with what you depict and use them for three sided machining of multiple parts. Actually one setup allows four sided machining through holes in the fixture.

[SlowRiderr]

Thanks Delw. You've got some good points that I'm going to take into consideration and play with this model a little bit more.

Also I am self-taught on SW. I have the student version which is only 80 bucks(yes I am a student), and it has a couple tutorials that will get you rolling. I use it mostly for locating points for Acu-rite controls and also do some design and CAD on Mastercam.

Originally Posted by Geof Yes do away with the chuck and just bolt directly to the rotary platen for greater rigidity and more room. To be picky your illustration does not show a trunnion table, or at least what my understanding of a trunnion is; I thought the trunnion was another rotary axis in the center of what your picture shows. We have several machines equipped with what you depict and use them for three sided machining of multiple parts. Actually one setup allows four sided machining through holes in the fixture.

You're right, so would you call it an indexing table? Also I think I will take the chuck off and just bolt up to the rotary.

[Geof]

Originally Posted by SlowRiderr You're right, so would you call it an indexing table? Also I think I will take the chuck off and just bolt up to the rotary.

I call them a rotary one-sided horizontal tombstones; my people call them rotary platforms.

[SlowRiderr]

Originally Posted by Geof I call them a rotary one-sided horizontal tombstones; my people call them rotary platforms.

So do you think there is a more versatile setup I can make- like a tombstone? There isn't too much clearance as the table to center of the rotary axis is 5.00"

[Geof]

Originally Posted by SlowRiderr So do you think there is a more versatile setup I can make- like a tombstone? There isn't too much clearance as the table to center of the rotary axis is 5.00"

More versatile setup? What are you planning to use it for?

We have one machine setup with a true foursided horizontal tombstone for a specific part. The tombstone is 4" square, the part is about 1-1/2" thick and the rotary center height is 6"; so everything fits and we can load four parts on four sides for a total of sixteen parts. Here is a picture: http://www.cnczone.com/forums/attach...2&d=1151711731

A lot of our other parts are too tall to put on the outside of a tombstone type rotary fixture so we have several underslung type much the same as your idea, as shown here: http://www.cnczone.com/forums/showthread.php?t=38283

My approach is design what is needed for the job it will do.

[mcphill]

Originally Posted by Geof To be picky your illustration does not show a trunnion table, or at least what my understanding of a trunnion is...

In fact that is a trunnion. A trunnion is simply a two sided support. It is common for a 5th axis to be mounted to a 4th axis trunnion (or I guess that could be a 4th axis rotary mounted to a 5th axis trunnion - chicken/egg deal ), but the one that is supported on two ends is the trunnion...

[Geof]

Originally Posted by mcphill In fact that is a trunnion. A trunnion is simply a two sided support......

I am guilty of being sloppy, thank you for the correction. I had the picture in my mind of the Haas trunnion with the rotary axis in the middle and was equating the term trunnion with the presence of the rotary.

At least now I know the correct name for our rotary fixtures/platforms; they are trunnion platforms. But I don't think I will try to change what we call them in the shop.

[SlowRiderr]

Originally Posted by Geof More versatile setup? What are you planning to use it for? We have one machine setup with a true foursided horizontal tombstone for a specific part. The tombstone is 4" square, the part is about 1-1/2" thick and the rotary center height is 6"; so everything fits and we can load four parts on four sides for a total of sixteen parts. Here is a picture: http://www.cnczone.com/forums/attach...2&d=1151711731 A lot of our other parts are too tall to put on the outside of a tombstone type rotary fixture so we have several underslung type much the same as your idea, as shown here: http://www.cnczone.com/forums/showthread.php?t=38283 My approach is design what is needed for the job it will do.

Oh thanks for the links that really helps me with the designing. I am making this for fun and also to do some 3 sided operations on a small kurt-style vise design.

[Delw]

Slowriderr

Look at geofs fixtures you can learn alot from them, especially some of the clamping ones he has..

Its a trunion but like geof said my first reaction when I saw the post title was the haas 5 axis trunion, I am think WTF this has to be cool. lol


I had org gotten the 6" but changed it to the 8" glad I did. I was thinking about building vises into them for the particular parts I run and then geof talked me into mitee bites, those clamps have come a long way in the last 10-15 years and there pretty strong too.
The one I am bullding right now is a square tombstone 24" long its 6.5 inch square ( close to) I will be able to put individual sub plates on it for flat parts and short parts, the edges will be knocked down and according to cad I have about a 1/8" clearance on the corners when rotating and 1/4" on my part height from the bottom when in the zero postition. its 4 sided and runs about 20 parts per side on one job.

I have a son with Downsyndrom and this is his project, so hopefully he will come down this weekend and help put it all together.
He is into machines and likes to work with tools so I figured he can do this one from start to finish, and actually see it in action.
He is usually on the front side of the parts during set up or the back side when there finished or just cutting, hardly ever see's something created from saw's parts to complete and finished. Maybe it will help him understand how things work a little better. and he loves to help around the shop.


Delw

[SlowRiderr]

So I milled down a slab of D2 I had. .998" thick, 7.5" wide, 17" long. Put it on the granite plate and it is within 4 tenths across the surface. I would have been happy if it was within a thou but it came out better than I expected - especially since I was holding it in a 6" kurt vise. My old VF-0 may be old, but she sure does cut well!