Thread: How would you hold this?

The first picture had me scratching my head for awhile

How many tips do you have in that head? First thing I would do is take most of them out(swtich to HSS if I could).

Does it just need to be flat?

Stuart

Does the head tilt? If it does I'd be temped to bolt the head flange to a piece of channel or a beam, secure that across the table and tilt the head up 15 degrees above horizontal. Light cuts, slow feed.

Michael

(PS - first picture? that implies more than the one that I can see??)

I would use exhaust clamps welded to extendable SHS (SHS inside SHS) mounted to some flat bar that can be bolted to the table. I made up a fixture like this to hold pipes before I welded them. Making the clamps extendable means you can get it all mounted solidly. Anyway a photo speaks a thousand words.

exhaust_fixture_1.jpg exhaust_fixture_2.jpg

To start with i thought you had cross bred your mill with an octopus.....

I'd go with what Michael said, otherwise build a false table that you can support the very edges of the flange with.

Ew

How good does the flange need to be? Draw filing or a face sander come to mind.

Originally Posted by Michael G

(PS - first picture? that implies more than the one that I can see??)

Sorry. the first pic was of an auto drive plate

Thanks guys
Yes i attached the wrong picture first (damn tablet)
Running 4/6 tips in the tool as i am missing parts, tips are cermet which eats through the welds like butter -no way i would use hss. The tool cuts extremely well as is, no need to mess with it.
Flange needs to be a machined surface to get a good seal
Not keen on tilting the head then having to tram it afterwards


I discussed a jig similar to what variant22 suggested with my mate, but its a lot of work for what is then a 1-off jig for this manifold.


Then i thought of ueee's second option, make something to hold it from underneath the flange, square to the bed. then i can hold anything with the same flange, regardless of pipe configuration. Also no mucking around trying to get the angle right.
So for this false table, would you-
make the whole assembly, maybe welded from SHS with a mounting flange at the top, then face the flange for squareness
or
bolt the big right angle plate to the bed and mount the jig off that? Less material/time to make the jig but you would have to square it up before each use


Oh and yes the hexopus has taken over my shed )
(Octopus would be an 8 cylinder?)

As Bob said its only a set of extractors and no big deal, thats what gaskets are for!
Will

That job can be done with a file - faster than making any jig to clamp it to the mill table. And just as good and flat as milled.

You probably could even scrape it "Bugatti style" faster than making the jigs

There is no guarantee that anything is square or parallel between the two mounting surfaces. If you don't get the turbo flange machined parallel with it's original setting you may have issues with the downstream exhaust sitting properly against the turbo.

Is it possible to mount the manifold so that the turbo flange is vertical with it's face parallel to the X axis? You might then be able to use a long end mill and light cuts?? It may not be very rigid?? also it will depend on your Z clearance and travel.

Alternatively, tack weld two small pieces of flat bar to either side of the flange. Turn the manifold around so it's hanging off the front edge of the table. Clamp the two flat bars to the table. Have at it! Cut off bars afterwards!

What is the manifold off?

Cheers

The Beryl Bloke

Originally Posted by andrew_mx83

As per title, how would you hold this bastard of a thing? Had a lot of trouble getting the turbo flange parallel with the bed and enough force holding the part so it would not move while cutting (even with 2 of us holding it)
The turbo flange is not at 90 degrees to the head flange so i cant use a right angle plate. Tried to use a borrowed tilting table but it wouldnt go the 15 or so degrees past 90 that was required.
Id like to avoid making a jig if possible, so im open to ideas (even ideas on making a suitable jig)...
Note the knee is currently at its lowest setting, thats all my Z

I agree with the Beryl Bloke: make a nice rigid jig and tack weld the turbo flange onto it, then surface it, change the cutter to an endmill and mill the welds off again. Should work well.

Originally Posted by Theberylbloke

There is no guarantee that anything is square or parallel between the two mounting surfaces. If you don't get the turbo flange machined parallel with it's original setting you may have issues with the downstream exhaust sitting properly against the turbo.

yep, which is why i want to mount is as square as possible to the original mounting face.

Originally Posted by Theberylbloke

Is it possible to mount the manifold so that the turbo flange is vertical with it's face parallel to the X axis? You might then be able to use a long end mill and light cuts?? It may not be very rigid?? also it will depend on your Z clearance and travel.

thought about this, but the surface finish off an end mill wont be good enough, nor do i have an endmill that long (flange is probably 120x150mm)

Originally Posted by Theberylbloke

Alternatively, tack weld two small pieces of flat bar to either side of the flange. Turn the manifold around so it's hanging off the front edge of the table. Clamp the two flat bars to the table. Have at it! Cut off bars afterwards!

this would work well, but i cant cut over the front of my table. i already had to go to considerable lengths to get it to cut all the way to the front and back edges.

Originally Posted by Theberylbloke

What is the manifold off?

it is off a fairly silly Nissan Patrol (4.8lt I6) making north of 550kw at the tyres.


it definitely needs to be faced off, no filing and ideally no gasket if the machining is done right.

i do like the idea of welding to the flange if we cant bolt it down, that might work well.



thanks for all the suggestions guys

G’day Andrew,
I can’t really offer any other suggestions for a way to hold the hexopus, but my mill has a tilting table which should let you clamp the manifold flange directly to it then face off the turbo flange.
I’m not sure where you are in Melbourne but I’m in Fawkner and you are welcome to bring the manifold around if you get stuck.
Cheers,
Greg.

Thanks for the offer Greg, much appreciated. As usual i am pretty keen to do the work in house (part of the reason for getting such a big mill is to be able to do jobs like this) but if i get stuck ill definitely shoot you a message.
Thanks again