Back to the drawing board Fixture plates??

[gundog]

My fixture plates I had planned for my Sharp SVL2416SE-M are not going to work as planned. With my new insert cutter installed I am out of Z axis by about 2". I have a .625" plate bolted to the table top and it ain't going to reach in fact it is not close which means even if I could get it surfaced most of the tooling would also not reach the fixture to make parts. I have some 1" x 2" bar stock I could make feet for the plate but it seems I would lose all the rigidity of the table by spacing it that high above the table.

I am still getting to know this machine and I have to say this one surprised me.Looks like I need to go back to my original plan of using fixtures in my vises.

 

[DethloffMfg]

Yeah, that's the catch on on-table fixturing. You need a spacer or to put things in a vise to take up the height. Do you have vises? I don't know if it's reasonable but you could remove the jaws and just use the tops of the vise body as a flat to bolt the fixture plate onto. If it's something like an Orange vise with the drilled/bored holes it's even easier, you could bolt the fixture to the vise body.

 

[gundog]

Yeah, that's the catch on on-table fixturing. You need a spacer or to put things in a vise to take up the height. Do you have vises? I don't know if it's reasonable but you could remove the jaws and just use the tops of the vise body as a flat to bolt the fixture plate onto. If it's something like an Orange vise with the drilled/bored holes it's even easier, you could bolt the fixture to the vise body.

Yes I have vises but I was trying to use the most out of the travel on my machine by making a bunch of fixtures to bolt to the table. Right now I am just disgusted with myself for spending the better part of 2 days designing and cutting these plates only to find out I am back to where I started. I made 3 of them I knew I should have just cut 1.

 

[fueler]

Any reason you can't spacer it up?
Had a situation like that. I bolted two pieces of aluminum to the underside and then milled them to square it all up.

 

[DavidScott]

Ask Wheelie about this one!!! You can spacer it off the table with rails but use at least 3, 2 will let the plate warp a lot more. Perhaps 2 bolts per spacer/plate instead of the one in the middle. It would make life easier if the spacers are bolted to the fixture plate/receiver. The biggest problem you may have is facing it, you may need to use something smaller like a 3/4" end mill. Don't worry, it's just another lesson in fixture making.

 

[Nerdlinger]

Maybe you could:

1) cut up four 16” lengths of that 1x2
2) drill/c’bore 3 holes in the 1” wide side of those rails to line up with the T-slots
3)screw those rails down to the table (so they’re going perpendicular to the length of the t-slots
4) face a smidge off all the rails at the same Z depth so you know you’re flat.
5) clamp another one of those 5/8” plates on top of the rails, indicate so it’s centered.
6) drill through the 5/8” plate into the rails, tap the rails, open up and c’bore the 5/8” plate.
7) screw that 5/8” plate down to the rails nice and good.
8) bore out one pocket close to each of the four corners of the permanently-located 5/8” fixture sub plate and install Jergens balllock receivers in each of those bores.
9) pick up the center of one of those receivers and store it as your reference work shift (G52 I think?) so you can use a G10 for all your other fixture offsets. That way if you ever have to move that sub plate when you put it back in you can reset just that one (G52?) work shift and leave all the G10’s in your programs untouched.
10) drill four holes in all the fixture plates you have that line up (exactly) with those receivers and install Jergens ballock liners in two opposite corners. That way every fixture plate you have can be installed in seconds with very good repeatability and no need to locate X0Y0. You can add more holes in your fixture plates and receivers to go with them (in the sub plate) if you need extra hold-down force between the sub plate and fixture plate.

That would give you 2-5/8” boost up in Z from where you are now and you wouldn’t need to scrap the three fixture plates you already made and you can keep your vices handy for other work.

Just an idea!