Fixture plate for the RT

cathead

cathead

CATWERKS LTD
Registered
Joined
Feb 7, 2013
Messages
2,487
Some years ago I was at a DNR auction and got some "stuff" on a pallet. On the pallet was a cardboard box
with a truck flywheel in it. So with no use for it, it has been laying around for years. Suddenly it came to me that it
might be a candidate for making a fixture plate. It was rusty but cleaned up really nice and it looks like it has never
been used. I removed the starter gear as that wasn't needed. Next was to fill in a 6 3/8 inch hole in the center of the
flywheel. I used the Monarch to carve out a round piece of 1/2 in thick plate by welding a piece of pipe to the back
of the 6.5 inch square plate. Then it was machined to the proper diameter.

P1030468.JPG
This is the flywheel with the machined part fitted with the new center piece. I welded a pipe on to the plate so that
I could machine a square piece into a round. In this photo I am fitting the machined plate into the flywheel for a nice tight fit.

P1030469.JPG

The flywheel had a tapered area on it so milled that material out so the disc would fit inside and flush with the top. P1030470.JPG
It beginning to look like something I can use now....

P1030471.JPG
This piece was machined to mate with the table and the small hole in the flywheel center.

P1030472.JPG
Here I'm tapping the holes I drilled to affix the plate to the flywheel. I didn't want through holes so only drilled in .45 inch
in the 1/2 inch plate. With 6 grade 8 bolts holding it down, it should be just fine.

P1030473.JPG
The grade 8 bolts that were actually in the flywheel ended up being a little long so I had to machine off about an eighth of an inch off each one.

P1030474.JPG
Here I am trying to determine where the threaded holes should go. It made the most sense to me to use the rotary table to position the holes.
I need to think this over before I start drilling. Maybe someone has some thoughts on this configuration. Also, I need to determine what
size the tapped holes will be. Maybe some in 1/2 inch and some in 5/16 towards the center maybe. The circles that are X ed was marked
as a spot not to drill because that is where the bolts are on the underside. One cool thing with the flywheel was that it had 6 equally spaced
holes perfectly spaced 60 degrees apart with smaller holes on each side of them making setup quite easy.


P1030477.JPG
The 12 inch table actually measured 11 3/4 inches and this fixture has a bit of an overhang.


So that's what I have been working for the last couple of days.
 
Be sure to send some pics when you make use of it! :)
Aaron
 
Last edited:
I was hoping several of you would foster some suggestions on the drill hole patterns. I am having some trepidation
in beginning the drilling operation as it's pretty final. There may be some credence in drilling the table with an XY
pattern as well. It occurs to me that with the replaceable plate in the middle, one could make two plates for the center
part, one being in angular orientation and the other in XY. At present I have no particular project in mind and that
makes it relatively difficult to know what my future needs might be. Just drilling holes in places at the time of need
seems ambiguous leaving the table to look like some drill press tables I have seen. The Swiss cheese approach isn't
in the works. Another way to approach this situation would to proceed in angular orientation and make another one
out of a piece of square plate in XY. One advantage of the removable fixture plate would be that a person could remove
the part along with the plate for some other operation on the mill.

P1030480.JPG
Yesterday afternoon 1 finished mounting the center part that fits on the RT. Here you can see how the disc on the
table top was mounted using the flywheel bolts to hold it firmly in place. Another option might be to dream up
a worm gear setup and make another RT out if it, a General Motors rotary table. :encourage:
 
P1030495.JPG

This morning I drilled 103 1/4 inch holes in the top surface. I can tap them all out to 5/16 inch x 18 or bore the holes out more if
I decide that is the way to go. It gets pretty old drilling away with three rotations of the crank plus 33 spaces
for each hole.
 
So how is the sacrificial top attached to the rotary table?
 
cathead said:
View attachment 398962
I just finished up tapping the 102
holes. I did a bit of power tapping. The cast iron went a lot faster than the steel center part...
Click to expand...
Nice work! Just finished a smaller aluminum plate today for my RT. Only 44 holes, but they were manually tapped. Got an arm workout! Yeah, no one volunteered a hole pattern for me either. See you went with radial, like I did.
 
You must log in or register to reply here.
Back
Top