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RichR
08-04-2014, 12:33 PM
I have a 6" rotary table that I've used a few times. Not content with being limited to clamping in the slots, I decided it was time to make
up a fixture plate. I started with a 1" piece of aluminum 7 inches square and marked out where to drill:
http://i57.tinypic.com/2hxvz4p.jpg

The hole in the middle will have an insert pressed in for centering the plate on the rotary table. The countersunk holes are for threaded
locating pins that fit the rotary tables slots.The four slightly over sized through holes are for the hold down screws. The remaining
holes will be threaded 1/4-20 for hold downs:
http://i59.tinypic.com/2whi4pj.jpg
Not shown, I also milled the rear edge as a reference surface to indicate off of later.

Test fitting the centering insert and one of the locating pins:
http://i59.tinypic.com/28s3u6a.jpg

Using the mill to hold the tap handle square while I start the threads:
http://i60.tinypic.com/30ie5w1.jpg

RichR
08-04-2014, 12:35 PM
With all the threads started straight, now I can finish them using a real tap handle:
http://i58.tinypic.com/2w4a73m.jpg

Bottom of plate cleaned up, ready to install centering insert:
http://i62.tinypic.com/2afblg3.jpg

The brass hammer used to seat the insert was harder than I expected:
http://i57.tinypic.com/yfyb.jpg

I made up some stainless washers for the hold down screws:
http://i62.tinypic.com/a0i2rn.jpg

RichR
08-04-2014, 12:36 PM
Plate mounted to the rotary table. Indicating off the previously machined edge so the remaining edges can be cleaned up:
http://i57.tinypic.com/9r3itl.jpg

Remaining edges have been milled:
http://i57.tinypic.com/2vlllkl.jpg

I still need to knock down the sharp edges and might skim a few thousands off of the top to make sure it's flat. I'm also considering
making up a block that will accept the locating pins that I can bolt the plate to so I can clamp it into my vise.

studentjim
08-04-2014, 04:46 PM
Excellent piece of work Rich. I'm sure it will be used many,many times.

Bob Ford
08-04-2014, 06:43 PM
Great planning and nice work. This should be very useful.

Bob

sasquatch
08-04-2014, 08:06 PM
Real nice!!

RichR
08-04-2014, 10:15 PM
Thanks for the kind words guys. This was a satisfying project, though hand threading all those holes through 1" aluminum got old really fast. While milling
the edges I did learn I have to get more aggressive with my feed rates. Watching the cutter I noted that as I cranked faster, there was less material being
dragged around the cutter which resulted in a cleaner cut.

boslab
08-04-2014, 10:36 PM
Its times like that when you wish you had a tapping head!, i think I'm lucky as my mill has a tapping facility built in, switch to tap, set speed run tap in press the button on the end of the lever it reverses out, took me ages to figure it out, not sure why but it frightened me a bit!
Nice work, pleasing to us nutters to see lines of regimented holes, are we all bonkers?
Mark

RichR
08-04-2014, 10:58 PM
Its times like that when you wish you had a tapping head!
Yeah, but hand tapping builds character, at least that's what I conned myself into believing while I was doing it.


... are we all bonkers?
Probably. If you look at the fourth picture in reply #2 you'll see I made my own washers. Only two type of people make their own washers,
madmen and home shop machinists.

Tony Ennis
08-04-2014, 11:13 PM
Your work is beautiful.

(I made washers the other day :-P )

RichR
08-04-2014, 11:22 PM
Thank you.

(I made washers the other day :-P )
Admitting it is the first step.

boslab
08-05-2014, 04:41 AM
So i discover making washers is another symptom of this yet unnamed disease, we need suggestions, how about Obsessive Compulsive Metalworking disease or for some guys i know Attention deficit coffee induced hyperinactivity syndrome, ok having a laugh but it is a beautyful job, i would rather look at that than some of the photos of famous artworks my student daughter shows me, todays education was " unmade bed" by Tracy Emmins, they call that art?, id rather look at prety swarf in the bin of the machine shop in work, often did?, the big swarf off the lathes with 15 foot faceplates used to fascinate me, it looked like strip steel rainbows, awesome, oops i found another symptom!
Mark

Lew Hartswick
08-05-2014, 09:19 AM
If had been doing that I'd have done the taping with a spiral point tap at the same time I drilled the holes on the mill.
OR ! even use a thread forming tap (with the right size drill bit) it woild have made that part a LOT easier. :-)
...lew...

RichR
08-07-2014, 02:27 AM
Hi Lew
Yes, that would have been nice, but I'm afraid I not as well equipped as you, so I make do with what I've got.

RichR
08-07-2014, 02:33 AM
Hi Mark

i would rather look at that than some of the photos of famous artworks my student daughter shows me, todays education was " unmade bed" by Tracy Emmins, they call that art?
I don't get it either, but art is subjective I guess.

So how do you feel about pinstripes:
http://i59.tinypic.com/dfzi2f.jpg

http://i62.tinypic.com/2rogcb6.jpg

http://i62.tinypic.com/2crabnm.jpg

I'm not much of a photographer. All the lines in the piece really played havoc with the camera.

boslab
08-07-2014, 05:09 AM
Now thats more like it, reminds me of looking at a ploughed field once from about 10,000 feet up strapped into an ejector seat of a hawker hunter fighter, upside down, i filled my toffee bag shortly after but the image of the lines stuck in my head!
Would fly cutting be applicable to flattening something like this?, or does the narrower cut produce more regular surface, as in flatter?
I suppose you could stick it in the lathe if you have swing enough, possibly with some concentric reference lines
Lovely job, well done, look foreword to seeing some clamps and vees
Mark

metalmagpie
08-07-2014, 08:45 AM
..hand threading all those holes through 1" aluminum got old really fast..

One of those $79 hand tappers would have really helped in tapping all those holes!

metalmagpie

Paul Alciatore
08-07-2014, 11:20 AM
That is not a trivial job.




Your work is beautiful.

(I made washers the other day :-P )

JRouche
08-07-2014, 05:39 PM
Real nice fixture plate!! Oh? I have made my fair share of washers also :) JR

RichR
08-07-2014, 09:28 PM
Would fly cutting be applicable to flattening something like this?, or does the narrower cut produce more regular surface, as in flatter?
A fly cutter can be a good tool for this. If appropriately sized, it can cut a wide swath across the surface. As the diameter of the cut gets larger, it becomes
more sensitive to tram. If the tram is out left to right, you cut hills and valleys (scalloping), it out front to back, you cut steps. This assumes cutting in the
X direction and stepping in the Y direction. Decreasing the step size increases the number of ridges but decreases their height. My mill is a round column
style so the tram is not easily adjusted. The pictures make it look like I made 5 passes per inch. If you look at the right corner of the plate in picture 1 of
reply #15 you'll see I actually made 10 passes per inch.


I suppose you could stick it in the lathe if you have swing enough, possibly with some concentric reference lines
I considered that, but I don't have a faceplate for the lathe.

I do have a 2" face mill that I might experiment with. Regardless, I'll probably take some 400 paper wrapped around a block and scuff the surface to reduce
any glare.

boslab
08-07-2014, 10:45 PM
Well youve got a nice square faceplare now!, ok iv never seen a square one, but theres a first time fore everything, and a second if it works!
Mark

RichR
08-10-2014, 02:37 AM
Well I found a small problem Since my mill does not have enough Y travel to mill the entire surface, I milled half, spun the piece 180, and
milled the other half. Running an indicator showed a 1 thousands slope crossing the centerline of the piece. So I set up a fly cutter and
skimmed it in two passes. Transition at the centerline is now about 2 tenths, close enough.

http://i57.tinypic.com/210nihl.jpg

http://i58.tinypic.com/256wsbo.jpg

http://i60.tinypic.com/102jb6f.jpg

http://i58.tinypic.com/qqwuxf.jpg