PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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The covers fit SO well that I was afraid of trapping air under the cover and perhaps having expansion problems.
So we drilled a little hole in the center of each cover, no more worries.
This nylon though soft in comparision to metal is really a bear to get a good surface finish. Sharp pointed tools with a lot of rake worked the best.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Ok, assembly of the Collimation Plate with everything finished except the Collimation Tube, spherical washers for the Collimation Swivel/Screw assembly and the Collimation Knobs the go in the above asembly.
Rockers, Rockers Shafts, Rocker Shaft Bushings, Rocker Screws with Ball Ends, Rocker Ball End Pads, and Rocker Ball End Pad Covers.
Sure does not look like that much assembled, but I SO glad to have it behind me. 
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A few I enjoy,
and a few more in the works ;<)
Edited by PrestonE (06/26/08 05:41 PM)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Next, center drilling the Spherical washer after turning the radius.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Turning the shoulder of the Spherical Washer after having drilled the center hole out to just over 5/16 for the threaded Collimation Swivel Screw to pass through.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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And finally the Collimation Swivel assembly with the new Spherical Washer.
Finish all three, to tomorrow we will assemble the Collimation Plate to the Back Plate
That's all folks for today, enjoy 
Regards,
Preston
--------------------
A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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So, no machining today...but Lots of measuring and remeasuring, checking design drawings and reworking the Collimation Tube design a bit.
I put this full thickness 12.5" diameter 2.125" thick mirror on the Collimation Assembly assembled to the Back Plate to measure the distance to where the secondary should be positioned.
Long story short, the upper truss tubes need to be 1.5 inchs longer...that's why they are mocked up with PVC 
We will build the entire secondary structure before cutting the CF tubes and will have to purchase another section of tube it appear.
But the Rocker assemblies work just great
Pic of mirror on Collimation Assembly.
--------------------
A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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A side shot of the Collimation Plate, with Collimation Swivel, Swivel Screw, and Set Bolt going through the Back Plate
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Finally a shot of the underside of the Back Plate showing the Spherical Washer on the Collimation Screw to allow for tilting without binding and the Push/Setting Bolt
With any luck, tomorrow back to machining. Looks like the Collimation Plate and Back Plate will have to go back on the Bridgeport mill and have thier central holes bored, as the surface finish is not quite smooth enough for the o-rings to slide on without binding or scraping.
So we will do that first and then start machining the Collimation Tube afterwords.
Take Care and Have a Great Weekend!!!
Regards,
Preston
--------------------
A few I enjoy,
and a few more in the works ;<)
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jasonharris
super member
Reged: 09/16/06
Posts: 137
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Hi Preston, it s still all looking very nice and I am convinced if I ever win lotto that a machining center will be in my future
I am curious about the mounting of the mirror cell. What is your feeling about lateral movement of the cell? I know you are happy that the mirror wont move in the cell, but what about the cell itself?
I am going to have to decide on the collimation bolt set up for mine. I am still deciding if I use the bolts that I had on my thread or not..
A concern of mine is how much movement of the cell would occur? Once locked down there will be none.. Perhaps its not a problem as it wont shift once its right..
Are you doing anything different in this area?
Thanks,
Jason
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Hi Jason, yes, as a matter of fact that's what's next up on the list of things to machine...and why it's taken a couple of extra days...
The Collimation Tube fixes to the Collimation Plate and the Mirror rest on the Pad Covers on the Rockers. A
At the center of the mirrors point of balance ie...if set on edge the center of balance...there will be an O-ring on the Collimation Tube in that position, that we will then slip the mirror over and down to rest on the Rocker Covers.
The Collimation Tube then goes further below the Collimation Plate and through the Back Plate. In the middle of the Back Plate another O-ring will be on the Collimation Tube in that position.
This will constrain the mirror to the Collimation Plate and to the Back Plate...
I'll try to put up a drawing tomorrow.
But now I've got a few pics of yesterdays and todays actions...
Regards,
Preston
--------------------
A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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So, Saturday involved more measuring and checking as we only want to do this once.
The Collimation Plate has a roughly 4.5 inch hole in the center for the Collimation Tube to fit tightly into, but the hole as CNC'ed on the Router was a bit less than a bored hole...so we'll just take a few thou off and clean her up.
Centering the Collimation plate with centering gauge on the Bridgeport. You turn the mill on to a slow speed and the arm sweeps around the inside of the hole. The dial indicator swings back and forth. The less of a swing, the closer to center. So you adjust the x and y axis until it moves the least and then lock down the mill top.
Pic showing about 0.001" of movement.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Boring about .005 inches at this point. You may be able to make out the roughness of the CNC on the upper left side of the hole at about 10:00 clock position.
At this point we are about 1/2 was there. Taking .002" per pass and a down feed of .001" per revolution, so each pass took about 10 minutes as we were only running at 80 rpm.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Here's a close up of the finish pass as we now have contact all the way around.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Today we started on the Collimation Tube... 
We could not get the proper size tubing or pipe, so had to do it out of solid stock...
That's 5 inch OD by 9 inches long, the little thin piece will end up being the nut to hold the mirror to the Collimation Tube.
--------------------
A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Chucked up in the 4 jaw chuck. You can see the markings on the end showing which side was high as we indicated it to get it running concentric with the chuck.
Cetnerdrilled first and now getting after it with what they call a parobolic flute, ment for drilling deep holes. Drill bit is 7.5 inches long and 3/8 " diameter.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Next up a 3/4 inch drill and turning the OD at the same time.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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We'll now swithch to a spade drill and use the 3/4 inch hole as a guide. 1.5 inch spade drill.
--------------------
A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Having finished the 1.5 inch we switch to the 2.0 inch. Here's a pic of the bit outside the hole.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Ok, Hogging out all of this aluminum is for the Birds 
But we are finally getting somewhere.
Yesterday's action continued to remove more material. Here's swithcing up to the2.5 inch spade drill from the first end...is 9 inches long and we can only reach in about 6-7 inches.
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A few I enjoy,
and a few more in the works ;<)
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Using the boring bar here and the last pass to get the 3.5" hole in the first side.
--------------------
A few I enjoy,
and a few more in the works ;<)
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