Sean Cunneen
professor emeritus
Reged: 08/01/07
Posts: 565
Loc: Blue Island Illinois
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Wow...First time in 25 pages I've felt qualified to contribute!
Try Grapeseed oil, less contaminants, cleaner flavor and the highest smoke point of any seed oil.
I'll sit back down now.
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Sean Cunneen
Blue Island IL
8" f/8 Home built Newt, Discovery mirror, curved vane spider, CG5 Motorized head with Intelliscope DSC, Pier
C102hd CG-4
100mm F4 Cedar Tube RF Refractor
2,3,4,5,6mm Televue Plossls
27T3,33T3,44T3
9-22 Ethos Zoom
NO, I'M NOT SELLING!
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Sean Thanks, I've got that in the fridge as we cook with that also...it may come in real handy when we start to machine the OTA mounting block with dovetail...
The bare block is 9 x 15 x 2.25 inches thick and weighs over 30 pounds...and I'd like to get it down to about 10ish...
Maybe putting the grapeseed oil in the Micro Mister will be the trick...
Regards,
Preston
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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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Update with pics 
Here is the second batch of 8 backing plates for the catch blocks being CNCed on our router.
Here we are using the new bit designed to be used for high speed aluminum routing, the finish is much better 
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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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Catch blocks and small backing plates deburred and fitted together.
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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 milling the lightening holes in the slider plates that the catch blocks will mount to for tensioning the spider vanes.
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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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Now we are roughing the OD of the slider plate. We will leave 0.025" for a finish pass.
These took 4 minutes to rough out each one, far faster than I could ever do with manual setups on the Bridgeport...I would be very lucky to finish one in an hour... 
We are really liking the CNC router with the new bit.
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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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Finish pass taking the last 0.025" around the OD and taking steps down by 0.050" through the total of 0.250" thickness of the material/
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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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3 of the finished and deburred slider plates.
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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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Close up of the single flute Micro 100 bit
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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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Mock up of slider plate, catch block, and CF tubes in place as seen from the right side.
We'll be using 1/4-28 SS threaded rod to extend from the upper ring to an acorn nut on the top of the slide 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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Rear view of the same.
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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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The other day we did the first JB Weld bonding.
First we cleaned the surfaces with alcohol. We then applied a silane solution of A-1100 that is an amino functional silane that bonds both to the CF and then leaves a reactive amino site to react with the slow curing JB Weld.
This looks almost like alcohol and is applied with a small brush to the area the you would be appling the small bead of JB Weld.
The we apply the well mixed JB Weld to both faces of the surfaces to be bonded.
We want to be sure that both surfaces get well wetted with the epoxy before we place them together.
Note, that CF edge is only 0.062" thick and the bead of JBW is not much bigger that the face thickness.
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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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That last picture is hard to see, but if you look closely you can see something shiny...that's the JB Weld, the CF is flat black/
Here's a shot of the finished bonding of the center tube to the Mirror mount plate and on of the 1/2" diameter tubes that surrounds the collimation bolt.
I'll see about updating again on Monday with pics.
Enjoy...
Regards,
Preston
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A few I enjoy,
and a few more in the works ;<)
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Mike I. Jones
Pooh-Bah
Reged: 07/02/06
Posts: 1103
Loc: Fort Worth TX
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A CF guy at my workplace said you could stir in dry paint pigment to the JB Weld to help color match it to the CF. Might give that a try on some test samples and validate the bonding strength is not compromised?
Mike
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56 mirrors, lenses, 16" f/6 Newt, 6" f/10 refractor, TOA-130S, Tinsley 5" f/15 Mak, 6" f/4 RFT, Coronado PST. Still to build: 24" f/10 Modified Dall-Kirkham, 10" f/26 Mak, 8" f/12 apo, spectrohelioscope, Herrig, Schupmann, and a new design you'll like.
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Sky Captain
Scope Builder
Reged: 11/07/04
Posts: 5745
Loc: Seattle Washington
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Quote:
ps...I do remember you saying something about peanut oil for cutting, but I'm alergic to peanuts...I use olive oil in the manual shop...and the kitchen
Olive oil is good...is it EVOO? 
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Equipment Overload!
Kerry.
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Gene Hunter
super member
Reged: 12/29/07
Posts: 194
Loc: SC
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preston, I am considering using JB Weld on a CF mirror cell that I am working on. Do you recomend it? does it bond great. A friend of mine swears by it.
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Clear Skies
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PrestonE
scholastic sledgehammer
Reged: 04/29/05
Posts: 817
Loc: Houston,Texas
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Thanks Mike, I could add carbon black but it increases the vicosity greatly with small additions and we will be spraying it with a flat black paint anyway...
I've got enough variables to not want or have time to retest something that works well now...
Best Regards,
Preston
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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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Hi Gene, I'm happy with the JB Weld for bonding the CF, but be sure to test your procedure first!!!
If the surface is glossy, roughen it...first...with our VARTM surfaces and those that we applied the peal ply nylon, the surfaces came out to a mat finish and are excellant for secondary bonding operations...
We used the A-1100 silane solution as a primer to increase the bond strength. We now see at failure that the break is in the CF rather than at the surface.
However, if your surface is very clean...no oils from handling with you hands or dust from another operations then the JB Weld to both mating surfaces well wet out should do nicely.
Regards,
Preston
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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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So now we will bond the upper CF plate to the previously bonded center tube of the Mirror Mount Plate.
We have put Lock Tight on the spherical ball end to the collimation thread and the 3 will be bonded inside of the sandwich between the upper and lower CF plates.
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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 all of the little stiffening tube ends as well as the outer ring have a bead of JB Weld applied just before alighing the upper CF plate and lowering it into place.
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A few I enjoy,
and a few more in the works ;<)
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