Rangefinder workup or "Another thing I never finished years ago!"

[drokkul]

Ughh...so many little pieces and details I've started and stopped...

So let's travel back to a long time ago in an apartment far, far away (others might call this 2007)

I posted a thread about my scratchbuilt rangefinder with a few pics and where I was going with it. These are a few of the pics







I used styrene (from a tow away sign) and WoF's templates. I bungled a bit and switched the ends on the Polaroid piece. I said I was going to rebuild it, but I never did as I found the correct camera at a flea market for $5 and extracted the piece I needed.

I also said I was going to make a mold for the clear block...and I did...and I cast one...and I was actually fairly pleased with how it came out. Until years later and the clear resin turned orange . I know some clear resin clarity can deteriorate when subjected to UV, but this was stored away in a drawer for years with little to no light contact so not sure what happened, but its another bridge that I'll have to cross.

So I think originally I was going to use the RF topper I built as the piece on the display, but I decided since I am looking for these little projects I would make a mold.

I made a squish mold (or compression mold if you prefer) for the topper





So 1st cast came out nice on the top...



Bottom not so great...



I knew air was gonna get trapped somewhere so this first casting showed me where I needed to cut some air vents and will get used as a test piece for fitting the internal support I'm going to make (you can see I've already cut the piece with the bubbles away)

So I trimmed out a couple of air vents from the silicone and...



Fully serviceable piece that just need some minor cleanup. Got a couple of pinholes in other spots, but some epoxy putty cured those pretty quickly.

I was afraid that since it was a fairly thin walled build it might possibly sag over the years with the extra weight of the clear block stilted so far to one side. So I decided that I would make a metal support for the inside.

Using the first cast I put together a cardstock pattern for the metal piece I want to make.





I then transferred the pattern to a steel sheet and cut it out with metal shears



Now I need to bend some metal!

MORE TO COME!!!

 

[ShortFuse]

Looks great. Can't wait to see the finished product.

 

[drokkul]

Get BENT will ya?





Worked it over a little and I think I got it into the shape I need.



MORE TO COME!

 

[ToEleven]

That sheet metal is a great idea.

 

[superjedi]

Very clever, you humans.

 

[drokkul]

That sheet metal is a great idea.

Thanks! It will serve a dual purpose. Both to give structural stability and to allow me to magnetize the clear block for easy removal.

 

[drokkul]

So I got a little more work done.

I have the piece pretty well formed for fit just needed to make one more adjustment to the top right corner in the pic.



This now fits inside perfectly and would require no glue at all. It really just snaps into place once you get the back into the rear housing. I will however use some glue on the top for magnetizing the clear block. This way the magnets won't pull the top support down as you pull the block out.

So the next thing I needed to do was mark off for the connection of the RF stalk. The stalk I have is solid aluminum. I want to say I purchased from BKBT years ago, but it has been a while so that may not be correct. I measured the end of the stalk and the bottom of the RF and worked a little basic math to get this.





So I was working out how I was going to attach the RF to the stalk and going through pics. I remembered seeing some have screws going all the way through the metal stalk, some with brass rods showing, and some with nothing showing. I decided I wanted to go with the clean look and have nothing showing.

I didn't want to bother with tapping threads into the aluminum so I figured the best way to go was to use miniature machine screws. Oh but where would I find such a thing?

Maybe that tray I bought from the True Value that closed down years ago! (PS I hated to see that place go. True Values are so hard to find anymore especially the ones that have been in operation for decades. Those old stores are treasure troves of cool stuff that you WILL NOT find at Lowe's or Home Depot.)

So I marked off a line on the stalk and drilled a couple of holes.



To mark where to drill the matching holes on the RF I just brushed on some paint (a little thick) right around the holes in the stalk and while the paint is still wet I pressed it to the marked off area on the RF. Hold it for a few seconds and when you pull it away you have 2 paint blots with clear holes in the middle. This gives you a pretty exact marking for where to drill your matching holes. (I didn't take pics of this process as it is time sensitive to perform, but if you've never done this or heard of it before hopefully you get the gist of it).

Once done there I cut off a couple of machine screw heads and test fit everything together to get an idea of the length I needed to trim the screws to. Once measured and cut I epoxied them into the holes in the stalk



While everything was test fit together I marked on the metal where the holes for the LEDs and the attachment bolts need to go.

MORE TO COME!!!

 

[ToEleven]

So True about the True Values. I've got an old Ace hardware near my house that I'm on a first name basis with. They have all of those trays full of odds and ends.

 

[drokkul]

So you know what's great? Well I'll tell you.

What's great is when you go to drill holes in your metal and they come out good like this



What's even better is when you go to drill the other two holes and your drill bit decides to catch on the last one and yank up your clamped piece of metal. The piece that you meticulously measured and shaped. Then proceeds to whip it around the drill press like a tornado headed for Dorothy.
:angry <<<< some emoticons just aren't strong enough.


So now I had a fairly warped piece of metal to deal with. I had a pattern so it's not like I couldn't cut out another one, but it was the principle of the thing. My problem was that since the metal was bent into the shape of a rangefinder I had to figure out how to flatten certain spots without bending others.

Apparently necessity IS the mother of invention...



It took a bit of restraint to not use those on the drill press.

 

[drokkul]

Well with the metal piece mostly straightened out I continued on.

My next hurdle was realizing that although I had a lot of tiny machine screws I didn't have a wrench small enough for the nut. So once again necessity rears it head...





So with my new invention ( I call it The Prenchsicle StickTM ) I was able to gain access to the small space and turn the nuts pretty easily.



And the finished topper and stalk is here...









So unfortunately this is where it ends for now. I don't have a good way to cast clear, bubble-free resin and the old stuff I used turned orange...how orange you ask?



Ugh...it used to be pretty smooth with a slight frost to it which I was happy with. I tried some sanding on this after it turned orange which I knew wouldn't do anything, but I have to try.

If anyone out there that has some experience and a vacuum pot wants to help me out PM me. I will supply the mold and materials and pay for shipping.

Thanks everyone!

 

[mainst69]

I have a possessed drill press too, it called many a project to the dark side