M38 Hollow Core Scope Project 2016 - Bulldog44

[MoSc0ut[TK]]

Bad news:

After just 3 test casts, my M19 mold was destroyed trying to remove the resin scope . My guess is that I used too much black pigment and it caused the resin to stick to the silicone like glue. Money down the drain. Trying to salvage the mold if possible but its not looking good. The M19 project is now on hold.

Oh no! Sorry to hear that. Dang, just dang.

[T-Jay[TK]]

Sorry to hear about the issue with the M19 mold. But once you start offering the M38 scopes, it will only be a matter of time to get some new silicone...

[tomm1999]

This is awesome!  Best of luck and cant wait until when/ if you do a run!

[kevin926]

Don't throw out your non perfect parts. I would be interested in buying some parts that are not perfect to make one scope. 

[Bulldog44[TK]]

Oh no! Sorry to hear that. Dang, just dang.

Just my luck as usual!

 

Sorry to hear about the issue with the M19 mold. But once you start offering the M38 scopes, it will only be a matter of time to get some new silicone...

Positive thinking Tino! Thanks. I will find out tonight if I can save the mold to cast b grade M19s. Lucky if I can get nicer castings. Report back on this when I get some results.

[Bulldog44[TK]]

This is awesome!  Best of luck and cant wait until when/ if you do a run!

Good to hear. Did a little research into shipping costs last night. One more step is to get the packaging. Almost there. I want to start selling but want to be sure what I am offering is quality. I would hate to sell something and then have someone say it is not worth what they paid. 

Interest post coming soon! Keep an eye out for it!

[Bulldog44[TK]]

Don't throw out your non perfect parts. I would be interested in buying some parts that are not perfect to make one scope. 

Certainly. I will start sorting all the parts out soon to get a better idea of how many A grade parts I have.  Hoping to have enough for 20 kits soon. There are plenty of imperfect parts and will be happy to offer these too. 

[kevin926]

I'm using the doopy scope and counter for my pvc build however, I would like to use your scope for my aluminum build. They look great!

[Bulldog44[TK]]

Somewhat Good News Update! - 

 

After examining the M19 mold I found that most of the damage was on the inner surface area of the scope. I put the real scope back into the mold and re-poured new silicone plugs- one for the front end and the back end. It was a small risk to take but it worked and didn't require a whole new batch of silicone. I think it only required 100grams in total.

 

 

I wanted to find out what went wrong with the mold so I did a bunch of reading and concluded that I added far too much black pigment into the resin. It dried well but acted more like glue during the curing process and attached itself to the silicone walls. You can see my Kylo Ren rampage as I destroyed the resin scope trying to rip out the silicone stuck inside. Many fowl words followed but I will leave out the transcript of that midnight rant I had by myself.

 

Lesson learned and for the salvaged mold I decided to do a straight up gray resin casting with no pigment (also powder coated the mold with talc powder. Results look good enough to use this mold for some scope kits I think. Some minor defects but nothing a little sanding can't help. I will experiment with some light doses of pigment in future castings. 

 

:)Very happy the side light socket ring is fully intact as well. Now on to more smaller part casting to get some inventory going! 

[MoSc0ut[TK]]

So glad to hear you were able to get this sorted with the M19 mold! I know what that silicone costs, so this is great news.

 

I did a lot of reading on molding before I attempted the first pour of my silicone and found that mixture of petroleum jelly and mineral spirits works well as a mold release medium too and it won't damage the silicone.

 

 

 

It works best to spray on but can be brushed on as well.

 

Just another tool you can add to your arsenal.

 

I can send you the pdf I downloaded as this may be hard to read.

 

Jim

Edited May 20, 2016 by MoSc0ut

[Thrawn's guard]

Brian I'm sorry to hear about the issues with the mould however it's good that it isn't as bad as was first thought.

[T-Jay[TK]]

This really gives an idea of all the efforts behind resin casting. Will look different at resin parts in the future...

[Bulldog44[TK]]

So glad to hear you were able to get this sorted with the M19 mold! I know what that silicone costs, so this is great news.

I did a lot of reading on molding before I attempted the first pour of my silicone and found that mixture of petroleum jelly and mineral spirits works well as a mold release medium too and it won't damage the silicone.

It works best to spray on but can be brushed on as well.

Just another tool you can add to your arsenal.

I can send you the pdf I downloaded as this may be hard to read.

Jim

Cool stuff. Certainly send me that PDF. Very helpful.

I will try this.

Brian I'm sorry to hear about the issues with the mould however it's good that it isn't as bad as was first thought.

still holding my breath on the next few casts but I think I can avert the same disaster. Cheers.

This really gives an idea of all the efforts behind resin casting. Will look different at resin parts in the future...

It is really not a good idea to re-insert the original object back into the mold from what I read but my mold design idea for casting these have me some flexibility. Lets hope the mold can pump out loads of nice m19 scopes!

[Bulldog44[TK]]

 Screwy Update:

 

I worked in an Ace Hardware shop many years back and remember how poor I was at grasping the different sizes of screws, nuts and bolts, etc. Still I struggle with it all . So I am reaching out to you all with help identifying and locating the best, most accurate screws available to match the originals found on the M38 and M19 scopes. 

 

I have found many shops on line that sell some of these screws but I don't want to order a box full of screws that don't exactly match. Some characteristics like the shouldered parts of the screw shaft or exact style threading cannot be matched but at least I want the following to be as accurate as possible:

• color
• length
• head diameter and style

Cost is also a bit of a concern as less common screws can be expensive. I found a company here in Japan that sells similar micro slotted grub screws seen on the scope body and eyepiece (to lock inner parts in place). The screws are slightly off in size but look the part. The cost for 300 of them is around $250.00! Ouch! 

 

Here are some not so great photos of the screw sizes so far. I will update the scope feet mounting screw size and the slotted adjustment pegs later on if needed. For now I am focusing on the outer 3 sliver cheese head screws and the 3 black inner fillister head long screws. The black fillister screws are important as these were used for the main eyepiece mounting screws on the M19. 

 

 

 

 

 

The measurements are not all 100% accurate, please feel free to add more accurate measurements if you have any.

 

Please let me know if you can recommend any suppliers who sells these types of screws as close to the original screw sizes. Thanks! 

[MoSc0ut[TK]]

I have a fastener speciality store a few miles away. Here is the website http://www.oregonbolt.com, you may be able to contact them with your inquiry. I've found them to be helpful when finding the odd bolt when working on my cars. I am unsure of these smaller fasteners but I'm sure if they can't help you they don't make it! As for cost you'd have to ask them. As most places like this charge a premium for shipping if the price works out on just the hardware, I can stop by and pick up and ship to you for probably much less.

 

 

Jim

[Bulldog44[TK]]

Thanks a bunch Jim. I will try contacting them and see what they can help me with. I contacted a few other shops in the UK but no reply from them at all. <br>

Let you know if I get a good response. Appreciate your help and offer regarding shipping!

[MoSc0ut[TK]]

Look what showed up today!

 

 

I took pics of everything as I inboxed it. If this is your "B" or "C" grade kit then I can only imagine what your "A" grade must look like!

 

 

 

I won't hijack your thread with my "un-enveloping" once I get over my amazement of this kit I'll start a thread with all my observations and build.

 

Now that I see the quality of this kit I need to find all the right screws and some lenses and I'm going to give that prism count chocula found a try.

 

As for that central lens has anyone been able to tell if it has any actual magnification? If I could get my hands on a real scope I know optometrists have a machine that can measure magnification on lenses. If you could talk one into measuring those lenses for you we could source the correct magnification lenses and get really crazy with this!

 

You know.....Leupold optics is based here in Portland, Oregon. I wonder if I can find a Star Wars fan that works there......hmmmmm!

 

 

Jim

[Bulldog44[TK]]

Look what showed up today!

 

 

I took pics of everything as I inboxed it. If this is your "B" or "C" grade kit then I can only imagine what your "A" grade must look like!

 

 

 

I won't hijack your thread with my "un-enveloping" once I get over my amazement of this kit I'll start a thread with all my observations and build.

 

Now that I see the quality of this kit I need to find all the right screws and some lenses and I'm going to give that prism count chocula found a try.

 

As for that central lens has anyone been able to tell if it has any actual magnification? If I could get my hands on a real scope I know optometrists have a machine that can measure magnification on lenses. If you could talk one into measuring those lenses for you we could source the correct magnification lenses and get really crazy with this!

 

You know.....Leupold optics is based here in Portland, Oregon. I wonder if I can find a Star Wars fan that works there......hmmmmm!

 

 

Jim

Awesome! It made it! I was worried about damage but it seems to have arrived unharmed. Thank you again for your kind words but seriously this is a B grade/ C grade scope. Each part had some hole or cosmetic defect. I can't wait to see what you can do with it. Please feel free to use this thread to post any progress or news you have. The more shared helps raise the possibilities what can be done with these scopes. Cheers!

[MoSc0ut[TK]]

Oh, by the way. This kit starts out a 1.6 oz. add lenses and a few screws and I'll bet you won't be much over 5 oz. this will be great for trooping.

 

 

 

Jim

[Bulldog44[TK]]

Oh, by the way. This kit starts out a 1.6 oz. add lenses and a few screws and I'll bet you won't be much over 5 oz. this will be great for trooping.

 

 

 

Jim

Cool. They are really light and not that fragile I think. Cheaper to ship as well.  Thanks for posting this info!

[MoSc0ut[TK]]

Indeed! Even though these are so light it feels very solid. Resin being a pourable two part epoxy will hold up to some abuse. I defiantly wouldn't intentionally drop this, or any optic real or reproduction. After all it just made the trip across the largest ocean and US postal carriers aren't known for their gentle touch. Last Christmas they left a computer I bought for my son in the pouring rain 7 feet from our covered porch! The computer survived, thankfully.

 

 

Jim

[sla73]

I hope you find a good supplier for the screws Brian. I'm still looking for a replacement for one of the three eyepiece mounting screws that is missing from my real M38..

 

I had to settle for a 8 BA 1/4" steel cheese head, they weren't stainless and have gone rusty....

[Bulldog44[TK]]

I hope you find a good supplier for the screws Brian. I'm still looking for a replacement for one of the three eyepiece mounting screws that is missing from my real M38..

 

I had to settle for a 8 BA 1/4" steel cheese head, they weren't stainless and have gone rusty....

 

Sorry to hear about the rusty screw. Hard to find anything close to the real thing. $500 or more to have a machine shop here make them no matter how little or many to make. 

I ordered some screws from the UK recently with the head diameter at 5mm, head height at 2mm. Very close to the screws I have, maybe off by a half a mm. Hard to tell yet, but I will post my findings when they arrive. 

 

Found another US based supplier for the long black screws that mount the prism cell in place and also used for the M19 eyepiece. Hope they match as well otherwise I am out of a lot of cash on useless screws. 

[Bulldog44[TK]]

Just a quick question to anyone interested in a scope kit, would you be bothered if the scope parts are not all from the same scope? I tried test fitting parts for each scope and found that some parts from the same scope did not fit as well as parts from the other scope.  

  Use of the black pigment created mixed results for how parts match up. I might have to recast some parts in the regular resin color to reduce shrinkage (or use less pigment) . This would result in some kits having a mix of different shaded parts and not 100% from one original scope. 

 

For future scopes I may cast in the plain resin color to keep things consistent and all components true to the original scope. 

[MoSc0ut[TK]]

I don't think anyone will care what color the parts are as they will all end up primed and painted in the end. Doopy's are the plain resin color and you see the amazing things people do with those! I say save yourself the $ and effort and make leave them pigment free.

 

 

Jim