HOW TO: Turn an M-38 scope into an M-19

[ZeroRoom[TK]]

So I ended up inheriting a random assortment of cast Sterling parts and it just so happened that I got two different M-38 scopes in the lot, one 1943 M-38 (or possibly M-40) and one 1942 M-38:

 

1943

 

 

1942

 

 

Since the 1943 is the more common model for ANH blasters, I thought I'd have a shot at converting the 1942 into an M-19 for use on an ESB blaster build. This mod turned out to be really easy and effective so I thought I'd share it here.

 

The first thing I did was bring this image of both scope styles into photoshop to measure the correct amount of material to remove to make the shorter M-19:

 

 

Then I laid a semi transparent version of the M-38 over the top of the M-19 and sliced it up into sections to make the right parts fit.

 

 

 

Then I dragged the chopped up parts back over to whence they came and it was easy to see what sections of the M-38 would need to be removed to turn it into an M-19.

 

 

Lo and behold I discovered a wee problem here: the M-19 has a thinner 'lens cap' on the larger lens than the M-38, 

 

 

but - if I cut the lens cap down to the right width I'd end up with the entire scope too short. I decided to cut my losses and leave it alone. 

 

Then I marked up my casting with a pencil as per the photoshop file:

 

 

Now, I knew the sections needed to be cut very straight since they were going to stuck back together, and any lopsided cutting could lead to a bent or droopy looking sight. Nobody wants a droopy scope now do they? So I opted for a mitre saw to cut the slices. However, this came with it's own set of problems. Firstly, obviously the resin is extremely soft. So I changed out my wood blade for a fine tooth plastic and metal blade. Naturally a hacksaw blade would have been even better but, again, I didn't trust free hand sawing. The other issue was that the mitre saw wasn't intended to cut such small or odd shaped objects. As a result, the clamps didn't fit to hold the scope in place while I sawed. So I had to attach an external clamp which meant undoing it and redoing it on every cut - which was a PITA but whatchya gonna do? Luckily the resin pour funnels were still on the casting so I knew I had a perfectly straight edge to line up against the guides. 

 

 

Thankfully the resin cut like butter, so the extra time messing about with the clamp was made up for. Cut slowly and gently here, especially since you'll still need to steady the scope with your other hand.

 

 

Once I'd sliced up the loaf of scope toast, I ended up with this:

 

 

Of course once I'd cut the smaller lens in half I ended up with a flat disc, so I had to drill the hole back out. I just did this with the old trick of progressively larger drill bits. I put the first few drill bits in my dremel just to make it easier to be gentle and not risk cracking the resin.

 

 

After that I finished it all of with a grinding bit on the dremel until the hole was as big as it needed to be but had a slight funnel shape. 

 

 

I didn't want the edge to have that 'just sliced in half' look either so I bevelled the edges with the dremel. Be careful here - the temptation is to go too far as you get perfectionistic over every little dimple. I didn't want to end up with none of it left however, so I opted to write any asymmetry or imperfections off as that Pre loved hand crafted look that we all know and love from the OT

 

 

 

Then I sanded the facing surfaces a little with some 180 grit and broke out the ol' E6000. Clamped the relevant bits together and left it to cure.

 

 

24 hours later (or 12 Kropogs in Imperial measurements) I had a very solid piece that looked like this:

 

 

Of course the glaring issue here is the massive drop between the two parts of different sizes. 

 

 

Nothing a few more minutes with the dremel, followed by a little hand sanding couldn't fix:

 

 

Be aware: This produces (as Darth Aloha would say) a crapton of resin dust. So if you're a pansy wear a mask and glasses. I'm still picking pieces of resin dust out of my eyes. On the upside - now it's starting to look like an M-19

 

The next step was to get the blended look where the front section meets the 'legs', as on a real M-19. Here comes my favorite magic cure-all Plasti-Bond! (I think our US brothers call it Bondo). I'm going to use it to mould the curve into the leg. The trick here is, once you've mixed your Plasti-Bond let it cure for a short moment BEFORE using it. This lets it part set to a putty like consistency, more like clay, making it easier to actually mold with. Be careful though - the curing time is exponential, so once it gets to this consistency you only have a few moments to work with it. Do not try to do both sides at the same time. Do one side, wait mix up a new batch and do the other side. Also do not get the Plasti-Bond on the brand new jeans your wife just bought you. Trust me on this one

 

A bit more sanding to perfect the shape (and remove the pesky little bits that insist on getting on parts they're not supposed to) and we're getting there...

 

 

I put a coat of brass paint on so that I can scratch up the black layer for a bit of weathering and voila! An M-19 scope:

 

 

 

Then I was struck by the nagging feeling that something was missing. Dammit! An M-19 has a focus knob (at least that's what I think I think it is). 

 

 

Luckily I happen to have this bit I sawed off the earlier:

 

 

Seems like just the thing for a focus knob. Looks just like it  Except I'm a fool and in my enthusiasm I already sprayed the brass undercoat... Nothing to be done except to wait for the paint to dry, sand it back and get the focus knob attached. I've got a dinner to get to though, so I guess this part of the thread will have to wait. 

 

Stay tuned....

[MartinSivertsen[501st]]

Cool!

[sskunky]

great idea and a great tutorial! Looking good dude!

 

[TD-3425]

Very nice!

 

On my hasbro conversion I re-created the target reticle and printed to transparency. You can download the file from my blog.

 

[TK-2126_MD[TK]]

O.O wow very cool. One question why not just trade your M38 for a M19?

[ZeroRoom[TK]]

why not just trade your M38 for a M19?

 

This way was more fun!

 

Fair question though. When I got the random lot of cast parts it was very random. Only some of the required parts for a pipe build were in the batch, some parts had doubles, some parts singles. So I figured with the doubles I could build two new blasters - one ANH and one ESB. I got the parts for such a ridiculous bargain I was determined that I would make all remaining parts myself and not spend any money on 'off the shelf' parts. Don't buy it if you can make it has been a lifelong habit

 

I suppose I could have offered someone a swap but since the M-19 is pretty rare and the M-38 pretty common I doubt there'd be any takers. Besides this mod was so easy to do - why wait?

[TK-2126_MD[TK]]

Great answer!!! i also like to build what ever i can!!

And makes a good tutorial!!

[ZeroRoom[TK]]

So I finally got around to working on this scope some more.

 

My intention was simply to add the missing knob on the side (According to the Encyclopedia Of Arms and Armoury the technical military term for this bit is "sticky outy knobby bit"), but, as is always the way, in the gap between working on it I came up with new things I saw needed doing.

 

The first was that I noticed the rear base mount on the M-19 is not square like on the M-38 but an oval shape as seen here:

 

 

 

I knew I'd have to fix this on mine or it would drive me crazy in perpetuity so I roughly marked out the smaller oval shape in pencil on the existing base:

 

 

Then, using the conical grinding bit on the dremel I did my best to shape it like the picture above. I say did my best, because the end result isn't fooling anyone, but I suppose this part will be mounted to the scope rail and barely be visible anyways...

 

 

Once I had the dremel up and running and figured I had already woken up the neighborhood, I decided I might as well carve out the larger end of the scope with a hollow, with a mind to filling it with resin later to simulate the glass lens. First I just hit it hard with the conical grinding bit again, just to remove as much resin as possible and create a deep pit in the cast. Then I switched over to the cylindrical sanding bit to finish the walls with as straight an edge as possible and avoid harming the lens edges that needed keeping:

 

 

It worked out pretty well, with a coat of ink black paint and filled with clear resin the depth will be very hard to make out:

 

 

So... Back to the reason I stumbled out into the workshop in the first place: Adding the sticky outy knobby bit. This whole affair was pretty "make it up as you go" so I kept my iPad handy with plenty of photo references to work from.

 

As mentioned earlier, I already had the knob itself saved from the slicing up of the original scope cast. What I needed to create next was this bit:

 

 

If i did this first then it would create a nice flat base just to glue the front part of the knob onto. (Sheesh - I haven't used the word "knob" this many times in a row since the last time I rang my ISP complaint line...) To create this sort of "bulge" first I took some 0.03mm aluminium flashing and wrapped it around a piece of curtain rod I had lying around that just happened to be the perfect circumference:

 

 

With the flashing being so easy to cut it was a simple matter of using regular scissors to shape it into a cuff of sorts that would sit against the underside of the scope in the right way:

 

 

Being very thin and hollow the cuff would need some surface area to use to fix it to the scope so I filled it with a very random blob of plasti-bond and let it dry:

 

 

Next I fixed it to the scope underside with a very VERY random blobbing of plasti bond. No pics of the process I'm afraid, for fear of getting the stuff on my phone, or it drying inconveniently while I try to steady my shaky hands for a pic. This is the "after" shot though:

 

 

I'm not showing this bit just to embarrass myself. I'm showing this bit just in case anyone out there is crazy enough to attempt this tutorial, as I want them to rest assured that, at first, it will look like something the dog left on the carpet. You do not need to do this bit neatly and it is no reflection of your modeling skills. This is the nature of these fillers and as you can see here is quickly and easily righted with some sandpaper work and a little care:

 

 

This also gives you a chance to sand off any stray Plasti-Bond (and there WILL be stray Plasti-Bond). This is very important because the downside of Plasti-Bond is that the slightest micro dimple or join that isn't perfectly smoothed and everything will look great until you paint it. The paint makes every imperfection stick out like the proverbial sore thumb. If in doubt it's almost worth sanding, painting, checking then sanding and painting again to perfect the blend. On the upside if the blemish is in the right spot it will add to the hammered metal look that these scopes have in the body areas anyway.

 

All that's left now is to glue the knob on and give a slap o' paint yeah? Wrong again! Turns out the knob on the real M-19 isn't a full circle - it has this bit:

 

 

If I may be so bold as to use another technical term I believe it's called the "slitty bit at the bottom". Easy enough to do - just a quick bit of slicing with a small hand hacksaw and done:

 

 

OK! NOW we can fix it to the scope. E-6000 to the rescue as always. A clamp and a wait overnight and we end up with this:

 

 

I gave it a good blast with the brass paint and here we go:

 

 

I'm going to leave it there for now. I want to let the brass fully cure for a week or so, sand it a tiny bit just to remove the uber shinyness and bring it back to the more realistic dull brass look. Coat it with another blast of brass, let it sit for a week then do the same. I'm hoping this will create a paint bond strong enough that when the black finally goes on any accidental chips or dings will only take off the black layer and just add to the weathered effect.

 

Only time will tell however, so come back in 2 weeks and we'll see the finished product!

[sskunky]

That looks great Lucas..... Good eye for detail.....Now you just need to change the M38 lettering on the front of the scope and you won't be able to tell the difference....

[TK bondservnt[501st]]

wow~!

 

now fill the 38 in and re sculpt a 19.

 

just kidding!

 

amazing job!

[Marv]

Man thats bonkers!!!

[Rich330[TK]]

Amazing conversion and major kudos for your dedication. I just got a very reasobly priced cast from Jesse for mine. Top notch resin scope!

[ZeroRoom[TK]]

Don't start me guys - I've gone over and over in my head every possible way I could get that M-19 engraved in place but I just don't think it can be done. No way I'm risking trying to make my handwriting look like a perfect stamp and mess the whole thing up!

 

Some small progress in some spare ten minute slots yesterday and today.

 

Dabbing some latex over the undercoat to provide the weathering effect later:

 

 

The trick here was just to let the latex graze the most prominent edges (ie the edges most likely to scratch and weather) rather than try "painting" it on and risk over doing.

 

Then a quick light coat with satin black which will be the look for the screw on metal bits at both ends. I peeled the latex off once the paint was touch dry so it would take a little paint with it. I'm pretty happy with the way that turned out:

 

 

It's hard to see in a photograph but I also gave the larger lens end a quick but very light twist in some sandpaper to simulate that machined metal look:

 

 

Once that's all dry - either today or tomorrow - I'll finish off the body with some hammered look black to simulate the heavey cast copper body.

 

Stay tuned!

[ZeroRoom[TK]]

Had to get up super early today for an international skype call but it gave me a few minutes to add some finishing touches to the scope paint job.

 

Taped of the ends to protect the satin paint from the hammered finish of the middle and used the hollowed out lens end to plonk it on a stick for spraying:

 

 

This turned out to be a very bad idea, because I kicked the stick and the scope hit the floor, quickly turning from "lightly weathered" to "weathered to *&$#" and I had to start back at the satin black layer all over again. It did however prove my theory correct that the brass undercoat should stay intact if the black chipped off, so there was a small upside.

 

The hammered black was too glossy for an authentic look so once I had achieved the texture I wanted using the hammered I gave it a light over spray of satin again to knock it back.

 

It's starting to look pretty good now:

 

 

You can just make out the hammered texture in these photos, but I can assure you it's great and really gives a cast metal effect:

 

 

Now all I have to do is add the resin inside the lens areas. If I just pour it straight in however, I'll end up with a flat lens which won't do at all. So what I need is something with the correct dome curvature to use as a mold to set the resin in - I'm keeping my eyes out around the house, ready to pounce when I find it (and I will find it)

 

But I've still managed to go from this:

 

 

To this:

 

 

pretty easily and in relatively short order. If you've got a spare resin M-38 lying around it's well worth doing

[ZeroRoom[TK]]

Actually - does anyone have any decent pics of the from lens of an M-19 to give an idea of the level of curvature?

[TK_LEPER]

It's inset a ways, so it's hard to tell unless you remove it.

 

Edited November 18, 2011 by TK 4702

[ZeroRoom[TK]]

Cool - it hasn't got nearly the curvature I thought it did - I'm glad I asked! Of course no I see these pics I'm already spotting things I did wrong or should have corrected

 

Thanks so much for taking those pics Jesse. That's very generous of you - especially considering that, like Joey and Rich said, I should have just bought one of your great casts in the first place!