Repairing older guns

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Tank
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Repairing older guns

Post by Tank » Thu Oct 31, 2013 4:35 pm

So, we have all been there. Bought a gun and it would work, if only we had just that one little part or seal as the original had perished or corroded away. To replace it means buying a whole kit - at ridiculous cost - or having the part made.
Bob asked me some time back if I had "any of those little round peg things that go into the front of the FWB 65 or 80 (and 90) cylinders. You all know the one (those of you who have owned this type of Pistol) it is the small cylindrical buffer that goes into the front of the pressure cylinder, right below the breech seal. Anyway, here is a picture for the rest of you who don't know what I am talking about (that probably means all of you, my descriptions aren't always too clear:-))

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So, we both, Bob and I, contacted our various people and the very best price was thirty two Euro's :shock:
I do realise that people need to make a living but at the end of the day this is a small plastic cylinder 9mm long and 5.5mm in diameter. A metre of nylon in 6mm diameter only costs £2.50 for goodness sake.
But that was the problem, it was 6.0mm in diameter, the requirement is for 5.5mm

So in order to save a few pounds, I bought a lathe. Well, it seemed like a good idea at the time. That is my excuse and I am sticking to it!
On a serious note, I had been struggling along for years now and the only thing that was my savior was the fact I have access to some industrial equipment. But that's a problem in itself. It is a bit on the large size and turning down a part that is 9.0mm long and 5.5mm diameter in a lathe the size of which I have access to is laughable. That and the fact I am in a pretty dirty oily environment. My workshop has fitted carpet, I like clean and tidy.

So now I have a lathe, amongst other tools. So I started out trying different materials, pure polyurathene rod, acetal, nylon, nylatron and anything else I could lay my hands on. The stuff I settled on is a semi rigid polyurathene as used on competition car suspension, it machines easily if the speed is high and cuts nice and cleanly. It is quite easy to measure. Pure polyurathene is hilarious, you take a measurement - make a cut - measure it again and it is still the same, because it deformed during the cut. Quite frustrating but interesting nonetheless.

Eventually I hit upon this material and the results are great. Here are a few pics of the exercise:

This is what we are looking to reproduce
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I found that turning the part down from a 10mm diameter rod was far easier than trying to turn down 6.0mm rod, clearly the rigidity of the material is an issue in any machining operation:
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This is a situation that can get you into trouble if it was stainless or aluminium, just slow down, back off, clear the birdsnest and go back in slowly:
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The finished part. Okay, I made two but nothing like having a spare is there?
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And this is the new part alongside the factory part, colour coded as it were :D :
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So if Bob remembers to bring his FWB65 tonight, he can use it safely once again.
graham.
I’m going off to go find myself. If I’m not back by the time I return, keep me here.
https://tamesidepistol.club/

micken
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Re: Repairing older guns

Post by micken » Thu Oct 31, 2013 5:58 pm

I'm loving this Graham, especially the idea of buying a tool to get a job done at a factor of X times the cost of the part. A man after my own heart.

I'm only envious really, as you know I hope to get tooled up in order to be able to do work like this. I was speaking with Bob yesterday, finally introduced myself to him over the phone, about FAS rear sights and other things. I'll start a thread when I get photos together. I'm thinking it's a job for a milling machine, hint, hint.

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Tank
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Re: Repairing older guns

Post by Tank » Mon Nov 11, 2013 8:48 pm

So, just following on from the "making of parts" article, I have quickly realised that my eyes are not quite as good as they used to be :cry:
S I wanted to install some DRO's (Digital Readouts) to the Micro Lathe. However, there is a stumbling block, the cost. Prices have come down dramatically in recent years and over on Arc Eurotrade you can kit yourself out with a three axis DRO for as little as £170ish but I really need to keep costs down right now.
I am fortunate that I have a couple of good toolshops nearby and one of them was having a special on 4" Digital Calipers. So, as they look just the same - don't they? - as these Digital Readout scales I "invested" in one for a bit of a trial.
They are, naturally, induction hardened. What this means in real terms is that they are as hard as the Hobbs of Hell. I took the Angle Grinder to it in the end to "modify" it.

Image

Now offered up to the cross slide bed:

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A little bit of a bracket (the hole had to be ground through the caliper end, yes - THAT hard) and I was thinking something as simple as a bit of servo tape for the actual readout part. Servo tape is double sided tape that is very strong and has little flexibility.

Image

Yes - I know the bolt is insightly, I will trim and grind it later.
Bit of a result really.
graham.
I’m going off to go find myself. If I’m not back by the time I return, keep me here.
https://tamesidepistol.club/

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