RGG gat build for the complete beginner

This thread will chronicle my RGG gat build.  New to machine work all operations will be documented not matter how boring so this thread may not be to everyone’s taste.

Photos of setup and operation will be included. Multiple part machining will only be shown if a clever way to produce the parts is found.

Basic information.  I am new to machine work, only had the lathe and mill a few months.  Lathe – Enco 14x40 308-0232
Mill – Grizzly 9x42 G9901 with DRO (woohoo!)

Tooling, measuring and work holding will be described for each operation.  Writing things down makes me think about it.  Notes allow me to review my processes and learn to be a better machine operator.

Next up is material.  Having read many of the builds (I am not worthy) the decision was made to stick to the RGG material list.  Too ignorant of metallurgy to go mucking about just yet.  The RGG instructions were reviewed many times and a list developed.  Could not figure out a simple way to post the spreadsheet on the forum so a link is provided.

[link_open={http://www.srbain.com/gat/gat.htm}]{RGG Material List}[/link_open]

Note the tabs at the bottom.  They navigate from a per drawing list, an order list, receiving list and finally an idiot list for fractional to decimal conversion.  The spreadsheet can be downloaded here:

http://www.srbain.com/gat/gat material list ver 3.3.xlsx

Note: version numbers may change.  Please report any errors please report so corrections can be made.

Thank you for that list I had just started one myself.

Looking forward to watching you. Several of us are starting to gather things together and planning to start the build first of next year.

Good Luck and may things machine the way that you want.

Note to everyone. Highlight the whole line and then copy paste in order to get it to work. It\'s a nice spread sheet. If you just click on the link it will not work.

Later 42rocker

Are you going to split the bolt carrier in two pieces or go one piece like the drawings?

Later 42rocker

Thanks for the encouragement 42Rocker.  Rest assured there will be many blunders along the way.  Modesty was lost many moons ago so mistakes and fixes will be posted.  I have always learned more from mistakes than success (or just got lucky).

I found out a bit late posts can not be edited after approval.  I know, rtfm.  More care will be given in future posts.

Gat spreadsheet

Version number removed from file name. Code corrected (hopefully)
RGG Gat Project

Randle
Just downloaded your updates. Thanks. As far as editing our old posts, I don\'t know. Some of the websites, after you have so many posts you can go back and edit you posts, just takes a while of posting before you can do it. I have 33 posts and can\'t edit at this time. maybe at 50 or never. LOL. ------#### As of this time I can now edit #### ----- So give a few more posts.

Are you thinking about making your bolt carrier in two pieces or one. It seems that most of the folks are going with 2 piece bolt carriers these days. I\'m sure thinking about it. What are your thoughts??

Later 42rocker

[quote name=\"42rocker\"]
Are you thinking about making your bolt carrier in two pieces or one. It seems that most of the folks are going with 2 piece bolt carriers these days. I\'m sure thinking about it. What are your thoughts??
[/quote]

Finally figured out the editing thing.  Read the instructions but they did not sink in until now.
You can edit your post until someone replies to it, then it is locked.  What messed me up was the post had to be approved (understandable) before posting.  By the time I got back around to it the edit function was dead because someone had replied.

News flash.  My replies post immediately.  That makes things much easier.  Thanks admin!

I have no idea about the bolt carriers.  Please explain, in detail, with pictures and a clay model.  .  I am quite happy to have figured out the material list and got it ordered.

NO  -- Clay model. I\'ve noticed that several of the other folks, cutter and others, have switched to a two piece bolt carrier. Cutting it in half and pinning the two half\'s together. Done where the major size change happens in the front not the rear. There are a couple of good reasons for it from what I can tell. Material savings and you don\'t have to cut a blind end hole, 10 times. There is a better term for that. That does not come to mind right now, happens as you get older.

I think that our group is going to go with the two piece method. I\'ve tried to find the better original threads and posts on this to show others and all I can do is remember that it\'s been done this way before.

Also some other things to think about are bolt changes and barrel changes. I\'ll try to post more on both of these later under a build thread that I\'ll be doing for our group build.

Later 42rocker

I remember a discussion of 2-piece breech blocks from way back.  Mine I did from 12L14 instead of brass for cost & availability reasons, but with the price of brass these days, it makes a lot of sense not to turn off a big whack of it.

After some thought this thread will be moved to the machining section and topics by drawing number.  It seems like a good way to organize and keep comments specific to the part.

On some sites they have a Q&A thread going and the build thread with only the posts by the builder that started the thread. Keeps the build thread clean.
Good Luck on keeping the other thread \"clean\". I\'ll bet that you will still get the \"well my uncle back in 1942 did something like this\" LOL not quite but.
I reviewed with the tool and die maker last night and our group is going with the two piece bolt carrier. drawing 48-01
Also remember that you should drill and ream the front and rear barrel carriers at the same time that you do the barrel carrier. At least that\'s what my RG-G notes say to do.

Good Luck on your build.

Later 42rocker

48-01  --  unknown dimension

Lets see if I get this right. Center of small holes is on 1 inch radius. Half of the 0.281 hole is 0.1405, that should be where the inner circle is drawn, so 1. inch minus 0.1405 is 0.8595 inches, ok drawing shows the the tip of the milled ares is 0.15 above the circle so add the 0.15 to 0.8595 and you get 1.0595.

Ok, that said I would not turn that area down till the holes are drilled. Leave it alone till the holes are drilled.

All of the above are just my thoughts at the end of the work day. Going home.

Later 42rocker

Try this

[rtbain]

I had to do several projects to find out what I didn\'t know enough to ask.  Now I am back and ready to begin anew.  Not much smarter but with lots of questions!

[rtbain]

Re: Front and Rear barrel plates.  My thinking is to try useing plate rather than sliced round stock to make the barrel plates.  Buy cold rolled steel in the proper thickness.  Rough it to round on the bandsaw.  Punch a center hole and use a mandrel to turn to diameter. 

 

Thoughts?

[Stirlingking]

Randy:

I do almost all similar parts using that method.

A couple interesting Gatling Guns will be ready to show in the near future.

 

- Ted

[rtbain]

Tried a couple of times to get the mandrel to work.  Just couldn\'t control run out consistently.  I am giving up on being efficient with materials and will use 3\" (dia) x 4\" (lenght) for the plates.  Hell I tried everything else.