My RGG Build

I have always been fascinated with Gatling guns and when I came across the RGG plans I knew I had to buy them.  So far the project has been going pretty good and I am having fun with it.  For the most part I am sticking to the plans but I have made a few modifications to some of the parts.  The first thing I did was make up a fixture that mounts in the rotary table to help in the machining of the front & rear barrel plates, carrier block and the main recoil plate.  The fixture allowed me to remove the part after machining one side and flip it over to do the other side without having to re-align and setup the part.  Using a couple dowel pins and a shoulder bolt for alignment it sped up the process.

I am making as many of the parts that will be visible from brass, to keep that authentic look.  Plus it is much easier to machine then steel.

So far I have made the Carrier Block, front & rear Barrel Plates, side arms of frame assembly and the Main Recoil Plate. I am currently working on the Breech Backplate and it will be done this week along with the main shaft.  I will next start working on the cocking ring and cocking switch or I will start machining the barrels.  I have a partially machined Box Cam that I bought that just needs to have the OD finished to size, mounting holes and the ID bored to seperate it into two pieces.  I pretty much have purchased all the springs, bearings, gears and screws need for the gun.

I was having a hard time sourcing the 3\" brass tube needed for the breech housing but found an online source for it that was reasonably priced  It\'s called onlinemetals.com incase anyone else is searching for brass stock.  

Here are some photos of the parts I have made so far.

Nice work.

What are you using for barrels?

gary

Thanks.  

I have 10 Ruger 10/22 factory barrels that I will be using.  Bought them pretty cheap and alot easier to get here than barrel liners.

Those parts look Great. Keep us posted on your progress. I have been to busy lately to get any thing done on mine but hope to get back at it soon.

Nice work on your parts. Do you happen to have a picture of your fixture that you used on your carrier and barrel plates? I am always looking for new ideas so that when I reboot my brain, things might go a little bit easier for me. Thanks,bruski

Thanks guys.  

I will take a picture of the fixture when I get home.  I have no problems sharing the CAD drawing I made of the fixture and you can modify it to meet your needs.  Just wondering if it would be against forum rules to share the drawing since certain dimensions of the barrel spacing can be obtained from them??

I am also working on a fixture to aid in the machining of the extractor slot in the bolts but it\'s not done yet.

I found a picture of the fixture on my work camera, it\'s not the greatest quality but gives you an idea.
I took the picture when I had just finished machining the extractor slot in the rear barrel plate.



The flats shown on the fixture are 90 deg from the #1 and #6 barrel holes and is parallel with TDC/BDC.  To re-align the fixture on the rotary table, if you happen to remove it, you just set the rotary table to 0 deg and use a dial indicator measuring along the flat on the fixture to set the fixture true.  l also added some thru holes in the fixture to allow you to bolt it directly to the bed of the mill using one of the T-slots.  There are also two 1/4-20 tapped holes at the #1 and #6 barrel position which allow you to hold down the part and remove the center shoulder bolt so you can finish the center bore all in one setup.

There might be better way but this worked like a charm for me.

[quote name=\"TheJackal\"]Thanks.  

I have 10 Ruger 10/22 factory barrels that I will be using.  Bought them pretty cheap and alot easier to get here than barrel liners.[/quote]


Where are you located?

I used 7 Ruger Factory Barrels, 1 Winchester, 1 Sears, 3 Springfields. The variance in the Ruger Barrels in hardness and alloy was surprising. I ended up with a 0-9 barrel and an X and Y extra barrel. All are chambered and headspaced and while they are matched to a location, they can be interchanged. I used draw wedges fitted to slots in the barrels to hold them in place rather than threads.

nitewatchman

Jackal, maybe you already seen this, in the general section there are some known errors on the rgg drawings. Just thought I would mention this to you so won\'t hit any brick walls in your build. bruski

[quote name=\"nitewatchman\"]

Where are you located?

I used 7 Ruger Factory Barrels, 1 Winchester, 1 Sears, 3 Springfields. The variance in the Ruger Barrels in hardness and alloy was surprising. I ended up with a 0-9 barrel and an X and Y extra barrel. All are chambered and headspaced and while they are matched to a location, they can be interchanged. I used draw wedges fitted to slots in the barrels to hold them in place rather than threads.

nitewatchman[/quote]

I\'m somewhere in Canada...

I haven\'t started to machine the my barrels yet so I can\'t comment on varying hardness.  I know the breech face of those barrels are case hardened and eat carbide tools up.  About .075\" -.100\" from the face they are soft and easy to machine.

I am familiar with that barrel mounting method.  I have been emailing back an forth with Cutter and he showed me pictures of the wedge mounting system he uses.  It\'s a pretty slick setup.  I bought a semi machined Box Cam from him and he has been a big help sharing his knowledge as far as the build.


Thanks bruski.  I seen the list of errors and Paul Moore mentioned some of them to me when I called him a month ago looking for some info.  That was before I found this site.  

I think I found a typo error in one of the Desc. sheets not mentioned in that list, but I can\'t recall what Desc. set it was at the moment.  I will check my sheets when I get home from work and make a note of it.

Here are some photos of the fixture I used.



It\'s kind of hard to see by the photos but there are two recessed bores.  The small diameter one fits the front & rear barrel plates and the carrier block (before the back part is machined down)  and the larger one fits the main recoil plate.  These bores are what hold the part centered in the fixture as they are just abit larger then the OD of the parts.  There are also 2 reamed holes 180 deg apart that fit 3/16 dowel pins.  You will see that some of my parts seem to have extra holes not shown in the plans.  These were added to accomidate the 3/16\" dowel pins in the fixture used for orientation of the part.  The center hole was originally reamed .500\" DIA for about 5/8\" deep and threaded 3/8-16 the rest of the way through to suit a 1/2\" shoulder bolt but I needed to counterbore it .625\" DIA to suit the one end of the recoil plate.

I basically modified the fixture as I went along to make it suit the part that I was currently working on.  

Thanks for posting the pictures of your fixture.bruski

Was able to get the Breech Backplate finished today.  Not sure what I will work on next but might get the barrels roughed out then take a break from the project for abit.

Well I haven\'t had much to update lately as work has picked up abit, so not a whole lot of time for those government jobs.  
I did get a chance to start on the cocking ring section.  If I am carefull and don\'t mess anything up I should get two complete cocking and de-cocking segments
made from the one piece of heavy wall DOM tube.  I decided to make the part from one piece and forgo the two sections of tube silver soldered together.  I was never good
at silver soldering.

For the T-slot section I will be using a #302-1/2 woodruff cutter that I bought and modified, by grinding down the shank.  I got this idea after chatting with a former member (cutter)
on how he made his modified endmill.  It may look large in the photo but the smallest part of the cutter\'s shaft, just above the cutting edge, is only .110\" diameter. :shock: I sure hope it holds up.
   

I will post photos after I get the parts done.

Looks good so far. I need to get back to working on mine.

I also am using 10/22 barrels. I cut about a 1/4\" off the chamber end with a chop saw to get rid of the hardening. After that the turned down with no problems.

I also used a bunch of 10/22 barrels but cut on the other end just behind the front site. When cut to length this left the heavy breech section as a cut off just in front of the rear site. Saved a little bit of turning which is in my opinion a miserable task on this long limber tube even using a follower.

I cleaned up the saw cut ends with a piloted chambering reamer then turned the barrels between centers to assure that the bore was in center with the outside. Switched to a collet to cut the tendon on the breach end of the barrels. I used a wedge retention so the tendons are not threaded. Moved the barrel to a Spindex Fixture on the Mill and the extractor groove was cut with a Woodruff Cutter and the Wedge Slots using an end mill in the same setup.

The barrels were turned end for end, indexed against a stop at the breech and cut to lenght. Barrels were chambered to minimum headspace using Forrester Headspace gauges. Result is that even though the barrels are indexed to location any barrel will fit to any location and the extractor will time to the Rear Barrel Plate.

nitewatchman

Well the cutter worked out great.  Now to finish the rest of the machinig off on the cocking segments.

Did you get some photos ? Also how are you going to cut into segments ? I am planning on doing them in one piece as well.  Thanks

Mike

Unfortunately I didn\'t take any photos as I was machining the part.  I really wish I would have since it is pretty hard to exlpain how I machined the segements without photos.  I used a piece of 2.5\" OD x .75\" wall DOM steel tube.  I was able to get two pairs of segments out of it.  I will take some pictures of how the segments look now before I finish all the machining to them.  Wish I would have taken a photo of how it looked before I seperated the segments.  They were all attached by a small amount of material.

Here are a couple CAD images I made that might help explain how they were machined.

Jackal,
Sent you a pm. By the way, very nice work!

Thanks Dave.  


I haven\'t done a whole lot more work to it since things have been busy at work the last little while, but have been working on the bolts a bit at a time.  I did manage to get the front bearing support done today and mounted to the side rails.  Will post a picture when I get a chance.  I have another build I need to get back working on before I can dedicate all my time on this one.  Will need to start thinking about working on the barrels sometime this month before the lathe at work gets tied up with a big job.  I figure through the winter time I will be working on this build alot more.