Material

[phsarge]

OK so where can I find metal to do the I beams on a Barbette carriage. I have been searching around online an can't find any place to buy some. Is there a place to buy the metal from or do I need to find a way to manufacture some.

Thanks
Jeff

[rampa room artillery]

been there, trying to find a way to build them cheap,   cant be done,  go find a milling machine or a friend with a milling machine. and make them.




 rick bryan

[GGaskill]

Depends on the size you need.  Most likely you won't find anything already made that fits your scale; it usually isn't made in small sizes anyway.  If you are a good welder, you can probably fabricate enough for your cannon from T and angle shapes or even flat strips.

[Cat Whisperer]

The folks that buy lots of odd bits of steel from the vendors are the small to mid size machine shops.  Some get steel deliveries weekly.  If the truck is coming anyway, it doesn't cost anything for shipping.  Get to know the local folks at the machine shops.  That gives you access to all types of steel that the vendor stocks.  I've used a bit of 1", 3" and 4" architectural channel.  Other forms are there too.

[seacoastartillery]

     Jeff,   Perhaps if you gave us a few dimensions and info such as what model carriage, what scale carriage /gun including length, width and height of rails your Chassis will have, we could all visualize what size Barbette Carriage you want to make.  It would also help Austin out by telling him if his mill has the capacity to do the work.  We know a little about the process having built a batch of the 100 Pdr. Parrott Seacoast and Navy Rifles upon such a carriage.  FYI, we are Not looking for this type of work.

     Looking at the photo we took of the 1859 iron, front pintle carriage below, you can see why all of our searching for ready made, scale I-Beams was for naught!  Nothing, not even British garden railway I-Beams were the correct size for a 1/6 scale carriage.  We needed 28 inch long, 2 inch high and 1 inch wide I-Beams with 15 degree gussets 4X. The big problem was that the web (vertical part) was only .200" in 1/6 scale.  All the webs on existing beams were Much thicker!  Making them was not fun.  They were just about 2" outside the capability of our Bridgeport Series 1 milling machine.  We built a gigantic shuffling fixture, a 70 pound device which held the 1x2x28" bar of 1018 steel, and after we got to about 50 % of total length milled, we shuffled the bar down about 3 inches and milled the other half.  The other 4 sets were farmed out to a local shop with larger mills.  We absolutely stole those rails from them at 250 dollars per set.  They told us weeks later that the owner's brother had goofed up the bid and they should have gotten 400 dollars per set!  He was too embarrassed to ask us for more money.  They also had to meet the .015" we specified for straightness in the 28" length.  Lots of arbor press time there!

    If there is anyway that two pieces of small U-Channel can be welded together would satisfy your requirements, then a rail set will be a heck of a lot cheaper.  Anyway,    Good Luck!       Can't wait to see some build pics!

Tracy and Mike


Fort Pulaski, Georgia...End of the Chassis upon which the upper carriage slides.  Carriage for a 100 Pdr. Parrott or a 10" Rodman Gun.



     

[phsarge]

OK so here is the best I can figure. Getting a 3/4 inch bore 9 inch Dalgren. The plans I am working from for the carriage are the William Greene Plans. There is a possibility I may be getting a 1/2 bore so my dimensions will be smaller if that's the case. Let me know if any of this sounds wrong. By the plans they are for a 3/8 bore so a 3/4 bore would be double. Going off that assumption and the plans the beam would be 14.25 in length 1 1/2 in tall and 9/16 in wide. Not sure about the thickness of the item I'm thinking everything will be 1/8 inch but my brain ain't working up to full par as I am at work. let me know what you think and see how close I am on this.
 
Jeff

[GGaskill]

I assume you are going to paint them so it would be a lot easier to make them from aluminum than steel.  I can't see that you would need the strength and hardness of steel in this application.

[phsarge]

Could be interesting to polish the Aluminum. Could make the whole carriage out of it. How well would the carriage portion hold up do you think?

[GGaskill]

I guess it would eventually show wear tracks if you fired it a lot but unless you were using loads that recoiled into the stops, I think it would be strong enough.

[phsarge]

What would you think of doing the whole setup minus the barrel in aluminum? polished up with a black barrel I think would look good if not different.
 
Also what are everyones thoughts on using Aluminum for this part? if so what grade would be best?
 
Last on the Aluminum. Do you think aluminum could be used for a dictator mortar base?
 
For the wear I have a clear ceramic coat I used on guns. The stuff takes like 50 or 60 thousand cyles to show wear in the clear.
 
I'm no rocket scientist or metalurgist. All i deal with all day at work is steel.
 
Jeff

[GGaskill]

7075 is the strongest commonly available alloy, I think; its primary disadvantage is lack of weldability but that shouldn't matter in the instance.  You probably should use thicker plate than scale to get the strength but other than that, I would be confident using it.  Not sure you can find 7075 in plate, though.

[Victor3]

What would you think of doing the whole setup minus the barrel in aluminum? polished up with a black barrel I think would look good if not different.
 
Also what are everyones thoughts on using Aluminum for this part? if so what grade would be best?
 
Last on the Aluminum. Do you think aluminum could be used for a dictator mortar base?
 
For the wear I have a clear ceramic coat I used on guns. The stuff takes like 50 or 60 thousand cyles to show wear in the clear.
 
I'm no rocket scientist or metalurgist. All i deal with all day at work is steel.
 
Jeff

 With such a small gun, I wouldn't hesitate to make it with plain ol' 6061-T6 and just beef up the thickness in high stress areas. You can get it anywhere, fairly cheap and in near any size you need, including I-beam and other extrusions.
 
 7075-T6 is very strong but relatively expensive and can be hard to find in some shapes.
 
 2024-T4 is kind of in between 6061-T6 & 7075-T6 as far as strength goes and can usually be found for cheaper than 7075-T6.
 
 If you're going to go with aluminum, I'd spend the ~$100 and get it hard (Type III) anodized. However, unless you have the plater dye it black (only color most plating houses will dye Type III at reasonable cost on a minimum order), different alloys will come out different colors in "natural" (non-dyed). 7075 non-dyed hardcoat comes out a lovely gold color, if that's what you're into.   Most other types generally come out some shade of green, grey or brown. If you want to go totally nuts, spend a little more and have the plater add a teflon seal to the anodize for added wear resistance.

[dominick]

There is available a thin web channel that is 1-1/2" tall and about 3/8" wide that can be fused together to form an I-beam.