What kind of steel?

[GUNNUT in Iowa]

I spend a fair amount of time cruising woodworking forums and a question that is always asked is "What kind of table saw should I buy?".  Everybody asks it.  Everybody hates it, but it is just the standard question.  Anyway,  here is my "tablesaw" question.

This forum has sooooooo much information it has taken me forever to take it all in.  I can't - easily - find the answer.  I have read and fully understand all of the warnings about the dangers involved.  You should see discussions concerning blade guards! 

My machinist wants to know what kind of steel he is supposed to use.  The project is a golf ball cannon.  Barrel is approximately 5" in diameter x 34" in length.  He uses numbers like 4140(?) and others.  What do I know?  I work wood.  He is the machinist.

This is not a sleeved bronze or cast barrel.  It will be solid steel.

Any help, please?


Thanks.

[Cat Whisperer]

GUNNUT in Iowa -

WELCOME to the board!

(I grew up in Grinnell, have lived in DSM, CR, Ames and Council Bluffs).

4130 and 4140 are great, high-end steels for the purpose.  Special techniques for welding are required.

1018 is my go-to steel (unless you're shooting at very cold temps and then it's likely to be .... hmmm - some of the folks are doing some low temp tests).  It is weldable, it is strong, and it is resistant to cracking.

[Double D]

Well for your "table saw" use 4140, I have.  But 1018 actually might be a better choice for a black powder cannon.  Installation of the  trunnions requires welding.  1018 welds better than 4140.  If your Machinist knows how to weld 4140 properly use it.

You barrel is a 1/10 of an inch to small in diameter for a straight bore golf ball cannon. If you use 4140 that lost tenth is meaningless.

Do you have a plan or pattern you are following?  

[Rickk]

With a sub-chamber, 5" in diameter would work fine.

Without a sub-chamber, you will be having problems getting it to work well anyway. An aluminum foil wrapped powder charge that will load easily in a golf ball bore would have to be at least about 1.7" long.  Anything much shorter than 1.7" would try to load sideways and not seat properly. That is a heck of a lot of powder for a golf ball I think.

There is only so fast that you can realistically launch a golf ball. A sub-chamber will allow the easy use of smaller, more realistic charges, and make for a decent margin of safety as well.

[armorer77]

1018 is the way to go , also use a powder chamber . 1"x3" will hold more than you need to launch a GB out of sight . This also allows the use of a smaller blank . 3.5" is more than acceptable . For evidence , view my thread "How to blow up a Cannon"  . Armorer77

[GUNNUT in Iowa]

OK!!!!

You guys are great!

Too many numbers for me to understand - wood, remember? - I will just print out this thread and give it to my machinist.

Random responses to questions/ comments so far.

Cat Whisperer - If you lived in Council Bluffs, you know where Atlantic is - and - yes, I know where all those places you mentioned are.  :>)

Double D - :>)  My "table saw" is a 10" cabinet saw by Grizzly - cast iron - probably not good for excessive powder charges, although the pile of dust under it could go "boom", if properly mixed.  I understand the welding the trunions part, so does my machinist.  I talked to him about boring the blank and then plugging them before turning it in order to align them with the bore.  He said something about "not everybody has a large milling machine".  I don't know.  Wood, remember?  :>)  He does know how to weld.  He builds parts to fix steam locomotives.  I am not sure, but he might have even built a steam powered Space Shuttle.  My "plan" consists of drawings of plans from a book (Round Shot and Rammers by Harold L. Peterson).  I imported them into my CAD program and have been going from there.  1/10 of an inch gets lost pretty quick using this technique.

Rickk - "Sub-Chamber". THAT is what I was trying to think of.  I spoke with my machinist about this this morning, but I could not think of the word.  I told him my drawing did not show the proper configuration of the chamber, but could not exactly explain what I thought I wanted.  MORE INFORMATON, PLEASE.


armorer77 - or "Powder Chamber".  I think you and Rickk are talking about the same thing?  Believe it or not, I am not really building this thing to shoot - much, but on the other hand who wants a cannon that won't shoot? - and you don't know what the next guy will want to do with it in another 50 years or so.  I will make it safe even though I may not shoot it - much.  So why would I want to make a cannon to not shoot?  Mostly for the look of the cannon.  You see, I have a very large gun collection, but nothing over .50 BMG in caliber.  I need something BIGGER.  Destructive devices load from the breech.  Cannons load from the muzzle.  :>)  Plus - I get a chance to build the carriage.  Wood, remember?  :>)  Anyway, about that "powder chamber".  If I understand you and Rickk, I need to reduce the breech end of the bore to 1" by approximately 3"?  Of course no "hard" shoulders.  Correct?

Thanks, again, everybody for your help with this.

Steve

[Double D]

Round shot and Rammers a much over looked great source for plans for making cannons. Take the book down to Kinko's and put it on the copy machine, blow the pictures up, get you ruler out and take measurements straight from the copies.

[Cat Whisperer]

Steve -
I think you're getting there fast.
Toss out a jpg of your barrel design when you get to that point.  Never hurts to have another set of eyes glance over it.
Yup, been through Atlantic!