Author Topic: Hello Everyone! (Read 2635 times)

Double D · « **Reply #30 on:** January 14, 2008, 05:51:19 AM »

Quote from: mortarmaker on January 14, 2008, 04:12:52 AM

Yes, I meant when the barrel pivoting back 100 degrees or so on the trunnion! I guess you have to have tight trunnions.

Yeah max,

I don't think that 1 is going anywhere!! How would you change the trajectory on that 1!

Range in a mortar is adjusted by increasing or decereasing the powder charge.

Point of impact, angle of attack or angle of impact are all changed by changing the elevation if using an adjustable mortar.

Use the charge to get your range, then using then use the elevation control move the point of impact backwards or forward a few yards.

Or to loft a shell over a fortification raise the elevation so the shell goes up and down at a steeper angle impacting closer to the back side of the emplacement.

Or raise the elevation so the shell goes up higher and comes down at a steeper angle for greater pentration---plunging fire like straight down on the lightly armored deck of an iron clad.

mortarmaker · « **Reply #31 on:** January 14, 2008, 06:21:54 AM »

That makes sense DD. I think I'm going to bore mine tonight. I'm gonna go with 1.732 on the i.d. and 3.375 dp. with a powder charge chamber of 1" i.d. x 1.125" dp. Maybe I'll have time to work on the Trunnion also. I believe I'll go with the rear trunnion. 1" in diameter.

Double D · « **Reply #32 on:** January 14, 2008, 04:19:15 PM »

For a golf ball mortar that is a huge chamber.

Cat Whisperer · « **Reply #33 on:** January 14, 2008, 04:33:31 PM »

I'll have to chase out those pix - the host I used is no longer in business.

Adjustable? The one I made could be adjusted a little bit, but is was at rest in one position.

I once made up ten golf ball mortars in 4140 (4" diameter for overkill) that could be adjusted every 15 degrees by locating a pin through the trunnions.

The 4.5" one in my avatar is adjusted by putting wedges between the tube and a rod going through the base. From 0 to 90 degrees in thicknesses of wedge material. Crude.

Terry C. · « **Reply #34 on:** January 14, 2008, 04:38:20 PM »

I recommend you reconsider the 1" diameter chamber. As DD said, this is large for a GB mortar.

My GB mortar's chamber is 1" in diameter, and I've often wished I had went with 7/8" instead.

A .875" x 1.125" chamber will send the ball out of sight. Any extra range from the 1" chamber is going to be minimal, if even measurable.

And with charges less than full capacity, you will get more consistent and efficient burn from the smaller chamber.

Don't get me wrong, I love my GB mortar. I worked hard on it and I'm proud of the way it turned out. But I do feel that I pay a price at very short ranges for the large chamber.

Terry C. · « **Reply #35 on:** January 14, 2008, 04:54:30 PM »

Quote from: mortarmaker on January 13, 2008, 03:06:54 PM

Question,

Don't mean to sound too dumb! But, when rear mounting your trunnion on a mortar, what keeps the barrell from kicking back?

The mortar above has trunnion caps that are snug enough that the barrel will not flop around, but the barrel can be moved fairly easily. Otherwise, the elevation mechanism would be useless.

It has never moved off the elevator, even with very stiff charges (moon shots).

This gun has a chamber that will hold about 240 grains of powder. If it was going to rotate under recoil, I think that would do it.

GGaskill · « **Reply #36 on:** January 14, 2008, 06:07:44 PM »

I have a 3/4" chamber in mine and I think that is too big. I would start with 1/2" and see how that works. You can always open it up.

mortarmaker · « **Reply #37 on:** January 14, 2008, 06:09:50 PM »

Terry,

Those are some nice looking mortars and cannon! Exceptional craftsmanship! What material did you use to turn your mortars? Unfortunately I bored my mortar earlier. I did go with the 1" chamber. Oh well. This 1 is just to get my feet wet anyhow. I'm going to go with a more traditional mortar next time. The bore came out great though!

Cat,

If you don't mind who do you get your materials through?

cannonmn · « **Reply #38 on:** January 15, 2008, 03:30:46 AM »

Quote

How would you change the trajectory on that 1!

More or less powder charge. Each model of mortar is provided with a range table that tells how much powder to use to achieve a given range with a given projectile type.

Most muzzle-loading smoothbore mortars were designed to be fired at 45 degrees Q.E. (in the Navy we called it "Q.E." for "Quadrant Elevation."

Cat Whisperer · « **Reply #39 on:** January 15, 2008, 12:01:25 PM »

Quote from: mortarmaker on January 14, 2008, 06:09:50 PM

...
Cat,
If you don't mind who do you get your materials through?

Steel is something I LOOK for. Some at yard sales, some a closing of small machine shops.

I bought for some time at a local machine shop that would give it to me at cost - usually small pieces, often larger.

I was a tooling engineer for a couple of years and developed a relationship with a larger local shop - they would give me the companies price (based on volume) and so they did a bit of machining for me as well.

If you're looking for something serious, get a numbered steel - then you KNOW what it is. If it's like a golf-ball mortar the pressures are much lower and doesn't need much.

I did pickup a bit of 1144 stress-proof seamless and some rounds that we made the golf-ball mortars from for the contests. Might have a piece or two left you could have for the postage.

mortarmaker · « **Reply #40 on:** January 15, 2008, 04:37:24 PM »

I never thought to look at yard sales for materials! We deal with a few companies in this area.
We usually get materials through M.S.C. Which they are pretty high. We have one company in Lynchburg (Va. Metals) that have pretty good prices, but they don't usually carry 4140. If you ever need anything, let me know. I may be able to get you a pretty good price on it. Thanks for the offer on the seamless. I'll try to remember that you have it. If it's not gone when I need it! If you ever need any machine work done let me know, I will try to help you out1

Terry C. · « **Reply #41 on:** January 15, 2008, 05:24:31 PM »

This thread describes the stock I used for my GB mortar:

GB Coehorn project

I've got six more pieces of this hoarded now.

mortarmaker · « **Reply #42 on:** January 16, 2008, 08:50:31 AM »

6 more pieces!

That's cool. that should last you a while. I bet they are calling you all the time!

I enjoyed the thread you sent, it's great to see peoples work in progress.

I'll be putting more pics of mine on here soon. I got it bored and the trunnion relief in.

Is anyone else having a any diffucties with the new server?

Cat Whisperer · « **Reply #43 on:** January 16, 2008, 01:30:40 PM »

Quote from: Terry C. on January 15, 2008, 05:24:31 PM

...
I've got six more pieces of this hoarded now.

MORTAR BATTERY! FIRE MISSION OVER

lance · « **Reply #44 on:** January 16, 2008, 01:50:52 PM »

Quote from: mortarmaker on January 16, 2008, 08:50:31 AM

Is anyone else having a any diffucties with the new server?

no, but i've been offline 4 days due to internet connection problems. i'll mention powder chambers though, of my 3 golf ball mortars, i like the 5/8" dia. chamber the best for all around shooting. i also think it makes the best sound when firing golfballs, that's something we can test if enough different golfball mortars show up next time Tim wants to hold a shoot.

mortarmaker · « **Reply #45 on:** January 16, 2008, 03:03:41 PM »

I was going to go with the 5/8 chamber on my next one. Which will not be far behind this 1. I just need to make a carriage for mine now.

Then I can test her out. If I can ever find any Goex around here. I would hate to pay that 20.00 Hazmat fee to have it shipped!

Double D · « **Reply #46 on:** January 16, 2008, 04:44:58 PM »

Mortar Maker,

Over out of Winchester is the Back Creek Gunshop. It is right next to FT. Shenadoah the N-SSA grounds. Back Creek is a GOEX Distributor.

If memory serves, you are about 3 hours away. We drive further than that just to get to Wal-Mart in Montana.

If you planned it right it right , say in May drive up go to N-SSA Mortar shoot, hit Sutlers Row, get powder and then head home. Makes a long Day, but we have done it in the past.

mortarmaker · « **Reply #47 on:** January 16, 2008, 09:14:08 PM »

DD,

That sounds like possibly a plan, I'll definitely keep that in mind, Back Creek is the one that is going to ship it to me. To get my fix now, I'm going to have to pay the Hazmat fee.

Thanks for the information! 3 hours to Walmart , Wow!, I could be at 2 different ones in less than 15 minutes!

MM

mortarmaker · « **Reply #48 on:** January 18, 2008, 02:26:37 PM »

My mortar is done! I need a carriage now. I promise my next mortar will be more historically accurate next time!
And I will have the Goex can also. my Zippo will have to do for now.

I have a 1 inch trunnion, held by 2 3/8-16 machine bolts. I left it a little long, because I'm not sure what kind of carriage I'm going to go with. You can see my big 1" powder chamber!

Mod note: Hit the enter key between pictures

lance · « **Reply #49 on:** January 18, 2008, 02:57:31 PM »

mortarmaker, i like it, if you want an unusual bed for it here's a few pics:

mortarmaker · « **Reply #50 on:** January 20, 2008, 05:02:05 AM »

Thanks Lance,

I'll be working on the carriage today. Just going to design something.

Brian

Graybeard · « **Reply #51 on:** January 20, 2008, 06:20:15 AM »

Quote

I'll have to chase out those pix - the host I used is no longer in business.

A GBO Moderator using a picture hosting service other than www.myhostedpics.com for shame for shame.

We may have to cut your Moderator pay in half.

Cat Whisperer · « **Reply #52 on:** January 20, 2008, 10:56:18 AM »

What can I say, Bill, those were posted a LONG time ago. (I think before the days of www.myhostedpics.com .)

MortarMan · « **Reply #53 on:** July 07, 2011, 10:09:27 AM »

Lol, It's been a while. I actually finished my cannon a couple years ago. I went with a carriage similar to Terryc's. It sat outside for a year and because it was 1018 it rusted big time. And the oak was a little faded. So I decided to revive it for the Fourth Of July. I actually ended up bluing the barrel. I havent fired this thing in the 3 years since I made it. I didnt know what I was missing. Also Ive gotten heavy into Civil War relic hunting. But Im looking to build another cannon now. This one will be more period. Im thinking maybe a Napoleon. Anyways heres my cannon finished and a video of it shooting.

http://www.youtube.com/watch?v=MoBk_n6g5-g&feature=autoplay&list=HL1310065563&index=2&playnext=1

Double D · « **Reply #54 on:** July 07, 2011, 10:49:34 AM »

Were you doing that with Triple seven?
Be carefull with Triple seven. It is a smokeless powder that unlike black powder leave corrosive residue after firing.

MortarMan · « **Reply #55 on:** July 07, 2011, 04:31:52 PM »

Thats good to know DD. Thats all I could find around here on the fly. Especially with it being out of black powder season. You know I just realized I somehow ended up with 2 different usernames! LOL! Dont know how that happened. It has been a couple years. I sware im not looney!