24 Shot Threaded Rod Rack Idea

[jamisonlm3]

I've been working on this idea for a while now and thought I'd see what everyone thought about it. This rack is made from glued together 3/4" and 3/8" plywood. It's held together with 3/8" threaded rod. I wanted a rack that would have a good chance of being undamaged if there is was a cato. I also wanted a rack that would be relatively stable, one that was at least 24 shots and one that's not too heavy.

This rack is 13.5" wide, 34" long and 9.5" high without the mortar tubes. With the rough calculations I've done, with it's mortar tubes, the whole rack weights around 30lbs. unloaded. Loaded it weighs close to 40lbs. The Excalibur mortars used in this rack have 3/4" between them and you can get more if you don't use the sleeves. Two 1/2" rods are used stake the whole rack down on each side if firing from a surface like grass. There's also feet that you can rotate out to increase stability which are held in place with a wing nut that you loosen and tighten as needed. These are made with bent pieces of 1/8" steel flat bar.

[chriskrc]

That looks like a pretty nice design

[displayfireworks1]

The problem with those large racks are they are heavy and create storage issues. The second for me is, I seem to get many of the smaller size salute fail. I swear if I shoot 20 of them one always explodes in the mortar. If one blows apart in the mortar in the middle of that large rack it may be an issue damaging a large rack requiring more work to repair. Nice illustrations by the way and nice touch adding the foot for scale.

[ilovecrackle]

I like that design Jamisonlm3. I use to something similarto that when i first started out.
Now, I just use "sleeves". What i mean by that is i build basically a 10 shot rack, all 10 mortars in a row. Then i screw metal eyes in the sides. I then use rebar to secure and stake them down. Obviously this won't work if you shoot on concrete but for me it works out great because i always shoot on grass or dirt fields.
I prefuse them ahead of time and leave a little extra fuse at each end that way when I arrive at the place I'm going to shoot, I can easily arrange them in any direction I want stake them down and connect the fuses accordingly .

Did any of that make sense? Hahaha if not, I can try and find a pic and see if i can figure out how to upload it. Haha

[jamisonlm3]

To be honest, I didn't even think about a solute going off in this rack. I wonderered what would happen if a canisiter shell would go off. My big fear was a shell going off in one of the corner mortars and the pressure inside being relesed through a single hole (https://www.youtube.com/watch?v=Mn-_jSWI4cs) at one of the pieces of threaded rod. The force of that blast might break the threaded rod from the rack and throw it out. Here's another picture. It show the size of the rack a little bit better. She's 5.5ft tall in the default template and is roughly 12" behind the rack.

[PyroJoeNEPA]

That is an interesting design. In Europe they use open frame metal racks & just drop the mortars in the frame---this is 1.3 I am talking about. It is a very popular design over there but not so much here--Grucci has a setup of open frame steel racks for 6" guns--we got a couple of them this year [used ones= but have not used them yet.
For 1.4 application I don't see a big problem if you have a shell blow in the tube--especially if you are keeping the collars on the Excal tubes. The amount of open air around the tubes would dissipate a lot of the energy in a blow out and not damage the adjacent tubes [as much] as if it were in a rack with all the tubes touching each other.
There are some pretty heavy overloaded 60g canisters making the rounds this year--I saw one destroy a 20 shot HDPE rack two months ago at a club shoot. It damaged 4 or 5 tubes & made toothpicks of the rack! And this was NOT loaded in upside down--it was a defective shell.
The one potential issue I see with your design is the all-thread oxidizing after a few times outside in the weather & the threads being difficult when you need to tighten\loosen the nuts. I guess a shot of WD-40 would address this? Also, I thing the swing out legs would need to be longer to give you better stability--especially if the ground is uneven. They are a nice touch, though.
Best thing is to build a prototype & use it a while & see what refinements you might want to make on it. July 4th is a long way off yet.
Keep us posted on your project. It is interesting.
Also--on the Excal tubes--are you cleaning the bottoms with a flush bit router & putting them into a recess of the two bottom plates?

[jamisonlm3]

Did any of that make sense? Hahaha if not, I can try and find a pic and see if i can figure out how to upload it. HahaI've seen where people screw pipe clamps to the side of their rack. Is that what you're talking about?


That is an interesting design. In Europe they use open frame metal racks & just drop the mortars in the frame---this is 1.3 I am talking about. It is a very popular design over there but not so much here--Grucci has a setup of open frame steel racks for 6" guns--we got a couple of them this year [used ones= but have not used them yet.
For 1.4 application I don't see a big problem if you have a shell blow in the tube--especially if you are keeping the collars on the Excal tubes. The amount of open air around the tubes would dissipate a lot of the energy in a blow out and not damage the adjacent tubes [as much] as if it were in a rack with all the tubes touching each other.
There are some pretty heavy overloaded 60g canisters making the rounds this year--I saw one destroy a 20 shot HDPE rack two months ago at a club shoot. It damaged 4 or 5 tubes & made toothpicks of the rack! And this was NOT loaded in upside down--it was a defective shell.
The one potential issue I see with your design is the all-thread oxidizing after a few times outside in the weather & the threads being difficult when you need to tighten\loosen the nuts. I guess a shot of WD-40 would address this? Also, I thing the swing out legs would need to be longer to give you better stability--especially if the ground is uneven. They are a nice touch, though.
Best thing is to build a prototype & use it a while & see what refinements you might want to make on it. July 4th is a long way off yet.
Keep us posted on your project. It is interesting.
Also--on the Excal tubes--are you cleaning the bottoms with a flush bit router & putting them into a recess of the two bottom plates?I've seen images of steel racks. Honestly, If I did shows, I'd probably use metal racks. I'm sure you could build wooden racks to survive 1.3 stuff, but I think you'd see racks more closely resemble timber frame construction. They'd be too heavy and bulky to be of any practical use. I plan on using lock nuts to hold the whole rack together. I thought about using normal nuts, but the price difference isn't too great and the added security is more than welcome. I do see the threaded rod rusting over time. I plan on using zinc plated rod and hardware, but even that will rust over time out in the elements. I could use stainless rod and hardware, but that increases the price by roughly double. Still, I wouldn't have to worry about it then. I plan on taking the base completely off the Excalibur mortar tubes. I do intend on using a router or belt sander to make the bottom smooth and round like the HDPE pipe mortars you can buy.

The rack from the images I've posted is a rack I designed for myself. By no means is this the only way you could build a rack this way. You could have as few or as many rows as you want. You could increase the spacing or decrease the spacing. You could have a little 12 shot rack like in the image below or a 60 shot rack. At that point, it would be a bit of a pain to move, especially if you're just one person loading and unloading everything like me. I settled on a 24 shot rack because it's not too heavy for myself and because I can load a whole box a shells into it.

[jamisonlm3]

Built my first rack today out of some scrap 3/8" and 3/4" plywood. The whole thing is held together with 3/8" threaded rod and loc nuts. For the larger racks, I plan on gluing the top and bottoms together. I used three HDPE mortars a local fireworks store owner gave to me. A 2-1/8" hole saw makes a perfect plug. The ID of the mortar was around 1.9". I sanded the edge that's going into the mortar down a little to make a bit easier to tap it in with a 3lbs sledge hammer. I'm amazed that it was that perfect of a fit, really. I used 9 small galvanized nails to nail each plug in. If you do it this way, I recommend you pre drill your holes with a drill bit slightly smaller than your nails. The holes for the mortars are 2-1/2". I think these are a little bit wider that DR11 mortars. All that's left is to test it.

[displayfireworks1]

Good job, that turned out just like your design pictures. That top board with the holes in has to to difficult cut. Are those mortars held in position or can you pull them out?

[jamisonlm3]

The mortars can be taken out. They slide in and out easily. Drilling the holes for everything wasn't that bad. Everthing was drilled out while clamped together in two phases on my drill press. The hardest thing to do was to figure out how to make the loc nuts go on backwards. Overall, building this rack was a learning experience.

[PyroJoeNEPA]

You dd a very nice job on the rack. Now you have to get some burn marks on it. It's too clean! LOL!

[jamisonlm3]

Thanks. It's still not completely done. I didn't even think to round the corners when I built it.

[RalphieJ]

Beautiful work, but I'm not crazy about using steel rods in racks, especially when firing salutes. Ever had a chunk of wood go whizzing past your head? How about a metal rod the size of a crossbow bolt?

[chriskrc]

Those racks look good, time to fire some shells out of them.

[jamisonlm3]

Honestly, I'm curious how it would weather a CATO from a solute as well. I don't plan on shooting any, but I think it has a much higher chance than a normal wooden rack to remain intact. Still, I wonder.

[jamisonlm3]

I've been working on this rack idea a bit. Originally, I was going to use the mortars from Excalibur. I shot of box of those shells off for the new year and won't be buying those shells again. I've modified the rack to fit the fiberglass mortars that you get with just about every other shell kit on the market. I've made a few other small changes as well. Instead of 3 rows of 8, there are 4 rows of 6. This makes the rack have a footprint closer to a square than a rectangle. I think this will help with stability. The extra space gained also lets longer stabilizing feet be made. The idea is still the same, but using the fiberglass mortars, the new version is quite a bit smaller than the earlier version. A single 4x8 sheet of 3/4" plywood gives you enough wood to make four 24 shot racks.

[jamisonlm3]

Man, it's been a long time, but I finally did it. I got two racks built for the new year. I plan on building another, but I won't be able to completely populate it with mortars. I'll at least get it 3/4 filled. After half assing it last year and not being able to do anything for the 4th, I'm getting all my ducks in a row well before the big day this time. I've also got 3 rolls of uhaul's brown packaging tape and a combined 150ft of fast and slow burning fuse. I was lucky to get get a case of Excalibur and I've still got a box of diablo I never got to shoot earlier in the year. Things are shaping up pretty well.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=2765&stc=1
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=2766&stc=1
.

[Rick_In_Tampa]

Very nice racks!! Have you test fired them yet? They do look very stable. Great job!

[jamisonlm3]

Thanks! Nope, not yet. Since I wasn't able to do anything for the 4th, I've been eagerly anticipating the new year.

[Kenny East]

They look very nice, what are the threaded rods used made of? I use a threaded rod for my adjustable launch pad for modle rockets, it corroded very quickly due to the sulfur and other residue left. That could be prevented by painting it with high temp enamel... Figured that out after the rod was pretty pitted up.

[jamisonlm3]

The threaded rod, nuts and washers are all zinc plated steel. You're right about the rusting. The smaller 6 shot rack I made last year has some rusting on the top. It's not so bad on the the nuts and washers, but the ends of the threaded rod where it was cut is the worst. I do have some high temperature paint. I'm still undecided if I should paint them. Maybe just the top? I've considered spraying the bottom and the feet with truck bed liner.

[Kenny East]

Only concern with truck bed liner is that it's going to be a pain if you need to take it a part... Otherwise it should be fine. The bed liner could act as an anti fragment coating by holding or slowing down any flying debris from a cato... Similar to the anti spaul coating on armor plates... Interesting idea, wonder how a fiberglass tube would benefit or be hindered by a coating of bed liner?

[RalphieJ]

I just can't warm up to using steel nuts and bolts in racks. No way. As the old Italian masters would say "PAZZO!"