Jawstand tower

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Buckeye

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I built this contraption for a 38mm minimum diameter rocket with a J motor. This is my first attempt at a launch tower. All materials are basic Home Depot stuff. Seems sturdy enough. Comments? Thanks!

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guywad

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I am using the same Jawstand with a little different mount for a 3/8" drill chuck so that I can mount various size rod and 1010 rail with a cut off Grade 5 bolt threaded into the end. Works great. Working on a better mount for the dirll chuck and will post some pictures when finished. Hope to use it this Saturday at the MMMSC/CMASS launch.
 

patelldp

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Have you considered turning the Jawstand head 90 degrees and then centering your tower over the stand's center axis? I'm not sure how deep the head is, but that may alleviate any concerns that you may have about the tower being offset.
 

75Grandville

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Looks great! You've got lines holding it in place, and you can always stake it down through the holes in the bottom of the legs.

How about a build thread? Or at least a parts list? I have a jawstand, but I've just got a 1/2" drill chuck on an "L" bracket and a 2 x 4. One of these would be great for getting into competition builds!
 

Buckeye

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Have you considered turning the Jawstand head 90 degrees and then centering your tower over the stand's center axis? I'm not sure how deep the head is, but that may alleviate any concerns that you may have about the tower being offset.
I agree, the offset looks concerning, but it should not be a problem. The guy lines hold the unit pretty solidly. My rocket is only 1000g, so the moment is not much. I prefer using the full length of the head in the vertical position (like you guys do with rails). The tower baseplate rests on the head also, which is good. If anything, I could have used a 2x4 instead of 2x6 in the jaw to better center the tower in the Jawstand.

EDIT: Hmm, I see what you mean, now. Yeah, maybe horizontal is better for the jaw.
 
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Buckeye

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Looks great! You've got lines holding it in place, and you can always stake it down through the holes in the bottom of the legs.

How about a build thread? Or at least a parts list? I have a jawstand, but I've just got a 1/2" drill chuck on an "L" bracket and a 2 x 4. One of these would be great for getting into competition builds!
OK, here is a parts list to the best of my knowledge. I built this thing last December! All parts from Home Depot/Lowes or my scrap bins.

1. Baseplate is 10"x10"x1/2" piece of melamine panel (scrap). 2x6 (also scrap) screwed to the bottom to fit in the jaws.

2. Uprights are 5' lengths of 1x2 "select pine" from the nicer part of the Home Depot lumber yard. I wanted these pieces to be as straight and true as possible. Screwed into baseplate.

3. Thin steel plate cut with tin snips to fit baseplate as a blast deflector. Screwed on.

4. Rails are 5' lengths of 3/4" EMT conduit. Ends cut at 45deg in a miter box to facilitate screw/nut on the inside. I really struggled with this selection. I first tried the expensive aluminum angle and channel, but found them to be a bit flimsy.

The pine and EMT came in lengths of 5' and 10' respectively, so that established my tower to be 5' of effective guidance.

5. Section of 6" PVC pipe to serve as the upper ring holding the uprights and rails. This was the most difficult component to find and apply. The 6" is barely big enough for the rocket fins to clear.

6. 1/4-20 hardware to mount rails to uprights.

In the pics you can see unused holes drilled in the PVC and uprights as I altered the attachment strategy a couple times.

7. Yellow plastic tent stakes from junk drawer

8. 10' lengths of all purpose nylon rope for guy lines. Secured to stakes with Trucker's Hitch (the most powerful, useful hitch around)

9. Rockwell Jawstand

I can also drive a long carriage bolt or similar through the baseplate and use this as a rod adapter to hold the tower in the club launch pad. So, Jawstand not really needed, but I like to have a stand-alone solution.

That's about it. Thanks for looking!
 

Salvage-1

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looks great, my only concern is that the 5' lengths of 1x2 "select pine" may get a little toasted at the bottom. If for some incredibly unlucky reason, the rocket sticks and doesn't launch, the flame may set the wood on fire.
 

Buckeye

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looks great, my only concern is that the 5' lengths of 1x2 "select pine" may get a little toasted at the bottom. If for some incredibly unlucky reason, the rocket sticks and doesn't launch, the flame may set the wood on fire.
Perhaps, but my club has been using pieces of wood for launch pad standoffs for years. Never seen one ignite.
 

Handeman

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looks great, my only concern is that the 5' lengths of 1x2 "select pine" may get a little toasted at the bottom. If for some incredibly unlucky reason, the rocket sticks and doesn't launch, the flame may set the wood on fire.
A rocket stick? We had a Hybrid K motor stick on the pad and it melted a hole through a 2" x 3" aluminum tube that was the main structure of the pad. Granted, there should have been a blast deflector in place, but there wasn't, and it essential cut the pad in two.
 

guywad

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Here are some pictures of my try on a mid-power pad using the JawStand. With the drill chuck, I can load up various rod sizes or either one of my 4' or 6' 1010 rail.LawStand_Chuck_1.jpgJawStand_1.jpgJawStand_2.jpgJawStand_3.jpgJawStand_4.jpgJawStand_Mount_1.jpg
 

Buckeye

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I tried my tower with my 38 mm MD on a G138. Worked great. The tower was solid and didn't flinch at all.

The wood uprights did get a little toasted at the bottom as the above poster noted. My next flight will be a J motor. So, I wrapped the bottom 2 feet with thin gauge steel and covered the sharp edges with foil tape. Does this seem like adequate blast protection?

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Buckeye

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Update: The J flight came off the tower a little squirrelly and my ground camera picked up some wobble of the tower. So, I am doing a little redesign.

First, I eliminated the Jawstand altogether and will just erect the tower on the ground. This eliminates one source of wobble.

Second, to promote more rocket stability, I swapped out the 5' conduit rails for 8' of square aluminum tubing. (I highly recommend www.onlinemetals.com. These square tubes were 1/2 the price of what Home Depot charges, even after including shipping costs. I received the well-packaged tubes in just 2 days.) I am wondering if the 3' of unsupported rails at the top of the tower is a problem. They can splay easily and maybe bind up the rocket on the way out?

tower.jpg

Between my backyard ejection ground testing and launch tower setup, my neighbors are probably nervous...
 

Tonimus

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I wouldn't worry about binding as much as I'd worry about one side flexing more than another and the rocket coming out at an angle. I would suggest supporting the top section as well.
 

Buckeye

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I wouldn't worry about binding as much as I'd worry about one side flexing more than another and the rocket coming out at an angle. I would suggest supporting the top section as well.
Right. This is the concern. Well, my supports are fixed at 5 ft and I am trying to avoid a complete rebuild. I think I will take a hacksaw and cut off one foot from the aluminum rails, leaving just 2' unsupported. Hopefully, this will be stiff enough.
 

Tonimus

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You could always build a halo ring that at least binds the top section together. If you used two tie-ins for each support, then tied all 3 together, it should be stiff enough.
 

Buckeye

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You could always build a halo ring that at least binds the top section together. If you used two tie-ins for each support, then tied all 3 together, it should be stiff enough.
Oooh. I like this idea. I am struggling with the halo design, though. Maybe another ring of the PVC pipe? Other?
 

Tonimus

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Two PVC halos tied together should work as long as you glue all the fittings.
 

Buckeye

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You could always build a halo ring that at least binds the top section together. If you used two tie-ins for each support, then tied all 3 together, it should be stiff enough.
I added this 2nd halo at the top. Seems to do the trick. Thanks, Tonimus.

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manixFan

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I built this contraption for a 38mm minimum diameter rocket with a J motor. This is my first attempt at a launch tower. All materials are basic Home Depot stuff. Seems sturdy enough. Comments? Thanks!...
That's somewhat similar to one I built. The most advanced tool I have is a drill press so I keep stuff basic as well. What I haven't been able to do is come up with a design that allows for fast adjustment of diameter and finally have decided a dedicated tower to each size is the easiest way to go. I am now looking at designs that are easy to disassemble/assemble for transport.

Tony

ps: whoops! didn't mean to post to this thread - meant to post to the current thread on launch towers.
 
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Rocketman19

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looks great, my only concern is that the 5' lengths of 1x2 "select pine" may get a little toasted at the bottom. If for some incredibly unlucky reason, the rocket sticks and doesn't launch, the flame may set the wood on fire.
If you're worried about that you can plasti spray the bottom foot of it and it should be fine. After all, they spray engine exhaust manifolds and they turn out fine.
 
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