Need tips on making a good sturdy HPR pad

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LarryH

Well-Known Member
Anyone got any ideas, tips, or designs for a really sturdy but versatile Mid to HPR launchpad? My design requirements are that 1. the pad is able to accommodate anything from a 3/16" to a 5/8" launch rod. 2. The pad must have easily accessable angle adjustment and the rod must be able to lay down entirely to make launch prep a little easier. 3. fold up or break down design, this pad must be able to fit in the trunk of a car for easy transport to/from launch site. 4. STURDY, it HAS to be STRONG!

I do have access to a metal lathe and a milling machine(along with various other machine tools), and I plan to have a MIG welding rig in by summer time(so that's probably when I'll start work on it), I'd like to make heavy use of aluminum because it's alot easier on my tooling, but I need to know which parts absoloutly MUST be steel in order to handle the stress of an HPR launch. Also need to know if the blast deflector plate has to have a ceramic coating or if a chunk of heavy guage raw steel will be sufficient.

I've seen the QuadPod by Impulse Aerospace and for around $190 it's probably a helluva deal, it looks to be a very good design, and it's actually what inspired me to make an attempt at rolling my own pad, I'll probably end up putting in atleast(and most likely more!) money into this project than the QuadPod would cost me, but what the heck I get the satisfaction of knowing I built it myself! Johnnie Well-Known Member$48.00 not including the rail...which from McMaster-Carr is roughly \$20...

For rods 3/16" and up, might as well go rail buttons, and put stability into every flight you make off of a rail. Instead of carrying around a carload of rods, I carry a rail.(Period!)

Johnnie Paul

n3tjm

Papa Elf

I flown everything from 1/8A.2-1's up to K950's on it.

Ray Dunakin

Well-Known Member
My launch pad design may not be quite what you had in mind, but fits in a trunk or just about anywhere, and it's super easy to build and to use. At first glance it doesn't look like much but I've flown 8' tall, 4" diameter K powered rockets off this pad, with an 1/2" rod. I don't think I'd try anything much bigger than that though.

Also, my launch pad design doesn't require any machining or welding, and can be built by anyone using ordinary hand tools. It's cheap too!

http://albums.photo.epson.com/j/AlbumIndex?u=3009006&a=30071618&f=0

You do need to put weight on the legs to make it stable for larger rockets. In the desert I just use whatever rocks are handy. If you're flying from a park or farm, you may have to bring weights -- a few bricks or even sandbags will do.

I've been using this launch pad for many years, and just occasionally replace the blast plate. Recently I've been using a blank, uncoated hard drive disk. It's not very big but it holds up well and makes a good blast plate.

LarryH

Well-Known Member
Yeah guys those pads all look great, and they all look like they'd be more than sturdy enough for my needs, and even better all are simple and cheap to build, but I 'really' enjoy machining and welding things and using 3D design tools, and I also enjoy the challenge of a complex design, nothing else in the world beats being able to combine two or more hobbies.

Cajunman06

Well-Known Member
Man, if you have access to machining, welding, and 3-D design tools, I can't imagine how nice your pad could be. I agree, I'd go with aluminum for the structural parts. With the exception of the parts exposed to direct eninge blast, I can't imagine any parts that couldn't be designed out of aluminum. Since it has to fit in the trunk, I can't imagine that you are looking for some type of truss system for launching 20' tall birds.

Just my thoughts

powderburner

Well-Known Member
For myself, if I was designing a pad from scratch I would want it up off the ground a bit, for several reasons.

I don't like to have the top of the launch rod at or below eye level, because when walking up to the pad I am absent-minded enough to walk right into it. And to do the pre-launch stuff it is just handier to work a few feet off the ground than to have to kneel/bend way down (hey, why not be comfortable?).

I would build the electric power system with a car or bike battery at the pad, and I would hang the battery from the pad and use the weight to help keep the pad settled.

Hey, I think I will go design my own . . .