foam problem

Dave Lyon wrote:
Oh, I didn't do that. How thick do I want to make it? How much/many
microspheres are needed to do a square foot?

You don't actually count them, they are ~20 microns in diameter. What
you do is purchase a bag of them from aircraft spruce (cheap). Make your
epoxy mixture, then start pouring in microspheres until you have a
slurry resembling thinnish peanut butter. Note, the color is a near match.


Yea, that's what I thought. I was just trying to figure out how much I
should order.



Don't forget, laying glass & spreading epoxy while fighting gravity is
messy business. If you can work it. Always try to figure out how to get
your work surface mostly horizontal.


I wondered about that. I've got a fork lift. Maybe I should weld some tow
hooks all around this thing so I can spin it.


As a matter of fat, that's what we do with our aircraft. Or, you can
make your layups on plastic bags on the floor, then apply them like they
were sticky wall paper. After the layup has been applied, peel off the
plastic bag.

Another ply on the outside will help, but eventually it will get too
heavy.

I'd go the other way. Skin the outside with 1/" wetsuit neoprene.

Really? Don't tease me, I'm an easy target. It's like making fun of Jerry's
kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap?

("Dave Lyon" wrote)
Really? Don't tease me, I'm an easy target. It's like making fun of
Jerry's kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap?


Unless I missed it, can you give us some more details on this project? Some
history. Some past failures of prototypes. g

Possible size?
Number of people inside?

Weapons against it (mass, speed, penetrating power, rate-of-fire, etc?)

Budget?

Mission?
Special functions to incorporate into unit?

Tanks... :-)


Montblack-ops

"Dave Lyon" wrote in message
news:avNCg.84182$FQ1.83676@attbi_s71...


Another ply on the outside will help, but eventually it will get too
heavy.

I'd go the other way. Skin the outside with 1/" wetsuit neoprene.

Really? Don't tease me, I'm an easy target. It's like making fun of
Jerry's
kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap?

A slightly different solution, that may add more weight , but might be
cheaper than the denser foam:
Skin the outside with lauan doorskins. They're pretty cheap, and it should
spread the load so that the paintballs don't ding the foam.
You might consider making another test panel of fiberglass inside, foam
core, and just the doorskin outside, or a lighter-weight fiberglass cloth on
the outside.

From a cost point of view, I suspect that door skin/foam/doorskin sandwich
glued with urethane glue will be cheaper than fiberglass. I don't know what
thickness plywood you were using before, but this should have the stiffness
of 3/4 inch plywood with about a third the weight. A thicker core will
increase the stiffness without affecting the weight very much.

Tim Ward

Tim Ward wrote:
"Dave Lyon" wrote in message
news:avNCg.84182$FQ1.83676@attbi_s71...

Another ply on the outside will help, but eventually it will get too
heavy.

I'd go the other way. Skin the outside with 1/" wetsuit neoprene.

Really? Don't tease me, I'm an easy target. It's like making fun of

Jerry's

kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap?


A slightly different solution, that may add more weight , but might be
cheaper than the denser foam:
Skin the outside with lauan doorskins. They're pretty cheap, and it should
spread the load so that the paintballs don't ding the foam.
You might consider making another test panel of fiberglass inside, foam
core, and just the doorskin outside, or a lighter-weight fiberglass cloth on
the outside.

From a cost point of view, I suspect that door skin/foam/doorskin sandwich
glued with urethane glue will be cheaper than fiberglass. I don't know what
thickness plywood you were using before, but this should have the stiffness
of 3/4 inch plywood with about a third the weight. A thicker core will
increase the stiffness without affecting the weight very much.

Tim Ward


The luan will eventually dent and break just like a single ply of
fiberglass on weak foam. I know, I play with paintball guns too

Evan

"Montblack" wrote in message
...
("Dave Lyon" wrote)
Really? Don't tease me, I'm an easy target. It's like making fun of
Jerry's kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap?


Unless I missed it, can you give us some more details on this project?
Some
history. Some past failures of prototypes. g

Possible size?
Number of people inside?

Weapons against it (mass, speed, penetrating power, rate-of-fire, etc?)

Budget?

Mission?
Special functions to incorporate into unit?

Tanks... :-)


Montblack-ops


How much history?

.....In the beginning.......

I've been into paintball for a few years. Probably as long as some of you
have been trying to get your planes built.
About 3 years ago, I built a tank for use at a big paintball event that
takes place each year in OK. They call it D-day, and try to get it as close
to June 6th as they can. The last time I went, there were over 3000 players,
and probably around 12 tanks. Most people make their tanks from 4 wheel
drive trucks. I decided that was too easy, so I pieced mine together from
scratch using plywood for the outside. There is a 5 mph speed limit for
tanks so kids don't get run over, so I used mostly lawn mower parts. It
sported a 3" main gun that would shoot 90 paintballs at a time like a shot
gun. Those cannot be used against people, only other tanks. At d-day, the
put a small box on the outside of the tank that hides a switch. There is a
1" hole in the box. If you can shoot a paintball inside the box, and hit the
switch, it disconnects the coil wire, and the tank is dead. The job is much
harder than you might think, cause while you're trying to hit that little
target, there are at least 2 guys inside the tank blasting away at you!.
Also, you can take out a tank with a "bazooka". Most of them are homemade
kinda like a potato launcher. They usually have a 2" pvc barrel, and shoot
miniature nerf footballs at 220 fps. Or, paintballs are allowed to be shot
at 300 fps.

I sold my old tank, and decided to build one that looks more realistic. I
started it over a year ago, but got busy on other stuff, so it just sat in
storage for quite a while The new one is modeled after a m1117 guardian, and
will look quite a bit like it. It will be about 14 feet long, and have a
crew of 3 people. A driver, a main gunner, and a crewman. My new tank will
serve a dual role. I have purchased some high end M.I.L.E.S. type gear, and
have been hosting birthday parties for people. The first turret I put on
there will be equipped with similar gear to replicate a 50 cal, and
automatic grenade launcher. I will use it as a promotional item in parades
and such, and also rent it out for private parties. I figure when I'm done
with the first one, I can build a new turret for paintball use, and hit some
of those big events too.

I've done a few more experimental lay ups. I've found that 2 layers of 10 oz
cloth is very strong. It may do the trick. I hit my small sample from 10
feet away with about 30 shots. It delaminated when it hit near the edges,
but not in the middle of the part. Since the tank won't actually have any
"edges", I think it may be ok. I think I'm going to finish the tank with 2
layers (3 if I have enough extra). Then I'll take a few shots in an easy to
repair area and see what happens. Besides, the actual tank doesn't have any
flat areas, everything is at an angle to deflect incoming shots hopefully
that helps some too.

"Richard Riley" wrote in message
...
On Thu, 10 Aug 2006 21:25:26 GMT, "Dave Lyon"
wrote:



Another ply on the outside will help, but eventually it will get too
heavy.

I'd go the other way. Skin the outside with 1/" wetsuit neoprene.

Really? Don't tease me, I'm an easy target. It's like making fun of
Jerry's
kids (Lewis, not Springer) , it just really should be done.

Anybody know where I can get some camo neoprene for cheap?


Sorry, that should have been 1/4" neoprene.

Just do a google search on it, there are LOTS of suppliers. The first
one I found was http://www.foamorder.com/neoprene.html

If you were going to be REALLY creative and cheap, you'd contact a wet
suit manufacturer and offer to haul away their scraps. Then jigsaw it
together all over your tank, paint it cammo with spray cans. Glue it
to the fiberglass with spray on trim adhesive.

Honestly, I thought you were teasing about the neoprene. But, I did a google
search, and not only did I find it in Camo, but I also found it with velcro
attached to the back. I think I'm going to make the body fiberglass with at
least 2 layers on the outside. Then I'll do some testing in an easy to
repair area. If it holds up, then I'm in good shape. If not, I may look at
making a "glove" for paintball use.