MMI Arcon fin pattern

[Phred]

OK Gang,

Here's a real toughie.....

I have recently obtained a semi assembled Model Missiles Arcon. The fins were gluded onto the body with the grain running parallel to tube, and have sheared off leaving balsa stubs.
Does anyone, anywhere have a fin pattern, or a tracing of a fin from an MMI Arcon?

Phred

[Initiator001]

Nice find, Fred! ;)

Sorry, I can't help you with the fin pattern. :(

Bob

[Phred]

Yeah, It wasn't cheap, but has oodles of cool MMI paperwork, and an unbuilt 'booster stage' kit. If worse comes to worse, I will use the scale Arcon fin.... but of course, that model is in the 2000 Supplement to ROTW: the only one I do not have !! :eek:

Ph

[snaquin]

Yeah, It wasn't cheap, but has oodles of cool MMI paperwork, and an unbuilt 'booster stage' kit. If worse comes to worse, I will use the scale Arcon fin.... but of course, that model is in the 2000 Supplement to ROTW: the only one I do not have !! :eek:

Ph

What is the size of the MMI kit? If it's close to 1.040" dia. x 20" long like the Semroc kit would the fin pattern for the Semroc kit help? I could post a .pdf of that pattern for you.

.

[Phred]

MMI had a sort of odd sized parallel wound tube: When ESTES bought them out, they called it BT40. The dimensions are ID: .765 OD .825.

Ph

[SEL]

OK Gang,

Here's a real toughie.....

I have recently obtained a semi assembled Model Missiles Arcon. The fins were gluded onto the body with the grain running parallel to tube, and have sheared off leaving balsa stubs.
Does anyone, anywhere have a fin pattern, or a tracing of a fin from an MMI Arcon?

Phred
A year or two ago, someone was selling the original dies for the Arcon fins on ebay. I figured we'd be seeing fins cut from said dies for sale pretty soon after, but I haven't been keeping tabs on ebay lately. Someone less lazy than me might do a search :o

Sean

[Phred]

Hmmm.... I remember this auction. I cannot seem to find reference to it here though... I thought that someone posted about it...

Phred

[shockwaveriderz]

Phred:

would it be too much too ask you to consider scanning the paperwork and allowing it to be online at the old rocketshoppe? also consider scanning the box top if possible.

I personally don't think making copies dimishes the actual worth of the real items. buts thats just my opinion. ymmv

tia

terry dean

[Phred]

Oh, I plan on sharing it.... do not worry!

Ph

[Phred]

OK, here is another try: I have re-exported this from Corle, and resized as a jpeg:

[Phred]

Call of the digital dogs! It works!!

Thanks guys

Phred

[Ltvscout]

Call of the digital dogs! It works!!
Cool. I wonder what it was with that other file. Weird. I deleted all of the old posts that talked about the file not working, including the original post with the bad file in it.

[tbzep]

OK, here is another try: I have re-exported this from Corle, and resized as a jpeg:

That one works. :D

I could have sworn I posted earlier that the file was fine, but the extention only needed to be renamed from .php to .jpg. However, it's not here now. At any rate, you didn't need to re-export, just rename what you had. :)

[Ltvscout]

I could have sworn I posted earlier that the file was fine, but the extention only needed to be renamed from .php to .jpg.
I deleted all posts relating to the file not being able to be opened along with the bad file itself since we now have a good one online.

[tbzep]

I deleted all posts relating to the file not being able to be opened along with the bad file itself since we now have a good one online.

Whew! I thought I was going crazy there for a minute. :eek:

[CPMcGraw]

So now, the real question is "Did this thing actually work?" In principle it should, but we all know how things which should work "on paper" (pun intended) don't always work "in practice".

Unless the paper was treated, any hot, burning particles of BP that stick to this "protector" are going to cause damage, possibly fire if the paper fully ignites.

Now, if it were cut from a sheet of Nomex paper...

[Chas Russell]

Craig,

Back when I started in the hobby, the instruction sheets in the Centuri motor tubes (might have been Estes) included the parachute protectors (3 per sheet to match the motors). I did try them a couple of times, but they were more akward to use than wadding, especially in 3/4 inch tubes. They worked, but with having to cut them out and roll them and trying to getting them installed...
Your rocketry enjoyment value may vary.

Chas

[Ltvscout]

Craig,

Back when I started in the hobby, the instruction sheets in the Centuri motor tubes (might have been Estes) included the parachute protectors (3 per sheet to match the motors). I did try them a couple of times, but they were more akward to use than wadding, especially in 3/4 inch tubes. They worked, but with having to cut them out and roll them and trying to getting them installed...
Your rocketry enjoyment value may vary.
I'm not sure about early 60's Centuri motor instructions, but the early Estes paper instructions that were rolled up in the tube did have the parachute protectors printed on them for you to cut out.

[tbzep]

I've used a variation on that theme with my old Centuri Saturn V. When I was a kid, wadding was very expensive to me, especially for the amount needed to fill a 4" dia. tube. I made a chute holder/protector out of cardboard. It had a small cardboard piston to fit into the stuffer tube to make everything eject nice and straight. It worked like a charm. :)

Think of the pattern in Phred's pic with 4" base and 3 inch "wings" and a 12" piston made of split popsicle sticks. It ejected, pushing the chutes out and fluttered down to be used again. BTW, I based the idea on plastic shotshell wadding. :cool:

[PaulK]

Yeah, It wasn't cheap, but has oodles of cool MMI paperwork, and an unbuilt 'booster stage' kit. If worse comes to worse, I will use the scale Arcon fin.... but of course, that model is in the 2000 Supplement to ROTW: the only one I do not have !! :eek:

PhGlad you succeeded on that auction so you can share info about the kit here. It looked intriguing.

[shockwaveriderz]

Phred:

I don't know if this will help any, but I am attaching a pic of an Arcon and since you know the length/diameter of the body tube and the length of the nose cone, you might be able to get very close in using photo interpretation to determine the correct size fins for your Arcon.

HTH

terry dean

[Royatl]

I just remembered, Bob Kaplow outbid me at NARAM 47 for an ARCON kit. He should be able to give you the correct dimensions. Are the patterns printed on the balsa? or are they die-cut?

[Phred]

Thanks,

As I understand it, the fins were die cut. I will email Bob and see of he can provide the dimensions.

Fred