Building the Atlas

Just started the Mercury Atlas I won on the ROL auction and need input, ya'll.
1. The motor hook is too short, which I'd seen reported in EMRR reviews. Looks like it'll handle a D (2.75") well enough. According to thrustcurve.org, Aerotech's 24mm E15 and F21 are the same length. Is that correct?
2. Those mounting tubes for the fin attachments are just begging for a 3-engine cluster. Anyone ever get bold enough to fly it clustered without fins? I reckon it would need a LOT of nose weight.

 

I would fly it without the fins.

Heck, I wouldn't even build it. the last two that went on Ebay went for $290 and $150...they're crazy!

sandman

 

You have GOT to be kidding!!! I wouldn't pay that much either.
Mine was $52 on the ROL auction.

 

I paid $49.95 at my local hobby shop last year!

sandman

 

Chilly - The aerotech single use E15 is the same size as an Estes D although really its a bit thicker at like 24.99mm so can be a very tight fit... you might wanna test fit and maybe wrap an old 18mm casing with sandpaper and sand the inside of the motor tube to make sure it fits nicely...

the f21 is the same length as the new estes e9...which is (what I forget) a little longer than the older Estes E15 by a 1/4 inch or so?? and remember to break off the inner motor hook tab if you want to use RMS in the future because the casing's delay closure will extend into the thrust ring about 1/2 inch or so...

 

If you use and E length motor hook, you don't have to worry about the tab at the top interfering with the top of an RMS casing, you'll just need an adapter to fly it. Opens up alot more options, too - fly anything from Estes D's, aerotech 24mm SU, reloads, and Estes D's in it that way. The estes E's are an inch longer than the D's, so if the F21 is the same length as an Estes E, keep that in mind.

Mark

 

But the problem is it didn't come with an E motor hook!

How long should one of those be? I have a spare Aerotech hook that came with an Arreaux. Somehow it was made about 1.25" too short so they sent me a new one. I've been thinking about using this short AT hook instead of Estes', but it might be TOO long. Suppose I could just put it in and be real careful about measuring where the thrust ring goes. Sound kosher?

Frustrating as this is I'm relishing the learning process. Every kit shows me more and more and more. I'd just finished the Redstone kit about a month before so getting the "next in line" was real exciting.

Next week is my birthday and the wife promised me a shopping spree at Magnum...

 

Chilly,

One of the members here (flying silverad) makes the Estes engine hooks. He sells 'em on Ebay.

He'll sell to ya.

Email him.

sandman

 

Estes C and D's are 2.75" long. The Estes E9 and Aerotech F21 are 3.75" long. BMS has hooks compatible with E9 motors.

 

If you get a used windshield wiper blade, you will note that there are strips of metal along the edges of the base of the rubber blade that stiffen it. Pull them free and you will see that they are a perfect width for engine hooks. Heat with a torch until red hot, cool and reheat, then bend with pliers. Once the two bends are made, cut the strip using a chisel. This will leave the rest of the strip ready for the next hook. I dipped mine in cold water right after making the bends, to harden the metal. This makes the simlper, older style Estes hook, which I prefer anyway. It appears that the metal is stainless steel. If you don't have an old wiper blade, a full service gas station might have a few in the trash.

 

I built the atlas and the D engine could not get it off the launch pad i purchased an areotech E(?) and never did try it but the warmer weather is coming maybe this spring. It is a great looking rocket when it is finished. Good luck! post pictures I'll post my atlas (when i can figure out how)
marlin

 

you guys are crazy spending 49.95 on a rocket kit that is only low power that equal to almost $100 New Zeland dollars the most expensive rocket i have ever purchased is my tethys kit that cost $89.95 around about $170.00 New Zealand

 

Matt, not really. I would rather spend $50 on that then a fancy dinner. The next time you see the dinner its going down the toilet. Think about that one.
Randy

 

Matt, I forgot to say that I also agree, we are crazy but I think its crazy in a good way.
I got an idea for you, move over here and it will only cost you $50.