24mm Fat Boy

[thrustnut]

I'm going to glass my fb. The end of bt is pretty smashed i don't see any other option. I was going to put the nose in with wax paper and glass away.

Beleave it or not i glassed a stormcaster
with 1/2 or 3/4 oz. Did bt. ftf and around lugs. it's doesn't seem heavy at all.If i can get it painted without 50 coats of priner i'll be alright.I'm still waiting on the thaw so i can get painting.

My experience with stability is if cg and cp are close or a little short.Your ok with light to no wind.

ron

 

[rocketdad0934]

I built one for a f21 and reiforced the fins with tissue paper and elmers glue it looked like a good flight thoughI lost it in the marsh and was not able to fully inspect it. so for my birthday I got another "husky" boy and am installing the flis kits 4x18mm w/1x24mm motor mount and plan to do the same with the tissue paper. as far as the cg goes I first put the fat theing together stock with a motor and found the stock cg and will add clay to match that when finished. hopefully I will get this one back for more than one flight.

 

[BobH48]

Originally posted by rocketdad0934
..... it looked like a good flight thoughI lost it in the marsh...

You actually lost a rocket?

You seem to have the most incredible luck with launching rockets out of sight and then having them magically appear later in the day at the RSO table.

 

[kelltym88]

I have a FB in the package that I'm going to make it for 38mm. I know someone here has already done so, that's where I got the idea from. That should be a hoot of a flight.

 

[Bowhunter]

Here is a few pics of mine

 

[Bowhunter]

and another

 

[Bowhunter]

and another view

 

[Bowhunter]

and the last one

 

[Bowhunter]

I wasnt able to get launch pics of it but Rob Fisher can tell ya that it kicked butt

 

[rocketdad0934]

Originally posted by BobH48
You actually lost a rocket?

You seem to have the most incredible luck with launching rockets out of sight and then having them magically appear later in the day at the RSO table.

actually it was not "lost" but was unrecoverable as I did watch it land and did get a good look at it through the binocullars. but could not physically get it. bills remote glider landed within 15 feet of it and was lost as well. maybe the reason it did not reapear was that I did see it land. :kill:

 

[m85476585]

Maybe they already replaced it:
https://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LNMCA8

I hope not because I like the fat boy better than this.

 

[Stymye]

Nice cluster FB Bow ! Now I know my next one will be a cluster

on my 29mm version I just put printer paper on with 3m spray adhesive. they turned out rock solid. on the first flight (F23) I used a streamer! not a scratch, but way to fast of a decent for me.

I've since flown it twice more on G motors(neck snapping G's) and no fin problems at all. so I can attest to the paper laminate idea , it works just fine

https://smg.photobucket.com/albums/v11/stymye/Fat Boy 29mm/

 

[Bowhunter]

Originally posted by stymye
Nice cluster FB Bow ! Now I know my next one will be a cluster

on my 29mm version I just put printer paper on with 3m spray adhesive. they turned out rock solid. on the first flight (F23) I used a streamer! not a scratch, but way to fast of a decent for me.

I've since flown it twice more on G motors(neck snapping G's) and no fin problems at all. so I can attest to the paper laminate idea , it works just fine

https://smg.photobucket.com/albums/v11/stymye/Fat Boy 29mm/

Thank You stymye When I took it to the RSO they looked at me wierd cause I had rail buttons on it. but I like a rail instead of a rod but then they held it and it weighs a ton then they seen four E9's in it and said OH YEA!!!!!

 

[Tucker5246]

Originally posted by Rob Fisher
I built a 24mm D size "Husky Boy" & didn't add any nose-weight. It flew perfectly fine about the first 6 times & then on the 7th launch it went completely unstable, chased it's tail a few times & then slammed into the ground & broke apart!
I WOULD NOT SKIP ON THE NOSE WEIGHT! I had to learn my lesson the hard way & the worst part about it was that it was at an SLRA launch with many people watching!
Here's a pic of my non-existant 24mm Fatboy:

Rob,

Is that the "Husky Boy" you extended the motor mount tube to prevent the ejection charge from burning the chute and recovery system? How long did you make the tube? I am considering the same set up in mine.

Thanks

Keith

 

[Stuck Fingers]

I am about 90% done with a 24 mm Fat Boy.

I replaced the stock motor tube with a piece of BT50 that ends about 1/8-1/4 inch below the bottom end of the nose cone.

I cut a 3/8 inch long piece of a 24 mm motor casing to use as a spacer tube . I glued that in the end of the BT50.

Inside that I glued a 3/4 inch length of 18 mm motor casing.

I opened the hole in the end of the nose cone until it was a slip fit with the motor casing. When installed the motor casing sticks into the nose cone around 1/8 inch.

I have not flown the bird yet, but blowing on the engine mount at the back pops the cone off very nicely.

I did not feel comfortable just cutting a 25 mm hole in the nose cone. That would have remove all the material that supports the shock cord anchor.

Motor casings are overkill for spacers but they are the correct diameter and it adds weight up front where it helps offset the E engine I can now install.

I'll report back after it flies.

 

[RimfireJim]

So, if I understand this correctly, the 'stuffer tube' arrangement extends from the motor all the way up into the NC, and the recovery system is packed into the annulus between that and the BT. Cool!
One thought I had on this is that the 24/18 spacer could be put just above the motor, and a use a length of BT-20 to extend into the NC instead of the 18mm casing. Would have to peel out a few wraps out of the inside of the 24mm casing spacer to fit the OD of the BT-20. This design would save a little weight and provide more room for the recovery system. Not sure if either of this are an issue at all, so it may just be an alternate method that someone might want to use.
-Jim

Originally posted by Stuck Fingers
I am about 90% done with a 24 mm Fat Boy.

I replaced the stock motor tube with a piece of BT50 that ends about 1/8-1/4 inch below the bottom end of the nose cone.

I cut a 3/8 inch long piece of a 24 mm motor casing to use as a spacer tube . I glued that in the end of the BT50.

Inside that I glued a 3/4 inch length of 18 mm motor casing.

I opened the hole in the end of the nose cone until it was a slip fit with the motor casing. When installed the motor casing sticks into the nose cone around 1/8 inch.

I have not flown the bird yet, but blowing on the engine mount at the back pops the cone off very nicely.

I did not feel comfortable just cutting a 25 mm hole in the nose cone. That would have remove all the material that supports the shock cord anchor.

Motor casings are overkill for spacers but they are the correct diameter and it adds weight up front where it helps offset the E engine I can now install.

I'll report back after it flies.

 

[Stuck Fingers]

I considered your idea of using the BT20. Two things made me decide against it.

1. I wanted to leave as much meat as possible on the nose cone where the shock cord mounting ring is.

2. With an E motor in it the CG is moved rearward, Adding the motor casings at the front is like adding nose cone weight, but it serves a real function as well.

My design sensiblilities are insulted by adding ballast to a nose cone for stability.

PS Jim, based on some of your comments on other posts we may know each other. Does Pasta club mean anything to you?