Thor Owners...

[firemanup]

Got a question for Thor owners out there....

Anyone flown any K flights on the bird, and if so was it built stock, glassed, or any other mods and how did the flight go..?

Contemplating a flight in two weekends on an Pro 54 K445 with mine, built stock...

 

[PunkRocketScience]

I haven't yet finished my 3" Thor, but plan on trying it out on the Pro54 motors when it is done. I have done tip to tip glass on the fin can, but that is the only reinforcement that is not stock that I'm planning. With the double walled tubes, it seems tough enough to handle the K's. I also plan on trying dual deploy for the first time with the Thor as well...If I'm gonna put in orbit, I'd like to try to get it back...

 

[firemanup]

The 4" bird isn't double walled..... Simulations are showing .85 Mach.. so i'm just hoping it will all hold together ok...

 

[BlueNinja]

.85 mach for how long?

Might be fun to fly it on a K185 if it's thrusty enough

 

[Damian]

I've flown Thor (4") a few times on Hypertek K-240's.
Absolutely no problem there at all. (albeit thay are only just a K motor and slow burns comapred to your typical solid motor.)

Never flown a solid K that would push the airspeed to Mach 0.85.

Personally I would stay sub M0.85 on an airframe that isn't structurally made for it. The stock Thor isn't.

If you take a look at PML's website they recommend fibreglassing their phenolic tubing if the airframe is going to go into the turbulent transonic period that is Mach 0.85 plus. The only exception to this rule are phenolic ariframes less than 2.5" in diameter.

I would suggest that the airframe stiffness is as important at those sort of speeds than purely the axial compression forces.

BTW
My Thor is paper booster and (following an accident early in it's life) PML phenolic payload bays.

I've strengthed the aged booster with a motor tube extension (and associated centring rings) and a fixed an epoxied coupler to meet the coupler from the payload bay.

my two pennies worth......

Damian

 

[firemanup]

Thanks for the info Damien..

You or anyone else for that matter wouldn't have the Thor setup in rocsim would you ..??

I'm running sims with wrasp.... and not completely sure how accurate they are..

My total weight is 105 oz without the motor

 

[Damian]

Find attached a stock Thor rocksim file.

You may want to tinker around with it to meet your own ends but it will save you a lot of initial faffing.

Damian

 

[firemanup]

I don't have rocsim.... i always end up buying another kit rather than spending the money on it...heh..

Will that work with the freeware version of it..??

And thanks...

 

[Damian]

I don't know if it will work with the freeware version.

Give it a go. nothing lost if it doesn't.

Damian

 

[Todd Moore]

I have flown my THOR on the AMW 1400GG K motor (can't remember the designation -K570 maybe?). The rocket is glassed with one 6oz wrap. I did see some wierd wobble (maybe from the coupler) at about 1500 feet. Like maybe it was just on the edge of going too fast. Might not fly it on something that fast again without adding some kind of strength to the coupler.

photo by Todd Harrison.

 

[Damian]

Airframe stiffness is important.

Couplers are usually the weakest points in this respect and are foten overlooked in the design.

BTW - Nice photo.

D