What keeps you from flying hybrids/What needs to be improved?

[nialloswald]

OMG, We got the best kick kick out of that! And its true. If customers really want a Fast as heck K Motor we would be happy to provide them with it. Remember though, our 3200cc M motor burns in just under 2 seconds. Cut that to 1500 CC's for a K motor, and your at about 1 second. Half of the thrust and burn is in Blowdown, so your Real high thrust is for 1 second or less. The Fastest Certified K Motor is currently a K-1275, by Aerotech (The Kosdon K-1400 is now certified as an L). If we see a demand for it and people can handle it we will build it.

But plans are to test motors on Sunday with TMT.

Having now seen a K1100 in a fairly heavy (20 odd lbs) rocket and a K660 (a 'mere' by contrail standards 1000N off the pad) in a very light rocket, I really want to fly a fast-burn K sometime!

If anything, a fast-burn 54mm J or K would be pretty cool, even if it was 48" long (for impulse). I know you guys have got some 54mm stuff planned, I'll be looking forwards to seeing what you come up with.

By that time I might be 'in the market' for some more shiny motor hardware. We'll see, but I would be very tempted by a high-impulse, fast burn 54 (or even 64mm) K motor.

My vested interest in 64mm is that I seem to be building/planning everything around 2.5" tubing, it would be rather convenient Then again, a 2.5" to 3" transition wouldn't be too hard to sort out. A future project, but if your 54mm stuff is anything like the 75mm motors I'll be looking out for it.

Then again I should probably quit dreaming and get on with L1, L2 and the rest of it!

 

[hokkyokusei]

So are you going to fly your 37" of Canadian hybrid love at UKRA?
Rita-Sue is waiting

 

[nialloswald]

Has it been flown yet?

AFAIK its still a 'virgin' piece of shinyness, I may be wrong however. I think its creator has been rather busy, but I did see some mention of firing it a while ago. I believe the long-term plan is to attach it to a certain rather successful gyroscopically-stabilised rocket.

It's often been stated that any anodized metallic object will sell to rocketeers. How else can you explain safejects?

Too true, can you guess who's got a few of those

I won one of Mr Rowe's finest coned retainers at Big EARS (going to have to build something to put it on now!), it truly is a thing of anodized beauty.

 

[nialloswald]

So are you going to fly your 37" of Canadian hybrid love at UKRA?
Rita-Sue is waiting

Dunno, my main plan is to fly my 16" of Canadian Hybrid love (WCH H100) in my own rocket for L1, I don't think I'll have my own 54mm booster sorted out (I won't!) by then.

I should have all the bits needed to fly it, I'll bring it along and we'll see. If Rita-Sue can be married to Uncle-Bob, with its super-spanky avionics, I could get a thrust curve to sim my own stuff with

The only things is reloads are $55, not quite so cheapy as a HyperTek.

So in short, my answer is 'um,arr,um,err,dunno'

 

[hokkyokusei]

Ooooh. I like that plan.

Sadly, I do not yet own any of Mr Rowe's conical loveliness.

Interestingly, Rita-Sue has a date with Uncle Bob at UKRA 2005. You bring the motor, Damian and I will bring the airframe.

 

[nialloswald]

Interestingly, Rita-Sue has a date with Uncle Bob at UKRA 2005. You bring the motor, Damian and I will bring the airframe.

I'm quite liking that plan. I suspect that the UKRA hut and some combination of beverages will make me think its an even better plan

I have the fill stems, I have Krytox, I have miles of fill lines, I have 2 reloads, 2 nozzles (good for many flights) and 2 casings - a 29" and 37".

I see no point in flying the 29" if Rita-Sue can handle all 37" of Canadian shinyness

I think Marcus Leech would be happy to hear that I'd actually flown the thing!

Ignition is pretty much as HyperTek, a bit of extra steel wool is recommended.

I have a rough/ready .eng file I cobbled together, HT K240 plus a bit would be a good starting point.

 

[hokkyokusei]

It will be fine ~~~~~~~

 

[Daedalus]

Originally posted by nialloswald
I won one of Mr Rowe's finest coned retainers at Big EARS (going to have to build something to put it on now!), it truly is a thing of anodized beauty.

Yes, he does make some anodized loveleyness (owner of 75, 54, 38 & 29mm cones and 54 & 38mm flats) and in multiple colors too - just to force me to buy more so the flats coordinate with the airframes!!!

 

[edwardw]

So for differing tank/case sizes - how about making an adapter that is a coupler tube that you just load your motor into, then slide into your rocket just like any other motor. Ie, the K motor would need a 4" motor mount, the J motor a 3" mount (though it will fit nicely in a 2.56 airframe).

Edward

 

[jraice]

Reloads are cheaper but nitrous is expensive, 4-6 dollars a pound. So a 20# tank is already $120.... that is what is holding me back.

 

[nialloswald]

But then look at how much nitrous you actually use per flight. A pound of nitrous is about what you need for a J flight, IIRC.

4-6 dollars is about 3 quid (I think prices are roughly the same once you do the US/UK conv). A pro38 J330 of similar impulse is about 60 quid.

60 quid/3 quid, I think it's fairly insignificant personally!

 

[ContrailRockets]

If your Paying Very High Costs for Nitrous Oxide, one suggestion I would make is Shop around. If your buying it from a Speed Shop, look elsewhere. We buy gas at just over 2 dollars a pound in Arizona. In a few weeks we will be able to transfill tanks as well.

Check out your Welding Suppliers, And other "Gas Shops" that deal with Argon, CO2, Helium, Etc. They usually have good prices.

Buy it from the same place each time, get to know the people there. You will be supprised at how much it will get you.

Also, If you still can't get a good price from your speed shop, or gas shop call up the manufacture. Airgas or Praxair are the 2 that i would recommend. I aranged for Airgas to supply Nitrous for LDRS this year at just over 2 dollars a pound, when it was going to be like 5 dollars or something near there!

Airgas and Praxair may be a bit harder to deal with on small quantities. But if you are going to deal with K Cylinders they are wonderful. They will even deliver them to you if i am not mistaken. Don't let the price of gas stop you from flying Hybrids. There are many options which are out there to check out.

Tom Sanders
Contrail Rockets LLC.

 

[jraice]

but to purchase a 20 pound tank it is a large upfront "down payment" but if you look at it per flight it inst bad at all.

 

[ContrailRockets]

Rent the Tank. Many Gas Shops, (Not the Speed Shops), or Praxair will rent you the tanks for only a few dollars a month. I think we pay 5 dollars a month on a K Cylinder. We own 4, and are going to purchase the last one for 5 (DOT Max). You can't drive with more than 5 full K Cylinders in your vehicle with out plackarding.

The Rental Fee is minimal. Many Gas Shops will even let you "Borrow" the tank for a week or so and not charge you a fee. Just for the Gas.

Also when you rent the tanks you can just bring the empty in to them and exchange it for a full one. It saves time from having them filled there.

Tom Sanders

 

[jraice]

So any places to rent or borrow a case in the bay area? What do you mean a "K" tank? What size tank would I borrow for a weekend of 6 I flights? But then I would still need the electronic valve thing, forgot the name.....

 

[ContrailRockets]

The K Tanks are 56 Pounds I believe. They weight somewhere over 150 Pounds Full. Not something necessary for a few I flights. I would think a 10 pound Tank would be sufficient. Maybe Todd or one of the Manufactures who produce the I Motors could help with that one.

I don't have all my conversions in front of me to give that information.

You will also need solenoids and GSE. Getting into them will be a few hundred bucks if your club doesn't have GSE. But the More I motors you fly at 10 bucks a piece the cheeper it gets.

Not to mention no ATF Permit! That on its own is enough for me

Tom Sanders

 

[jraice]

I think I will go for it, will an art applewhite 10" delta saucer take the sk ripper J144 and I114? Todd says the average may actually be higher because at the end of the burn there isnt much thrust and it drasticlly lowers the average. Art recommends an aerotech I150 or an AT H112 as the largest motors but I dont see why a hybrid would be to much thrust. Plus they are heavier and slow it down. So if I can rent a tank then I am sold. Pratt hobbies sells a large solenoid for only $100 and a smaller one for g-h, that is about $60. What do you mean by GSE, I know what it stands for but they solenoid and tank is really all you need, and a simple to make electrical solenoid switch thing

 

[ContrailRockets]

You got it! The GSE (Ground Support Equipment) is just some type of power source and usually relays and switches to turn on and off the solenoids (open and close them), as well as a fire circuit and purge circuit. (At least thats what our motors require) Hypertek is a bit different. And last i checked thats what the Skyripper Motors require as well.

Your making a great choice by going with the Pratt Hobbies Solenoids. They are what we use, and have not had any problems. For the I-J Motors the Standard Valve is probably your best bet. You will still need a way to get power to them, which can be done with minor electronics knowledge.

Check around for a tank rental place that sells cheap gas. As you progress you will pick up a lot of new information, and probably some parts and pieces as well.


In Regards to the Burn Time of Hybrids.... All Hybrids are regressive burns. (They taper off) at the end. However, Motors are rated by Average (H-150 is 150 N/s Average). So on a Hybrid the first half of a burn may be 200 N/s and the second half if 100N/s but the average to 150. I would not worry about it to much on smaller motors, as there is not such a huge difference as there are with larger motors. The Skyripper motors are a great choice and i am sure you will be happy with them.

Tom Sanders

 

[jraice]

Well they wont work with the saucer because it is to heavy, I will FOR SURE be using a hybrid for my L3 and when I get into larger L's, the prices are great. I plan on building an L3 rocket when I am 16 but fly it on L's under my dad's cert, then when I turn 18 I will get L1, l2 in my name and fly it on an M hybrid, I am actually looking at using one of your contrail hybrids. Nice stuff

 

[protogen]

most people i know say it is the low power to weight ratios of the micro hybrids

but i have some ideas on this (a grain composed of parafin wax with Magnesium powder in suspension)

but i really can't comment till i get my screamer from areoconsystems

 

[Len B]

What keeps you from flying hybrids/What needs to be improved?

Nothing!

I have a Rattworks I90 and friends of mine have West Coast Hybrids motors. They all rock.

Our club is putting togther GSE after LDRS and will be launching them soon. I plan to get a Sky Ripper G at some point. I like the idea of a 29mm G hybrid. I am building a slightly longer Hawk Mountain Raptor primarily for hybrid motors. It should fly on the Sky Ripper G as well as the I90.

Anyway, the GSE slowed us down a bit as we are a small club without a lot of $$ but it will come together soon.

Len Bryan
CAR 620 L3 TRA 10220

 

[cjl]

The main reason why I don't right now is the lack of an ejection charge, although this summer, that will change. I will be building a BBX with dual deploy and a 30" long 54mm MMT, so I may try a hybrid in it sometime.

 

[KarlD]

Any Plans out there to make your own GSE? I know that some of the solenoids would have to be purchased for this project, but I am pretty handy with a soldering iron. A lot of cash could be saved by scratch-building my own controllers and fill-dump boxes…

 

[Rocketmaniac]

This weekend I flew my LOC Expeditor 3 times with HyperTEK motors. 2 I-195s and 1 K-200 (EX motors because the orifice/tank combinations are not certified) The I motors cost me $17 each and the K motor cost me $37. That is the cheapest K motor I have ever seen!!!!!!!

 

[Todd Moore]

The Sky Ripper 54mm reloads will be 25 dollars each..... Add 10 dollars for N20, and you've got a 35 dollar K...

And it will be certified

 

[Rocketmaniac]

Originally posted by Todd Moore
The Sky Ripper 54mm reloads will be 25 dollars each..... Add 10 dollars for N20, and you've got a 35 dollar K...

And it will be certified

Very nice!!!! Could someone use the Sky Ripper system with HyperTEK GSE?

 

[Todd Moore]

Originally posted by Rocketmaniac
Very nice!!!! Could someone use the Sky Ripper system with HyperTEK GSE?

Yep.

With just a very simple conversion. (Remove the GOX plug, and insert a set of aligator clip leads into the HV outlet)

 

[Johnnie]

Originally posted by Todd Moore
The Sky Ripper 54mm reloads will be 25 dollars each..... Add 10 dollars for N20, and you've got a 35 dollar K...

And it will be certified

What!!?

Post the pic of that flame already...

 

[Todd Moore]

Originally posted by Johnnierkt
What!!?

Post the pic of that flame already...

Awww Shucks...

You mean this flame?

photo by Marc Klinger of Big Kid Productions

 

[fyrechaser]

DROOL!!