Search found 1659 matches

by PK
Fri Jun 17, 2016 9:17 pm
Forum: Whooshtronics
Topic: clust-o-matic
Replies: 31
Views: 12767

Re: clust-o-matic

Sorry guys, but I've made the decision to step back (further) from hobby rocketry. This means no more making stuff for folks.
The build thread for the clust-o-matic has the schematics and parts, you should be able to put some together.

PK out...
by PK
Thu Jun 16, 2016 10:49 pm
Forum: Whooshtronics
Topic: clust-o-matic
Replies: 31
Views: 12767

Re: clust-o-matic

OK, sounds like it might be worth doing a batch. I'll post progress.
by PK
Thu Jun 16, 2016 8:17 pm
Forum: Whooshtronics
Topic: clust-o-matic
Replies: 31
Views: 12767

Re: clust-o-matic

I could probably put one together. Might take a couple of weeks to get some PCB's made though. I'll dig out the files..
by PK
Sat Mar 26, 2016 11:37 am
Forum: Hybrid - Crossbreeding Rocketry
Topic: Contrail hybrid reloads
Replies: 27
Views: 9170

Re: Contrail hybrid reloads

Slice of Blue thunder (or other catalysed) propellant (more is gooder) Pressed BP. Copper thermite (can be tricky to get right, too much will lift the piston and make a new nozzle in the case wall) Pressed candy (use very fine KNO3). If you reroute the vent through the piston and enlarge it to 0.5m...
by PK
Sat Nov 28, 2015 11:41 am
Forum: Scratch Built
Topic: Igniting two rocket engines
Replies: 8
Views: 2011

Re: Igniting two rocket engines

If they are BP motors, it's hard to go past flashpan ignition, just a little bit of BP in some alfoil wrapped around the bottom of the rocket. One igniter gets the whole show going. If they are composites then you have two problems to solve: 1. How to get the igniters to fire at the same time. 2. Ho...
by PK
Fri Nov 27, 2015 8:31 am
Forum: I could use that
Topic: Laboratory Power Supply
Replies: 52
Views: 6399

Re: Laboratory Power Supply

Luxury! Try troubleshooting earth loops in a live, 3 phase, switch panel whilst standing in a wobbly as all F&$K cherry picker, in the wind, 15m off the deck! We do this at least a couple of times a month working on overhead cranes.. The young bloke at work has the right attitude: "Electric...
by PK
Fri Nov 20, 2015 7:49 am
Forum: I could use that
Topic: Precision Aerial Delivery Systems
Replies: 8
Views: 1970

Re: Precision Aerial Delivery Systems

That's a NASA Parawing. There have been a few variants over the years. Many calculators available online..
by PK
Fri Nov 06, 2015 4:40 pm
Forum: Scratch Built
Topic: SpeedStack
Replies: 25
Views: 4006

Re: SpeedStack

Vent the ISC.

Here's a shot from some crappy downlinked video (date on the file is 2004) showing the second stage of Craigs solid to hybrid flight igniting.
IIRC the stages were a pretty snug fit but the flight went perfectly.
by PK
Wed Oct 21, 2015 12:14 pm
Forum: News & Events
Topic: DARE - Delft Aerospace Rocket Engineers
Replies: 15
Views: 2153

Re: DARE - Delft Aerospace Rocket Engineers

Bit of a pisser losing the bottom half. There was clearly a problem with propulsion (<50% of their altitude target).
The fuel used was a little exotic, but they claim to have 14 tests on it, which should have be enough to dial it in.

Maybe there wasn't a problem and 50Km was just an ambit claim...
by PK
Wed Oct 07, 2015 10:05 pm
Forum: Rocketry Control Room
Topic: At what altitude does Earth's gravitational pull weaken?
Replies: 37
Views: 3856

Re: At what altitude does Earth's gravitational pull weaken?

Like I said:
nozzle.jpg
nozzle.jpg (193.87 KiB) Viewed 1033 times

Man up son!
by PK
Wed Oct 07, 2015 5:57 pm
Forum: Rocketry Control Room
Topic: At what altitude does Earth's gravitational pull weaken?
Replies: 37
Views: 3856

Re: At what altitude does Earth's gravitational pull weaken?

SpaceManMat wrote:Which it it was long would really... Um.. Suck!


They're about 30mm long. If that's a problem then you'll just have to stop flying your boyfriend's rockets..
by PK
Wed Oct 07, 2015 10:29 am
Forum: Rocketry Control Room
Topic: At what altitude does Earth's gravitational pull weaken?
Replies: 37
Views: 3856

Re: At what altitude does Earth's gravitational pull weaken?

drew wrote:
CATO wrote:If you what to lose weight, you can always move to the equator :roll:


If you move to the equator make sure you don't fly with a magnetic apogee detector! :|


:-) Actually, it'll work fine. You just have to mount it sideways.
by PK
Sun Oct 04, 2015 8:15 pm
Forum: Rocketry Control Room
Topic: Should be space related, if only ... Mars, within reach.
Replies: 6
Views: 1151

Re: Should be space related, if only ... Mars, within reach.

The book is... Well, I enjoyed it immensely. I mean, it's not going to win any literature awards but, if you're a compulsive problem solver type of person, you won't be able to put it down. Haven't seen the flick yet, but the book should adapt well because it would be easy to leave a couple of 'it a...
by PK
Mon Sep 28, 2015 9:50 am
Forum: I could use that
Topic: Launch Tower Truss - Heavy Duty
Replies: 7
Views: 3235

Re: Launch Tower Truss - Heavy Duty

Agree on all counts re the purchase rather than build argument. Given how seldom this advice is heeded on hobby boards, I thought I'd chip in that you don't have to notch the little struts, you don't even have to cut them! Just bend them back and forth every few hundred mm and tack weld the apexes o...
by PK
Sun Sep 13, 2015 11:20 am
Forum: Propulsion
Topic: How to calculate thrust required to lift a heavy rocket?
Replies: 22
Views: 4007

Re: How to calculate thrust required to lift a heavy rocket?

Oh, so you're a sort of ignore all advice, eschew understanding, try stuff and use what works on the next (usually bigger) project.

You will find rocketry a frustrating pastime...

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