Knifemaking and other cool hobbies...

[Boerseun]

I have just finished off a hunting knife, and decided my next project is going to be a sword. Now - I considered posting this in the physics forum - I heat-treat my blades at 1200C, for roughly 30 minutes, after shaping them. Sometimes the blade comes out buckled, and have to be hammered on an anvil. Obviously the risk for this happening with a sword is much greater, seeing as the blade is a lot longer. Now, my question: Can the buckling be caused by uneven heating of the blade? Won't it help if I put the blade in cold, and let it heat up gradually with the kiln? The kiln takes about an hour to get up to 1200C, so I could let it heat with the kiln, and then leave it for 30 minutes? Could impurities in the steel cause the buckling? I have to build a new kiln for the annealling on the sword in any case, seeing as my knife kiln is too small, but I want to get behind the process 100% before wasting bucks on a new kiln.

Any other cool hobbies out there? Share it!

[C1ay]

Originally Posted by Boerseun

Any other cool hobbies out there? Share it!

Rockets

[Boerseun]

Schweet! Solid fuel? Altitude achieved? Parachute system? Gimme some details!

[C1ay]

Originally Posted by Boerseun

Schweet! Solid fuel? Altitude achieved? Parachute system? Gimme some details!

Yes, ammonium perchlorate and binders. Around 2300 meters on the last flight. We deploy a small drone chute at apogee that allows the rocket to fall fairly straight while slowing it enough for the main chute to deploy at 100-200 meters.

[orbsycli]

i used to love making/launching rockets. i still do, i just don't do it anymore. it's time for me to buy another kit.

when i was a kid i colleced hot wheels and i have hundreds of them still, unopened. i think i'll see what they're worth in about 50 years.

but now, i love to record music. and once it's recorded, i love to mix it. and once it's mixed, i love to tweak the hell out of it. and once that's done. i love to listen to it.

i also love to explore and make abstract art

[C1ay]

Originally Posted by orbsycli

i used to love making/launching rockets. i still do, i just don't do it anymore. it's time for me to buy another kit.

Try Smokin' Rockets for a nice kit. I particularly like his Mega-Nuk It rocks on an M series motor.

[orbsycli]

M!!!! the biggest i've ever used is a D. wowowwowow

[C1ay]

Originally Posted by orbsycli

M!!!! the biggest i've ever used is a D. wowowwowow

Well, A D motor is in the range of 10 - 20 newtons or about 2.2 to 4.4 pounds of thrust. An M motor runs from 5120.01 to 10240 newtons or about 1128 to 2256 pounds of thrust. You'll need to be Level 3 certified to fly it though.

[nkt]

Well, lockpicking is one of the big upcoming hobbies at the moment, and I'm pretty into it.

I'm very in to mechanical things, hacking stuff together (and apart) and popping a lock open, whether to look inside, or popping it open with two bits of wire and a lot of skill.

I've actually set up as a locksmith, as I like it so much.

[Boerseun]

Haha, nkt - I won't invite you to my house any time soon

I reckon this is a pretty cool thread - we should see some weird and wonderful things coming out of here, I reckon. We're gonna have a hard time to top the rockets here, but heck, give it a go!

By the way - are their any metallurgists out there who can help me with my problem in post #1?

I'm also trying to build a jet engine from a car turbine impeller, I just have to get my lathes set up to balance the little bastard. I've got some plans off the net, but its for a different sized impeller. Getting the combustion chamber not to flame out all the time will be the biggest hassle, I suppose. Apparently, using the right bearings, these little suckers can go to 100,000 rpm, delivering close on 20 pounds of thrust! I suppose ceramic bearings will be the order of the day. Take that, rocketboy!