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Post by Johansson on Jun 12, 2014 15:19:31 GMT -5
Thanks andreinke!
There is no need at all to buy a CNC mill to build a gas turbine, I´ve seen amazing stuff having been built on a manual Myford lathe with some clever jigs added to it.
A table top lathe, a small mill and a tig welder are the main things I´d find useful, along with the usual workshop stuff like angle grinder, propane torch etc.
I have no engineering background other than that I´ve always been interested in tinkering with things, I started building my first valved pulsejet 12 years or so ago and have been learning ever since.
Cheers! /Anders
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Post by Johansson on Jun 12, 2014 15:35:28 GMT -5
Today I´ve been building the jet pipe extensions during a few spare moments, I´m making these in mild steel as prototypes and when I´ve found out if the angles and length are ok I´ll make new ones in stainless. I guess that I´ll find out pretty quick if they are directing the jet exhaust far enough away from my legs. Sitting on the bike it feels like the length is pretty ok, it sure looks better now than before with the stub exhausts. They´ll probably have a different colour after the first start.... I have also made a small fitting for a Hobbs adjustable switch before the boost pressure gauge, I will have it shut off the fuel pump if the P2 rises above 3 bar. This is a safety feature in case the PWM controller for the fuel pump fails and lets pure 12V through to the pump, that would severely overspeed the engine before I have managed to pull the safety chord. Oh yeah, the safety chord. I had to run out to the workshop to take a picture of it since I forgot earlier. It will act as both a safety chord and a quick kill for the fuel pump that can be easily reached with the left thumb. The bike class rules clearly state that the driver must be able to kill the engine without removing the hands from the handlebars, and this kills two birds with one stone so to speak. Cheers! /Anders
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Jun 12, 2014 16:03:30 GMT -5
Hi Anders
coming on good mate, just wanted to ask what current draw are you expecting, the lipo I have at 7.5 amph has worked out real well, still holding 15.4 volts after one halted start, full five minute run and run down with oil running, big weight saving over lead acid.
Back to santa pod on 27th, so :-) lets hope
All best Andy
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Post by Johansson on Jun 12, 2014 16:10:02 GMT -5
Hi Anders coming on good mate, just wanted to ask what current draw are you expecting, the lipo I have at 7.5 amph has worked out real well, still holding 15.4 volts after one halted start, full five minute run and run down with oil running, big weight saving over lead acid. Back to santa pod on 27th, so :-) lets hope All best Andy Hi Andy, I have the numbers somewhere but the main consumers are the three oil pumps, since you are running ball bearings in your gas producer I recon your oil pump load is much smaller than mine. Keeping all fingers crossed for the 27th! Good luck! Cheers! /Anders
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Deleted
Joined: January 1970
Posts: 0
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Post by Deleted on Jun 12, 2014 16:19:25 GMT -5
Hi
main oil pump is pushing 65 psi.... and flow for both engine and gear box, it is drawing about 20 amps, clearly the scavenge pump and fuel pump not much, but chris did the math at 45 amp, he worked out I should get good 7 minutes, even if you put two 7.5 amp together , 4 cell give you 16.8 volt, would be more than plenty, and still a good weight saving
Well if it don't go down the track under its own power, I will push it down :-)
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Post by Johansson on Jun 12, 2014 23:02:58 GMT -5
A land speed vehicle doesen´t suffer from weight like a drag bike like yours do, I need all rear wheel traction I can find so a heavy battery is actually a good thing. Plus it cost me aprox. 1/3 of what a LiPo with the same capacity would have.
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Deleted
Joined: January 1970
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Post by Deleted on Jun 13, 2014 14:14:50 GMT -5
Hi Anders
yes you are right.... just wanted to give you the information, as for cost Dans just broght three 7 amp for less than £100
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Post by Johansson on Jun 17, 2014 13:22:29 GMT -5
I started wiring the bike up last night, will be at it again tomorrow if I have time to buy some more cables and couplings. I will solder every crimp connection to avoid problems with oxide and cables coming loose. Cheers! /Anders
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sven
Veteran Member
Joined: February 2012
Posts: 102
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Post by sven on Jun 18, 2014 12:46:42 GMT -5
Hi Anders, nice work you have done here as always:) Soldering is good thing to do, cause cripming only isnt good enough, I been working as car elecrtican almost 7 years and I have seen lot of lose and oxide covered connections, worse people can do is use so called Quick Splice Terminals. Hope to see it run soon
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Post by Johansson on Jun 19, 2014 15:30:34 GMT -5
Thanks Sven! I´ve done a couple of hours more on the wiring but it isn´t exactly interesting to read about so I didm´t bother to make an update about it.
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Post by Johansson on Jun 20, 2014 11:43:24 GMT -5
Ernie, my father sends his regards for the t-shirt! We are celebrating the Swedish mid summer holiday and things are as they should be.
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Post by Johansson on Jun 20, 2014 13:54:17 GMT -5
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fanxing
New Member
Joined: March 2013
Posts: 6
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Post by fanxing on Jun 21, 2014 3:52:18 GMT -5
Bad Dad
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Post by pictsidhe on Jun 22, 2014 21:25:24 GMT -5
Wow, that's a metric shit ton of quality work you've done there! One thing bothers me, what are the critical speeds of the power turbine? it looks a bit heavy for 25mm shaft and 32,000rpm. It's got very little damping too. If that turbine gets out of control; it could seize, or worse; break loose. At this point, I'd be inclined to take the chain off and rev the turbine up slowly while checking for bad vibes.
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Post by Johansson on Jun 23, 2014 7:45:30 GMT -5
Before any high speed runs I´ll rev the power turbine up to its rated max revs with the rear wheel lifted from the ground, with the chain still attached it should rev up a bit more controlled and I can use the rear brake to slow things down.
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