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Re: M500 build log

Posted: Mon Feb 03, 2014 12:15 am
by metiz
It's not a thermojet though, it's a chinese. The blended body makes it look like a thermo

Re: M500 build log

Posted: Mon Feb 10, 2014 8:27 am
by ganuganu
Woooow thats severely cool. I really appreciate your effort and interest towards pulsejets. One day i would like to do an CFD analysis of this monster engine. It really looks amazing, all the best for your first run. :D :D

Re: M500 build log

Posted: Mon Feb 17, 2014 9:17 pm
by metiz
The frame is done, I'll take some pictures later. Next up are the pumps. I'll be using a Karcher cip (12 bar at 5.5L/min) and a Karcher 695 (130 bar at 7.5L/min) The pump on the left is the 695. On the left pump there are 2 knobs. they were both pretty seized up so I couldn't rotate either of them when I tested the pumps. Now that they're clear of their housing, the knobs are loose and rotate freely. One knob has 0-5 on it and the other on at the top (markings are on the housing)has "- +". Doesn anyone know what these controll? I can't find a manual anywhere of course.

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The engine will consume an estimate of 10 liters of fuel a minute so neither one of these pumps alone will do. Prefably I'd like to hook them up together so I can controll fuel flow with a fuel return valve. Both of these pumps pruduce way more pressure than I need: does anyone have a suggestion on how I might manage this? If I use bernoulli's equations to increase fuel speed, that would get rid of the excess pressure. If I get both pumps to 8 bars of pressure, could I hook them up like that (paralel for greater debit)?

Any suggestions are welcome!

Re: M500 build log

Posted: Sun Feb 23, 2014 7:26 pm
by metiz
Build a fueltank. 12 liter capacity.

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Both pumps have 22 and 26mm outside diamater thread. Can I asume that those are 1/2" and 3/4" NPT?

Re: M500 build log

Posted: Tue Feb 25, 2014 5:49 pm
by ace_fedde
metiz wrote: One knob has 0-5 on it and the other on at the top (markings are on the housing)has "- +". Doesn anyone know what these controll? I can't find a manual anywhere of course.
Mixing shampoo into the water... No need for that...
metiz wrote: Both of these pumps pruduce way more pressure than I need: does anyone have a suggestion on how I might manage this?
Pressure build-up in the pumps depends entirely on the resistance of the "outlet", in this case your injector. If the pressure gets to high you can feed back some fuel into the tank, but you'll lose some volume by that. If you that want to lose to much volume you'll have to adjust the injectors resistance (widening).
I think I rember that I made a design for you, both on paper and with the couplings.

The thread on the pumps is some strange metric one, I included the metric couplings in the design i build for you. Must be somewhere in the boxes.

Fedde

Re: M500 build log

Posted: Wed Feb 26, 2014 3:54 pm
by metiz
Hey Fedde

I can't remember you mentioning anything about a design before, but I'll rummage through the boxes again. The thread fits sanitary couplings, available at a DIY store near you, but I have a hard time figuring out what kind of thread it is. They couldn't tell me in the store either.

Re: M500 build log

Posted: Wed Feb 26, 2014 8:17 pm
by ace_fedde
But you allready have some (enough) of these special couplings somewhere in the boxes. If I remember right I build some combination of valves, a cross-joint, short hoses, and those special couplings. That was the design (made out of parts).

Re: M500 build log

Posted: Wed Feb 26, 2014 11:08 pm
by metiz
Ah right that one :) Yeah I have that here. I'm going to make a few modifications, put some ballvalves and pressure gages in different places

Re: M500 build log

Posted: Sat Mar 01, 2014 4:47 pm
by metiz
I just finished the fueling system, minus a few details. All that's left now is an air supply and a realy beefy ignitor with a nice hot spark. I'm open to suggestions on both accounts!
(the threads are BSP btw, if anyone was curious :P)

Re: M500 build log

Posted: Sat Mar 15, 2014 6:11 pm
by metiz
I build a remote controlled throttle for my leafblower
http://www.youtube.com/watch?v=0QxSsde4IR4&amp

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and also this little elbow that slides over the leafblower's nozzle
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Re: M500 build log

Posted: Sat Mar 15, 2014 10:15 pm
by cadet
Very impressive. Can't wait to see it running!

Re: M500 build log

Posted: Thu Mar 27, 2014 2:36 pm
by metiz
It isn't pretty but it'll work

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Ace_Fedde also provided me with a LPG tank. It's 70% full. I want to use it at least to preheat the engine before liquid is introduced. Does anyone know how I can get (controlled) gasflow out of this thing?

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Sorry for the red hue, annoying phone-cover.

Re: M500 build log

Posted: Sat May 03, 2014 9:57 pm
by zono
hope, we will meet you and your Beast at the "Days of Speed and Thunder" 29th-31th May?

see here: http://www.pulsotriebwerk.de/

PS: there will be also many other dutch pulsejet-freaks

Re: M500 build log

Posted: Tue May 06, 2014 10:28 pm
by metiz
zono wrote:hope, we will meet you and your Beast at the "Days of Speed and Thunder" 29th-31th May?

see here: http://www.pulsotriebwerk.de/

PS: there will be also many other dutch pulsejet-freaks
I wish I could come, but it's way too far away. Organise something closer to the border and I'm game!

Re: M500 build log

Posted: Sat May 24, 2014 2:42 pm
by metiz
All done!

Construction on the M500 is complete and all the supporting systems are working. All that remains is little jobs like getting some hose clamps, steel wire, and a hunting scale or similar (can anyone give me a heads up if they know a store/ someone who has such a scale?

Anyway, I set up the M500 and the pumps to get some pictures.

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don't know why the pics are so shitty. Maybe the lens is dirty or something.