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-   -   Looking for Pulse Jet Help (Dynajet Redhead?) (https://www.rcuniverse.com/forum/rc-jets-120/3461548-looking-pulse-jet-help-dynajet-redhead.html)

Woketman 10-21-2005 04:41 PM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
ITS RUNNING, ITS RUNNING!!!!!

Ha!!!

Ray Davis 10-24-2005 10:44 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
A Double Whammy....that's nut's but I love it!

Harry, the V-1 weighed about 5000-pounds at 'TO' w/ anywhere from 6-900 pound thrust engines. At 1/6 scale, WS about 36", the fuse length would be maybe 50", the engine/nacelle maybe 5/8 of that...or perhaps 30". The DJ itself is...what....22"? So, off the top of my head, all this is about right for a pretty good scale reproduction. Now, weight and CG: three-pounds between ballast and engine is not bad at all (they used explosives....I gotta use lead shot, I suppose...plus the model engine will be kept foreward in the engine nacelle, systems/battery/etc crammed foreward, too). So, a model of 8-10 pounds max should easily be doable w/o sacrificing necessary strength. Not the TW ratio to be concerned about (model better than 1:2, V-1 less than 1:5) but the wing loading. Gonna be 'heavy' re that......need a non-scale higher lift section wing, I guess (but, so what?) and it will, indeed, be fast landing/TO speed!

And, yer welcome to beat me to it!

Ray

Woketman 10-24-2005 10:53 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
Ray, the heck with the lead shot... use explosives too! It'll be a GREAT motivator for not crashing!

MJD 04-23-2007 10:54 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 

ORIGINAL: BruceTharpe
Spark is the tricky part, you need a "buzz box" with a Model T coil and battery to provide a spark while starting.
A 12V input neon tube power supply works well. I use one called "the Boss" by West Coast Custom Designs LLC in AZ, 480 820 9517. 12VDC input, 7.5kv output.

MJD


jetpower 04-23-2007 11:20 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
maybe stupid quesstion
is the dynajet redhead still available from dynafog ?????

Pulsejet_Harry 04-23-2007 12:10 PM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
I called Dynafog within the last year. And technically, no, they do not sell the Dynajet to the public. It is such a small part of their product line that they only sell large quantities (I think 100+). It takes time to pull the tooling out and set it up. The general manager said that they don’t make a lot of money off of the deal. I purchased one from them about 6 years ago. Evidently, that was an anomaly. The hobby store that they advertise on the Dynafog web page does sell the Dynajet.

Pulsejet Harry

jetpower 04-23-2007 12:18 PM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
'i can not find the adres or url of that hobby store on the dynafog web page

Woketman 04-23-2007 04:41 PM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
PulseJet Harry SPEAKS!!!!

Praise the Lord!!!!

(I guess we'll have to wait a few years to hear his hallowed voice yet again)

gary350 11-01-2009 10:00 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
If you want to do a static test run of your Dyan Jet engine then you need to mount it to a work bench or table. Car radiator hose clamps work fine to clamp it to a metal mount. Do not mount it closer than 4" to anything that will burn. Move everything away from the exhaust of the engine because it will blow everything off your work bench.

Check the reed valves to make sure they are in good condition. The valves need to be centered correctly there is a tiny little pencil point hole in the head that is a location device for the reed valve. Make sure the reed valve is centered over that tiny hole between 2 of the pedal valve flaps.

Screw on the head. You can locate it in any position you like it is usually best to have the air fitting on top. Screw the locking ring tight against the body.

Connect a model airplane fuel tank to the fuel inject on the nose of the engine. Fill the tank with high octane gasoline. The tank should be mounted so it is just low enough that the fuel in the tank does not gravity flow on its own, about 1/4" below where the fuel wants to gravity flow.

You need a cooling system for the engine if your going to run it very long in a static position. A good powerful fan will do the job. Mount a fan in front of the engine so it blows air over the engine from the front to make air flow over it like it would do if the engine was on an airplane. Use a good strong powerful high volume fan.

Connect a neon sign transformer to the spark plug and the metal motor mount. Plug in the transformer.

Use an air compressor to blow air into the fuel flow injector. This will suck the fuel from the tank and blow it into the engine. The engine will start up real quick about 1 or 2 seconds. Once the engine starts you do not need the compressed air anymore. You do not need the high voltage for the spark plug either.

The engine will turn RED HOT in a very short time probably 30 seconds. With out a good stream of cooling air the engine can be damaged. The reed valves may be distroyed and the engine body can crack. If you don't have good air cooling turn the engine off by turning off the fuel.

Here is a video of a 10 lbs thrust pulse jet that I built running static. I have it clamped in the milling machine vise. After 1 min 20 seconds the reed valve brakes. There is no cooling on the engine at all.

http://www.youtube.com/watch?v=u2apj002QwY

.


Woketman 11-01-2009 10:41 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
Guess I was right about the Pulse_Jet Harry time frame, eh?

j.duncker 11-01-2009 11:29 AM

RE: Looking for Pulse Jet Help (Dynajet Redhead?)
 
Great video clip Gary350, loved watching the tail pipe heat up.

In the UK there has been a bit of a resurgence of interest in Control Line speed pulse jet flying at Nationals. Here is one doing 200 mph

[link=http://www.youtube.com/watch?v=bGkOX9n4eMA]CLICKY[/link]

Matagordababy 06-19-2014 02:56 PM

HELP! What is this thing?
 
1 Attachment(s)
http://www.rcuniverse.com/forum/atta...mentid=2006926:confused:

Can anyone help me identify this little Pulse Jet? When I purchased it I was told it was a Dyna Jet, but it seems this is not the case. Any assistance on identification and operating instructions will be GREATLY appreciated!

Thanks in advance!

Steve
[email protected]
(USA) 1-512-985-5203

Woketman 06-19-2014 03:57 PM

Is that an OS PulseJet? PJ Harry had one!

Matagordababy 06-19-2014 04:43 PM

I'm clueless Sir, but I appreciate the input - I'll see if I can dig up anything on the internet about them!

Keep the dirty side down!

Steve

Matagordababy 06-19-2014 05:57 PM

Help!
 
1 Attachment(s)
http://www.rcuniverse.com/forum/atta...mentid=2006966

Woketman says you may know what this little jewel is - any assistance you can provide will be GREATLY appreciated!

Keep the Dirty Side down!

Steve
[email protected]
1-512-985-5203

adrhadthakhu 06-20-2014 01:35 AM

Get in touch with Bruce Tharpe. He has had lots of success with pulse jets.

http://finanziellede.de/hu6l.jpg

MJD 10-29-2015 06:55 AM


Originally Posted by Matagordababy (Post 11826434)
http://www.rcuniverse.com/forum/atta...mentid=2006966

Woketman says you may know what this little jewel is - any assistance you can provide will be GREATLY appreciated!

Old thread, I know.

http://aardvark.co.nz/pjet/availablenow.shtml ??? Similar, not identical.

http://aardvark.co.nz/pjet/images/pj8c020.jpg

Woketman 10-29-2015 09:29 AM

PJH, you gonna weigh in here?????

MJD 10-29-2015 11:56 AM

I'd write the guy in NZ and see if he knows.

Art ARRO 10-29-2015 12:44 PM

MJD,
The pulsejet depicted appears to be a MEW for Minnesota Engine Works, Model 607- I'm not positive on the model number though.
These were manufactured and sold in the 1960's an d I passed on one to purchase an OS Tiger pulsejet which was a virtual copy of the US made Dynajet Red Head. I flown the Tiger in several controline speed meets in my early youth. The MEW's were not consistent or competitive against the Dynajet/Tiger jet.
Rgds,
Art ARRO

oel123456 02-08-2016 05:09 PM

High efficiency ear plugs are very important when near the operating pulse jet. I have about 50% hearing loss because of a Dyna Jet Redhead. The first time I started the engine on a work bench I noticed it suddenly became quieter and things have been quieter ever since. It is interesting that after starting with the original exhaust tube length the trust become much greater if the length is shortened with a tubing slide arrangement. Several times the trust at the expense of reed valve life. Not practical unless better reed material is found. The steel cracks along the outer edge of the valve..

GilForbes 05-01-2020 10:38 AM

Help with a DynaJet RedHead
 
Actually, it's quite simple to start.

Before you do anything about running the jet, anchor it to a solid base (a 3 ft length of a 2x6 will do nicely) with two steel braces, one around the large end right behind the spark plug and the other around the exhaust tube about 3 to 4 inches from the end. Pipe hanger strap will work. Form them completely around the jet body and close with a bolt and nut. The large end needs to be more than an inch above the 2 by 6. Gauge the exhaust clamp length so the tube runs parallel to the plank. Each bracket needs two flanges so the assembly can be fastened to the board.
CAUTION: Once it fires, it gets glowing red hot in a matter of seconds. It was my policy to place a flat metal heat shield between the jet and the mounting board.

Now you're almost ready. After mounting the jet, connecting an 8 or 10 oz fuel tank filled with WHITE GAS (no additives, alcohol, or lead), and a 12v battery w/a momentary switch in the wire leading to the plug (the negative lead can be connected to the front mounting bracket), You are finally ready for noisiest experience ever.

Connect a tire pump to the attachment point near the fuel line.
Pump a few shots of air into the jet to make sure you have injected fuel into the chamber.
Press the switch to activate the sparkplug and plug your ears.


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