Jet Luge Update

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Lugebob
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Jet Luge Update

Post by Lugebob » Tue Aug 08, 2006 2:20 am

Just a liittle update.
I have had a little public action lately..

2 weeks ago I opened a community parade in Munnsville, NY the day before our annual Gravity Fest Race. (gravity vehicle racing)

This past weekend I did 2 exhibition runs per day on a 50x3400 ft runway at the Liberty Bell Jet Rally in Lebanon PA.

video: Start, taxi, takeoff.............. cam out of memory ugg http://www.jetluge.net/video.html/Jetlu ... y_bell.MPG

And last: August 19th @ Maryland International Raceway(MIR) I will once again open the "Jet Wars" event. This will mark the one year anniversary of the Jet Luge.... Come hang out at the Party in my pit area...

MIR Jet Wars http://www.mirdrag.com

Once again thanks to all for the help getting this show on the road.
Bob Swartz
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Johansson
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re: Jet Luge Update

Post by Johansson » Tue Aug 08, 2006 5:11 pm

That Jet Luge of yours must be a great way to draw attention to the sport, nice work!

I am just curious, when you travel around on all these events and run the luge, does the income cover your expences for the trip or are you taking it all out of your own pocket? I know that there is a huge difference in terms of sponsorship money in US compared to tiny Sweden, but anyway...

//Anders

Lugebob
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re: Jet Luge Update

Post by Lugebob » Tue Aug 08, 2006 6:00 pm

Well so far.... it is almost all out of pocket....
My original goal of drawing attention to the sport is working. This was a personal endevor and I was not looking for money. But ever since my local dragstrip experience last year, I have had "promises" of event bookings with pay and people telling me I could get sponsors. But as I am finding out.... it is a hardcore business and cutthroat. People everywhere want the show for no money and the sponsors are only willing to give up product not cash. I get the "Your Welcome to Run Here, but I have no budget" story.
My wife and I love to travel and meet people and could see ourselves doing this as a retirment job for 30 some weeks out of the year.. Most of the exhibition guys are retired and having fun doing this. So for now I am trying to keep postive and like to think of what I am doing is growing the exhibition business. For the time being, I do events that do not cost me much and I barter for perks....like free tickets for my friends and crew , prime spectator contact location, free food and permission to sell t-shirts (which I do not have designed yet)
I finally have most of what I need for a portfolio of proof that I am worth the $$$$ as a ticket selling attraction and that I am not just a fly by night freak show looking to get paid to kill himself with his hobby.

I get a kick out of that my "character" as I was told last weekend, is also a good selling point... A wild, crazy and excited 47 year old dad (soon to be grandpa) that lives a good clean Christian Life and is not afraid to talk about it in public when he interacts with the fans of all ages. I am still waiting for confirmation that this may be my mission from God, one that I will do for free. As my sticker says on the side of the turbine.. "God is the Pilot...I am just along for the ride" If I can show just one person per event how trusting and faith in God can save your life, then I am "Paid"

I really wished I had a major sponsor... I get so large count views (up to 20,000) and many one on one contacts at event (100-5000) per day I could really be pushing someones product the best way.

so in short... The Jet Luge show is a work in progress. I still need a fire show though.

thanks for asking

Hey Anders did you get to check out out world cup event in Ã…re?
http://www.longboard.nu/IGSAsweden/inde ... =home.html

I had to pass on it this year because our first grandchild is on the way.


bob
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re: Jet Luge Update

Post by Johansson » Wed Aug 09, 2006 4:33 pm

So I thought, it is a tough market to get in on. Especially since you cannot do a triple back-flip through a brick wall covered with napalm 20 meters above ground like the motorcross guys... *smile*

I would say that your luge draws as much attention to the world of micro turbines as it does to street luge racing, if people would realise that they can build a similar engine with some machining skill and know-how someone ought to be hooked for life!

I didn´t even know that there was a world cup in Åre, and I live just 300 km away from the place. I don´t think that I would have gone there anyway since I am totally uninterested in all kinds of sport except dragracing and such, I don´t even bother to watch Sweden in an icehockey final...

Have you had any progress with the afterburner/flame thrower? A fairly light AB made out of thin stainless wouldn´t be hard to make given that the ECU won´t be upset by it, a 30 cm long one with an internal flameholder should work fine.

//Anders

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re: Jet Luge Update

Post by Lugebob » Thu Aug 10, 2006 3:06 am

Funny..... I was asked to run through a wall of fire last weekend...by a bunch of pilots.

You are right in the promotion of micro turbines. I have fielded many questions about the engine alone. I tell them what I know and then refer them to a few books and experts if they want to know more.

I did a little show and tell at an accelerated level High School engineering class. The top 90 math and science students in the state of Virginia... a real excited and special bunch. I told my life story and talked about dreams, how to obtain them and the engineering field and then told them to get out paper and pencil and start calculating the basic physics of the luge, then a powered luge, and then went over the specs of the engine.. and how it works... like most, they were blown away with specs of 113,000 rpm, 750 degrees C and how all that stays together and running. One kid is now determined to build a WASP engine and put it in a self designed RC boat and his father is funding it. He is also on the schools robotics team.

after the class I demonstrated all the safety procedures and rode the thing around the parking lot to show that it really works I loved doing that with a bunch of inspired kids and hope to do more.

time for sleep

bob
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multispool
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re: Jet Luge Update

Post by multispool » Thu Aug 10, 2006 9:46 am

Hi Bob,

I hope you take this in the spirit that it is intended as I am interested only in your continued health and my express wish for you not to get injured!

If your declared EGT figures of 750c was not a typo then you are running the engine with no or very little safety margin! The TIT (turbine inlet temerature) is likely to be only a few tens of degrees below where secondary cooling of the turbine blades are necessary, this is pushing things too close to the limit!

If I had an engine with those temps then I wouldn't even run it in public, let alone next to my head! Would suggest that if you need more power then go for a larger engine which will diliver more power than you need and will have a realistic safety margin. I know what I'm talking about!

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re: Jet Luge Update

Post by larry cottrill » Thu Aug 10, 2006 1:27 pm

Bob -

Let me know if you would consider a second luge, with twin valveless pulsejets. Instead of a single engine that MIGHT explode behind your head, you can have two that are always exploding, one on each side of your head. (Heat shields needed, of course.)

What is the total thrust you believe you're actually getting, and with what specific fuel?

I would like to do something similar to what you've been doing, but with a dual-pulsejet lightweight trike at oval dirt tracks. What do you think? Dirt track stock racing seems to be the motor sport of choice around here.

L Cottrill
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Lugebob
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re: Jet Luge Update

Post by Lugebob » Thu Aug 10, 2006 2:09 pm

Well you certainly got my attention :shock: Although what I do may seem wild and crazy to the casual observer, I go to great lengths to make this as safe as I possibly can... and I welcome the caution or penalty flags thrown by the subject matter experts... that is why I talk about it so publicly..... kind of a public design review... for my own safety.

I am talking to the manufactuer about this.. to see what is up. I have not pushed or changed any of the ECU settings in this and the turbines has been regularly factory maintained and always comes back with these temps. This engine (serial#12)does run hotter (ECU Readings) than the new one (serial#212) of the same model by about 100c, The hot one also has about 3lbs more thrust at the same RPM, and seems to be finicky on throttle up in real dense air. I have logged instantanous peak temps on this as high as 861c ever since I have had it. it idles at 520c. I wonder if the EGT probe is not linear. I calibrate it each day, but only at low temp. I say this only because I do not see any difference in the exhaust cone glow at night between the 2 engines. Another thing is that I have never had an overtemp shutdown from the ECU. I wonder if it is working. Would it be a good idea to get an infrared thermometer for the tool kit to double check now and then?

Be assured. I will not run this again till I sort it out...

thanks
bob
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Lugebob
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re: Jet Luge Update

Post by Lugebob » Thu Aug 10, 2006 3:58 pm

Larry, Yes I would consider a second luge... and plan on a twin for next year, but not a pulse jet... Dont get me wrong I think they are real cool, but after careful study I choose not to go pulse jet... and here is why.

The key to a street luge being stable and fast is the low mass and low and very centered center of gravity. putting anything on the back starts to upset the formula, so the mass/ size of the power unit had to be small. This also includes the fuel source. I have had this idea for over 10 years, but there were no power sources available to meet the requirements until 2 years ago.

I am running just over 50lbs of thrust on a 70 degree F day and my total weight is 205lbs to include the luge, fuel, me and my safetygear. The total weight of the power unit.(box in the back). turbine, starter system, fuel, tank,batteries, soleniods, computers, sensors and the mounting hardware are right at 6.8lbs
That is 50oz of fuel and it will give me 2minutes and 20 seconds at full throttle. I will never be on the throttle for 2 minutes... 30 seconds takes me to 100mph on flat roadway.

I don't know how I could do the same or better with a pulse jet. Another problem with pulsejet is the WOW and Scare factor..... I am already finding it hard to convince people to let me run this setup... even on a track with concrete jersey walls to protect the crowd.

If you make that thing I want to try it... we can trade rides for a day.

bob
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multispool
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re: Jet Luge Update

Post by multispool » Thu Aug 10, 2006 4:23 pm

Bob,
I'm sorry, I didn't mean to frighten you but just bring to your attention the risk of running an engine so hot, Particularly so close to yourself. They are potentially dangerous machines whether commercial or home-made. I'm very familiar with miniature turbine design and development but not with individual commercial designs other than that they all use inconel 713 turbine wheels which lose strength rapidly if taken over temp.
Peak temps while starting is to a certain extent inevitable and it's usual to program the ecu to pass through these quickly.
The thermocouples are normally quite reliable so I would imagine that the temps you see are quite accurate. Many ecu's allow the user to adjust max running rpm and max/min shutdown temps.
Any attempts to add an afterburner will impact on engine temperature, ie. Likely to increase it further...

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re: Jet Luge Update

Post by Lugebob » Fri Aug 11, 2006 1:36 am

Well it's not a triple back-flip through a brick wall covered with napalm 20 meters above ground like the motorcross guys. but i was just asked if i would match race with a Jet Funny Car....at Jet Wars hmm Bracket Racing Jet Style.... that would be a show huh? I don't thinK so...... this time.

I could see it now.. he spots me 15 seconds on the tree. I take off and then 20 seconds later he runs me down (or over) at the finishline. I might do it except I have no idea what happens to the air near a 279mph funny car as it passes by with the engine shutting down and the chute popping.... It may spin me like a top while I am doing 80 mph. Not good, but for the show worth a little testing of the winds so to speak near the finish... I wonder which crew member will stand there with a flag. ha ha nuts

bob
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re: Jet Luge Update

Post by larry cottrill » Fri Aug 11, 2006 11:59 am

Bob -

For a flame effect without a lot of hardware, try rigging something that dumps a SMALL charge of non-dairy creamer powder into the exhaust stream. It has been reported that this can be fairly spectacular. (Proceed with caution; some experimentation required ;-)

Some fair-sized pulsejets have actually been run on finely powdered solid fuel like this, drizzled into the intake at an appropriate rate.

L Cottrill

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re: Jet Luge Update

Post by Mike Spike » Fri Aug 11, 2006 1:35 pm

Looks cool!
If it doesn't fit, use a bigger hammer!

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re: Jet Luge Update

Post by El-Kablooey » Fri Aug 11, 2006 7:45 pm

Yeah, if you toss a handful of non-diary creamer over a flame it will make a huge fireball. It's pretty fun to do when sitting around a campfire with a bunch of unsuspecting drunks.

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re: Jet Luge Update

Post by Lugebob » Mon Aug 14, 2006 3:30 am

well it's not a car-b-que like Bob Motz does with his J79 powered Kenworth, but in the spirit of things @ the Jet Wars show on the 19th in Maryland, I thought the crowd would like a little summertime satire skit before I rolled up to the christmas tree. Lawn Chairs and Wurst to the stagging lanes!!!!!

Image
Image
Bob Swartz
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