My latest mad project - PICS ! * UPDATE: and movies too ! *

[jeepinator]

Hello !
Well, last night I got a bot bored :p

Here is a pic of the creation I made last night and finished this morning. I just went out for a test run. It works perfectly. No bizaare handling issues, no excessive torque steer, etc. The suspension seems to be set up about right, although I am going to add a rear sway bar today.
Is it fast ? In a word, YES. But this is with a 14 turn Sonic motor and 8 cells. Acceleration is really quite sad, but once it gets going it really flies. I am guessing it's thrust to weight ratio is quite good though as it will go up suprisingly steep inclines with ease.
It is VERY VERY loud though ! Kinda cool for neighborhood attention ;)

For many more (MUCH bigger :warning: )pictures, visit my website HERE (http://www.theshreves.com/rc_stuff).

http://www.theshreves.com/pics/s_fancar1.jpg

I will be making some improvemnts soon. Anyone have any ideas ? I really no nothing about propellers. I don't even know which way they are supposed to spin! I need the most help in this area. Thanks !

[ 08-28-2001: Message edited by: jeepinator ]

[Spinner]

interesting to say the least!! :rolleyes:

[Nitro_Rustler_15]

Cool creation jeep, stick on some wings and make it fly lol :D as for the way the prop is supposed to spin if theyre anything like ceiling fans, it should spin clockwise, but of course I have no knowledge of airplanes. :D

[Andrew the RC man]

jeep- i got nutin to say, you knoe my hush hush project and i got nutin else to say

[1 Krazy Foo]

thats cool jeep. Have you done any jumps with it? that would be something to see. As for the props, do you know of a flying feild for R/C planes in your area? If so go out and ask them or visit a hobby shop that specializes in planes

[Jo_bomb17]

jeep, you want your propeller to spin Clockwise!
Jeep, im just jealous!I cant do nuthin like that!I swear, u invented electricity!>LOL :p

[TC3Racer]

i made something like that but it wasn't radio controlled. i had these old air powered planes wher you would pump up the tank with air and flip a switch and it would go. i put 2 of these on an old tonka dumptruck and let em' rip.... is said RIP.... lol. well by the time it got going it was out of air. so i gave it a push and it went up to speed and still went pretty slow, but i couldn't beleive it even went cuz it was so heavy! it was a neat little project though...

nice work jeep.... i would look at some airplane props and ask some guys what a good prop is. nice projects too on your site too... good luck with all of em'!

[jeepinator]

Here is my prop rotation question:

http://www.theshreves.com/pics/prop1.jpg

[OR

http://www.theshreves.com/pics/prop2.jpg

Plus, I guess some props were designed to be pushers and some not ?
If 2 props have the same diameter and pitch, but one is a 2 blade and one is a 3 blade, what charactersitics will change ?

Thanks.

Andrew, I did this prop on a car thing a LONG time ago, and I have proof of it on my web page ! (was probably like 94'ish). Don't even think I stole your idea :rolleyes:

Strange Desires, I have not jumped with this car, but I did on the last time I tinkered with this idea. I used a XXT previously, but I barely modded it (I just kinda stuck a motor on the rear shock tower :p ). I did jump the XXT ... it was no good. Almost like gravity increased or something weird. It would forward endo like mad. I quite simply could not jump it at all. Had to ROLL over the jumps. Plus, on the dirt track it made a huge dust storm everywhere it went. It was quite funny actually. A couple of times I just drove it around instead of sweeping the track ;)

[draggerman11]

My chin was to the floor for about five minutes as I just stared at it. Jeep, make sure you send it in to rcca's readers rides. Wow! Jeep, your a genius. You know those cheap fans with the foam props? I put one on one of my 10 turns, and it spun so fast, that it ripped the foam off, and shot it at my friend. He said it hurt like heck(Well, the other word, but I'm not going to type it in) and left him a bruise. LOL! That was the same night we invented popper bombs(You know, those paper strips with gunpowder circles on them. I actually went deaf for about a minute when I hammered one)

[Hairball]

Jeep.. Heres an idea, and i'll be amazed if you actually pull it off!

Add a second servo and put the motor on a movable mount, so when steering, you turn the wheels and the motor...

Just thought it might be cool.

[the_yawn]

Did you modify a fit or build it with spare parts?

[Andrew the RC man]

jeep- until your car does what mine will do when i get the cash...it isnt stealing my idea

[gubbs3]

Use the two bladed prop. Three bladed props look cool but are less efficient. For that motor you should be able to use up to a 10 inch prop. But for that "thing", use the biggest you can fit without it hitting the ground. Experiment with props to see which is best. You can judge it just like gearing by checking the motor temp. With the cooling from the prop you should go up to a prop that will make the motor a little uncomfortable but still cool enough that you can touch it.
Remember, diameter equals torque, pitch equals speed. You can't have both so if you use a larger prop use a lower pitch.

[gubbs3]

Forgot to mention a few things:

Use a three or four bladed prop. Even though they are less efficient, for the size the diameter is much less for extra ground clearance.

Preferably, use a speed control with reverse so you have some sort of brakes for when you figure out the sweet prop.

Try a prop in the 8x3 - 9x5 sizes. I'm not completely sure about the prop size because my experience with electric planes is limited but that should be a good starting point.

BTW: I just got back from flying an electic plane. First flight was flawless, couldn't have been better. Second flight was looking great but on a pass above the runway about 15 feet up, there was a mechanical problem that "landed" my plane at about 50 mph (it was a pass going with the wind). It's in a few peices but its fixable.

[jeepinator]

Gubs3 !
Thanks dood.
I am currently experimenting with 2 props. One is a 5D x 3.5P (3 blade) and the other is a 6D x 2P (2 blade).
I did not mention it, but I am using 8 cells. They are 2400's.
BTW, it seems my selection is quite limited since I need a "pusher" prop.
I have a variety of stuff in my Tower Hobbies shopping cart right now:
1) 5.5 x 4, 2 blade
2) 7 x 3.5, 2 blade (wood)
3) 7 x 4, 2 blade (wood)
4) Another 5 x 3.5, 3 blade

Do you have any recommendations for where to look for props ? I think an ideal prop for me would be 6 x 4.5, 3 blade. Or maybe 6 x 4, 3 blade.

And, since it is a pusher, the motor does not benefit much from the air (it gets might warm !). In fact my 2400 packs are too hot to touch. I am getting MONSTER RPM though. It sounds like a leaf blower on meth !

Hairball, that sounds too complicated to even try! Plus, I am not sure what gain I would get. This things steers like mad as it is. I almost wish it had a solid rear axle. It spins out at high speed (only when under power). It would probably work fairly well if i could "mix" the channels so that the motor rotated like 25% of the steering servo, but in the OPPOSITE direction, to counter the spin out forces a little. That would require a fancy airplane radio ... NO THANKS !

the_yawn, Some of the parts were custom fabricated and the chassis had to be drilled, but for the most part this was made from stuff lying about in my massive RC drawers of parts. A few years ago I bet a friend I could build 4 RC10's from what was in the box. I came really close. I was missing like 10 parts to complete the 4th car. Like a shock shaft, and similar stuff.
I have at least 2 XXt's and a XX in there as well .. oh and a XX4, 3 Kyosho kits worth of parts (Lazer, Triumph, Outlaw Rampage, and a Kart (go kart thingy). If you go to my web page and click on "kits I have owned" or something like that, you will see them. I never sell anything, so I have all of them in some form or another. My monster truck sucked up quite a few spare parts :)

[Railman]

Amazing Jeep! How do you stop it though? Unless I'm mistaken, no one answered your question on the direction. The thick edge is the leading edge, just like on a wing. It's the old tear drop thing only slightly teaked for better push...round edge 1st. Have fun!
:D

[XXXER]

Jeep, okay, this is just sort of what I gathered from working at my hobby shop, the first number, I know to be the length, of course, and the second, is the pitch, now, I believe, the larger the prop, the faster it will go. As for pitch, the steeper the pitch(the higher #) the more 'pickup' it will have, obviously due to the...yeah, you understand, mr Rocket Scientist. Either way... I would suggest using Composite props, mainly for Durability reasons. As for your batteries and motor, what do you think they will do when you keep the throttle pretty much pinned the whole duration of the pack, with any luck, you will have not cooked your brushes(be sure to check em!)

Either way, it looks sweet. I am a fan of Carbon Fiber, if there is C/F, I dig it, Nairb will agree with that, hehe.

[jeepinator]

Railman, because of my superior chassis tuning skills I was able to set up the suspension in such a way that a hard turn at high speed will result in a long sideways powerslide, scrubbing speed in a big hurry.
Hehe, ok that charactersistic was luck, but it is true. I really don't need brakes. It would be nice though. I am considering a reversing controller, but this is just a fun project. Not sure if it worth anoterj $100+ just to get brakes on a car that will just sit on the shelf for eternity :p

OK, nobody answered my rotation question in the simplest way: Is it the top pic or the bottom one ?
I was thinking the leading edge is the straight edge (top pic would be correct), but Railmain, you seem to be saying it's the bottom pic that is correct ?

XXXER, thanks for the help. I was thinking the second number (pitch) determined top speed (a steeper prop would accelerate the air faster) and the diameter determined the volume of air being moved (kinda like torque, and bigger props would make for better acceleration). But, hey, I am no airodynamics expert ! ;) The chassis is from an RC10 Graphite. I wish they still made chassis like that !

[R/C Homie]

ROCK ON JEEPINATOR!!!! YOU BE DA MAN!!!!!! mad peaces

[Mason Copeland]

:read like a chant:
jump it, jump it, jump it, jump it. If your not afraid to break the prop put wings at the side too so itt'l soar and keep tweaking it till it works, maybe not...dont forget to bring a camera if you do!!Can it go off road?!?

[ 08-27-2001: Message edited by: Mason Copeland ]

[Interceptor]

I did the same thing back in 89 with the remains of my Striker and a Cox .09 engine with a pusher prop. Worked great, just not very fast and no brakes :-) Glad to see someone else carrying on the tradition :-)

[outsider]

This is a pretty good idea: most cars lose speed when going off jumps. Not this one; it will actually GAIN speed since there will be no ground resistance. For accelleration maybe you can devise a sort of switch with a 3 chanell radio so that initially the motor powers the wheels then you can switch to prop power.

(BTW I'm still interested in my generator idea, and have investigated small generators and alternator diagrams to see what modifications to motors will make them more efficient electricity producers instead of users. I wish i could afford a metal lather :) )

Keep up the good (interesting) work.

[Nitro_Rustler_15]

Its your top pic jeep, that'll give u push, the bottom gives u pull which'll make u go backwards. :D

[rjb]

Actually, if you took the top pic and flipped it over, I think that's it (push). If the prop blades were sloping down towards the table that is.

[jeepinator]

Hello again.

Today I had a buddy drive my fan car (what should I call it ? Air car ? Fan car ? propeller car ?) while I took movies with my Nikon digicam. They are not super high quaility, but just about right for the web ...

MOVIE #1 (http://www.theshreves.com/pics/fancar1.mov) 1.9 megs
MOVIE #2 (http://www.theshreves.com/pics/fancar2.mov) 3.4 megs
MOVIE #3 (http://www.theshreves.com/pics/fancar3.mov) 2.5 megs
MOVIE #4 (http://www.theshreves.com/pics/fancar4.mov) 5.7 megs
MOVIE #5 (http://www.theshreves.com/pics/fancar5.mov) 4.1 megs


EDIT: These are .mov files. If you want to view them and don't have a Quicktime player, go to http://www.apple.com and download the free player.

[ 08-28-2001: Message edited by: jeepinator ]

[outsider]

Acceleration doesn't look too bad... on the road. I'm thinking this thing isn't too hot off road, especially from a dead stop. How about using 2 or 3 smaller props inline covered with a tube to act like a turbine?

[Railman]

Jeep, Cool video, Looks like fun! I'm sorry I didn't respond to the prop thing sooner, & after rereading my post it kinda sounded like I contradicted myself. I do think it's the top pic. of the prop also. I was refering to the cross section of the blade. Isn't the straight leading edge a little thicker, & rounded like a wing? By now this is old news anyway. Anyway keep havin fun!

[HauntedMyst]

It will be a whole new class of racing!

BTW, I just looked on Jet Dragster (http://www.jetdragster.com) to see about any info on a real jet dragster. Take a look, it's very cool.

my favorite quote from the page:

Fuel Capacity: 30 (22-24 gallons burned per run).
Engine: Westinghouse J34 built in 1960.
Air Consumed: 12,500 cubic feet per second (the equivalent of sucking the air out of a six bedroom house in one second). <-LOLOLOL


[ 08-28-2001: Message edited by: HauntedMyst ]

[J mAn]

jeep- you are using the wrong kind of prop, the prop you're using is meant to pull something not push it. if u turned the motor around it would work more eficently. It matters because prop blades are in the shape of airfoils and your prop will only work eficently if you turn the motor around. I dont know if it would make much difference though.

[J mAn]

sorry, you already figured that out i should have read the entire thread first

[Hairball]

Jeep - after reading your post about changing prop speeds with turning you gave me the coolest idea.

Ok, use a R/C helicopter rotor head so you can actually change the angle of the blades on the fly. Then link the servo that controls that to your steering servo so when you turn the wheels, it slows the prop down, or hook it up as a third channel so you can use it as brakes and reverse on the fly. Now THAT would rule.

Or am I just crazy??

[ 08-28-2001: Message edited by: Hairball ]

[jeepinator]

Heh, that is a GREAT idea.
It would take me about 10 years to figure out how to do that though ;)
Problems: the collective plate and associated hardware that helicpters use is proundly complex. Also, the center part takes up too much space. Thirdly, I have never even heard of helicopter blades small enough. My max radius is 3.5 inches (7" diameter for all you math geniuses :p ). That is not a lot to work with.
I sure do like the idea though. I will be mulling that one over in the back of my head for some time, to be sure.

[Hairball]

Well, you could always use one of those multi-bladed helicopter rotors. I've seen them for the kyosho concept 30 with configurations of 3 to 6 bladed heads.

That may fix some of the proplem, and you could also put the con-glob-er-ation (couldn't think of a better way to put it) in a duct, so it would be a ducted fan with on-the-fly forward and reverse thrust changes. I'm seen this on a home-made hover craft once, thing was BAD-A$$. I've got pics if your interested...

[old phart]

Maybe I can help you here......

A propellor is a "rotating wing"; and that is exactly what a helicopter uses, only a really big rotating wing, commonly called a rotor. A helicopter is a rotary wing aircraft.

If you look at a wing in cross section, it has a curve to it, on top. That shape is the airfoil. When air moves over it, it has to travel faster over the curved surface to meet the air travelling over the shorter flat surface, at the same time at the rear of the wing. This creates a "low pressure" area over the curved surface. This "low pressure" in relation to atmospheric pressure, is what creates "lift".

If you look at a prop, it has the same shape as a wing. It is in fact, a rotating wing. The curved surface, is the "frontside" of the propellor. Whenever it spins in the correct direction, which is with the "thick" leading edge, the curved surface will be creating a low pressure area. That is what makes a plane move when the propellor spins. Not the fact it is churning up the air, but the fact it has created a low pressure in front of it.

Now, knowing that you can realize there is no difference, basically, in a "tractor" or "pusher" propellor. As long as the thick, leading edge is rotaing in the direction it should, there will be "thrust" (actually low pressure area) in the direction of the curved shape of the airfoil. So, you can take any prop, and fix it either way onto the motor. As long as it is turning the direction you need, to make a low pressure area in the direction you wish to move the vehicle.

The prop numbers are "diameter x pitch"

You can use a smaller diameter with a deeper pitch, and vice versa. Larger diameter with a shallower pitch. for example, a 8x6; or a 10x4. If you go to a multi-blade prop, you will need a shallower pitch.

The most efficient prop is a single blade; however it must be counterweighted for balance. The reason real airplanes use multi-blade props, is because they make so much horsepower that a single blade, or 2 blade prop would have to be so big to absorb the horsepower they would be larger than the wing of the plane! Or at the very least would require stilts for landing gear. The big planes of WWII had 14' diameter, 4 blade props to harness the 2500+ HP the engines made.

BTW, your car idea is very cool! :D

[Hairball]

WOW! An edumacated person! (spelled wrong on purpose)

Great post... Sounds like you've done this sort of thing before? :)

[HauntedMyst]

Jeep,
That car looks great! Did you hand cut the chassis on it? If you put skis on it instead of wheels, it would look like the snowjet my dad built when we were kids!

How about using 2 or 3 smaller props inline covered with a tube to act like a turbine?

I've actually been thinking about doing something like this, except I was thinking of making a ducted fan dragster (I would use a micro jet but their like $3,000!!!

I think I can get killer speed out of it but it would definately be a dragster given its sheer length. It would look like one of those land speed racers.

[ 08-28-2001: Message edited by: HauntedMyst ]

[jeepinator]

Railman, yep we are on the same page. I understood what you wrote ... it just took a few times reading it :p Yes, the leading edge is straight and shaped like a wing. You were right.

Originally posted by HauntedMyst:
If you put skis on it instead of wheels, it would look like the snowjet my dad built when we were kids!
DUDE ! Maybe you have not checked out my web site, http://www.theshreves.com . I did just that a few years ago. I have a write-up on the project. Of course that project was not nearly as cool as this one. I bascially just slapped soem stuff together on that fan car, instead of spending time with it, like this one.

Ducted fan ... multiple motors/props ... hmm ... this could get expensive ! Hehe, the original goal was, "free fun from parts out of my drawers". Well, you know how it always goes ... :p

[Gutter Ball]

Wow, cool stuff Jeep! Macguiverism at it's best :)

[gubbs3]

Old fart- What you said made me think of an airplane hovering vertically. Most poeple call this "hanging on the prop" but what is really going of is it's "floating" in the air.

[racerman333]

nice jeep in that video jeepinator.

[R_C_MAN]

Great work on the project jeep!

If the motor gets hot you could try a motor heatsink. It will get tons of airflow on your car.

I checked out your website too.
(Note:Bill Gates isn't the richest man in the world anymore. The guy who runs Walmart is. Walmart includes Sam's Club too. He supposedly has like 60 billion.)

[jeepinator]

Well, I took this thing to the track.
It was fun as heck !
To my utter amazement, and the to the amazement of all the crowd that gathered to watch it, it performed quite well.
Speed was way, way better than I expected, acclerations was not too shabby, and cornering was almost perfect.
By the end of the straight away I was doing stock motor speeds. I would have realy been wasted by a stock motor buggy/truck because of slow acceleration, so I am not claiming to be very fast ... but by the end of the straightaway it was flying !
Cornering was a tad tricky. I just could not be on-power when turning. When I gave it juice while doing sharp turns it would spin out pretty easily (and abruptly, almost violently). But if I rolled around corners (very easy as there is almost zero drag) if would just haul butt without spinning out.
The big HUGE problem though were the jumps. OMG ... jumping IS NOT POSSIBLE AT ALL, IN ANY WAY !
Getting any air whatsoever resulted in a violent endo (back flying over front). The first time I tried scarred the crap out of me. It went over like a snap-roll. Hehe, oh well, no jumping for me ;)
I was soooo bummed I did not bring my digicam! I could have poted movies :( It was really quite cool to drive. It was so dang loud that dudes were running out of the hobby shop to see what the heck was going on.
Then disaster struck :(
I came round the last turn and nailed it for the straight away when the motor mount thingy broke! Too much power I guess :p There was a loud crazy crack snap pop sound followed by some other horrendous noises. When the dust cleared my prop was wasted and the motor was laying on the dirt with the motor wires twisted up like CAT 5 wire !

For MUCH LESS than 6 million dollars I can rebuild him ;) In fact, I already bought a new motor holder gizmo and will be making round 2 improvements. I am also going to figure out how to keep the thrust from unloading the rear wheels and loading up the front wheels (most certainly the cause of my on-power turning problems). Some sort of F-R sway bar might do it ...

[gubbs3]

Try pointing the motor upwards when you remount it. That should help plant the rear end when on power.

[jeepinator]

Project update:

Version 3.0
http://www.theshreves.com/pics/fancar_v3.0b.jpg

version 3.1
http://www.theshreves.com/pics/fancar10.jpg


Current setup:
Motor: Aveox 1409/3Y
ESC: Aveox something or another (hehe, I forgot)
Batts: 12 cells. Cells are 4/5 subC 1700 Mah (smaller & lighter than normal cells). All cells in series.
Prop: 7x8 APC composite, normal rotation

According to Aveox's "Virtual Test Stand" this setup is producing 23 ounces of thrust at 120 MPH and drawing 30.2 amps at an efficiency of 86%. Not too shabby :)

I have tried up to 16 cells and from a 7x5 to a 7x10(!) prop. The 7x8 prop with 12 cells seems to be a nice ballance. Although the 16 cells with a 7x7 prop was pretty off the scale in all categories. It was loud, fast, and HOT. I almost cooked my cells :)

[Poolboy51]

I think you've really outdone yourself! Hos fast does that thing go?:confused: :eek:

[jeepinator]

Not quite sure. I haven't driven it on a space big enough to reach top speed yet. I'd say more than 40 though. It's so hard to say...

[Poolboy51]

How much was the B/L system and where'd ya get it? Does Aveox Have a web? And how does the throttle control feel on that?:confused: I bet its hard to tell ona fan car but please do your best. Thanks.

[jeepinator]

Ooops, sorry for the late response. I am a retard.

The BL system was bought directly from Aveox, and it was over $300, but that was back in about '97 I am guessing when I got it.

http://www.aveox.com

Throttle control is superb. The Aveox setup is in it's element in this application. I don't need a lot of control, but I can drive very slow, and navigate well, so it has pretty good resolution.

Hope I helped :)