Mopzilla

Hello.. a few years ago I was into cars, now I have a plane waiting for a reciever that will never come and an .061 throttled engine and a few servos. AND some legos.

OK well I think I will custom make a car from these parts.The car will be made of lego, of course. I have to make the clutch, transmission, and the body/layout. The hardest part is figuring out how to make a clutch out of all-lego parts.

Well, anyways, I figured out a way. Here is how the engine to tires will work:
Engine --> belt (smooth, no teeth) drive (kinda like a slipper clutch) --> clutch --> reduction gears --> belt (smooth) -->Differential/disc brake --> wheels/tires

I will have at least 3 channels: steering, engine throttle, and clutch on/off + disc brake. Cool thing is that I have the 6XHS helicopter radio which allows me to do mixes of 2 of the channels right on one stick - so anyhing below 2/3 of the throttle stick is clutch off/engine idle/disk brake on and anything above is clutch on/engine moving/disk brake off.

So, my clutch is basically gonna be two shafts and two tires, and when the two tires meet they move the shafts that they are on, causing a clutch type move.

If the plastic parts don't hold out, then i will forget it.

hagur

Hahaha, that actually reminds me of something I did maybe 8 years ago or something ....

I had a Cox .049 black widow just sitting, collecting dust, and me being a HUGE Lego fan, I started thinking ...

So ... I made a small 4wd car out of Lego-technics parts, probably not bigger than 25 cm in length or so. I made a transmission with extremely low gearing so the car would go really slow, because it had no steering and was not R/C. I used superglue to glue a couple of Lego bricks together to make a firewall to which I could fasten the engine. Since the Cox is not meant for cars, it has to be cooled by means of a fan. I would also need the propeller in order to start it up. So I managed to attach a small Lego wheel on the crank in front of the propeller. Then I had a bigger wheel below the engine which drove the transmission.

I then ran a rubberband over the small wheel and around the bigger one. So, basically there was no clutch.

This was quite a project ..... anyway ..... to make a long story short ... after a few attempts the engine roared to life. This is a control-line engine and has no throttle control. Therefore it just goes WOT once started. What happened next .... well the car, being geared so low, just barely moved. Eventually, the vibration from the engine caused it to start falling apart ! Hahaha, I got pretty scared and ran away .... didn't dare to go near it until I heard the engine had died. What happened was that my custom made Lego-propeller guard which was supposed to prevent the propeller to hit the ground, had fallen of .. causing the prop to ... well hit the ground.

This was the story of my first I/C powered Lego 4wd car! And yes, the only one.

Anyway ... good luck with your project!

Mopzilla

well, my micro 555 reciever just came when i thought i would be waiting a few more weeks, so now its a 50/50 situation with the continuation of this project.
my reduction ratios are 1:9 then 2:3 so comes out to 2:27 which is 1:13.5 . That sounds good to me.

I ended up putting a heavy wheel on the engine as the flywheel, with the 6 holes in it, them made a main shaft adapter, then it goes to the clutch (two tires together or separated) then goes into the 1:9 reduction, then a double belt drive for bump relief, then the 2:3 reduction, then the tires.

The chassis will probably fall apart by the time I hit 5mph

hagur

You have to post some pics of this project!

theclinch

what if you put some kind of metal chassis and just have the body and everything else be lego? just a thought and definately post pics

Mopzilla

Ok, well i will get pics up, but I am not sure how to do the engine mount. I don't want to make a special lego firewall and stuff, it would just take up too much weight. I need some heat resistant yet easily drillable stuff. Maybe I will cut two small pieces from wood and cover them in gasket material to make the engine mount.

So far I have all lego parts done, engine/shaft adapter is ready, just need to mount engine, fuel tank, servos, reciever, battery, ummm and glue a few parts together. Will post a pic of everything soon.

the chassis is all lego, maybe I will also make an upper deck for strength but I'm not sure if the .061 will be able to haul all that weight. Damn, it would be so much easier if only I hadn't sold off my batteries, speed control, and motor 3 years ago.

About strength: I hesitated to put in a differential for better traction when I noticed some parts were starting to crack. Like a shaft extender, in fact I already cracked two of those, and a beam, and a gear. My big fear is that unless I use my JB weld and CA glue on everything it will all fall apart just from the engine vibration while idling.

Metal chassis, well if you are going to even mention that again I will have to make ALL parts custom, and just make a small car. I'm sure you could just do this with something like an HPI Micro but this costs me nothing.

Mopzilla

k here we go..

the clutch is just two tires being pressed together. Their total separation is about 1mm. The clutch level moves around on the shaft so I can position the linkage anywhere. and it is adjustable by length a tiny bit.

If you notice there are three equal sized gears going across on one part, I could have dropped those but in case something goes wrong, those get stripped out first before anything else does, because I have simply tons of those type of gears.

The part of the chassis aft of the clutch will be different.. much stronger.

The engine is just a lego wheel, with the 6 holes in it. I use 3 of the holes to make an adapter that goes in line with the crankshaft. I tried to make it strong so that it doesn't flex.

edit... finally got the pics onto my own account...

caseyddr

My Feedback: (13)

no steering? bummer

Mopzilla

No, there is steering, of course. see the rack and pinion steering up front? The toothed bar (or linkage) will probably be replaced by a real servo linkage, like a ball or something. No steering means no fun.

The only thing is that I haven't put the radio on right now. I think I'll be using standard servos because taking the small ones from my plane just isn't worth it right now.

It has everything except for reverse, shocks, and some funding..



oh and I will be putting a small video camera on it if it works well. That would definately be cool considering space is not a problem and there is room for 3 more channels after the steering, throttle, and clutch. (Futaba 6XHS FM heli radio 6 channels)

i8tweety

My Feedback: (11)

It looks like the beginnings of a rack and pinion steering setup (anyway, the rack is installed).

Good luck with your project,

i8tweety

caseyddr

My Feedback: (13)

get a cheap mini servo for 12th scale cars

Mopzilla

I know I know, you're into 12th scale cars but you know what, I have a few small servos and at least 7 different standard servos, 5 of them on my heli, BTW you still wanna buy that heli? I'll give it to you with the engine installed.

I will not be spending ANY additional money, if I did, I might as well just buy a bunch of crap and just make something that any other dude could slap together in 30 min. Maybe I will make a small trailer with additional fuel tanks (although the .061 like the tank right next to it)


The crash, if it happens, would be spectacular, plastic pieces flying everywhere, I'll make sure my crappiest equipment it on it

packfan88

My Feedback: (2)

that thing is awesome .....i love crazy stuff like that.
what brand and model # engine is that?
how much is it?
got another one cheap?

i was try and make my very first r/c live again. it an old radio shack lamborghini countach(sp?). id love to see it drive again. only this time with a nitro engine.

Mopzilla

thanks.. well it took me exactly 5 minutes to put on the steering servo, had all materials in a 5 foot radius - standard servo, 24 tooth lego gear, a piece of already cut to size foam rubber, and a few zip ties. I just put the foam between the servo and lego to make a vibration free, easy to secure mount.. with 2 zip ties. the steering shown in the pics is the same except i just added the servo and these small parts.. and I thought i would use real linkages but rack and pinion works great. I'll post pics later after I redesign the clutch, if needed.... And i modified the shaft adapter a bit, so it is about 10mm smaller. the chassis so far will be about 20 inches, i wanna make it 15 or 12 if possible.


I calculated some stuff and at 20k engine rpm in an absolutely perfect friction free, drag free environment i can do 26 mph. MILES per hour not millimeters

packfan, the engine i have is a Norvel BigMig .061 throttled engine. I have no other engines, sorry. I got it used actually, in fact it was in a deal with my airplane. so basically its new, and it cost me around 15 bucks. You can get a new one just like this one for about 30 or 40 dollars. not sure where to buy, but you can ask in the 1/2A planes section, they know.

caseyddr

My Feedback: (13)

hurry up and get that thing built so we can see a lil video of it

Mopzilla

Well, I am really in the finishing stage. The car is almost fully different.. it now has an upper deck, different gear setup, and a different clutch.. I found a great way to mount the servos without doing any drilling of lego parts, and they all fit perfectly! The reason why I haven't posted much is because I am working on a good clutch design, it has to be very short and small, but very functional. I already have a working clutch, it is great, but a tad too big. And I have already mounted the engine on a flat piece of lego (which was already broken in half), so the steering servo, throttle servo, fuel tank, and engine mount are all done, just need some smaller details. More stuff to come later this week. Then after I try to run it I will use epoxy or CA on all the vital parts.

All servos will be futaba unless someone wants to send me ANY servo horn for a JR standard servo for free?

thx..

theclinch

omg i had that exact same car thats so weird

Mopzilla

I got the car fully built, with radio installed, 3 servos - steering, throttle, clutch; with the engine, tank, battery, rx, switch, antenna all mounted, and finally all the small lego parts for more strength.

Well, the thing pretty much fell apart, at least the smaller pieces, when i was just trying to start the engine.. the rubber wheel flywheel (shown in the first post) got totally messed up, the frame broke down, the front end fell apart, the tank leaked and got fuel all over the bottom of the chassis, and even the clutch parts broke off each other.

Conclusion: Nitro engines and anything soft plastic fantastic with no screws do not mix. I decided not to abandon the whole project as I had gone pretty far, but in this new project the engine will be on the car but with a different form of linear power. I'll post a pic later of the broken car.


Anyways, it probably wasn't such a good idea with the nitro engine in a lego car with such a fragile clutch... I think for a good clutch design something along the lines of - flywheel > clutch shoes > clutch bell - design is a lot better.. but I don't have the resources for that!

I was even going to use my heli radio mixes for the car... throttle to clutch mix, and throttle to X% throttle and full control of the clutch... so for braking.

The new car will not accelerate very fast but it will most probably move at least a few inches.

Thanks for posting.. c you guys here again soon

hagur

But how about dumping the clutch altogether ..... and make this thing thrust driven .... like a hovercraft .....?

No ... that's no fun .. and not challenging enough probably

But I wonder if that's even been done .... an r/c car driven by a propeller.

packfan88

My Feedback: (2)

why dont you super glue the weak parts together?

it will cost you some legos but if you can spare them go for it.

you got me thinking about all this styrofoam i had laying around.

i took apart one of my newphews radio shack hunk-ajunks and used some big styrofoam that came with my tv.

it drive sand steers fine....i think the steering needs to be redesigned. the area where the steering travels l/r is wearing down and will soon fail. but ill fix that later.

now what i want to do is find someone looney like myself and get those bb shooters like on war tanks/war ships, and blow each other to pieces and last man standing(rolling) wins

wins what i dont know but its all in good fun.

Mopzilla

I AM THAT LOONEY!!!

Seriously, I have always wanted to put a bb gun such as those for sale by Swampworks or some rockets on an airplane, or the heli I used to have.. I have the rocket launcher all fully built, it shoots 6 consecutive rockets on command with only a retract switch, and it actually did fit on my heli (i have sold big parts of the heli so it doesn't fly now)

The rocket launcher will probably go on the plane, or I will make a bomb drop that actually does blow up with flour upon impact with the ground. That way, you could mark the places where it hit if you try to do it for points I guess!

I am guessing it would take too much superglue, plus the parts are weak as is, I mean, they can easily be snapped in half with your hands, or bent.

Wow, you hit it right on the money.. that's exactly what I was wanting to do. Except not with just a prop, I was thinking of using a thin short length of pipe to make a ducted fan type of thing to direct the thrust a little better. My norvel is for an airplane, and with the airplane I got two 6x3 props so I was thinking of using those.

The difference here is that instead of a clutch, this car will have a disk brake. Much easier to build, and more functionality. I think I might put rockets on the back of the car, since even with the engine running the car will always be a rolling chassis, so it can roll as fast as it wishes... so... ch1 steering, ch 3 throttle, ch 6 brake (mixed to throttle) and ch 5 for the rockets (as it would have been on the heli)

I'll start work right away.

hagur

Keep us posted!

Mopzilla

here is a pic of the finished yet slightly broken car - the steering servo is under the reciever up front, the clutch servo is just forward of the battery in the back, and the throttle servo is forward of the engine. I will see what i can do with ducted fans or just propellers!