Dirty_Vinylpusher

Hey...
I'm the new guy.

Am working on my first ever RC project, which involves a 47cc McCulloch chainsaw motor.
Just thought I'd throw you a couple of pictures and see what your comments are.
A lot has changed since these pictures, but the general setup is still the same.
It will run from 14 cogs from the sprocket on the motor, to 28 cogs on the first axle, then another chain from the small one (14 cogs again) to the large one on the rear axle, which is also 28 cogs.

Note how well the hub, holding the sprocket fits on the teeth on the clutch.
Like it was made for it.




Please comment.

Giorgos_cupra

Those sprockets are comming from a bike correct?What will your gear ratio be?Is it an on road or an off road?Also we need pictures of the chassis.One thing is sure though,it will be very very heavy!Good thing you got a lot of torgue comming from that engine...Any hp estimate on the engine?If you got time to spend,check out my thread and Lars_from_Norway.He is using a chainsaw motor too

savagecommander

i always wanted to try a sprocket deal like that... looks good. that motor will have power but dont expect it to rev high, prolly 12k max. good thing you have gear choices

dar123

how are you going to change gear? are you gonna use the de-railer on the bike?[&:]

Fabe

Interesting project! I've toyed around with the idea of using a derailleur but never had the space for one. What scale are you going for? I'm interested in seeing how this pans out.

Keep at it and keep us updated [sm=thumbup.gif]

Lars from Norway

Looks interesting,and promising!I was thinking a lot of this too,using the derailer from a bicykle to change gear while driving.But this was too much for me to have enough creativity forLooking forward to follow this thread!
[link=http://www.rcuniverse.com/forum/m_7677148/tm.htm]Here[/link] is the link to Giorgos thread,and [link=http://www.rcuniverse.com/forum/m_7681456/tm.htm]here[/link] is the link to my thread,there are also some others who have done this,use the search to find more

Mudgy

welcome to RCU

will the rear axle work freely as a one way , like a bike?
Or are you going to lock it up?

good ides, there.

Dirty_Vinylpusher

Wow!
Lots of replies.

Ok, I'm not going to use the gearchange thing from the bike.
Just go from small to large to small to large.
14 to 28.
Twice.
So that will make it a 4:1 ratio no?

Still thinking about the freewheel thing on the rear axle.
Suppose it would come i handy.


I've been in contact with [link=http://www.ericstoffers.com/loves/radio-control/home-made-car/default.asp]this[/link] guy and he's running a similar setup.

Lars - I've already studied Giorgos pictures closely, but will have a look at yours later as well.
(I grew up in Sweden by the way)

It will be mainly for beach use, as we live about 5 min walk from the ocean.
I'm looking at getting [link=http://www.gadgetgalaxy.com.au/Land%20Overlord%20Nitro%20Truck%20Spare%20Parts.ht m]tires[/link] from the Heng Long Overlord monster truck for it.


More pics to come soon.

Thanks again for all the comments.
I think I'll be right at home here with you guys!

da mad maori

nice work so far man
looks very sturdy
cant wait for more pics

savagecommander

yeah, i think using anything with the name "overlord" in it will certainly be cool

Mazda ute

I'v made a few useing the same type of chain saw and and set up you have to make it drive on BMX bikes made to fit over the back wheel. I went small to small sproket and i could do 80 to 85k's with it went crazy i also put one on a 16in pushy that was just nuts death wobels at 70 to 75k's not fun, well yes it was but it was biteing teeth moment thats for sure. So it does work and that on a BMX bike with me on it (i was 65 to 70kg) and had no bog and would rev. I did make my own stinger pipe for it stainless pipe to run exhaust out the back that made it go harder and not as noisy to. I did jump it and did not have any probs. It went up hills with no prob and if you did peddel as well it flew up hills. 40 min max run time flogging it 50min near full flogging it.

Dirty_Vinylpusher

Ok, here are a few pix of today's effort.
I had to move everything over to the right, as I originally had it set up for a whippersnipper/weedwacker/grasstrimmer/weedeater/strimmer/whatever they call it in your part of the world motor.
And the drive was of course on the other side.
But - after a number of beers and lots of fiddling it is now set up for the chainsaw motor.

Lars - I had a look at your car - Amazing.
Very good attention to detail and well made.
I like how you did the steering, which is going to be my next headache once the motor and gears is all set up.

I'd be interested in pictures of people's home made steering setups as well, as I most likely will make it up myself.
Trying to avoid buying parts as much as possible, and make it up from what I have laying around at home.

Mazda ute - a lot of the kids here are putting chainsaw/whippersnipper motors on their bikes.
One guy had a roller on the driveshaft and just had that running against the rear tyre - not as fast as what you're talking about but it was still moving pretty good.
Do you have any pics of how you made the exhaust pipe for the chainsaw?
I figure that the original one will have be replaced.


Also - once I get this thing going, I will build a new, better looking frame for it, but I don't want to get too far ahead of myself.
One step at a time.....

da mad maori

Nice work man VERY nice

you asked to see other steer systems , here's mine but its for a buggy and its "oversized" but it might have a few designs you could maybe use





a vid of the steering..... pretty simple set up

http://au.youtube.com/watch?v=ZXEIuu...e=channel_page

yes Lar's steering system is a very good one also

Dirty_Vinylpusher

Thanks maori.
That's a neat setup.
I was actually more interested in the part by the wheel though...
What's the motor in that buggy in the video?!??

Before I posted that last message I had typed out another one that got lost in cyberspace.
I remember now that I was gonna ask you guys about the weight of your projects.
I haven't put mine on the scales yet (come to think of it, I don't think we have any...) but I don't think it's THAT heavy.

Anyway, I'm gonna go back out to the shed and have a smoke and dream about tearing up and down the beach.....

Mazda ute

I'v done that as well used a bit of nylothan to drive on top of the back wheel useing a smoth road type tire got about 60 to 70km's max useing a 23cc wipper snipper running race fuel and 20% nitro mix it went realy well about 1hr run time out of that one.

The pipe i made was made out of around 20mm ID stainless pipe made to suit were it had to go it came out the side about 80mm then went back 160mm from the 90 deg and angled down 30 to 40 mm.Did not seem to loose back presher at all.

Lars from Norway

My car ended up on 11,6 kg (ready to run with body),i am very pleased with that as i thought it would end up on about 13-14 kg without body!I cant say i have tried my best to get it as light as possible either,i guess i could have got it down to the lower 10's if i really put my mind to it.

Thanks a lot "søta bror",nice to hear that i maybe have put some ideas to your head aswell

Dirty_Vinylpusher

Lars
11.6 kg....
Don't think mine's even that heavy at the moment, but there's still some stufff to be added to it.
Will go and borrow some scales off a mate today and see where I'm at.
Where did you get the gear setup for your car?
Is that something you bought from an RC shop or did you make them yourself?
Obviously they would be a lot lighter than the bicycle gears I'm using at the moment, and in the future I might be looking at doing something like that as well.

You also mentioned scale earlier....
Well, I'm not really going for a scale as such, and while I was looking at the 1:8 monster truck wheels earlier I'm thinking that I might have to go a bit bigger for more clearance.
That rear sprocket is sitting about 25mm off the ground at the moment....[X(]
The Heng Long wheels would bring it up another 10 mm tops, and I'm not sure I'm happy with that.
Maybe I'll get away with using the second largest sprocket on the rear axle though.....

I'm a bit concerned about the weight distribution as well, and am thinking that the motor might be sitting a bit high.
I'll take some more pix later today and you can have a look.



Mazda Ute
Nitro you say eh...? *strokes beard*
So you just go all "World's Fastest Indian" and pop a nitro pill in the tank of a normal chainsaw motor?
Does that put extra stress on the motor - I guess it would as it will run harder, no?


I was really hoping that I'd be able to fire it up on the bench this weekend and give the rear axle a go, but I broke 2 teeth off the sprocket when I tried to get it off the hub.
So I'm gonna have to wait til Monday and try to get a new one, as the hub has to be welded on to the clutch bell. (See pics in first post)

Fabe

About your tire quandary, I guess I would ask if you're thinking of adding suspension as well, as I don't think you mentioned it. From the looks of it I guess you're going for a solid rear end? I went a fairly simply route and used some T-Maxx parts that you can see in one thread on my car [link=http://www.rcuniverse.com/forum/m_8272667/anchors_8272667/mpage_1/key_/anchor/tm.htm#8272667]here[/link]. If you machine your own parts, you can obviously make them sturdier, but this was fairly straightforward to mount up.

I believe your 4:1 gear reduction should still be relatively fast as I had way more reduction in an old car I had and it was decent. The car in the link I gave is about 7.5:1 reduction...

Dirty_Vinylpusher

Fabe
At this stage it will be a solid rear end yes.
How big is the engine on that car in your pics?
At this stage I have a 1/2 inch solid steel rear axle.
I'm thinking that when I get the proper wheels for it I'll just take the axle in to one of the engineering workshops in town and get them to grind it to the desired shape and size at the ends, and to drill holes in it for pins.
My workshop at home is limited to powerdrills, angle grinder, bench grinder and welder.


Bear in mind folks, as I said before, that this thing ain't gonna be raced on a track or anything like that, but on the beach,
so stuff like brakes, suspension and body isn't on the the cards.

I should add that the beach where we live is very VERY tidal.
When it's low tide we have about 1.5 k's of flat, beautifully smooth moist sand between us and the ocean.
There is plenty of space for a car that might not be that quick off the mark to reach top speed.

Well, I better go back to the shed and tinker a bit more.
More pics to come at the end of the day.

Thanks again for all the comments.
You have all been really helpful.

sam123

My Feedback: (1)

Hey man good work on your rc car. here are some pics of the steering setup I used on the front of my car. Much of it was inspired by what Lars did with the steering on his car.





The front steering hubs were made from 2 modified aluminium pulleys with skateboard bearings pressed into them



My car ended up weighing a little under 6kg, but with a much smaller, lower powered engine than your using.

Anyways, keep up the good work [8D]

Dirty_Vinylpusher

sam123

Yes I've studied it very closely on some other messageboard.
I love how you make everything so simple and un complicated and extremely functional.

I just weighed it on some dodgy scales.
I think it's around the 8 kilo mark at the moment with not much more to be added to it so I shoud be ok, no?
Even if it comes in around 10 lilos I mean.


More pix tomorrow.
Was gonna do some today, but got sidetracked.
With building.

Later yo.

da mad maori

this is an example simplistic brilliance....
a steering arm and bearing retainer in one.....
nice work Sam123


comon Dirty_Vinylpusher let see some pics of the work ya did today

Dirty_Vinylpusher

Ok Ok, give me a sec to get the pics of the camera.

(sorry about the bad quality)
Doesn't look THAT different from yesterday.
Made engine mounts for the other side and drilled out the holes so I could put a bolt through it.
It was threaded before.

Also, I've decided that the motor is sticking up too much as it is, so I'm gonna tilt it forward 90 degrees.
And move it down by the thickness of the aluminium tubing, which is about 25mm.
Need to get that weight closer to the ground.

Spent a lot of the day working on the engine mounts and playing around with the gears.

Fabe

The engine is from a pocket bike and is 47 cc, so a tad larger than on conventional large scales.

In my build, I saved some weight by using 1/2" aluminum rods as opposed to steel. Also easier to machine since I don't have a machine shop at home either...

What are you plannnig for the steering servo, btw?

Lars from Norway

I mostly made the rear setup myself,but the gears are from the [link=http://www.rcuniverse.com/forum/m_7970048/tm.htm]FG Marder[/link],here in a onroad version rebuilt by meIts originally an offroad car with bigger wheels and body,there are some pics attached of it in the link.

The brake setup is from a FG Marder too,but the "calipper" is homemade to make it easier too install.Had some parts left over from the FG so i used them on this one.I went for plastic gears to start with,but they were toast after the first start up as the throttle was stuck on wide open!The tires spun 2 rounds,got the grip,and toasted the gears.Pretty funny and educational experienceThats why its steel there now,and some plastic to make a weak link if anything should happen