derbyguy78

[link=http://www.rcuniverse.com/forum/m_8581282/tm.htm]My Other Forum[/link]

This post is an update of my homemade- large scale- rc car . the link above was my first post,it shows pics from the start of the build and 2 pages of replies. i started this new post just to try to make life easier for those viewing i also posted some new pics here of my latest progress which includes my homemade tuned pipe(1st one ever) [>:] ummm what else......my electronic box that houses the battery,throttle servo,kill switch(with mechanism)and the receiver. and last but not least my very own steering system, it is only a mock up for trial purposes...until i get my ball joints and mount the servo. the great news is that it all works !!!! anyhow hope you all enjoy and please feel free to comment or ask questions talk to you soon ............derbyguy AKA Scott

SAVAGEJIM

I am digging it, I cant make out any sloppy welds or craftsmanship, for what you have, the workmanship looks clean!

As for the belt and pully, have you figured up your gear ratio yet?
When you get it going, please pos a vid!

derbyguy78

thanx jim i appreciate the thumbs up i will post pics as the build progresses and video when it is done i still have alot of fab work to do though

da mad maori

nice work man

ya might need to look into the gear ratio but the over all design is good...
i like ya belt tentioner on the axles there nice work

Dirty_Vinylpusher

Looking good!

Wouldn't mind a couple of close up pics on the steering setup, as I'm looking for more ideas on how to do that.
Thanks.

derbyguy78

i sure will ....i will try tonight after work talk to ya later..scott thanx for the compliments guys

RCguru09

Problem with belts is you won't get low enough gearing in a small space unless you double reduce it then you will still have problems. Their isn't small enough pullies.[] 25 pitch chain is the smallest you should use.

derbyguy78

it seems that every time i post you have something negative to say about my build, everyone on this site has been helpful and all out decent to talk to . do me a favor if you dont like it dont look at it rcguru...half of what you think makes sense, turns out to be mindless babble belts are used for many diff. applications (motorcycles,go-carts,trikes, drill presses,etc.etc.etc.)so just stop and think for a second .......

Dirty_Vinylpusher

Erm.
In this case he's probably right though...

To achieve a gearing of 5:1 or 6:1 that rear pulley would have to be huge.
I think I mentioned this before, but I'd seriously consider a dual axle setup with 4 sprockets in total.

These are #25 sprockets I ordered through a local bearing/machinery shop.
Cost me AU$110 (US$75) for the 4 sprockets and 3 metres of chain.
They weigh next to nothing, and are very small.

derbyguy78

i didnt mount my rear pulley permanently yet just for that reason.....my apologies to those who took offense to my angry post but it seems to be the truth i am going to try the belt idea just because nobody else has....why not? if it does fail miserably i have another axle,bell,clutch,etc. no worries....i would however need to acquire sprockets and chain.......geeeeezzz i love this hobby

Dirty_Vinylpusher

There's always bicycle sprockets and chain.
A bit heavy but it works.



So...
Did we take any close up photos of the steering setup perhaps......?

drewcrew6

Hey Derby Don't sweat it.
Looking good by the way. Have you thought about spinning the tires on the rim, You might not have that issue with the current gearing. When you do run it keep an eye on the clutch temperature I have a feeling that it won't lock and be slipping creating lots of heat. Hate for you to toast a bearing in the motor on the first run. Keep us updated with this, Looking forward to a v-belt machine running, there are definate advantages to it as well as some drawbacks just like all methods.

I am assuming the green box under the belt is the radio and stuff, you might want to think of a gaurd by the belt in case it starts to shed.
Oh yeah how did you design and make that pipe?
I have been thinking about something for mine just can't seem to know the sizes are right.

Drewcrew6

RCguru09

At least someone gets it.

V-Belts are mainly used for great distances and misalignment. Timing belts are smaller but more expensive than chain. Chain is the cheapest and stronger than belts. Gear is the smallest and strongest but the most expensive. I'ts a no brainer what to use. It's a standard as you can see![8D]

drewcrew6

Lighten up "guru"

Why would a v-belt hurt?
It would give a bit of error in a 4 wheel drive by allowing some slip.
Also it takes some of the harsh speed changes that a hard link (chain or gear or shaft) out to help protect the drivetrain.
Granted there is more power loss due to friction but that just means more powerful engine.
You know there must be a reason that you can buy a motorcyle that is belt driven, granted they are timing belts but they still get rid of vibration and drivetrain shock.


V-belts for great distances and mis-alignment? Like a power steering pump and alternator, or the lawn tractor or self propelled mower?

As far as standard, whatever.(since the world has gotten where it is by always using a "standard")

A no brainer? where is that comment suposed to lead to.

I agree with Derby that your comments lead no where.

And to me they sound like someone that I have had run ins on here in the past?

Later
Drewcrew6

Dirty_Vinylpusher

Here's a couple of sites that I got pointed to when I asked the same question a while back.
Useful information.

[link=http://www.motorcycle.com/how-to/how-twostroke-expansion-chambers-work-and-why-you-should-care-3423.html]One[/link]

[link=http://en.wikipedia.org/wiki/Expansion_chamber]Two[/link]

[link=http://www.modelpowerboat.com/forum/article/tunedpipe-designer.htm]Three[/link]

derbyguy78

thanx for the support drewcrew it is nice to know that someone agrees with new or different approaches to a problem or innovation

i guess that all of the engineers @ harley davidson who decided to use belts had a bad idea too huh? lol yes i understand the fact that they use a" timing " type belt(or toothed belt) so, maybe i should go a step further and do the same if the v-belt doesnt work[>:]


i have many tricks up my sleeve yet , and i WILL make this idea happen. for all of the people who think you have to use chain and hats off to the ones who use gears also if you cant step out of the box and go against the grain then why bother at all?

as far as the exhaust goes i just found a diameter pipe that i wanted to go with and kept on cutting and fitting until i got the "most" hp and rpm out of the motor(i used an extra weedeater for testing) the only problem is that it was not 100%modified.
after hours of cutting,shaping, and welding i built my first tuned pipe i guess its all part of the hobby and welding is my first and fav. hobby.


i will take your advice about the belt guard too.... good idea!!![sm=thumbs_up.gif][sm=thumbs_up.gif]

uuummmmmmm let me know if i forgot anything




talk to ya soon


derbyguy

RCguru09

Yea what's in front of the belt drive on a motorcycle????A motor then a gear box and then a belt!!! I would hate to get stuck in the desert with a cut belt. Chain holds up bettter than a belt. The only reason that belts are used are because of the noise and they are cheaper to replace and sell.its all about the cost. I would never buy a chopper with a belt.

drewcrew6

Definetly an important point for an rc car!

Only if purely neglected and abused, however high power machines make better use of a chain. A chain is a lot of maintanance

and belts are easier to tell when worn.

Hey to each his own.

I think we can agree they both are usefull for different reasons on different applications.

Derby I like the pipe keep rolling with this also think about a full gaurd as a stone flying up into the belt will probably toss it.

Vinyl I will check those out thanks.

Drewcrew6

Dirty_Vinylpusher

As long as you have that attitude you're unstoppable.
Keep up the good work.







edit
Dunno if you have come across [link=http://www.rcuniverse.com/forum/m_7674601/mpage_1/key_/tm.htm]this[/link] on your travels.

Speaking of belts....

derbyguy78

thank you and i promise to put pics of the steering set up in tonight

RCguru09

I doubt that he will toast a bearing in the motor. Common causes of clutch bells heating up and slipping are: Over gearing-too much weight- load to move. You need to lower the gearing for the clutch to engage properly or reduce the weight or smaller tires.

Soloratov

My Feedback: (1)

I know I am late to the party, but consider one other item. V-belts are used in CVD transmissions. Assuming you have the correct type of pully, you should get quote a lot of power transfer, but the added bonus of slippage if something binds up in the axles.

derbyguy78

Here is a picture of my steering set-up that you requested. As you can see I took a picture of the drawing I did because I thought it would show more detail this way. The steering set-up is very similar to that of a standard go-kart. You have a threaded steering arm with adjuster that has ball joints on the ends that go to both spindles. Off of one of the spindles is a bracket that connects a second steering arm to the servo motor. I used a larger servo as mentioned before and with proper adjusting this set-up is working great. The only thing I need to add yet is some type of servo protection of which I have several ideas.

Hope this helps!

sorry it took so long


derbyguy

Dirty_Vinylpusher

Looks good.

drewcrew6

Looks good Derby

For clarification the bearing I mean is the one that the clutch rides on. I am not sure about zen's or cy's but most weedeater engines use a bronze bushing in there and it won't withstand a lot of heat. Mine toasted the first or second outing. I found bearings with close to the right dimensions and modified to fit. Haven't had 1 issue with that since. I am also assuming that chainsaw also use that bronze bushing in there.

Agreed Solo

Later
Drewcrew6