Complete newbie question - RC car from scratch

I've joined this forum to try to help my son, who wants to build an RC car from scratch, making all that he can and only buying what he can't make. He loves metalwork at school and I hope to help him along in our workshop at home. Tho I have no metalworking kit at the moment!

So, have I joined the right forum? I'm not sure exactly what model engineering is - does it cover the kind of project he wants to do?

Many thanks for any advice, Chris

If it's metalwork then you are definitely in the right place. Mind you, we also work with various plastics, wood and resins etc, not to mention electics and electronics.

Ask your questions and someone will be sure to come up with the answer.

Brian

An idea of scale, type of car and what functions would help as there is less work in a basic 1/12" electric indoor racer to a 1/5th scale IC monster, though I expect he would prefer the second option.

I build tether cars the forerunners to RC cars they are pretty fast I hold a few British records at speeds from 163mph to over 200mph actual speed.

If I can help I will, I live near Leicester.

Thanks all!

Old School - I had to check what a tether car is, that looks amazing, as do the speeds!

Jason - we just committed to the idea yesterday, tho we've talked about it before. I'm really keen to help as he wants to go down the automotive engineering route as a career. Scale - I'm assuming smaller models are more tricky as the parts are, well, smaller and more fiddly? No idea really. He talked about 1:8, but any advice gratefully received on that one. As for type, he said something based on a Nissan 350Z, but I'm sure that's very approximate - the real interest is the engineering and electronics (he might disagree).

He's going to ask in school today if he can use the equipment they have to work on his own project; if not, I'll be on the lookout for things we need to do that at home. I don't know what that'll consist of, presumably not cheap. I have plenty of woodworking kit but no metal kit.

Thanks again for the replies. C

The specific car is not such an issue as most will be the same mechanicals with just a Lexan bodyshell over the top. You can get them in both 1/8th and 1/10th scale for the nissan and as that is a part that would be hard to make best bought in.

Body suggests a track or drift car and with modern motors electric will suit both scales and possibly the simpler to build but more electronical engineering than mechanical, IC would be more have been more usual on 1/8th but the smaller engines are now readily available for 1/10th scale too.usual.

I had never heard of a tether car either and was amazed by what I saw after Googling them!

Hi Chris152, It's great that you are supporting your son in this car project. Whatever you guys build, he will learn invaluable skills for his future work, as well as the satisfaction of making something.

Just an idea for body shell construction- as Jason mentioned many RC cars use a vacuum formed Lexan shell, and that is a great way to do it. But another way, considering you mentioned your woodworking skills, would be to make a wooden body form or "buck" and lay up a couple of layers of fibreglass on it with polyester resin. Boatbuilders and model aircraft builders still use this method, and very fine weave fibreglass cloth is available. You could make the form a "negative" cavity, boat style, and use a gel coat for a fine finish, or make a "positive" core or buck, lay up the glass, and finish with body filler. It might be easier to carve a "positive" core or buck than a "negative" cavity.

The vacuum formed bodies are made on a "positive" buck usually but require use of a vacuum forming machine. The benefit of the fibreglass method is that you don't need any machine to do it, just gloves and a paintbrush , and a nice sunny day outdoors (the fumes of the resin are smelly and lots of ventilation is a must). Costs of resin and fibreglass cloth are relatively low. The method is scalable, too - lots of full size kit cars and 100 foot yachts are made of fibreglass the same way. Have a google for Burt Rutan / Scaled Composites to see how far you can go with fibreglass technology.

Good luck with the project.

You need a shed, or part of the garage as a workshop. I wouldn't buy any tools for a while until you know a bit more. Just some stuff to complement what is at work.

Further two what Jeff said about the bodyshell you are probably now more likely to find a vac former in the DT department of a British school than a lathe so that may be a possibility.

There are also plenty of 3D cad files of suitable Nissans that can be downloaded, these could be used to 3D print the buck or former or some slicing software used to make a series of profiles along the length of the car to guide you while using more traditional methods.

The school my well also have a small CNC router that could be put to good use making components from fibreglass or carbon fibre sheet.

It's been a few years since as a teen I built a complete rear end for a 1/8th scale IC buggy with adjustable camber, wheelbase, anti roll bar etc. All done in the loft with a Unimat lathe

I think it'd be great if he could shape the body by himself, so we'll look into that - I've done some (v little) work with glass fibre/ epoxy, so definitely an option - but I also remember a school I worked in many years ago having a vacuum-forming machine, which maybe they have in his school. And they have cnc. They seem pretty well equipped, he's done welding, lathe work and other things that I understand some schools stopped on account of potential risks. And the good news is, he's been told he can use the kit they have so long as he organises it with teachers (he's just started a-levels, so gets free periods). Saves me money and means he can make mess there and bring bits home to assemble/ work on the electronics at home.

I really appreciate your replies, tbh when I first posted I wondered if we could do it but I'm starting to feel more confident. Thank you!

As far as the electronics are concerned, perhaps look at DT (Deltang) receivers and transmitter modules for a DIY build. I have found Micron R/C very helpful.

Brian

This car body was made using a blue foam plug you simply shape the foam to make a plug to build the body onto no need to worry about draft angles or getting the plug out of the finished body.

Now cover the plug with glass cloth I use a lightweight cloth around 28g square metre build up a few layers at a time allow to cure rub down till smooth more layers of glass repeat until get to the thickness you want. I use epoxy resin.

Then cut out the foam and melt out the rest with solvent it's quick and easy for complex shapes.

Edited By Old School on 19/09/2019 20:14:46

I remember when i was in high school and absolutely hooked on RC cars, i would peruse the few R/C magazines in the school library and marvel at some of the cars people had built -one was a 4wd chain driven twin motor jobby that I literally drooled the print off the pages ! Anyhow some 40yrs later i have restored , built ,made and raced a lot of cars - mostly on road but id play around with offroad stuff occasionally.

I would advise you to sit down with your son and figure out exactly what he wants to build as there are a few options that will require different skill sets .

So a list similar to this might get you both pointed in the right direction :

On road or offroad - remembering that an offroad car can drive on a road but an on road car will struggle if it has low ground clearance.

Electric or internal combustion engine - mostly governs your drive system and battery requirements and is governed by the size of the car - big cars need big motors and the line trimmer engine is perfect for big cars.

Suspension or a basic pan car - setting up and making suspension components adds to complexity and will require machinery, a pan car has no suspension and is a lot easier to make ( just for clarity i call a pan car a car that is made from a flat plate chassis , no suspension and no differential) some have different descriptions.

Physical size - 1/12 ,1/10,1/8 or 1/5 - bigger is easier to make but will cost a bit more for materials but you can use engines from old line trimmers to power it but you will need beefier servos to control it.

Radios - this is an area you don’t want to skimp on so don’t use those cheapie radios as they have a small transmission range and usually no failsafe features .

You used to be able to download a car set up guide from Hudy which explained in great detail how suspension geometry , shock settings and spring rates worked - the basic fundamentals are the same for a model car or a full sized vehicle - physics is physics - it doesn’t change .

You could build a lot of a Mardave Maruder with basic tools

Not sure about the Maruder being possible with basic tools but their stock cars are a lot more basic in construction being solid rear axle and rudamentry front springs.

Still got my Maruder in a cupboard, twin wishbone front and single wishbone independent rear suspension would tale a bit more tooling.

I had a Tamiya XR311 when I was a (lucky) teenager. pretty much where off-road RC started, although it was only 2 wheel drive. Went like stink with two extra nicads on the back seat.

Makes me feel like getting another one!

Neil

I used to be into nitro RC cars when I was younger so may be able to help.

If you have never had an RC car and you are just starting out with machining it might be easier to buy a cheap second hand car and simply copy all the parts in metal, or adapt to your own design IMO.

I had the Rough Rider when I was about 14, that is where it really started as they were the first ones people started to race. The XR311 and the Lambo were a year or so before that.

Neil, I had a Tamiya as a kid too - the pick up truck, it was very fast but the suspension and steering always needed fixing. You can get them now but they are very expensive. I not sure what happened to mine, probably got sold when I left home.

Chris - good luck.