Scratch build electric tethered car racer

[Greywolf74]

that’s a comfort :0)

Early on in my career I worked with a client in the US and as I got to know them more I found my self lapsing into using slang words and quickly realised that there were words used in the UK that didn’t transfer well to my US counterparts, nothing embarrassing or rude most simply led to mild confusion.

LOL, yeah. I used to game with a group of Aussies and I was always having to ask them, "What does that mean?!" or "WTH are you guys talking about?!" lol. Took a few but I learned a fair amount of Aussie slang that way though.

 

[Roog]

Its been a bit slow on the build front over the holiday period, plus I have another project on the go, but I did manage to finish the wheels for my 3 wheeler.

The fun bit, my new RC gear arrived, I find it quite swish, but there are some aspects of my even lower cost gear that I prefer, like the physical trim knobs.

Oh and along side it is a picture of the next part I need to make, the live rear axle bearing housing, aluminum with phosphor bronze insert's should be easy enough, famous last words!

 

[Roog]

Made a bit of progress yesterday, shed was 4.6 degs C warming to 9 by the end of the afternoon!
Started on rear axle bearing housing, roughing out to 13mm diameter ready for phosphor bronze bearing inserts.
I am going to use 10mm diameter shaft for rear wheels.

marking fixing holes when meal time stopped play. I know I need to eat but how come it always happens just when you are starting to make progress? :0)

 

[Roog]

Bleed'in cold in my shed this evening, at just above freezing (2.2C), but, the rear axle bearing housing now has M4 sized mounting holes and one edge milled away to allow the axle to be mounted lower in the chassis to give the required ground clearance

 

[Roog]

Bearing shell being machined, weird stuff phosphor bronze, as it got hot it started to grab the larger drill bits, pretty pink swarf was a bonus.

Two similar bearings fitted into each end of the rear axle assembly with temporary 10mm shaft to test alignment.

shaft is next item to machine, then I can fit the axle to the chassis rail and fit some wheels

 

[WickedFog]

Bearing shell being machined, weird stuff phosphor bronze, as it got hot it started to grab the larger drill bits, pretty pink swarf was a bonus.

View attachment 179547
Two similar bearings fitted into each end of the rear axle assembly with temporary 10mm shaft to test alignment.

View attachment 179548


View attachment 179549

shaft is next item to machine, then I can fit the axle to the chassis rail and fit some wheels

I always used solid carbide straight flute drills on the bronze alloys. They seemed to do better at breaking the chips up. Some really nice machine work you're doing there.

 

[Roog]

Thank you @WickedFog i am, for once making the effort to concentrate on doing a good job! Bearing shells are a really snug fit, which makes a change for me as I have used epoxy to take up the slack in the past. Funny what you say about drill choice, the 10mm reamer I put through at the end has parallel flutes and it went really easily, I live and learn

 

[WickedFog]

Thank you @WickedFog i am trying to concentrate! Bearing shells are a really snug fit, which makes a change for me as I have used epoxy to take up the slack in the past. Funny what you say about drill choice, the 10mm reamer I put through at the end has parallel flutes and it went really easily, I live and learn

That material wants to break chips into small bits, like pencil sharpener shavings. So a more blunted cutting edge will do best for that, vs the raked cutting edge of a twist-flute drill. And yeah, like the cutting edges of a reamer

 

[Roog]

Rear axle day, I chose to use a 10mm dia. ground silver steel bar for this

Slow progress but got there

Cross drilled the holes for the drive pins, here it is with pulley and spring pin fitted

Loose assembled the complete rear axle with wheels out of the chassis rail

 

[Roog]

Front suspension day today, I’d better make the most of today because I’ve been banned from the shed tomorrow due to having to be sociable. Where’s the fun in that? I’ve got a car to build.
here’s the section of the drawing.

being sensible I bought enough metal to make the front swing arm twice, then cut the wrong side of the line, so now I have just one go at getting this right, idiot!

I should say something about the stock material, here in the UK we have been metric since the late 1960’s, people of my generation (too old to play with rc cars) are used to both imperial and metric, but I still find it weird that I get a greater choice of sizes if I select imperial, as is the case here, the suspension arm is cut from 1” x 3/4” rectangular bar, 300mm long! Duh :0)

First operation square up 4 sides, the top and bottom aren’t critical, but the bar is very uniform.

To give the milling cutter a chance I drilled lots of holes, on reflection I’m not sure this was a good idea as it caused the cutter to jam a couple of times.

then on to the main bit removing most of the metal whilst hoping it doesn’t fall apart! This was done using the digital read out, (DRO), no marking out just spot 3 edges and work out the required distances from those read directly off the digital readout. Takes an act of faith but as long as the datum points are right and you follow the drawing it works!

on with cutting the large rectangular slot

next a step at one end, easy but I still managed to make a mistake, oh well it’s not critical, I see from the image that the poor cutter is looking a bit beaten up. Oops.

Add a few carefully positioned holes, a front wheel bearing and tiny shaft, just needs assembly.

This is my first reasonably involved milling job, I learnt a fair bit as I went through it including how much help the DRO is, but you do have to be disciplined. There are a few edges and corners that need tidying but the hard part is done here. Phew!

 

[Roog]

Managed to get an hour in my shed today, social duties done, a bit of tweaking and I have one dry assembled front wheel assembly, I am on the look out for a compression spring of the right size and rate, most rc car springs look too long and squishy for my application, I don’t fancy having to make one, must be something kicking around in the bottom of one of my tool boxes or boxes of screws.

 

[WickedFog]

Managed to get an hour in my shed today, social duties done, a bit of tweaking and I have one dry assembled front wheel assembly, I am on the look out for a compression spring of the right size and rate, most rc car springs look too long and squishy for my application, I don’t fancy having to make one, must be something kicking around in the bottom of one of my tool boxes or boxes of screws.

View attachment 180207

You can find a lot of springs on Amazon and ebay. I hsve bought a number of springs for custom 3d printing projects over the years, and never have much truble getting exactly what I need. McMaster over on this side of the pond also has a selection of compression springs. I am sure you guys also have similar industrial supply companies.

Loving this build man. I miss machining, and this is bringing back memories of when I was still working. Nice work.

Is that counterbore on the left end the spring perch?

 

[Roog]

Thanks @WickedFog Amazon is a good call, must try eBay too, I need to figure out what I need and have a search.

Regarding the machining, I bought a shed last year, insulated it and boarded it out, that was the start. I was going to buy a lathe when I planned to retire, a few years off yet, but a nice used machine came up for sale locally on eBay and I couldn’t let it go and that restarted my interest in building steam engines, after a 45 year break it’s been fun. however steam engines are really just glorified paper weights hence my interest in cars.

As hobbies go it’s a bit time consuming as everything has to be just so, its no where near as much fun as assembling a tamyia kit for instance. There is an early Tamyia Baja Bug somewhere in the loft!

And yes the counter bore at the end is just that, a perch waiting for a spring.

 

[WickedFog]

I worked with a guy who was one helluva machinist. He looked like a 25 year old caveman. He showed me a photo of a working steam engine (train engine) him and his dad built from scratch. It was about 6' long, and you could ride it around on the track they built around their property. It looked exactly like a shrunken down steam train, like a 4-4-0 or something like that. One of the coolest things I ever saw. But they also made standalone steam engines as well I believe. Very cool stuff. You should show off your steam engines in a thread here. I'm sure a bunch of us old farts would love to see them.

 

[Roog]

Ah yes locos are top dog for me, they are amazing, although the endless list of parts that require machining, weight, plus the cost and the fact that I simply don’t have the talent puts me off! Ihave a friend (who is still working as a mechanic) who has just started one, I have no idea how he will have the time to complete it. Another retired friend buys part finished locos and traction engines to complete, it’s a grim statistic but quite often the original builders never get to complete them, all a bit sad.

I have a couple of completed steam engines a decorative brass oscillator and a Stuart turner double cylinder 10 in 5ft 6 inch long RC model tug and a third part machined Stuart Turner horizontal engine, then tethered cars caught my imagination. Having the speed challenge as an objective really helps the motivation.

I hope to have my electric car ready for the new season, no great loss at the moment because the track is currently in the middle of a water logged field.

 

[WickedFog]

Ah yes locos are top dog for me, they are amazing, although the endless list of parts that require machining, weight, plus the cost puts me off, I have a friend (who is still working as a mechanic) who has just started one, I have no idea how he will have the time to complete it. Another retired friend buys part finished locos and traction engines to complete, it’s a grim statistic but quite often the builders never get to complete them, very sad.

I have a couple of completed steam engines a decorative brass oscillator and a Stuart turner double cylinder 10 in an RC model tug and a third part machined Stuart Turner horizontal engine, then tethered cars caught my imagination. Having the speed challenge as an objective really helps the motivation.

I hope to have my electric car ready for the new season, no great loss at the moment because the track is currently in the middle of a water logged field.

I can't wait to see it completed. What are you planning for a body?

 

[Jamr]

Nice job!

 

[Roog]

I can't wait to see it completed. What are you planning for a body?

Good question, make a mould for a carbon fibre and resin body, might look techie if a little rough, as materials go it is a bit unforgiving or fibre glass maybe? The traditional approach would be beaten aluminium or tin plate. The speed models generally don’t look like much, I’ll have a think.

it has funny proportions to fit a scale like body. motorised sausage perhaps?

I suspect the test runs will be without body shell.

 

[Roog]

Made a few more parts including the front suspension pivot and the suspension spring thrust block complete with hole in the wrong place!

Oops no pictures of thrust block!

 

[WickedFog]

You're having too much fun. Can't wait to start seeing parts get bolted on.