Scratch build electric tethered car racer

[Roog]

I haven't exceeded 64mph that I set last time :0(

But yes I have an excuse to muck about in my workshop (shed) again, if only I didn't have to finish a couple of house jobs over the next couple of week ends.

 

[ahr43]

Congrats, Roog. At 64mph, you've well made entry into the 100kph Club.

 

[Roog]

Congrats, Roog. At 64mph, you've well made entry into the 100kph Club.

Now why didn't i look at it that way? I've reached a ton!
I like your thinking @ahr43

 

[Roog]

The torture that is insulating and boarding out my house loft and fitting a loft ladder is now ended, phew!

Today I have mostly been making new wheels to fit the commercial tyres I have acquired.

Wheels not quite finished but close, now I need to make a new drive shaft because the old one, pictured isn’t long enough for the new hubs which are a little wider than my previous wheels to accommodate the new tyres.

New ‘design’ ha ha, has just one cap head screw to hold each wheel together and keep it on the shaft!

This could be interesting.

 

[WickedFog]

The torture that is insulating and boarding out my house loft and fitting a loft ladder is now ended, phew!

Today I have mostly been making new wheels to fit the commercial tyres I have acquired.

View attachment 188247

Wheels not quite finished but close, now I need to make a new drive shaft because the old one, pictured isn’t long enough for the new hubs which are a little wider than my previous wheels to accommodate the new tyres.

New ‘design’ ha ha, has just one cap head screw to hold each wheel together and keep it on the shaft!

This could be interesting.

Are you doing reverse threads on the passenger side (driver's side for you guys across the pond )?

 

[Roog]

Are you doing reverse threads on the passenger side (driver's side for you guys across the pond )?

Oh come on that would be proper engineering, no I’m relying on conventional threads and lots of high strength threadloc :0)

 

[WickedFog]

Oh come on that would be proper engineering, no I’m relying on conventional threads and lots of high strength threadloc :0)

That's scary! At least mill a groove in the wheels to locate on a pin through the axle. I'd really hate to see a wheel fly off. I really don't think thread loc is not going to hold it with all that power.

 

[Roog]

I think I misunderstood, yes there will be a slot in the hub, just as my previous efforts albeit to accommodate a thicker pin this time. I hadn’t quite finished the hubs when I took the photo.

I’m currently thinking 2.5 or 3mm pins, my concern is the larger the pin the less metal remains in the 8mm diameter shaft at the pin hole. With my previous runs I have seen no issues with wheel screws undoing, just tires trying to escape!

I do agree I probably should invest in reverse threading taps and screws, I expect I did do this correctly back in my days in the apprentice training centre but not since.

You raise an interesting point though, in all of the wheels and car plans I have looked at very few incorporate such drive engagement, perhaps the engineering guys do the reverse thread thing.

 

[Roog]

New wheels on my wagon and it rolls along very nicely

New hubs are a little thicker than my last wheels. It was a concern that I was able to distort my old wheels during tightening and I felt I could afford slightly greater thickness due the the reduced diameter of the new hubs

 

[Doom!]

I think your going to see a decent improvement on your next run.

 

[Roog]

I think your going to see a decent improvement on your next run.

Well I hope so! Next track day is week after next so I have a while to find out.

It would be good to get full throttle in without things trying to escape. Ultimately that will be the test.

 

[Weezel]

I'm glad you caved in to peer pressure on using molded tires.

Those tires are going to be much better than what you had. They should allow you work on the chassis and gearing set-up to improve speed rather than worrying about not getting a good run in.

Looking forward to your next test

Does your cable connection point need to be where it is or can you put it anywhere? I was thinking how much the chassis might twist? With the center of gravity being higher than the mounting point and everything (battery,motor,esc) mounted on the high side of the aluminum angle I'm thinking it'll induce chassis roll.

 

[Roog]

I'm glad you caved in to peer pressure on using molded tires.

Those tires are going to be much better than what you had. They should allow you work on the chassis and gearing set-up to improve speed rather than worrying about not getting a good run in.

Looking forward to your next test

Does your cable connection point need to be where it is or can you put it anywhere? I was thinking how much the chassis might twist? With the center of gravity being higher than the mounting point and everything (battery,motor,esc) mounted on the high side of the aluminum angle I'm thinking it'll induce chassis roll.

The offer of some molded tires came out of the blue, the track owner seeing my frustration said, “hang on I’ve an idea” he wandered back to his workshop and came back with a pair of tires.

Its a bit awkward but I am currently having trouble sourcing some replacements here in the UK.

One other issue is that now I have them on their hubs, I can see that they aren’t truly round, so they are going to need grinding before use. :0(

My current tether connection has a strap across the top and a lower one preventing the turning out, this causes extra wind resistance and weight so I might revert back to one attached to the lower position, a set up which worked during the first ‘ton-up’ run (ha ha..)

As you say it would be good to focus on the tweaks to make it faster.