Brimod Prototype Car

[matt1ptkn]

Although I have zero experience with Brimod, and my only knowledge of the company comes from your posts, this is a very cool car. Its great to see it restored with such care. I'm looking forward to the finished result!

[dinglem]

Yes, it is certainly something a little special. I have never seen anything quite like it before. The small details on it are quite amazing.

I have added these last few pictures on the RC10talk Fb page, so i will add them here too. I have stripped and rebuilt the entire car now, and am currently just waiting on a few odds and ends to arrive.

Sorry for the massive picture overload on this thread but i wanted to document everything as i went so people can get to see what this car was all about. I am very much aware not many people here will have heard of the brand let alone know of this car.

[Dadio]

I'm loving the pictures , keep em coming

[dinglem]

Ok, a few cool things have happened today.

Firstly, my luggage has finally showed up a week after i lost it, and the pair of chain drive gearboxes that came with the car were still in it. Result.

That has meant i have been able to switch the Brimod spur adapter over from the chain box on to the belt drive set up in the car. I also happened to have a random wing from one of my Pro Radiants in the bag as well, so i mocked that up to check it out. Looks kinda cool.

With this having arrived i sent a message to the previous owner to hassle him for the chain which he told me came with the car (for the spare gearboxes) but he had misplaced. He had a good dig and it turned up.... it was in a box of motors which also came with the car - complete with Brimod sticker on the outside.

So i have the chain. That should help me place the gearboxes as i have how far apart they are supposed to be.

Looking at the pic of the motors it didn't take me long to clock the engraved MG second top right.

I then had a quick re-scan of the original Brimod prototype articles....

Now it might be just me, but i think the gold label matches, and i can also make out the engraving on the can. Even the yellow capacitors are the same.

Brimod MG zoom.jpg (25.74 KiB) Viewed 2023 times

Brimod MG zoom.jpg (25.74 KiB) Viewed 2023 times

Brimod motors morris.jpg (35.61 KiB) Viewed 2023 times

Brimod motors morris.jpg (35.61 KiB) Viewed 2023 times

I have asked for that motor from him so we shall see....

[dinglem]

He then tells me something else.... the car also came with an ESC in it when it arrived!

Not only that but he still has it and said i was welcome to it as long as i paid the postage, so i am hoping that it goes into a box with the chain and the motor

He sent me some pictures of it, and it looks really rough, but what IS interesting is that they have added a set of lovely additional silver alloy heatsinks.

I have spent much of this evening trying to work out what it is.... and got there eventually thanks to a few hints from people on Fb and then the model ID from bluewormx on this very forum

Proper old school. It is a very very early Nosram Advanced FET esc, one of their first, which was advertised in 1988 for 67.95pounds. That must have been a lot at that time! I gather it is 6 forward and 2 reverse FETs, but unconfirmed at the moment.

Pretty awesome piece of history to go with this car anyway, especially with those additional custom heatsinks. Hopefully i can get it tidied up and working.

[EvolutionRevolution]

Considering the lack of outer case, maybe a prototype unit? Or didn't they have a case?

[dinglem]

Considering the lack of outer case, maybe a prototype unit? Or didn't they have a case?

For the sake of the build i took the time to do a little online stalking last night.... (as you do!) and managed to track down Mr.Nosram himself, Nick Marson. My question was to confirm it as an early Nosram, and to hopefully determine the model and spec, and to gain advice on restoring the unit. I also asked about those lovely heatsinks.

His reply:-

'Martin you are 100% correct. It is a very early one. Originally I used a 555 timer in a voltage tripler mode to produce the FET drive voltage. The reverse FETs of which there are 2 has a temp sensor attached to prevent overheating. I changed the voltage tripler in later models because the 555 had a couple of failures. I never did find out why, that is why I changed the circuit design in that area. The earlier ones also suffered from ESD damage, especially when running on carpet. I fixed that with a 4v7 zenner diode from the white signal wire to ground.
As this was an early one, maybe 1985-6 it was primarily intended to standard motors. I think a 15 double would have been OK.
I love the Brimrod, and yes those were not my heatsinks. Later on we extruded a heatsinks and put more modern designs in plastic boxes... This a very early one. Does it still work?
Fascinating pictures, thank you for sharing...I now live in Houston Texas and sadly all of my Nosram drawings didnt make it over here. Yes it is forward and reverse, this is accomplished with the relay.
Yes this is the first Nosram design, prior to this there was the Marfet ESC.. There were several esc designs but you have an original one' Nick Marson

He also said he could help me out with some original decals for the unit and the bodyshell - which is awesome.

[dinglem]

Next up, the chain drive gearboxes.

The chain that came with the car has appeared, and is approximately 9inches in length (doubled). This has given me some feel for how the gearboxes should fit in the car. With the front outdrives lined up with those in the car then 9 inches behind the front drive sprocket lines the spur gear shaft on the rear chain gearbox up exactly with the current spur gear shaft. Apart from that, i cannot really see how this set up can fit into this particular chassis configuration. The screw holes and cut outs do not exist. I am wondering whether that small silver gearbox behind the motor has some significance in all of this though?

The front gearbox is very simple and compact, yet still has the same one-ways as per the belt system. It is tiny in fact, with a very small central spline! It runs off a series of three pinion gears which are well greased via a large screw hole on the top which appears to be there purely to enable grease to be added into the box itself. Very very smooth and free.

The rear is quite an awkward shape and bulky, and shows a chain tensioner which has obviously had a bit of use. Lots of ballraces everywhere. No outdrives (which i cannot really understand). It also has a plastic gear in it with some sort of very small metal fitting which enables a grub screw to be used to secure it to the shaft.

All of this is very very well made and has obviously seen some use. Perhaps it was on a development mule chassis before they swiutched over to the belt configuration?

Anybody got any ideas??? The front chain gearbox would certainly be nice to use as a 4wd conversion on a 2wd car....

[Dadio]

Looks to me like you may be short of a rear gearbox , you have a front and centre but no rear gearbox , unless this was a front wheel drive car ? But that's really odd if it only has one ways up front , to my mind your missing the rear gearbox and it may have been a twin chain setup , a short chain from the centre to rear and a second chain from rear to front , the chain tensioner you have does not look like it could serve a single chain to both ends and have enough wrap to transmit drive , just guessing though , its a puzzle for sure , wish I had it in my hands to study but i doubt I'd see anything more than you .

[bluewormx]

RC archaeology at its best.

Martin, did you notice the RC10 idler gear in the transmission?

[Dadio]

The chain drive parts may even be for another chassis ? The complete belt drive car is designed for a central belt but the chain drive gearboxes have an off set chain , very different design concepts that are hard to fit on the same chassis , love the thread

[jwscab]

I'm guessing same as Dadio, you have a front and center gearbox and need a rear gearbox/diff Assembly. Probably different cars.

[dinglem]

Yes, i agree with all of you. There seems to be a missing element somewhere. It also is missing the centre drive as seen on the rear of the belt car so the drive direction seems to be reversed when compared to the belt drive system. I think anyway. I was so confused i had to stop for a coffee!!

I am still wondering whether there is some sort of link with those side gears in the small silver gear cover.

It is very odd that there are no rear outdrives so yes there might be a third part missing. Seems odd though that the chain is that long if this were to be the central gearbox only.

Certainly there would have to have been another chassis.

bluewormx... you have an incoming PM as i have found an old mag article on the Nosram (and i just noticed that the guy who made it, 'Nick Marson' reversed his last name to get NOSRAM!)

Great feedback and input guys, and glad to hear the thread is being appreciated.

[Dadio]

I was thinking that if the side gearbox had the pinions removed and a sprocket fitted then a chain drive from the centre could work but then it would have a centre chain off the rear diff and the front chain gearbox has an off set sprocket not centre line like the belt ..... I hate that the rear diff assembly is missing but it does look that way

Is there any way that another drive sprocket could come from the centre chain drive gearbox ?

[dinglem]

There are no exit points from the rear gearbox housing whatsoever. I have been thinking along the same lines - sprocket on an extended drive spline that goes into the little silver box. It would work i think. That way you would retain the gear drive to the rear and have chain to the front.

That is the only way it could work and is actually the most simple fix. In that case though you wouldn't even need the rear gearbox at all.... The shape of the rear box clashes with the motor position as well. I will message the guy who sold me the car and bits and see if he has any other random spares floating about.... he did only just find the chain out.

I have just been trying to figure out the spare front steering hubs/knuckles too... another headache! They also suggest another car. I have looked at The Concept Car (RC10 with Schumacher drivetrain which was also developed i nthe West Midlands at around this time) and that car has remarkably similar front steering set up to these spares....