Brimod Prototype Car

[Dadio]

It really is quite something , from that angle in the last shot it reminds me of the fibre glass chassis I had on my hot shot , obviously nothing like it but from that angle it does remind me .

[KidAgain]

you made the wheels???

[dinglem]

you made the wheels???

No, i actually sent off a set of my Pro Radiant plastic rims to a wheel guy and he made them up to fit onto my Pro Radiant, but in the back of my mind i also thought they might just work on this and they really do. My father typically machines all of our alloys but i wanted something very specific in this case.

[winner_evo]

from that angle in the last shot it reminds me of the fibre glass chassis I had on my hot shot , obviously nothing like it but from that angle it does remind me .

I thought exactly the same thing



Edit: I didn't mean your Hotshot, I meant a Hotshot that I had

[Coelacanth]

Not too much of an update with this, but I have had a set of alloys machined which really seem to set it off

79686066_10159160744121258_1390137861239472128_o.jpg

Those wheels look like they're from Pargu in Korea. I bought a set, I believe they were for the Kyosho Scorpion but will fit any 12mm hex, and I believe are 2" diameter. I'd link to them but Pargu's entire website is totally borked, practically none of the links work, all of them serve up page coding errors.

http://www.pargustore.com/index.php?dispatch=categories.catalog

[dinglem]

Yes they are from Minsu. I had been messaging him for quite some time and sent over a pair of my Pro Radiant plastic rims (front and rear) for him to use as a template to make a set of this design of rims fit my Pro Radiant, but they also cross over well onto this Brimod car. They seem to suit the machined look!

[dinglem]

I gave the car a quick wipe down to check it over last night - the front shocks a re a bit of a mess and will take some sorting i think. The hex adjusters are locked up solid so i think i will try soaking them in WD40 overnight to try to get them moving. Reluctant to try forcing them too much as they are so rare. I started polishing up one of the hex rears though, and they are going to come up a treat

I had a pair of original Brimod UJ's for the rear end (fronts were already fitted) so they have now been added.

I was also curious about the main drive mechanism to the rear gearbox. My initial thought was that it ran off two 32DP pinions running on the two shafts which then mated to the rear diff, but on closer inspection the front pinion on the main spur shaft is absent. I was presuming i would have to add one, but i then tried turning the main spur shaft and it actually drives the entire drivetrain (very freely i must say!), so i now presume that there is some sort of gear link within that tiny alloy box to the rear of the motor. It never really crossed my mind before as it looks too small to house anything! I will whip it off shortly for a closer look.

The spring-loaded belt tensioner is a really cool detail also.

There are also holes in the wishbones and through the central chassis plates to accept the anti-roll bars at either end so i will have to add those, based around those i have seen in the prototype mag pictures from 1988.

It is an absolutely beautiful machine to look at - i keep finding more details here and there.

I am also wondering which bodyshell to go for - 1988 gives plenty of choice and as there was never an official shell made i can go for pretty much anything!

[dinglem]

Not much chance of shattered late 80's plastics here!!!

[dinglem]

Well having just checked it turns out that small alloy case behind the motor actually houses a pair of meshed 12tooth pinion gears. Clever way of making the drivetrain relatively easy to refresh i suppose. There is a third pinion gear mating to the diff itself, and the whole set-up spins very very freely indeed. The outer alloy casing is incredibly thin, and the whole lot is coated in gobs of grease. Pretty cool.

[ChisaiKuso]

I have pretty much immediately started looking at what parts might be required for this. I know from studying the old magazine pictures that the two prototype cars I have seen had slightly different Brimod shocks than the typical versions which were commonly available. They had smaller shock caps for starters, had a coarser thread on the bodies, and had hex adjusters rather than the usual round rough-finish items. The upper cap was made to accept a diaphragm but did not have the bleed valve which was one of the main selling features of the commercially available Brimod shockers.

I noticed on the car I have purchased that the correct hex adapter versions are present on the front, including the lower profile caps, but the rears are the more common type. I contacted a friend who also has a few sets of these shocks and having checked what he had, he discovered his rear pair were the missing hex adapter versions. Quite a stroke of luck, and he has agreed to make a trade with me for a standard set so the prototype will have the correct versions all-round

Question: How can you be certain that this particular prototype was originally assembled with the hex versions on all four corners? It is a prototype after all.

What I mean is that it was not uncommon for prototypes to be built and tested using whatever random, readily available parts happened to be sitting on the shelves. It seems to me that you are making an assumption about what style shocks should be on this particular prototype based on magazine ads that you have seen for a different prototype. Your assumption is a logical one (and the switching of parts will make the car look nicer too), but what if you are actually modifying this piece of history instead of restoring it?

[dinglem]

Yes, of course you could be correct. The only real way for me to know is to ask somebody involved with the original prototype builds (which i am still actively trying to do).

I am basing my assumption on a couple of things.... there were two articles on the 2wd prototypes, and in the same magazine Brimod also ran an advert for their new 'lightweight' shocks which had a smaller upper cap without the bleed valves. As both prototype cars had the hex shocks all-round in the pictures i can only assume they were using their latest design shocks for those builds. They were the final type of Brimod shocks to be made before they closed their doors, and in fact the only examples i have ever seen are on the prototype cars. The threaded body shape is completely different to accommodate the changed lower seal design.

From what i gather from my research (and memory from bitd), the Brimod shocks as we know them were around in '86, with an earlier version without adjusters also being released prior to that (never seen those). The adjuster version with grub screw valve and 32tpi thread were the 'S' type, replaced in early '88 by the 'SX' which had a pan head screw bleed valve and a coarser 24tpi body thread for faster adjustment. June '88 saw the 'SX-L' for lightweight which had a smaller cap profile, no bleed valve, 24tpi and hex adjusters. June '88 also saw first pictures of the prototype Brimod cars. I have seen S and SX types in packets with spec variations so am guessing there was some stock cross over between each type. I am assuming that the prototypes and the hex adjuster shocks were being developed at the same time; it therefore makes sense to see them mounted on these prototype cars.

As the rears which came on this car have the grub screw bleed valve they can be identified as the earlier 'S' type which pre-date the car by a short period.

Unless i can contact the Brimod owners I will probably never know for certain, although i have heard back from one of their main distributors this morning (the owner of Penn Models - the model shop closest to the Brimod workshop) who said he recalls seeing this 4wd car when it was being developed. He is now trying to reach out to the Brimod folks.

I agree with your comments entirely, and i will be carefully storing the rears which came on the car 'just in case'. The car looks to have barely been run, if at all, so it would seem odd to have changed out the rear shocks.

[ChisaiKuso]

Yes, of course you could be correct. The only real way for me to know is to ask somebody involved with the original prototype builds (which i am still actively trying to do).

I am basing my assumption on a couple of things.... there were two articles on the 2wd prototypes, and in the same magazine Brimod also ran an advert for their new 'lightweight' shocks which had a smaller upper cap without the bleed valves. As both prototype cars had the hex shocks all-round in the pictures i can only assume they were using their latest design shocks for those builds. They were the final type of Brimod shocks to be made before they closed their doors, and in fact the only examples i have ever seen are on the prototype cars. The threaded body shape is completely different to accommodate the changed lower seal design.

From what i gather from my research (and memory from bitd), the Brimod shocks as we know them were around in '86, with an earlier version without adjusters also being released prior to that (never seen those). The adjuster version with grub screw valve and 32tpi thread were the 'S' type, replaced in early '88 by the 'SX' which had a pan head screw bleed valve and a coarser 24tpi body thread for faster adjustment. June '88 saw the 'SX-L' for lightweight which had a smaller cap profile, no bleed valve, 24tpi and hex adjusters. June '88 also saw first pictures of the prototype Brimod cars. I have seen S and SX types in packets with spec variations so am guessing there was some stock cross over between each type. I am assuming that the prototypes and the hex adjuster shocks were being developed at the same time; it therefore makes sense to see them mounted on these prototype cars.

As the rears which came on this car have the grub screw bleed valve they can be identified as the earlier 'S' type which pre-date the car by a short period.

Unless i can contact the Brimod owners I will probably never know for certain, although i have heard back from one of their main distributors this morning (the owner of Penn Models - the model shop closest to the Brimod workshop) who said he recalls seeing this 4wd car when it was being developed. He is now trying to reach out to the Brimod folks.

I agree with your comments entirely, and i will be carefully storing the rears which came on the car 'just in case'. The car looks to have barely been run, if at all, so it would seem odd to have changed out the rear shocks.

That is a great response. Thank you for taking the time to write it.

You definitely seem like the right person to own this rare piece of RC history.

[Dadio]

Just trying to think why they went with the double lay shaft and two pinions , my guess it changes the direction of rotation as many stock motors had fixed timing that went faster in one direction , it also keeps this system of reversing the drive out of the way of the belt path , it might offer a gear ratio change option with odd size pinions but I don't think that's it because the housing doesn't look like it has much space for a larger pinion that would couple to a smaller one .
The mystery of this car is making this one of my favourite builds to watch , will you ever run it or is it destined for the shelf ?

[dinglem]

I was thinking the same regarding adjusting the final drive ratio somehow. I presume if the car had been developed it would have been simple to make alternative gear cover to house different sized pinions where necessary.

It all seems very efficient though.

The next thing for me to look at is the front one-ways which are built into the front diff out-drives somehow.

As with all of my cars they are built to run so i am already gathering suitable electrics for it. Nothing brushless/Lipo going anywhere near it!

[Coelacanth]

Yes they are from Minsu. I had been messaging him for quite some time and sent over a pair of my Pro Radiant plastic rims (front and rear) for him to use as a template to make a set of this design of rims fit my Pro Radiant, but they also cross over well onto this Brimod car. They seem to suit the machined look!

If those wheels are your design, then thank you! It's a great-looking wheel and after I spent time going through all the wheel options that would fit Kyosho Optima/Mid at Pargustore, that also had a matching 2WD narrow front wheel (since the OptiMutt car is a RWD conversion of the Mid), I just had to buy them.