Jerobee electric to glow conversion nr 2

getback wrote:That's a pretty cool car , wonder why the front tires are so skinny , looks like a dragster  Are you going with TD or Bee ?  

The choice of the engine dépends on the driven gear I have. I still have a 56T gear for a Babe Bee. I believe the TeeDee powered cars have 58T gears. I don't have a spare engine with flywheel and clutch but can borrow the unit from the Corvette. The front tyres are mostly worn out and are ready for the bin.

Rear axle disassembly

The rear wheels are mounted on a Lightning 2000 round shaft and fixed by a nyloc nut. The motion is transmitted by a roll pin fixed to a flange which is locked to the axle by a grub screw on a flat. The Jerobee wheels were modified by inserting a brass bushing and extra holes for the roll pin.










On the right side is the differential. The axle slides out on this side.





The plastic split bearings were replaced by ball bearings. These are thicker and the chassis needs to be drilled out a bit.





The chassis needs to be cleaned to remove dirt and glue. To brace the radio gear, foam patches were stuck in the middle.

Hi Lieven, That's quite a project that you're undertaking. If anyone can get it done; it's you! I'd noticed that most of the Jerobee/JoMac glow-powered chassis' that I've seen, have a left-side drive-axle. This would naturally be dictated by the Tee Dee engines.. but the reed-valve variants are also left-side drive. I see that this elec. chassis does not have provisions for a left-side drive-axle. Is this why you're choosing to run the reversible-rotation reed-valve engine?

Roddie, as you pointed out, the glow powered cars have the drive on the left and the electric cars have the drive on the right. The chassis remains the same, equipped with the standard hexagonal rear axle or with the upgraded Lightning 2000 rear axle. I will not reuse this axle with diff and wheels. The drive will be again on the left side with a hexagonal axle and wheels that fit. That's what's so interesting on these cars: a lot of stuff can be modified and/or upgraded. I think that in the second half of the 70's, when electric driven 1/12 cars became popular, many Jerobees were transformed from glow to electric because it was ever so easy to do so.

The modular design is definitely a plus+ I have documented (photos) most every Jerobee/JoMac project that you've done.. and saved some random photos from elsewhere on the inter-web too. The models fascinate me.

Front wheels

I took off the front wheels from the stub axles. On the left side extra washers were found. On the right side, washers were replaced by a spring. The brass bushings in the centre of the wheels are worn. I tried to remove them with a bolt / washer and tube but they didn't move at all. They were possibly glued in place when the 2 wheel halves were bonded together.






And the cleaned chassis:



I must say that these Jerobee chassis are very well made and of the right material. This is the 3rd chassis I'm working on and I never saw any warps, or cracks or brittleness knowing that these cars were used and abused and that they have an average age of 45 years!!

The white front wheels are the ones that were on the car, only cleaned! For tyres, I will use the Jerobee rubber front tyres. They fit the rimmed wheels.

Rear axle assembly

The 1/4" round Lightning 2000 rear axle cannot be used for glow power. To fit the gear and wheels, a hexagonal axle is needed. The difficulty is to insert such an axle when the chassis is equipped with ball bearings. This axle only has round parts where the plastic bearings go. They are split and need to be pried open and fit in place after inserting the axle in the chassis.

But the Jerobee guys made an adapted axle to fit the ball bearings. This axle is made out of 2 parts that screw together after being mounted from both sides. This gives an axle that is round in the centre part.

I have a Jerobee axle and a Bolink axle. The Bolink one doesn't use E clips to hold the wheels but domed screws and washers.







The half axles are both drilled and tapped. A threaded stud was then inserted. I assembled both shafts and the match is incredible. No joint is visible or can hardly be felt. The Bolink axle is a bit shorter than the Jerobee one.





I fitted the Jerobee axle to the chassis. It turns very smoothly.

To complete the rear axle, I mounted a new 56 teeth gear and on the right side the spacer I was looking for for a while. I found and bought a Jerobee parts lot on EBay. This cost me 4,5 EUR. I was the only bidder. The purchase price need to be multiplied by 4 to get it to my home but compared to other sales going on, this was still reasonable. In the parts lot was a axle replacement kit with plastic bearings and the spacer, rear Wheel E clips (always useful!) and a Lightning 2000 gear.




The wide rear wheels without tyres are a spare wheel kit sold by Jomac. I mounted a pair of hard Twinn K AJ's.

What ever happened with this one Lieven?

Y like the light weight upgrades Nice efort from the owner wit som strange modification wy Not use the diferentiel

Cribbs74 wrote:What ever happened with this one Lieven?

For the moment, it's on stand by. I have to drill out the worn out front wheel bearings to 4mm and insert a piece of brass pipe that I will drill out again to 3,2 mm for the 1/8" stub axle. A new thing to do is to find a 56T gear. I took off the one that was on it to put on the Porsche with Teedee power. I have no engine for the moment. Sooner or later, I'll find a Babe Bee, I hope.

It's not possible to use the Lightning 2000 dif on a Cox powered car. The gear teeth are different and the gear is to big as this is for an electric motor.

I have a Jerobee gear and axle somewhere. If I find it I'll count the teeth. I do have the matching reed engine as well with starter and clutch, but I know nothing about which car it was from.

Rod

Thanks Rod, Anyway, if it's a matching pair, that's always good. Gear ratio's change from 5,6:1 for the high performance cars to 7,2:1 for the Comando Dodge. But whatever, they are all fast to me!

The gear pitch difrent wel y have found Good way To use difrent engines clutch Bell wit that larger pitch smaler like the gtp gear the Kyosho f1 use larger pinion exept use one way bearing Witch y dont like its possible To use its pilot chaft To fit clutch Bell wit bearing Good upgrades the team ae clutch Bell fit and tink its the same pitch u have the clutch Bell from rc10 gt 15 engines wil fit the f1 pilot chaft on that frame is no place for larger gear on m'y prototype its Not trouble y have lots of space To work with;)

Lieven, Check your email....

OVERLORD wrote:Front wheels

I took off the front wheels from the stub axles. On the left side extra washers were found. On the right side, washers were replaced by a spring. The brass bushings in the centre of the wheels are worn. I tried to remove them with a bolt / washer and tube but they didn't move at all. They were possibly glued in place when the 2 wheel halves were bonded together.

Let's get on with this one! I decided to remove the front brass bushings but I remembered they could not be hammered out. I drilled a larger hole and milled out the brass bushing on one side using such a tiny milling tool. When the tension of the bushing was gone, I could knock them out. Then I found out why they didn't come out in the first place: the outer surface of the bushings is knurled.

Now I have to find new bushings in brass or oilite to fit. They need to be 1/8 x 1/4 diameter and about 3/8 in length.