TB-03 Slow restomod

[Honza]

This project is unlike my other ones - no 3D printing involved! (yet)

After seeing a spare bathtub on a local store, I decided to put my old TB-03 back to its onroad glory. It's served as basis of my rally builds, which involved lot of cutting, last iteration even sporting custom chassis. However, it ended up in a semi-dissasembled state after I moved on to other projects... So I decided to go through all the parts I have accumulated over the years and found that I could slowly put it back together, of course with some little updates in the process  It won't be fully upgraded, the parts are becoming rare and I have tight budget, so the new parts will be ordered in small batches.. But hopefully I'll end up with equivalent to the "Pro" version of the later TB series.

Starting with brand new bathtub. I don't know where I got the right servo mount, but it fits. Maybe I'll get aluminium mounts in the future, maybe not.

Steering - reusing stock arms that have a lot of history and it shows. It'll be mostly hidden anyway. The bridge was modified shortly after I got the car (it's been 15 years already?), inspired by the prohibitively expensive carbon bridge - the bearings reduce play in the right wheel.

Stock motor mount, I don't mind the silver colour, but there's first blue upgrade - the stock plastic piece is prone to stripping, so this blue mount is an essential upgrade. The used motor hints the planned theme of the whole build

I have had a YR TT-02 spur mount laying around, so I tried, if it can be used on the TB - and it fits I had some spare propshaft cups, so I replaced it. Unfortunately the upgrade ones with the blue driveshaft I found in a local e-store got sold out just when I ordered them, so stock ones will have to do.

Another old upgrade with some battle damage is a 70T 48p Kawada spur. I might get a replacement later.

More of the cheap retro upgrades - back in the day, I found that TRF502 gears are perfect replacement for the stock gears. 12 smaller bearings on the larger diameter provide smoother action and allow to run the diff a bit looser, which was positive change on loose gravel surface. I didn't run them long, so they are as good as new. The diff joints are new from the spare stash - Eventually, I may replace the diffs with TB-04 gear diffs, but over time, I learnt how to make these old units reliable

Another reliability improvement - 2,5mm screw and locknut from an Ansmann buggy. It's much more reliable than the stock 2mm screw. This was done before Tamiya themselves adopted a similar solution. But they still didn't realise that you can use a locknut in a plastic insert instead of plastic/aluminium nut with a threadlock 😁

Diff all assembled, ready to be put into the chassis. I'll shim it before the final assembly.

The spur and steering covers are again old, cleaned up parts. Back in the rally days, I did some modifications to fit the purpose - the spur cover was modified for quick acces to the rear differential, while the steering cover lost damper mounts, as they collided with larger rally tires. I never liked the IFS system anyway, so dampers will be mounted on a standard upright damper tower.

Everything put together, without screws so far. Basically I have complete drivetrain, some essential missing parts were ordered in the first batch from Tamico, together with new silver driveshaft to replace the old, scuffed one.

I still have the original suspension, but it's mounted on my rally chassis and it has quite a lot of battle damage, so it won't return - I have other plans in that area

To be continued...

[Honza]

Some parts arrived, so I had to add them to the car, although it's not big a progress in the build. Unfortunately Tamico sold out some items before I managed to order them, but the most important bits are there.

First, the suspension mounts. Although I like the modern solution with exchangeable blocks, they cannot be used on TB-03 due to reinforcement that runs under the inner blocks. Tamiyas idea was to put 3mm shims under a block flipped upside down, which cannot be really done on the newer type of block.

Rear. I'm using 1XA setting, inspired by stock setting of TB-05R. The plan is to use the adjustable mount on the rear for easy toe-in settings - the mount will be in the next order.

Front - 1A blocks front/rear. Don't mind the arms, they are just placeholders.

I also replaced the scuffed propshaft. I missed opportunity to get the option part, but I kinda like the look of the silver shaft. 

So this is the current state. Still a bunch of the car is missing and I'm not even putting in all screws, since I expect to disassemble the whole thing again, as the new parts will arrive. But it's slowly going together.

And back to hibernation...