Professor TC's Tinkering - Page 7

tigertc · 03-02-2008

After a Summer of being thrown around the garden Winter has been a great time for uprading, adjusting, and practicing paint techniques.

First up, a couple of much needed upgrades to my King Tigers. The standard Tamiya 1/16 King Tiger is without doubt a great design, but sadly not designed to take the incredible amount of stress that adding metal tracks, upgraded idler system and the general extra weight of metal add ons.
It was noticeable that the hull had been twisting while going over rough ground. This effect had caused the rear plastic lugs wich hold the rear plate on had shattered. to address this prolem i have made alloy backplates for both KT's and added an extra base plate.

Alloy Back plate. Glued and screwed.

3mm thick alloy base plate.

I have also been trying my hand at weathering techniques. Something of which i have not been too successfull with in the past, but i think i am getting there slowly!

The Mudguards on this one are the metal ones which NigelD had spare and he kindly sent me when i first got into tanks. i would hope i can do them justice and will be if in a small way my lasting memory of a great modeller and kind man.

tigertc · 12-02-2008

It is well documented on other websites that the main problem with adding metal tracks to any R/C tank that has been designed for plastic tracks, is the insredible extra stress placed upon the motors and gearboxes.
I have already had to replace a few gearbox bearings and 1 motor so far.
It has been my intention for quite some time to try and eleviate some of the stress caused by the use of metal tracks. To this end I purchaced a pillar drill and a few drill bits that i thought would suffice to complete the mission in hand.
The mission-
To add support and reduce the friction caused by the add on brass drive shaft support.
I purchased some correct sized bearings and set about drilling the hole necessary to accomodate the bearing (14mm).
My plan was to drill out the hole to 13.5mm then heat up the brass drive support so it would hopefully expand to the required 14mm and then drop in the bearing, the cooling of the drive shaft support would then lock the ball race bearing in place. I could not have been more wrong!
The thought had already occured to me that heating the brass support (a disc with a hole in it) would mean that the outer diameter would increase and a possibillity that the inside hole would get smaller with the overall expansion, but i carried on regardless to see what would happen.

My worry was well founded...after heating the support the inside hole did indeed shrink in diameter!!

So, with there now being only half a millimeter (radius) to play with to get the bearing to fit, i resorted to gently grinding the tiny amount necessary to enable a tight fit.
With the tight fit gained i then used super glue to keep it in place.
Just to make sur i gave it a belt with a hammer and i can asure you it aint coming back out

The picture below shows the original drive shaft support

The picture below shows the modified support with bearing in place.

Stay tuned for more homemade upgrades gang!!!

tigertc · 18-02-2008

Anyone with a Tamiya 1/16 scale R/C tank knows that the upgrades for these things can cost a fortune and are rarely worth the money. I know I tend to berate Heng Long fans, but on this particular part of tanking they have the upper hand, all Heng Long upgrades are a quarter of the price of the equivelant "made for Tamiya" hop ups and upgrades . I intend to keep posting homemade (Done on a shoestring) upgrades which anyone can accomplish! (If I can do it, you can too)

The Task!

Tamiya 1/16 scale R/c tanks are all, without exception the incorrect scale speed. Once you add metal tracks and other weighty upgrades the stock motors just cannot cope.
To solve this two fold problem a further method of gearing down is required. This will have a twofold effect.
1. slow the tank down to the correct scale speed.
2. Increase torque.

The Problem

All current gearbox upgrades available from dealers cost in excess of £50, with some upto £100.

The Solution

I set about trying to find some add on geardown mechanisms that were cheap and i could tinker with. I remembered seeing on this forum somewhere gearbox designed for R/C aircraft that looked incredibly similar to the ones which wre being sold for £80 a pair by places such as Backyard armour and Schumo. I then found an ebay supplier selling these gearboxes for ....wait for it.........£2.50 each!!
Although it was obvious that they would not fit without adjustment i bit the bullet and bought ten (I have a few tanks

)

Pictured above are the gearboxes, i will get to "how to fit" shortly.
You will need to use four gearboxes per tank (Two of them you will use as parts to make two good ones).
You will notice that the holes in the brass gears are too small too fit the output shaft on the gearboxes. This means that you will have to grind down the output shaft to the correct diameter or strip the gearbox and use a mini lathe to shave some off. I do not have a mini lathe so my only option was to strip the box And fit the spindle into a drill and grind it down using a sharp stone (brutal i know, but it worked)

As i mention before you need two spare boxes for parts. The large white plastic cog needs to be removed from its spindle on the spare boxes. I used a socket bit and rested the gear on top then gently tapped out the spindle. You will see why in the following pictures.

The newly removed cog will need glueing to the one already fitted to the intact gear box (Obviously you will have to take this one apart to fit it!) Make sure the teeth are perfectly aligned when glueing. to ensure that the cogs did not slip or come apart during use, i drilled some 1.6mm holes 8mm apart in both cogs and used epoxy two part glue to bond them (the glue seeps through the holes you drilled)
All that remains to do once the glue is set is to put the finished box back together. Remove the motor from the original gear and put the new geardown inbetween.
Voila Tamiya gear down for £10

More shoestring upgrades coming!

tigertc · 25-02-2008

After looking at some of the upgrade fender photo-etch kits available, I wasnt to impressed. All seemed designed for static kits (You know shelf queens!

)
If you have a Tamiya tank, one thing is for sure you will want to take her out for a run in the mud/sand/grass etc.

I wanted my fenders to have the abillity to "jump off" rather than break off if i hit something but also to look a lttle more authentic, like photo etch but without the crumple factor . So the original plastic parts were the way forward.
I used 1mm x 3mm strips of plasticard for the missing fold on the fenders (rests on the superstructure mounts) and 2mm x 3mm for the mounts. The holes drilled were .875mm to take m1 stainless steel screws which are also nutted on the other side. With the money i saved on the fender kit I purchased 100 m1 screws (an expensive extravegance i know)
the keyholing on the fenders was done with 3mm and 1mm drill bits.

My first attempt was with metal mounts, but no matter which formula of cyano i used they did not have a strong enough bond.

After the failed attempt with metal, the plasticard worked a treat!

More upgrades coming soon, watch this space

**Bunkerbarge** · 26-02-2008

You know what Tiger, there are some pretty impressive pieces of work going on there. We may even make an engineer out of you yet!!

tigertc · 26-02-2008

Hi Shipmate!!!! (chuckles to self). I am rushing to finish off my tanks so i can.....(wait for it................................................ .................)

make a start on a recently found (incase the wifey is looking in) Revell 1/72 viic Uboat. I saw the one you made and i thought what the hell! I will give it a bash. I dont suppose you have a parts list that i will need to make it R/C do you?

**Bunkerbarge** · 26-02-2008

Good on you Tiger, about time you got your feet wet and did some real modelling!

The bits were bought from a place called SHG Models. They have a web site that has been under construction for a long time now so you could try e-mailing them through it or getting hold of a phone number through BT.

Some people put the motors in the rear compartment making the shafts shorter but having another deck opening to worry about. I used 10" 4mm tubes with 12" 2mm shafts, so I had a realistic exposed shaft at the back end and this puts the motors under the tower. Always a danger of getting something wrapped round it externally but I have two! The brass props were also supplied by SHG as well as the couplings and motors, which are in fact servo motors. I didn't like the couplings as they were a bit of a naff plastic casting and off centre so I eventually changed them for a pair of the Robbe rubber tube type ones. They work brilliantly and are far smoother. The model is actually quite reliable nowadays and I enjoy watching her on the water but you are limited to calm days.

tigertc · 26-02-2008

I'll do some investigating and put some planning into this build (something which i didnt do with the tanks)

subzero · 05-03-2008

Hello Tiger , GRRRRREAT work on the mods.

I have an early Tamiya Leopard 1 A4 tank, it has the original metal tracks single motor,clutch etc that I obtained a while ago. It was originally only a 2 channel model F+R, left / right etc

I have started to convert it with more functions. 5 at present. I have installed a turret ring and motor gear from an old sick Hen Long and fitted a tiny speed controller for proportional control so I can move the turret left or right very slowly or quite fast as I wish and modified it for 360 degree travel. Put in working rear lights and flashing amber beacon and an electronic diesel engine sound system with start up etc that is linked to the motor ( speeds up when the motor does etc )

I intend to fit a moveing barrel and firing mechanism from the old tank too, and micro LEDS for the headlights are on order and I am in the process of converting the road wheels to being ball bearing raced ( too much friction with the plastic bushes )

A bit of a rolling restoration/upgrade but its worth it, you don't see many early leopards these days ( I don't anyway )

Will post a couple of pics if your interested ?

Sub.

subzero · 05-03-2008

Hello Tiger , GRRRRREAT work on the mods.

I have an early Tamiya Leopard 1 A4 tank, it has the original metal tracks single motor,clutch etc that I obtained a while ago. It was originally only a 2 channel model F+R, left / right etc

I have started to convert it with more functions. 5 at present. I have installed a turret ring and motor gear from an old sick Hen Long and fitted a tiny speed controller for proportional control so I can move the turret left or right very slowly or quite fast as I wish and modified it for 360 degree travel. Put in working rear lights and flashing amber beacon and an electronic diesel engine sound system with start up etc that is linked to the motor ( speeds up when the motor does etc )

I intend to fit a moveing barrel and firing mechanism from the old tank too, and micro LEDS for the headlights are on order and I am in the process of converting the road wheels to being ball bearing raced ( too much friction with the plastic bushes )

A bit of a rolling retoration/upgrade but its worth it, you don't see many early leopards these days ( I don't anyway )

Will post a couple of pics if your interested ?

Sub.