Go Back  RCU Forums > RC Cars, Buggies, Trucks, Tanks and more > RC Tanks
Reload this Page >

Min/max Tamiya King Tiger build

Notices
RC Tanks Discuss all aspects of rc tank building and driving here!

Min/max Tamiya King Tiger build

Old 11-04-2019, 08:23 PM
  #1  
dingobattler
Member
Thread Starter
 
Join Date: Jun 2019
Posts: 43
Likes: 0
Received 2 Likes on 2 Posts
Default Min/max Tamiya King Tiger build

Starting my Tamiya KT build. The name is called min/max for a reason - I will attempt to build this KT to have maximium performance and looks for minimum cost. Why this philosophy? I posted the following in another thread:

You get a metal lower hull. Now your tank becomes heavier, so it drives slower. Then you get more powerful motors which your gearbox can't handle, so you get an upgraded gearbox too. Then your idler becomes too weak and break, so you get a metal idler. Then the whole tank get heavier, so your suspension gets weak, so you get all new suspension. All that extra weight is a pain for the swing arms, one snaps, and you get metal ones. Your plastic tracks now break at the snap of a finger due to all the weight and torque, so you get metal tracks, or maybe you want metal tracks. Then you strip all the gears in your gearbox thanks to the weight, and now you have to get metal gears. In the end, you were better buying just the Tamiya computer, and metal/aftermarket everything else.

Except that now, all these aftermarket stuff don't fit well at all. The metal hull lacks screw tappings. The metal tracks throws itself off every 2 minutes, and barely meshes with the sprocket. The aftermarket idler has a weak grub screw that loosens itself every 5 minutes. The DMD doesn't play well with all the extra weight, and makes your tank move like a tortoise, or a racecar, so you might as well have bought an aftermarket computer as well. Your new motors plus all the extra weight causes it drink power, so your tanks can only run for 10 minutes, so now you have to upgrade to Lipo, with a low voltage warning, and a charging bag, which you half-suspect will not work and is a massive fire risk. All your fancy Aber PE is falling out every session, and you only notice when you pack up each time, at first its a tiny bolt, then things like tool clamps, skirt hangers, maybe a metal shackle and eventually an entire mesh disappears into a grass, as you frantically search the entire battlefield for your tiny folded metal detail, held to your tank by a thread of superglue.

How nice your tank looks and drives is mainly due to your skill as a scale modeller and a RC tank operator. In the hands of a decent scale modeller, a completely plastic tank will look exactly the same as a all metal one. Skills like gap filling is the reason why we have metal turned barrels with broken turret elevation arms.

Tamiya KTs seems to have a number of issues, number one of which is the very weak idler system, that causes the tracks to throw very easily. What happens in the stock system is that the springs in the idler are so weak that it compresses for anything, especially sharp movement and turns. The drive train has only 9 teeth, hence it'll throw the tracks very easily the moment it becomes slack.

In this first instalment, I'll attempt to address the weak idler issue. People usually go down either the following 3 systems to fix it:

1) Darryl turner system - This one uses springs. Advantage is that its still spring loaded, so any pebbles/etc. that go through it has a lower chance of breaking the tracks. Disadvantage is that it costs $65 plus shipping, and is no longer being sold.
2) Henntec - Its basically a fixed idler, held in place by a grub screw. Advantage is that it fixes the issue. Disadvantage is that it costs $40 plus shipping, is fixed, and the grub screw apparently comes loose easily.
3) Schumo - Its basically the Tamiya idler, except its completely filled in, which doesn't allow any movement. Advantage is the same as above, disadvantage same as above, except it has no grub screw to come lose. It's $20 plus shipping.

I live in Australia. Shipping is $50, no joke. The weak AUD increases the cost to $50 + $50 shipping = $100+10% GST = $110. Just for a simple fix.

I thought about it, and came up with 2 solutions:

4) What is the main issue with the current idler? Lousy springs. Can I change that?

$3 from bunnings. They feel like something else completely different. Only downside is that they need to be cut. First number is diameter. You want somewhere around 4.75-5.25mm. Second number is length. Third number is thickness of spring wire. You want this to be as high as humanly possible.
Click image for larger version

Name:	jZ99UPd.jpg
Views:	42
Size:	215.9 KB
ID:	2265679

Another image, just by themselves, you can see how much thicker and higher quality the bunnings compression springs are.
Click image for larger version

Name:	v8difG7.jpg
Views:	31
Size:	259.5 KB
ID:	2265680

The main issue is actually cutting them. I use a chisel and hammered it on a brick. Then heated up the ends and pressed it on a brick till flat.
Click image for larger version

Name:	ab2RDeO.jpg
Views:	48
Size:	201.2 KB
ID:	2265681


Its much harder to compress. From touch alone, seems around 6-8x harder to compress. Don't take my word for it though. Check this out. Hung 1.25kg weights on both. Left one is with the Tamiya one, its already completely compressed. Right one is the bunnings one, barely even budged.
Click image for larger version

Name:	EoKnNBS.jpg
Views:	46
Size:	320.4 KB
ID:	2265682

Increase the bunnings one to 2.5kg. Its a touch less compressed than the Tamiya one, so at this point, its 2x as strong at the very least.
Click image for larger version

Name:	xdR9rPq.jpg
Views:	54
Size:	322.7 KB
ID:	2265683

hung a 5kg weight. Finally got the bunnings springs to compress all the way.
Click image for larger version

Name:	d0EgzwP.jpg
Views:	39
Size:	293.3 KB
ID:	2265684

Mission accomplished.

The 5th method, which I actually got scouring around the internet is this:

5)Fill the idler with silicone/putty. Spray the idler arm with oil and stick it into the silicone/putty, and use some sort of method to leave it fixed there. Take it out once the silicone/putty has dried. This will make it become fixed. $5 at max, usually free, since most scale modellers have this lying around. If you don't want to mess around with springs, then this method will work well too.

Will tackle the other issues in my next instalment. If anyone has a cheap solution to hull flex, let me know. That should fix the last of the performance issues.

Last edited by dingobattler; 11-04-2019 at 09:04 PM.
Old 11-05-2019, 04:00 AM
  #2  
Crius
 
Join Date: Sep 2015
Location: Detroit Rock City
Posts: 3,032
Likes: 0
Received 32 Likes on 27 Posts
Default

Good thread. The Tammy King Tiger is on my list to build one day so I'll be watching this closely to see what improvements you make and what pitfalls I need to watch out for.
Old 11-05-2019, 06:32 AM
  #3  
sevoblast
 
Join Date: Feb 2008
Location: East
Posts: 2,952
Received 6 Likes on 6 Posts
Default



You will want to rough up the inside of the idler clasp and the outside of the idler drum for better adhesion to keep your idler adjustment in place. Springs are useless, if you get something caught in the track to make the springs work, it'll also probably break the track link. Also, if your track set has the pins going in from the inside, take the time to remove each and every one and insert them from the outside. Track pins tend to walk out a hair and it only takes a hair on a KT for the head of the pin to catch the rear plate as it goes around the idler, which will also break a link.

Attached are photos of a rear hull brace you can make from simple brass plate. Since the photo shows a much older KT hull than you have, simply make the plate flat to bolt to your hull sponsons on each side. You can also use the plate to give extra support to the upper real hull since you will no longer have the hull flex endemic with the stock hull. You can put another cross hull brace on the front of the hull, but be careful to position it to clear your transmissions.
Old 11-05-2019, 07:48 AM
  #4  
Tanque
 
Tanque's Avatar
 
Join Date: Feb 2003
Location: East Bay, CA
Posts: 2,482
Likes: 0
Received 17 Likes on 16 Posts
Default

How do folks run a model like the King Tiger? I have one KT- my original from the first issue of the thing from what 35 years ago?
I've never broken anything and I ran the original poly tracks for years until I got Kenny Kong's. I began a update to the model
some years back to make it 'full function' but never completed it as my other models keep me busy.

I have to assume since all these threads have seemingly sound ideas to make the model sturdier I either 'under drive' the thing or
I'm far too cautious in driving and where I drive it. It was a heavy under powered tank, not a off road thrasher. I should revisit my rebuild.
I think I'm using Tamiya's own later style gear boxes and perhaps I should try to fit 4:1 or 3:1 speed reduction on them. I want power first.
Slow, parts breaking, clod busting power. So I'll observe and learn from this thread.

Jerry
Old 11-05-2019, 03:05 PM
  #5  
Pcomm1.v2
 
Pcomm1.v2's Avatar
 
Join Date: Sep 2013
Posts: 961
Received 18 Likes on 11 Posts
Default Tamiya King Tiger full option RC Infrared build experience.


My first Tamiya King Tiger full option RC IR model built stock out of the box was a good indoor carpet runner, but a complete failure when participating in outdoor RC IR Tank Club Battle Games.

After a couple of hours or so of club battle play the stock KT hull under the transmission stanchions was deformed, there was a slight twist to the right in the length of the hull plus the model was underpowered, climbed terrain poorly, and was not at all a competitive runner when compared to the other more dialed and upgraded club tanks. For RC IR club battle games the basic KT upgrade list included 400 motors, gear reduction units, gearbox mount brace, metal elevation arm and hull sponsons to help keep dirt out. The KT kit tracks did break links during even slow turns, indoors or outdoors, so I later went to metal tracks and the Daryl Turner spring loaded idler system from ETO Armor, but reluctantly.




Last edited by Pcomm1.v2; 11-05-2019 at 05:58 PM.
Old 11-05-2019, 03:06 PM
  #6  
Pcomm1.v2
 
Pcomm1.v2's Avatar
 
Join Date: Sep 2013
Posts: 961
Received 18 Likes on 11 Posts
Default Tamiya Tiger II Daryl Turner RC Infrared Custom.

I sold that first KT model on and later commissioned Daryl Turner to design, engineer and fabricate the ultimate Tiger II Porsche Turret RC IR club fighter. After receiving the magnificent hull and turret system back from Daryl, a mutual friend bought the by then finished model from me, as I had lost interest in Infrared battle games. Anyway, study Daryl’s hull, it his total concept on what a proper club fighting hull is. To me, this is a great example of his past and best custom work! The turret elevation and recoil system is a work of art too and all parts are maintenance serviceable. The build uses the DT spring loaded idlers. The project cost was way less than what you might guess. The USA Tamiya KT Porsche Turret static kit was $175.00. Parts and Daryl’s fee for custom work was under $700.00.

John















Last edited by Pcomm1.v2; 11-05-2019 at 03:40 PM.
The following users liked this post:
Artemis2020 (01-26-2020)
Old 11-09-2019, 02:19 PM
  #7  
Shabbernigdo
 
Join Date: Dec 2009
Location: city
Posts: 763
Likes: 0
Received 0 Likes on 0 Posts
Default

5)Fill the idler with silicone/putty. Spray the idler arm with oil and stick it into the silicone/putty, and use some sort of method to leave it fixed there. Take it out once the silicone/putty has dried. This will make it become fixed. $5 at max, usually free, since most scale modellers have this lying around. If you don't want to mess around with springs, then this method will work well too.

Will tackle the other issues in my next instalment. If anyone has a cheap solution to hull flex, let me know. That should fix the last of the performance issues.[/QUOTE]
I filled my stock idlers with putty and it kept them solid but there was still play between them and the part that holds the idler wheel its self allowing the wheel to kant at an angle giving it a bowed in look. went the henntec route and just tossed out the grub screws and used 4mm allen head bolts instead.
Old 11-10-2019, 03:40 AM
  #8  
dingobattler
Member
Thread Starter
 
Join Date: Jun 2019
Posts: 43
Likes: 0
Received 2 Likes on 2 Posts
Default

Coming in from a scale modelling background, there is an issue with the King Tiger far worse than the idler, the tracks, or any other mechanical concerns.
Click image for larger version

Name:	7zt8OuW.jpg
Views:	44
Size:	174.4 KB
ID:	2265708
See it yet? Really poor form from Tamiya. I know its an old kit, but this forces you to either use Zimmerit or texture it.

The Tamiya Zimmerit is really pathetic. Its very soft, and pretty much unusable. Your choices are either to buy the $100 Atak zimmerit, or buy a tub of putty and spend several days putting Zimmerit by hand, which I feel is the better way.

My build is an extremely late war KT, so no Zimmerit. I won't teach you how to do it. Instead, I'll point you to a really good channel:



Click image for larger version

Name:	Vt8ktyl.jpg
Views:	40
Size:	202.3 KB
ID:	2265709
This is my attempt (plus weld seam)

Click image for larger version

Name:	GNExbAa.jpg
Views:	34
Size:	189.6 KB
ID:	2265710
This is with primer. The effect should soften a lot once camo is on.

A few photos of examples here:

Last edited by dingobattler; 11-10-2019 at 04:14 AM.
The following users liked this post:
Artemis2020 (01-26-2020)
Old 11-10-2019, 07:22 AM
  #9  
sevoblast
 
Join Date: Feb 2008
Location: East
Posts: 2,952
Received 6 Likes on 6 Posts
Default

My only advice is don't overdo the pitting and roughness of rolled and/or cast steel. One has to remember that most anything we see today is over 75 years old and more and much of it has not had the best of care. Extensive exposure to moisture and general abuse whilst stored often in open air lots takes it's toll. However, the only absolute is there are no absolutes. Here's a couple from Kubinka including Object 279.

Also, tanks and AFV's in general usually don't last long enough to become a rust streaked fugitive from a junqueyard. That, and no Spiess or Shirt or Starshi Sarjant worth his salt would allow that to happen in his unit.

Old 01-26-2020, 07:28 AM
  #10  
mustclime
 
mustclime's Avatar
 
Join Date: Jul 2011
Location: westwood, NJ
Posts: 1,415
Received 1 Like on 1 Post
Default

Update?
Old 01-26-2020, 08:23 PM
  #11  
Artemis2020
Member
 
Artemis2020's Avatar
 
Join Date: Jan 2020
Location: Fort Worth, TX
Posts: 37
Received 3 Likes on 3 Posts
Default

Dingobattler, that texturing is really cool. Ive never seen that before, thanks for sharing.
Old 04-03-2020, 03:07 PM
  #12  
Jeff489
My Feedback: (12)
 
Join Date: Jul 2005
Posts: 1,300
Likes: 0
Received 0 Likes on 0 Posts
Default

Just thought I'd share a pic of the Munster King Tiger tow shackle. Pic taken with my wife holding the shackle for some idea of scale...


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.