Maybe somebody can help me on this one?
I have a Hobby Engine Abrams in 1/16 scale and need to take it apart to replace the radio gear and so make it fully proportional.

How the Dickens does it come apart?

I have contacted several dealers and the manufacturer with no success...

Any ideas?

Calamity Jane

Hi,

i googled for this tank a bit, as im not familiar with its internals. Some action videos show it probably has some board to work with all aditional functions. Joystics might fool me, but looking at its travel speed, those look more like buttons than actual joystics.
It would be best if you would specify, how "advanced" controls you want. Easiest way is to use control board from tamiyas tanks, then you just take any 4ch radio, and you got it. in other case, you might buy bit more advanced radio system, and do all programing/mixing yourself. In any case, this wont be "drop-in" replacement, and will require some soldering and major head scratching too

Here in the UK there is a guy who does electronics for boats called JJC Electronics, he's got a site so it's worth a visit. I used a lot of his modules in my 4 foot long destroyer, HMS Solebay.
He has done 'specials' for me in the past so I am trying to get him to reply to my mails, which he isn't.
It's no good with a Tamiya board because of the engine sound, it's wrong for the Abrams which has a gas turbine I believe.
JJC has 2 turbine sounds, but I need a few other modules modified to suit. A gun module that has a recoil rather than the turn of his and without the ships loaded gong or shell discard.
I will use Futaba stuff, an F14 and a Robbe 12+2 set for toher functions because a standard RX won't work like the Taliya setup when pushing trims forward, so I need a couple of extra functions. That's no problem.
But I need to know how the Abrams comes apart without damaging it. I don't want to just start undoing screws and then have that awful 'clonk' as something inside falls off!
I think that with the expanded F14 the 2 joysticks will work the forward/revers, steering, turret elevation and turret rotation. I need some switches for firing the main (passing contact or momentary) and machine guns (hold/release) and maybe for lights if I fit them, a standard on/off. I suppose smoke could be fitted too, again an on/off. These are the sort of controls I used on the destroyer that had mixer steering, main gun and secondary (all working) firing and rotation, destroyer siren, signal lamps, morse code sound, 2 different asdic sounds and smoke. I ran out of space in the hull after that lot!

Thanks for coming back on this one.

Calam.

The Abrams handset.



The 2 sticks are only one way working, up/down (I think they missed a trick there...) and control movement of the AFV.

At the bottom are 5 buttons. The right 2 control turret rotation (usually left stick horizontal); in the centre is the main gun firing button (Tamiya use the trims for this); left 2 buttons have an odd setup because they fire the MG and raise/lower the barrel at the same time (!)....

There is no sound when the vehicle is stationary which I feel is wrong, the turbine would still whine.
All-in-all this is a very poor RC installation and screams out for replacement.

All I think I need to keep are the motors/gearboxes (if there are any gearboxes....??), the on/off switch and that's about it. JJC modules should be able to operate everything else via the F14 TX/RX setup.

The snag is I have no idea what sort of voltage the motors use.... whether or not the MG rotation is by servo or motor (if a motor again what voltage?) and of course the turret rotation motor voltage. My idea is to use a 40 Mhz RX/TX with probably a 7.4V Nicad of NimH battery as in Tamiya models (that simplyfies battery purchase). However, the JJC modules may need a 12V supply, they used that in the destroyer, so weight will be plentiful.....

Hope that helps guide you guys with answers....
The model is a fairly well presented one, although on the light side, but maybe I can weight that a bit.





Calam

Hi,

I beleive you still can use tamiya module in most cases. The only module you need, is one for control of motors. sound and recoil is separate box there. Aswell, for turret rottation i would use modifyed servo, , with diconected pot. In this case, you can set it up the way, that turet rotation speed is bit different, depending on your stick position, but it halts when you release the stick to neutral. this is done by disconecting pot shaft from rotating along with servo arm. Ive used servos as drive motors for my small tanks in past, exactly same way. it has nice gearbox, small motor, and goot FET amp, whitch is all you need. and allready radio compatiable. For gun elevation, throtle channel with ratchet (non return spring) is ideal. I personaly hate idea of using trims for separate functions, i prefer MORE CHANNELS and i realy like radio you got, with all expansion posibilities, its just right stuff for tanks etc. its good idea to mix smoke to throttle, especialy if you can do mixing curves.
Im bit aware that transmission is at bit speedy side in this kit. wont be big problem with new management board, or you can always use 2 speed controls, but then again, those will cost closely same as DMD module, plus mixing free. If you can get custom made 2 chanel speed controll, with all mixing preprogramed, then its great, as you wont be willing to use most of DMD functions anyway

Not sure about the seperate sound. Which DMD module are you referring to?
And I am also not sure which bits to disconnect in a servo, I have never done that before so a big adventure. It sounds a good idea though. There are nice little gearboxes in servos so they would make super motors.
The Futaba F14 is expandable to 108 functions (they assure me!), although I would not need that many obviously.
The Robbe Multi Switch Prop 12 + 2 Mod #8101 for F14, FC-16 & FC-18 Transmitters would give me 6 switches and 2 rotary controls for extra functions, see the link below and scroll down the page.....
http://www.pandanmodelboats.co.uk/acatalog/Our_Online_Catalogue_Robbe_F14__FC_16__and_FX_18_Radio_Accessories_137.htmlone

It means getting the decoder too, this one in fact and the module immediately below the one mentioned above, Robbe Multi Switch Prop 12+2 DEC Mem #8370

The next module allows for 4 of each, this one... Robbe Multi Prop Module 4 +4 #8039, as d enoted by the 4+4 notation.

If I remember rightly the JJC modules can work on 6V, which is the setup I had in my destroyer seen here,


This shot shows the real ship alongside my model...
.

I used the F14 setup to control her and the motor mixer worked superbly allowing her to turn in her own length, so it should be okay in a tank. The only thing is that they have a rudder connection and I am not sure if they work with that disconnected.

Thanks for the info and interest.

I still have no idea how to take the Abrams apart..........!!!!!

Calamity

What you might want is DMD T-03, it is responsible for everything, except recoil, and sounds. Now MF-01 is redundant bit. You can purchase those separately, i just lost the link, but will try to find it. Theres static kingtiger conversion to full optpion article avialible too, will drop in link later.

Now about servos. if you got old servo, try falowing. remove gears, and now plug servo into receiver slot. you will see, that motor starts spining. theres certain stick location, where servo motor stops, and if you pass that spot, it goes reverse. now if you turn pot on servo, you can change that point. All you need to do, is disconect potentiometer, so it does not rotate with gears, and aswell remove any limiters, so servo can spin as long as it wants. now, basicly you have small sized engine/gearbox combo, with speed control, with reverse . some smaller servos use potentiometer axle as axle for final gear, those arent best choise.. you got to make sure pot isnt turning with final gear.

http://www.freewebtown.com/jyliang/
heres some good stuff, but might be more suited for smaller stuff.

Hi and thanks for all the trouble you have gone to for me.

Sorry if I seem a bit of an idiot - what's a potentiometer?

I have an old servo somewhere I took apart so can have a look. I would probably use a standard Futaba one if needed, say for gun elevation....

Would the Tiger DMD be okay for a modern tank? I suppose as long as the DMD is only for traction it would be okay. What else would it control?

The turret rotation sounds on an Abrams would be like the Leopard I expect.
As you may have seen I am building a scratch Challenger II and intend to use a Leopard kit for the running gear and electronics because I think they would be about the same. The only snag is the Challenger has 1 set of road wheels less, but with a desertised skirt on I don't think that would notice.
But the Leopard DMD is a total unit (I have built a Leopard, great panzer) so the sound would be very wrong for an Abrams.... a pity.

If you can find that link I would appreciate it. I am UK side though and try to buy over here is possible. I bought airsoft guns from HK and the US (I love shooting) and got caught badly with Customs and postal charges, so try to avoid buying overseas if possible. But if there's no option then so be it.

A very grateful Calamity

Heres link on how to convert servos :
http://www.kronosrobotics.com/an116/GAN116_3003.shtml
and potentiometer, is variable resistor. Servo procesor measures voltage drop on resistor, and uses this value to calculate servos current postion. According to signal, it decides whitch way motor should turn, so position calculated from servo, matches position given by receivers signal.
heres potentiometer picture (linked for visual reference only):


Now about DMD T03. it is used probably in all tamiya tanks. Only earlier ones had T01 model.

And heres link on moding tamiyas KT:
http://www.rcgrabbag.com/rctanks/kingtiger/index.htm

Hi Cactus999,
Thanks for those links, they are very interesting.
I know the DMD you mean now, they are in both our Tigers I and II.
But the leopard uses a completely different type which is fatser and represents the modern tanks much better.
Also the turret rotation sound is very different to the old WWII machines.

I will have to phone this guy over here to find out why he has not teplied to my mails or letter. I have bought from him in the past and the moduls are excellent.
I wondered if the Heng Long recoils were any good, but then I bought 2 of their tanks, the Pazer III and Tiger and found the recoil is very violent and rocks the whole tank far too much.
The Tiger recoil shown in the video clip you gave me the link for has a good action but uses the wrong sound for an Abrams, sadly....
In modern tanks there is an electric motor whine, very loud on the turret rotation, so there would be no rachet noise as the gun cranks up/down.
This module is ideal for most WWII machines and some post war ones.

But in the end, until I can find out how the Abrams comes apart there is little I can do with it...

I am hoping some kind sould will be able to tell me the secret....

I put the servo link into Favourites and the Clark one, both very useful.

Many thanks for taking the time out to help.

Calam

I beleive Tiger 1&2 modules arent too fast, as those are bit too fast for original tanks allready. Leopard uses more advanced one (T-07 DMD ). aarlier ones had separate sound and drive modules.
Post some updates and pictures as you will start diging into internals

I have a series of photos from the Tank Zone, Kin kindly sent me them, so at least I can get the turret off the Abrams now. How I get into the turret is another thing altogether!

Calamity