Elmod - The answer!!! At long last!!

[wibblywobbly]

Hi All

The saga is over, after 12 months of trying to get an explanation as to why my Tiger would not operate at full power, I turned to the Panzerketten forum, one of the Elmod tecchies is a moderator there. After describing my problems he posted this response...

Hello Rob!

I read your message several times and finally I found the nub of the matter! Your Tiger is too heavy!!

The Tank Module simulates mass inertia. It's because a usual RC tank has a way higher power-mass-ratio than a 1:1 tank, so it accelerates much too fast. To compensate this, the Tank Module accelerates slowly.
On the other side the torque-voltage-characteristic of an common electric motor is adverse. The torque is very low on low voltage which is necessary for slow run.
The parameters of the module are set in a way which fits for 99% of the 1:16 tanks which weight around 4kg to 8kg.
In your case, the starting voltage is much too low and raises too slowly. It results in the point that it takes several seconds for the tank to move at all. The RX14 just sets the motor voltage to the point that corresponds to the stick position of the radio without a delay. I'm pretty sure, your tank only moves when using the RX14l when the stick is in the upper most position.

To keep it short: the Tank Module isn't ment to be used with an 18kg tank. There are plans for a "heavy metal" version for tanks like yours but there is no fixed date for the release. The parameters may be theoretically set to reduce the mass inert simulation but it cannot be guaranteed that the ESCs will be able to take that.

Cheers,
Darky

It just so happens that Jake also saw my post and contacted me by PM, with a few suggestions. It looks as though my tank is just over the weight limit (it weighs around 13lbs, 18kgs was a typo on my part). After trying a few things I did this:

I charged up another battery.
Put the jumpers on WW2 German Metal Gearbox settings. (101)
Ran the tank.
No torque in the motors at all. It gave all the signs of a flat battery in minutes and the tank would not move. This is what it has been doing since day 1. Even tried an 8.4v battery with no luck.

then,

I did not recharge the battery.
Put the jumpers on 000. Fun tank
The tank ran perfectly. Full power, still get momentum, inertia, and it will climb over anything. The battery lasts forever too.

So,
I only get full power when jumpers are 000? This explains all of the power problems that I have been getting. The other jumper settings will not allow the tank to run.

Without forums I would have been dead in the water, it has only been due to access to the pooled knowledge that exists out there that I have been able to get a solution. So, if your Elmod tank drains batteries and lacks power, pull out the first three jumpers (000) rather than (101).

A huge thanks to Jake, and to Darky. 

Rob G

[grim_marmazet]

Glad to hear its finally sorted Rob. Hows the speed when you set the jumpers to 000. Does it still retain scale speed? I bet you'll be having loads of fun with it now! 
Maybe it will get people back into elmod again. I swapped to Tamiya after the short battery life problem, but I do miss some of the features of the elmod system.
Cheers,
Rik

[STEINER]

Glad to hear its finally sorted Rob. Hows the speed when you set the jumpers to 000. Does it still retain scale speed? I bet you'll be having loads of fun with it now! 
Maybe it will get people back into elmod again. I swapped to Tamiya after the short battery life problem, but I do miss some of the features of the elmod system.
Cheers,
Rik

Grim, have you had any problems with your Tamiya electrics ? If not, there lies your answer.

STEINER.

[grim_marmazet]

I've zero problems with the Tamiya DMD and MFU, they are as robust as you could want. I've attached god knows how many extra things to them, i've attached a bigger speaker, I've run them through as much punishment as I could, I even spilt a glass of water into the DMD while it was on (I don't recommend this though as its likely to give you a heart attack! lol  ), and they still run fine. Also you get a lifetime warranty on them. I personally will stick to Tamiya from now on, but that's just me. 
Cheers,
Rik

[wibblywobbly]

Glad to hear its finally sorted Rob. Hows the speed when you set the jumpers to 000. Does it still retain scale speed? I bet you'll be having loads of fun with it now! 
Maybe it will get people back into elmod again. I swapped to Tamiya after the short battery life problem, but I do miss some of the features of the elmod system.
Cheers,
Rik

The speed is fine, it doesn't run around like a Tamiya, but then they are way too fast. It is equivalent to an RX14 but with mass inertia, so it accelerates slowly with full proportional control on the right stick. If I let go of the stick it will coast to halt, if I gently pull back on the stick it will apply the brakes, and full down on the stick is an emergency stop. Of course, being Elmod I get all of the associated brake screeches, and gearchange sounds too.

It is still only around 60% of what my HL Jagdpanther does, but that is a much lighter tank. So light that the metal tracks spin at the slightest provocation.

Pulling away from a standing start there is still a 3 second delay, I think this is due to one of several things:

1. The initial kick from a 7.2v battery isn't enough to immediately move the tank due to the way the Elmod board detects voltage required. It may therefore take a few seconds to calculate that more power is needed and deliver it to the motors. If I shut the throttle and then open it again before the tank stops it will pick up speed without a delay, presumably because the inertia takes the load off the motors. Once moving it will spin the tracks when the power kicks in.

2. It could possibly be the tx. It is a high spec tx designed for planes and helicopters. I may be able to program the tx to tell the throttle exponentials to deliver more power faster.

3. A 9.6v battery may solve it. Elmod boards will take 12v.

4. Jamara 480 motors and a 9.6v battery may solve it, more volts and more torque.

One thing that is surprising is just how powerful the Heng Long El-Cheapo Suntech motors actually are? They are shifting a lot of weight, and pulling it up an incline without any bother using standard metal gearboxes.

Although the tank functions perfectly in '000' mode, I am still curious as to why it does not perform at all in '101' mode. If as Darky says, the board is designed to cope with 6-8kg  weights, well it doesn't. Mine is heavy but it is under that limit. Something is restricting the power massively unless it has all 3 of the jumpers removed. Maybe it needs a 9.6v battery, but as anyone with Elmod instructions knows, they only tell you how to install it. They make no mention of batteries, tank weights, gearboxes, motor drive outputs or anything else. It is down to the owner to figure that out.

That is where Tamiya have the upper hand, it is plug and play and totally dependable. I just happen to love the fact that I can reprogram the Elmod sounds, and the inertia effects during running (and I love a challenge).

Rob G
PS - Just found out that 'Darky' on Panzerketten is none other than Thomas! 

[Matdragon]

hi there,

excellent news mate, my be the answer im looking at if mine goes slowely (thats if it even runs LOL )

One question though - how does having the jumpers on 000 effect the CSI ? as in hit points and re-load time ect .. ??

cheers,

Matt

[Ex_Pat_Tanker]

The CSI has its own dip switch for setting vehicle class.

[971wright]

Hi Glad to here you have found the problem,if you change the voltage to 9,6v you will also increase the revs of the motor v/rpm,so for instance if a motor does7,200rpm with 7,2v it will do 9,600 with 9,6v,just something you will have to account for you might be better using swaths gearbox calculator to sort out the final speed I.E. scale and work out which gives maximum torque and scale speed with a motor that is compatable with El-mod.I find the calculator to be very good can chop and change pinions to see how it effects the overall ratio .Have found the nearest gears and motors  for panzer 3 and 4 this way.


  regards pete 

[tankman]

I said that you would sort it out Rob  . Look forward to seeing the improved running abilities next time we meet. All the best for now
Alan

[grompix]

That's really great news Rob. I've followed your threads on unreliable Elmod boards and had, quite frankly, given up on ever buying another Elmod setup. Looks like the problems are (more or less) solved - at least the situation is better now than it was. This is all through your tenacity Rob so well done. Puzzles me though why Thomas didn't pick up on that until you contacted him through the 'Panzerketten' forum.
Give yourself a pat on the back mate - you deserve it (and Elmod should give you another free thinktank setup of your choice for raising customer confidence in their products again!).

Cheers
Chris