Robitronic Pro Master Motor Dyno, help!

[obsession4x4]

Hi,
I have a Robitronic Pro Master dyno Plus Version (made for motors under 10 turns), and I'm very happy with this Dyno but unfortunately the unit software simulates the voltage drops of the NiMh batteries (about 0,04.Ohm).

I would like to have the dyno without voltage drops, that doesn't simulate batteries, NiMhs or LiPos.
The max voltage on the motor under a test run is always under the set value.
I would like to know if there is some chance to change the NiMh simulation.
EPROM?

Thanks in advance.

 

[EddieO]

Not gonna happen...I've even asked Robitronic myself to get it and they say it would take a full rewrite.

The Robi is tricky to use on some motors, its often glitches in the torque readings on the higher turn motors.

Later EddieO

 

[obsession4x4]

I even asked Robitronic, but they replied:

"... It is impossible to have no drop! Any supply will have voltage drop – you have voltage drop on wire – on connector and on battery internal ...".

They haven't understood that I was speaking about the voltage drop simulation made by the Dyno software!
I have sent another email but I haven't received reply any more.
Robitronic produces good items, but the customer service is very bad...

 

[EddieO]

No they fully understand it.....they believe testing without voltage drop applied is worthless, which is what they are stating in their statement to you.

They took a year once to respond to my email once, and I used to be their distributor in the US.

Unless you have a way to reprogram the the EPROM and the ability to rewrite the software from scratch basically you are not gonna get it removed. Its not a huge difference with or without it though, so I would not worry to much about it.

Later EddieO

 

[obsession4x4]

I haven't any programmer or software to rewrite the EPROM, so I have to ask to somebody here in Europe.
Yes, there aren't too much differences, but I would like to have 7,5 volt (or other setting values) on the motor.
So I can compare the dyno results with today LiPo batteries performances.
The Robitronic Pro Master uses a 12 volts - 40 Amps Pb battery to test the motors.
The software of other dynos, like the Fantom Facts Machine or the CS Electronic Power Check, don't make corrections regarding the set values.

What type of dyno are you using for your motors?
I also would like to know what dynos uses brands like NEU Motors, Castle, Plettemberg, etc.

 

[EddieO]

The cs doesn't have a drop built in cause its meant to use a race pack anyways, so the drop will happen. Fantom didn't put it in the software at their choice.

The testing will be fine with it, as eve lipo batteries suffer the same fate. Just your tests, you will be able to compare the motors just fine. If you are worried about a little voltage drop, increase the voltage of the testing... The Robi goes past 8.4v easy

I use a turbo dyno and a Robi as the main two... I have almost every rc dyno ever made.

Plettenberg had a custom dyno last I heard... Same with castle.

Later EddieO

 

[JohnRobHolmes]

Castle, Astro, Nue, etc.. all use custom dynos that they built. The last one I saw at the Castle plant was pretty cool, it had about 10 slave motors on it.

 

[obsession4x4]

EddieO, me too have a CS Electronic Power Check dyno, and some other modern and vintage (Kyosho, Shinwa Motor Dresser, and Motor Torque) motor checkers.
There are some differences in the motor test between CS and Robi, due to the voltage drop (I think) that the software Robi dyno does.
Some time ago the owner of a LHS tested a Reedy Ti 11x2, and he found about 30 watts of differences between the test on the CS and on Robi (248 Vs 216).
On the CS he used a Turnegy Nano Thech 6600 Mah 65C/130C 2S1P LiPo battery.

John, I would like to see the pics of the "custom dyno" used by the rc motor brands.

 

[EddieO]

I would never attempt to compare numbers between dynos. There is no correlation at all really from one type to the next. Even between the same type you can see variances that make you scratch your head.

The Robi will work fine to compare motor to motor on it. Worrying about how it compares on the CS is pointless. I always felt my CS read high anyways, hence why it collects dust in a box some where.

Good luck getting pics of the other dynos. I've seen a couple, but only because a friend showed me some....I think there was a pic of the castle dyno in an RC mag a while back. The companies are pretty top secret with them....just the nature of the business. If you can get stuff machined and don't mind doing calculations yourself, you can actually build a pretty reliable unit fairly cheaply.

Later EddieO

 

[JohnRobHolmes]

I agree on comparing specs between units, even two build from the same parts will have variance enough without high dollar calibrations or software corrections. It isn't useful.

The castle unit used fluid bath cooling on all the slave motors for consistent readings all day. They used it for dynoing and testing controllers so there was no load cell or torque output.

 

[obsession4x4]

Thanks for the replies.
I know that there is some difference among dynos, but 13% is really too much.

In the coming weeks I will check different type of motors, using both the Robi and the CS. And I'll try to change the EPROM software.
But I think, like others, I will have to wait to see the dyno that John is planning ;-)

 

[vintage guy]

For the Robitronic it´s important using a computer to display results as this dyno could produce some peaks on certain motors or motors in bad condition what you could iron out when seeing the graph. Just using the display of the dyno could display results what are not true. Also using a computer you can see a full graph and not just max readings.

 

[obsession4x4]

As far as the dynos used by the companies, click on the link below:

ALIGN 800MX 110A Current Test - YouTube

I also have found some pics in the june 2012 RCCA. There are some pics from Castle Creations and Novak labs.

 

[obsession4x4]

800MX 115A Continuous Current Test - YouTube


Using 800MX 520KV as an example:
Load torque 4Kgt-cm/ load current of 33.9A
Load torque 6Kgt-cm/ load current of 44.1A
Load torque 8Kgt-cm/ load current of 54.8A
Load torque 10Kgt-cm/ load current of 65.1A
Load torque 12Kgt-cm/ load current of 75.3A
Load torque 14Kgt-cm/ load current of 85.9A
Load torque 16Kgt-cm/ load current of 96.3A
Load torque 18.8Kgt-cm/ load current of 110A