Author Topic: vipers and mach5's  (Read 1544 times)

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Offline AllWight

vipers and mach5's
« on: May 25 2018 13:08 »
Hi All

I have been fitting some radio control components in to 3 locos for a friend. Two of the locos are gauge 3 and will be fitted with the Brian Jones Machfive/Saturn 2.4Ghz system.

The third loco is not gauge 3 but 16mm kit of a Quarry hunslet. Owing to its diminutive size a smaller battery pack and speed controller was sought. I decided on Wednesday to fit the quarry hunslet first as the space was the premium here and it was closest to the workbench. Just as well really. This loco is fitted with 6AA rechargeable batteries and intended to have the same Saturn controller as used for the gauge 3 locos. The only difference was that the Machfive from Brian Jones was too big so I opted for a viper. I have used these before on my Wickham trolley and a friend 0 scale locos so I know they work.

I wired up the operating and charging circuit as per the diagram and checked the charger was doing its job with a volt meter and all was good. Then I decided to set up the throttle throw for full forwards and full reverse on the viper. An easy job. You have to turn on the handset/transmitter then turn on the loco and you have a window of 4 seconds to push the little button on the viper and then do the full forward and full reverse on the throttle. Once the green and red lights stops flashing it is all set up. I was not able to do the setting up as the motor sprung into life instantly.

The reality was that as soon as I turned on the loco it sprung into full forward so I turned it off and disengaged the motor from the mechanical drive so it would not fire itself off of the workbench while I investigated. Upon chatting to a fellow gauge 3 modeller he said that his friend had had issues with a deltang device having a different setting of the “zero setting”. If I turned on the transmitter and then the model the motor would go into full forward speed. If I pulled the elevation stalk (channel 2) backwards to half of the reverse throw it would stop as if the Zero position was off centre. Once you release the stalk it springs forwards to the “dead man’s handle” position and the motor goes into full forward again. So, I tried adjusting it using the trim buttons but that did not make any difference. If I pulled the elevation stalk in to full reverse the motor would then go in reverse. So, it does work. Just not in the way that one would hope. So now I need to find a speed controller of similar size to the viper that will not be deltang and will work with the Saturn transmitter. For peace of mind I did try wiring up a Machfive and it worked faultlessly. However, this is simply too big to fit inside the saddle tank and boiler space.

Anyone out there have any ideas?


Offline John Candy

Re: vipers and mach5's
« Reply #1 on: May 25 2018 20:06 »
I fitted a Viper 10 HV (the larger 24V rated type) to the 45XX I have just converted for Mark T and have used the same unit previously on my own Dean Goods and Johnson 1F 0-6-0T (the two Sentinels with 9.6V have the Viper unit you are using) without any problems.

I used Planet T5 r/c until now (they are no longer available) so settled for a RadioLink T8FB.

I normally use Channel 3 for the speed/reverse (i.e. connected to the ESC) and did the same in this case.

All went well until I switched off the transmitter and the loco (which at rest) took off full speed in reverse (fortunately it was on the rolling road so no harm was done).

It took me a while to fathom out what was going on..... there are pre-programmed "fail safe" settings in the transmitter which which are intended to ensure an aircraft safely comes back to earth if control is lost..... but channel 3 was set to maximum thrust by default!

Eventually cured problem by switching ESC to Ch. 2 and whistle to Ch. 4.

I asked Mtroniks why this was happening and they said the transmitter was overriding the Viper's inbuilt fail safe controls which ensure last good signal was held if contact lost (i.e. to enable the loco to coast with the transmitter switched off).

Could this be the problem you are having?

Incidentally, my first built G3 loco (N5) has a Mac5 with Planet T5 and I had always since avoided Mac5 because that loco always "took off" if the transmitter was switched off....I have now changed the channel on that from Ch.3 to Ch.1 and that is now fine.


My fellow Members, ask not what your Society can do for you, ask what you can do for your Society.

Offline AllWight

Re: vipers and mach5's
« Reply #2 on: May 29 2018 10:27 »
Hi John

With regards tot eh Machfive from Brian Jones i have them in all of my locos and they have worked faultlessly for the last ten years on 27 Mhz, 40Mhz, 2.4 Ghz and with either futaba or spektrum handsets. Spektrum is my personal choice but they are no longer for sale in the UK so i had to make an alternative choice for the models that i am fitting with RC.

The 2 gauge 3 locos that i am fitting will be no issue with a machfive and Saturn as the bits all came from Brian Jones.

The reason I went for a viper was that i have one in my wickham trolley which is binded to the spektrum system. I just presumed they were compatible with all handsets/transmitters. The truth is i was wrong. I know the first time in 15 years!!

I will be experimenting with another speed controller that a friend is lending me if that works then i will swap the component around. If not then the transmitter will need changing to suit the viper for the one loco.

I will let you know how i get on