Deltang Rx61-22-W - Please help

[Corbs]

Hello fellow BPRC fans, I have a few issues getting one of my setups to work.

 

The loco has been butchered a lot, but the essence is a Hornby 'Pug' chassis, now with a 3v motor fitted.

 

The receiver is a Deltang Rx61-22-W and it uses a 1s LiPo battery. I use a Tx22 controller.

 

It has a few problems. Firstly, it takes so long to synchronise the Rx with the Tx. They seem to constantly forget each other. Whilst it has a solid light to indicate they are in synch, there is no response to any input from me. I have to switch them off and re-bind the Tx to the Rx, sometimes multiple times.

 

Then, often I will only get a short period of responsiveness before the motor stops responding to controls and just keeps going of its own accord and won't stop until it's switched off.

 

Are these two issues related? The binding problem was there before I changed the motor to a 3v one.

 

The aerial snapped off the Rx some time ago, could this be part of the issue?

[fallen]

Hi Corbs,

 

That sounds a sorry tale! It's difficult to diagnose problems like this at a distance as it were but here are some suggestions.

 

I don't think the change to the 3v motor would cause any problems.

 

I have had problems like this with binding locos and lack of response when using them near a strong WiFi signal. For instance, if I try to bind locos next to my domestic PC and it is switched on then this can cause problems. Switching the PC off or simply moving away sorts it out. Once bound, though, the problem usually goes away.

 

I think the aerial snapping off won't help. I suggest you replace this if you can.

 

Frank

[fallen]

Hi Corbs,

 

Getting the aerial length right could be important. It will give the best signal and help reject interference on other frequencies. Just measured the aerial on one of my receivers. It is 29 mm long.

 

Frank

[Corbs]

Thanks Frank. How should I attach a new aerial, would soldering work?

[fallen]

Hi Corbs,

 

Yes, solder it on. It will need a fine tipped soldering iron and some electrical solder ie solder wire with flux cores inside it. If the receiver has the heat shrink sleeve plastic cover you will need to cut this away to get to the pad on the board.

 

The aerial can just be any fine flexible wire, nothing special about it apart from the length, it will need to be insulated wire of course. I suggest soldering it on first then cutting to length, easier to handle and easier to get the length right.

 

Frank

[Corbs]

That's great. I'll do that next. Do you think that the receiver dropping signal might be causing the issues with the motor running away?

[Giles]

I had all sorts of strangeness going on when I was building my mobile crane.

 

First of all, when you turn everything on, you have to waggle everything until it wakes up. It obviously wants a signal from one specific input in one direction to come to life. After this, it operates normally.

 

I had to build my own four-stick transmitter, using some of the pots from Micron, and also using the little mini joysticks, which I modified individually. During this process, I would find that eventually a winch motor would start to creep - usually with devastating results. This rather lengthened the whole job.

 

After a few weeks of frustration and rdbuilding the crane which meanwhile had torn itself apart through motor creep, I had the transmitter box apart again, looking for loose or shorted wires and finding none (I had the crane powered up) and it started to creep again, so I frantically started poking about. I touched a pot, and it immediately stopped.

 

I was able to test this again later.... creep starting, and touch any pot and it stopped.

 

Not being electronically brilliant, I understood that I was earthing it, and that made the difference - but why it should - I don't know. To cure it, I wired an earth lead to all the pots, and put a brass plate on the outside of the transmitter case where I hold it, and soldered the earth to that.

 

Since when there has been no problem.

 

This may or may not be any help in this instance!

Edited November 28, 2017 by Giles

[Corbs]

Thanks Giles. Was this the case when using the transmitter with any of the other receivers? All my Rx41 type ones seem to work fine as does my other Rx61.

[CME and Bottlewasher]

Im not yet full conversant with Deltang equipment Im old school RC and have been messing about with such for about 40 yrs [gulp!].....

 

Aerial length and function is often critical, so are good joints and bonds. Shielding from interfernce too if reqd.

 

In the early days of RC with live steam we used to get 'glitching' on AM sets, some FM too, due to the 'rusty bolt effect', wet & hot locos and even wet rails. Modern RC shouldnt be affected by such things...yet we have encountered similar. On our H&BLR we still get glitching from time to time. Large ancient drystone walls, local interference? We still have yet to find out. A new mobi/WiFi phone node seemed to hamper us for about a year-then ceased. When operating indoors at exhibitions, certain types of lighting coupled with the metalic environs has also caused issues.

 

The aerial fix is a priority, then be methodical in your elmination of other factors.

 

These days with so much RF, Microwaves-we live in a militarised area-newish police radio systems etc etc, lord knows what such does to our RC models, let alone our bodies!

 

Hope that helps.

 

ATVB

 

CME.

[davetheroad]

I have knocked an aerial off a Deltang Rx a few times, after which nothing worked properly or consistently. Get the aerial fixed before trying anything else.

 

 

That creep issue is interesting. The Deltang TX transmits 49! data packets per second. In that packet is the current throttle setting which the Tx reads from the pot. I wonder where that irritating leccie is coming from?

[Corbs]

To clarify - it's not increasing in speed when it 'runs away', it just maintains the speed it was at and won't stop.

I'll fix the aerial first, thanks guys.

[Giles]

Ive only ever had this with the Tx2 (working the crane) paired to an Rx47. I've never had it with anything else.

It's definitely a Tx issue, not an Rx problem, and, as you say, the creep starts, and just keeps going at a steady pace until you switch the power off....

 

The grounding plate fixed my issue, though.

 

I did once lose the arrival off the Bagnall, but simply measured the correct lengthnoff another receiver of the same type and soldered it on - no problem!

[Corbs]

Interesting! I will see how this fix goes, a bit cautious of opening up the Tx at the moment as I wussed out and bought a pre-built one rather than the kit

[Giles]

If it's my problem (and I'm not saying it is!) All you need do is take the back off, and if it creeps, start touching things! It will just stop and start behaving normally if it is..... at that point you can consider a more practical solution, or if not, start looking elsewhere!

[Corbs]

Thanks Giles

[fallen]

Corbs,

 

I found that if I tried to bind the loco with a strong WiFi signal nearby, it would sort of bind to the WiFi and then it did odd things as the Rx tried to do what it thought the WiFi was telling it to do. This included not moving at all and also sometimes moving steadily along. So some form of interference may be the problem. The lack of aerial will not be helping the Rx pick up the right signal, so it may be more susceptible to interference perhaps.

 

Giles,

 

There is a safety feature in the Deltang system, the receiver will not "arm" itself ie start up unless the speed is set to zero, which may mean the speed channel pot being at mid point if it is assuming a centre zero speed control as they normally are by default. So this might explain why you had to waggle the sticks - it was waiting for the channel that is normally the speed channel to pass through the mid point. With any of my locos you have to set the speed to zero to get them to work.

 

No idea about the creep though. You can calibrate the Tx to get the centre "off" in the right position on the pot, but you sound to have had an intermittent fault somewhere. Maybe a dry joint problem?

 

Frank

[MickRalph]

I have so far only built the Tx22 kit and am still building my first railcar, so I have no experience of binding the transmitter to a receiver.  However, I wonder whether the "creep" is due to the Rx losing the radio signal and continuing at its' previous speed because of the "cruise control" setting?  I note from the Deltang site that the Rx-61-22 has cruise control enabled as standard; presumably this won't be noticed if the Tx sends out the signal properly, but if the problem with the aerial causes a loss of signal, then the loco will continue running.  It looks as if you can turn off cruise control by a paperclip change.

 

Mick

[Corbs]

Thanks guys.

 

I have fixed the antenna with a length of wire and it mostly works better now.

 

Here is a test with the 3v motor, inertia set to midway.

 

 

What is strange is that it still does the 'runaway' thing, but only if you jam it in to full speed reverse. It doesn't do it when going forward.

Edited November 29, 2017 by Corbs

[Giles]

Giles,

There is a safety feature in the Deltang system, the receiver will not "arm" itself ie start up unless the speed is set to zero, which may mean the speed channel pot being at mid point if it is assuming a centre zero speed control as they normally are by default. So this might explain why you had to waggle the sticks - it was waiting for the channel that is normally the speed channel to pass through the mid point. With any of my locos you have to set the speed to zero to get them to work.

No idea about the creep though. You can calibrate the Tx to get the centre "off" in the right position on the pot, but you sound to have had an intermittent fault somewhere. Maybe a dry joint problem?

Frank

Yes, I'm familiar with that - with the lorries I usually have to waggle the steering first in order to enable arming, as the trim tends to inhibit it. The problem with the crane is that one has the same issue multiplied!

It could be a dry joint perhaps on the RD itself - certainly the rest of the wiring is fine in that respect. It wasn't 'intermittent' in the classical sense - it always occurred after about five minutes - almost as if a static charge built up (I know that's probably rubbish). It can still happen if the operator holds the transmitter box differently and doesn't ever contact the plate.

It's not a practical problem to me, and I shall happily live with the work-around.

[davetheroad]

Has your Rx-61 the latest software version?

 

Have you done any programming on it?

 

Also continuous running on loss of selecta position could last as long as the 'sleep' time. i think the minimum time for sleep might be one hour!

 

Try running the test again with inertia set to zero. All the inertia pot does is 'wind up' the throttle %age delivered from the Tx over a variable time, This works for deceleration as well so if you shift the throttle rapidly from 100% forward to 100% reverse the inertia setting will cause the deceleration to stop and acceleration to full reverse to take a number of seconds, or maybe a minute or so if you have a high inertia setting.

 

There is also an programmable inertia setting in the Rx. This governs how long the Rx takes to go from 0 to 100%. It can be varied between instant and 8 seconds, I think the default is 1 second. You can't change this on the fly like you can with the inertia pot on the transmitter.

[Corbs]

Hello Dave, thanks for the reply. The 'runaway' test did have inertia set to 0, I only had inertia turned up for the video. The Rx-61 is about 2 years old (I think) so doubt it has new software on it.

[fallen]

If the Tx is switched away from the Selecta position, but the Rx does not lose the Tx signal, then the loco will carry on running indefinitely at the same speed setting.

 

I have had an Rx 6, can't remember which model exactly, that responds slowly to a change in the Selecta knob, which sometimes resulted either in slowness in gaining control or the Rx responding to throttle changes after the Selecta switch had been moved to another loco position. It is a loco I don't use except for demos as it's not a scale I have a layout for, so I have not got round to investigating it. It sounds like a problem with the Rx I think, as the Tx is fine with all the other locos, although it might possibly be because a resistor in the Tx Selecta switch circuit is incorrect or on the edge of the tolerance band, which would only affect that particular Selecta setting, or indeed a dry joint.

 

Maybe you have something similar, the Rx is losing the Selecta setting at some point and so just keeping going at the same speed setting? Difficult to see how this would happen in the Rx though.

 

Thinking aloud there, but it might be worth trying binding the loco to a different Selecta position.

 

Frank

[Chris M]

I would be inclined to email Phil at RC Trains (http://rctrains.co.uk/). He incorporates Deltang rc components in equipment he sells and is a genuinely helpful guy who knows his stuff. I had a problem with my tx22 losing its binding and he provided swift and helpful service even though I am a novice on all things RC. I ended up fitting a new tx2 module into my tx22. Even though my tx22 was Deltang Phil was happy to sort things out for me and supply and fit a new tx2 at a reasonable price. I currently run 7 locos from my Deltang TX22 plus have a basic rc trains transmitter linked to one loco.

[Corbs]

Thanks guys. David at deltang has also been very helpful. I am not able to test right at this minute as the chassis is in the vice waiting for some chemical metal to go off.

[davetheroad]

Have you any other Rx's? If so try another one. Fit it plus the battery in a wagon and run the motor leads to the loco.

 

Have you made any paperclip changes?