KRModels announce a GT3 Model

[Wagonmaster]

7 hours ago, John ks said:

It sounds like there may be an internal short in the loco/tender wiring possibly between the Motor (orange) to the RH rail pickup (red) or the motor (grey) to the  LH rail pickup (black) 

The blanking plug joins the Motor (orange) to the Rh rail pickup (red)

& the motor (grey) to the  LH rail pickup (black)

Test the resistance (with the blanking plug & decoder removed ) between the motor & rail connections. There should not be a low resistance on any of these tests (M+ to Rail+  & M- to Rail- you could also do M+ to Rail- & M- to Rail+)

My guess for the most likely places for this sort of short to happen would be the mother board in the tender or the connecting plug/socket between loco & tender

Do these tests from the tender

If the test fails with the loco, tender uncoupled then the short is in the tender

If the test passes with the loco, tender uncoupled  then the short is in the loco

 

I have had this problem with at least one loco where a badly installed pick up wire was touching a motor connection

The loco worked OK on DC but destroyed a decoder on DCC

 

If you don't feel comfortable doing these tests then it might be time to contact KR to make a warranty claim

John

 

Thanks for your reply John. Yes, I'm guessing it is a short somewhere between the track and motor feeds. I'll follow your suggestions and see what I can find over the next few days.

[chris p bacon]

39 minutes ago, Wagpnmaster said:

 

Thanks for your reply John. Yes, I'm guessing it is a short somewhere between the track and motor feeds. I'll follow your suggestions and see what I can find over the next few days.

 

Just to add a note of caution.

 

In trying to ascertain a fault you may be invalidating your warranty.  If your models tests for a short without taking it apart then that's probably ok, but if you have to start delving inside then you might invalidate your warranty should there be a fault that could be attributed to the disassembly of the model.

[scots region]

@KR ModelsHow long will the second production run be and will you let us know when the stock gets low?

[Wagonmaster]

1 hour ago, chris p bacon said:

 

Just to add a note of caution.

 

In trying to ascertain a fault you may be invalidating your warranty.  If your models tests for a short without taking it apart then that's probably ok, but if you have to start delving inside then you might invalidate your warranty should there be a fault that could be attributed to the disassembly of the model.

 

My GT3 is a DCC Ready version.  Therefore I have to take the tender body off in order to fit the decoder. Hopefully that won't invalidate the warranty as you have to take it apart to fit a decoder! 

 

As I mentioned, it runs fine on analogue dc, the fault only appeared when the decoder was fitted.

 

However, I do acknowledge your note of caution.

[Pre Grouping fan]

36 minutes ago, scots region said:

@KR ModelsHow long will the second production run be and will you let us know when the stock gets low?

 

I believe the 2nd run is the same as the first where its made to order. 

[truffy]

6 hours ago, gordon s said:

Those that put in high bids and then refuse to pay make a mockery of eBay.

No more than the scalpers.

[mattkimster]

2 hours ago, Pre Grouping fan said:

 

I believe the 2nd run is the same as the first where its made to order. 

 

Having been pretty gutted to have missed the first run, I got my order in straight away this morning for the second run! 

 

The proposed delivery date of September is a lot earlier than I had expected too, so a bonus that there is something else to look forward to in 2021. 

[Georgeconna]

21 hours ago, Colin_McLeod said:

 

Sorted. 

did you get a mail Colin, Still waiting here myself, Second name is Norman so close to you.

[stewartingram]

Having had the email invitation to purchase, I ent through the process, but when it came to payment the site went round in circles. I've emailed KRM direct, but wondering what went on?

 

Stewart

[Retro_man]

2 hours ago, stewartingram said:

Having had the email invitation to purchase, I ent through the process, but when it came to payment the site went round in circles. I've emailed KRM direct, but wondering what went on?

 

Stewart

 

I also went through the process and at the end it said 'error with validation code', however I did receive a notification from my card company that there had been a charge. There was no confirmation email from KR so I have emailed KR using their contact form to ensure the order has actually been placed.

 

Steve

Canada

[Colin_McLeod]

3 hours ago, Georgeconna said:

did you get a mail Colin, Still waiting here myself, Second name is Norman so close to you.

 

I e mailed Keith and all is well.  Keith had agreed to fit a decoder for me and he advised me that he is concentrating on getting the boxes out to customers then he will fit my decoder and send out the loco.

 

I had forgotten that I  had approached him and paid for a non sound decoder and fitting.

 

If you are concerned send a quick e mail to KR Models.

 

Colin

Edited March 31, 2021 by Colin_McLeod

[Pre Grouping fan]

25 minutes ago, Colin_McLeod said:

 

I e mailed Keith and all is well.  Keith had agreed to fit a decoder for me and he advised me that he is concentrating on getting the boxes out to customers then he will fit my decoder and send out the loco.

 

I had forgotten that I  had approached him and paid for a non sound decoder and fitting.

 

If you are concerned send a quick e mail to KR Models.

 

Colin

 

I had similar experience, I upgraded via Keith after hearing the sound project the last Warley but ended up getting a silent model, contacted Michael and one will be sent out to me in due course. 

[Wagonmaster]

More on the 'shorting' problem with a Zimo MX638D being fitted. An examination of the wiring revealed that two plugs on the PCB were transposed. These were the two 2 pin plugs at the loco end of the tender PCB, i.e. the loco track feed and the motor supply. Swapping these around cured the problem.

 

Now GT3 works with the Zimo decoder and I am now addressing the lighting problem.

Edited April 1, 2021 by Wagpnmaster
Typo

[John ks]

40 minutes ago, Wagpnmaster said:

Swapping these around cured the problem.

2 things

first  you got it sorted

second Thanks for letting us know what the problem was.

 

its a bit disappointing when a thread ends with "sorted"(or just ends ) & with no explanation on how it was sorted

 

When i get an email showing mine is on the way & it arrives I will know to look out for this problem when i go to fit a decoder

 

John

[Hilux5972]

Happy to report GT3 has arrived in my hot little hands. Can’t wait to get her running this evening. 

[boxbrownie]

10 hours ago, Wagpnmaster said:

More on the 'shorting' problem with a Zimo MX638D being fitted. An examination of the wiring revealed that two plugs on the PCB were transposed. These were the two 2 pin plugs at the loco end of the tender PCB, i.e. the loco track feed and the motor supply. Swapping these around cured the problem.

 

Now GT3 work with the Zimo decoder and I am now addressing the lighting problem.

They probably will see it in here but just in case might be a good idea to message KR Models to make them aware of a manufacturing error.

[Colin_McLeod]

5 hours ago, boxbrownie said:

They probably will see it in here but just in case might be a good idea to message KR Models to make them aware of a manufacturing error.

 

Likely they will discover that when they fit my decoder!

[Philou]

Just to say that mine was factory fitted with sound and worked out of the box - was the issue 'sorted' then or is it an intermittent issue in assembly?

 

To add that last Saturday, I took mine to the club where they have more than a yard of track set up to enable testing to be done under DCC. There was an 'oo-er' moment as nothing happened, nor to any other chipped loco. Turned out that there was a loose connection twixt the Roco hand-held and the track. Once sorted, it worked! However, the members present couldn't work out what was the 'problem' with the sound as there was no 'chuff-chuff'! I let them think about it for a few moments.

 

Insofar as the lights are concerned, I decided to let it ride until I get my ECoS fixed and I shall fiddle with F0/F20 at my leisure.

 

Looked good and went well.

 

I await the Fell and the Leader as and when.

 

Cheers,

 

Philip

Edited April 1, 2021 by Philou

[boxbrownie]

1 hour ago, Colin_McLeod said:

 

Likely they will discover that when they fit my decoder!

Not if it was an assembly error by a particular workstation employee, it might only be a tiny percentage of the production, or even just a few.....but better fore warned.

[zr2498]

?

 

??

[Philou]

@zr2498 The bottom one in your post appears to be a kit body on a rather old chassis - possibly H/D though the pick-ups remind me more of Triang/Hornby ones. It looks quite good for a kit, but looks unrefined in terms of detail around the front end. (Modern injection moulding against cast whitemetal).

 

Cheers,

 

Philip

[zr2498]

1 minute ago, Philou said:

@zr2498 The bottom one in your post appears to be a kit body on a rather old chassis - possibly H/D though the pick-ups remind me more of Triang/Hornby ones. It looks quite good for a kit, but looks unrefined in terms of detail around the front end. (Modern injection moulding against cast whitemetal).

 

Cheers,

 

Philip

You are correct. Kit on Triang chassis. It was in the description. I hope the buyers have scrolled down the page! It is not KR models - timing is spot on.

[Philou]

I should have gone to Specsavers! I just looked at the pictures and didn't scroll down further - just as well I wasn't bidding for it!!!

 

[Hilux5972]

So I’ve had a chance to get mine out and give it a good run. I found 2 predominant issues.

 

1 was the bogie derailing. I went to remove it and found that it was screwed on so tight that it couldn’t swing like it was supposed. Also on top of the bogie is a small lip about 2mm high that circles the opening for the mounting screw. I shaved this off and now it runs like a dream. Also removed the coupling and turned it around as well. 

2nd was the front wheel set on the tender hardly had any play and this derailed the front of the tender. Upon removing the wheels, I found that on the ends of the axles that go into the side frame, was a little washer on each side. Removed this and the tender now glides along without the slightest hint of derailing. 
 

1 more minor issue is the blanking plugs for the head code discs need painting on the back other wise the light shines through. 
 

Beyond that, it is a cracking model and sounds amazing! 

[Wagonmaster]

More work on GT3 trying to solve the lighting problems. Firstly the front tail lights. Two issues, they are white and they are on all the time. Some investigation of the circuit board with a multimeter revealed that the they are connected to the Ground pin, so on all the time. They should be connected to the F0(r) pin. They are white quite simply because it is a white LED illuminating them! So, I decided to rewire the circuit board. This involved cutting the wire marked NF close to the plug. A separate wire was soldered on to this to extend the wire so I could put a resistor in series, a 2k one in this case. Another wire from the resistor was carefully soldered to the F0(r) pin on the decoder plug. I also took the decision to have switchable tail lights, so that I could turn all of them off when hauling a train. This involved cutting the rear tail wire and re-routing it, along with a 2k resistor in series, to Function Output 2 on the decoder plug. The picture shows the modified board.

 

The resistors are placed back on the board to clear the decoder. The DCC chip was inserted and the loco tested. A bit of remapping of the functions was required so that F1 controls Function Outputs F0(r) and 2. The lights behavior was also modified so that the front and rear tail lights came on and off in the right directions. F2 now controls the cab light which is Function Output 1. F0 remains unchanged and only controls the headcode discs. This was fairly easy in DecoderPro.

 

Now to turn the front tail lights red. Very simply, I cut a small rectangle off a Quality Street Strawberry Delight sweet wrapper, which is clear red and stuck it over the lower LED! The photograph shows the wrapper and the LED housing.

 

The result of these modifications can be seen in the photo below.

 

 

Now for the red cab light. All I did here was to glue a white SMD LED to the underside of the cab lighting circuit board and move the wires from the existing red LED to the new white LED. In the event, it was too bright, so I added another 2k resistor in series to reduce the brightness a bit. The results of this can be seen in the photo below.

 

 

Sorry for some of the blurry photos, but I hope you get the idea. So now I have all the correct colour lights. They operate in the fashion expected. The tail lights can be turned off when hauling a train. And finally, the cab light is white. 

 

Hopefully you will find my modifications and how I did them useful. A word of caution though, this will probably invalidate your warranty!

Edited April 3, 2021 by Wagpnmaster
Adding photos