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DT
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EDIT to topic: As this is the ongoing topic on the DJH SAR GMA/M Garratt 4-8-2+2-8-4 model that I've finally started, here is a photo of a very well made model of this type.



I can only hope to get mine to resemble something as good as this.

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Studying the plans for my SAR Garratt - again... and wondering how the connectivity would work out in practice. It is set up as follows with the front water tank being live on the RHS and the rear coal bunker being live on the LHS, so these two components would connect to the two terminals of the motor/s.

I'm not really keen on changing the supplied wheels and getting insulated wheels and adding pick-ups, but would the above configuration be really bad if I plan on adding a DCC decoder to the loco? I think that as long as there are no shorts, then it would work. The boiler body will be insulated from the water tank and the coal bunker.

I'll run the two chassis units around a bit and if they get stuck on any difficult part of my layout, I could perhaps add some pick-ups to the insulated wheels as long as the pick-ups are insulated from the chassis - right?
 

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oah i see, sorry. i asumed that the chassis was live on one side and there were pickups for the other side. i didnt realise that i was only picking up on 4 wheels each side.

i dont see it being a problem. ideally both sides would be insulated but sometimes thats just not convenient. it could be a problem if you plan to couple ot to a loco if the buffers are connected to the other rail! but lets face it, this is a garret we are talking about! you arnt going to be doing much double heading!

Peter
 

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Doug, the DJH NSWGR Garrett I built picked up in the same fashion as you propose but it was supplied with pickups so you could if you wanted to liven up the insulated wheels. I didn't like this method so I replaced the the live wheels with insulated ones and used pickups on all wheels. It can be a bother but I think it's a better method of electrical pick up.

Charles Emerson
Queensland
Australia
 

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Just another modeller
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QUOTE (Doug @ 31 Oct 2008, 00:06) <{POST_SNAPBACK}>Studying the plans for my SAR Garratt - again... and wondering how the connectivity would work out in practice. It is set up as follows with the front water tank being live on the RHS and the rear coal bunker being live on the LHS, so these two components would connect to the two terminals of the motor/s.

I'm not really keen on changing the supplied wheels and getting insulated wheels and adding pick-ups, but would the above configuration be really bad if I plan on adding a DCC decoder to the loco? I think that as long as there are no shorts, then it would work. The boiler body will be insulated from the water tank and the coal bunker.

I'll run the two chassis units around a bit and if they get stuck on any difficult part of my layout, I could perhaps add some pick-ups to the insulated wheels as long as the pick-ups are insulated from the chassis - right?

***Doug, it will work fine as is but it can create problems as follows:

if you have two locos with this form of pickup and they touch while on the track, a dead short is possible. I have seen metal Kadee couplers glow red hot as a result of coupling them!

it can create problems with DCC autoreversers.

if metal detail both ends touches, (ie if the drive unit end details at both ends both touch the centre section simultneously) you can have intermittent shorts.

Generally, these sorts of problems do end up being bothersome with The DJH Garrats.

Simplest idea for lowest cost is to reverse the wheels one end so you have pickup from one side via chassis and phosphor bronze pickups to the insulated wheens on the other. This is equally as effective as "all insulated wheels" pickup wise and as long a both motor brushes are isolated there are no DC or DCC issues at all to consider, and personally I'd do it that way.

BEST idea of all is to use split axles and make both ends as split chassis, so you still have no pickups and absolutley no change of accidental shorts from metal brake shoes etc...but thats a big change from DJH standard methods in many places and whole new set of skills - perhaps a step too far for most builders of DJH kits i think!

Richard
 

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DT
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Well, I have started the model.

I must say many thanks for many helpful posts that members have posted that have given me the courage to start this model. Ozzie and Pedro who recently have given me the starting motivation.

These kits are quite complex and I was aware that they were tricky. I bought the kit in March 2005 and it has been waiting patiently since then. I bought an extra motor and gearbox with the intention to motorise the water tank mechanism as well as the coal bunker mechanism.

I bought the Right Track DVD series (1, 2 & 3) from Tony Wright that sows quite a few useful techniques.

So, here we are and after a couple of days I now have the two driven chassis at a nice stage of construction.

I do realise that this is a kit and I do realise that some extra work is need to get it looking right over and above just sticking it together, but I'm amazed that virtually every piece needs work. The side frames need reaming to allow the bushings to be fitted; the bushings need reaming to allow the axles to be fitted; the square holes on the back of the wheels need to be widened... I thought that with the precision that it is made, the axles would fit the bushings which would fit the frames.

Here below, the bushings are soldered to one of the side frames.


I must say that the instructions are awful. I think that considering the price of the kit, they could have produced a better set of instructions and labeled some of the items in the packaging and electroplated sheets.

There are times when a guess is the best way forward. I can see that more guesses are up ahead...

A view of the instructions.


The two driven chassis with wheels fitted.


The free wheels spin well now and the gearbox runs smoothly. Putting some juice into the motor turns the driven axle perfectly.

Detail of one of the units.


I'm using flux and solder supplied by DJH that works well with brass. That's going well. No problems yet. I just need a better soldering iron as my old clunky one is a bit too fat to solder the studs on the push-rods.

The underside of one of the units.


I've cleaned up the major white metal parts. I'm going to have to modify the front water tank a bit to accommodate part of the motor gearbox that will come out of the rear wall a few mm. Shouldn't bee too much of a problem.

Looking forward to the rest. A bit tired now after sitting hunched up over the work bench. Fingers hurting - getting old. These kits should have a warning: "Not suitable for children under 16 or adults over 40".
 

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That looks alright so far Doug. I'll be watching this with interest as this is the kit that I really want to build. Is this your first kit? Have you had to fork out quite a bit on tools for this?

I'm over 40; should I just forget it?
 

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DT
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Discussion Starter · #9 ·
I make quite a few models and my son and I build RC trucks, cars and planes. This is the first brass and white metal loco that I've done.

I have all the tools thankfully. I just need a better soldering iron. I have a big one and a small one and neither are just right. I'll get one next week.
 

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Looks good Doug. Now is the tome to decide on the pickups before all the brake rigging goes on. Looks odd seeing one with an open frame gearbox. The aussie Garrett as supplied comes with NWSL gearboxes.

Charles Emerson
Queensland
Australia
 

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looking good so far doug.

i realise it might be a little late to say this but you might like to concider high level gearbox that can be cranked so you wont have to chop away the rear of the tank. it woul mean swaping both which you probably wouldnt want to do but its a thought.

the DJH gearboxes do seem to be good though.

i am quite supprised that you managed to get 2 free running units by putting in the bearings before assembling the chassis. you certainatly had luck on your side today doug!!if you do have any problems with that just let me know and i can pop it on my jog.

Peter
 

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DT
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As I said, nothing really fitted at first. It all had to be reamed. So the bearings were soldered on flush and then when the side frames were attached together, I carefully turned a 1/8" reamer through them. They spin freely without jamming and without any play.

I'd love one of those axle jigs, but at over £200, it's a little dear right now.
 

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QUOTE (Doug @ 2 Nov 2008, 08:04) <{POST_SNAPBACK}>I make quite a few models and my son and I build RC trucks, cars and planes. This is the first brass and white metal loco that I've done.

I have all the tools thankfully. I just need a better soldering iron. I have a big one and a small one and neither are just right. I'll get one next week.
Good, I did mean to say brass and white metal kit. I'll see how you get on and assess whether I can start with one of these too.
 

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DT
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Discussion Starter · #15 ·
I've been watching a few of Tony Wright's DVDs on metal kit building. I bought the videos when they first came out and watched them then, but only when you start building these kits do you realise the importance of the principals that Tony Write drums home.

You see his tips and techniques on getting the job done without fuss. Watching the videos does inspire quite a bit of confidence and I recommend them to anyone doing this sort of modelling for the first time.



I've added a link to the DVDs at Amazon at the bottom of our Resources page.

I know that there are more in the series. I haven't seen those yet. I may get them and add them to the list. The First two are about metal kit building, the third is about painting and lining.
 

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Paul Hamilton aka &quot;Lancashire Fusilier&quot;
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Just a query here and by the way thanks for sharing the photos and progress notes. I see that there appears to be no springing or compensation on the axles and you hadn't mentioned how you made sure everything was square in terms of axles in the chassis etc. How did you ensure it is all square and aligned?
 

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DT
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Discussion Starter · #17 ·
The brass chassis are quite thick. They have aligning pins that are held together with screws. Etched metal spacers also are used. Screw it all up and it lines up. No rocking at all when the model is placed on a glass surface. All wheels touching the glass perfectly.

These rigid chassis for the driving wheels don't have compensation, but there is a bogie and a pony of sorts and there is another motorised chassis on the other end with another bogie and a pony so any undulation in the track will be met by these six sprung units.
 

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Wow Doug that chassis looks great. I wish i had the confidence to have a go at kit building!. Mind you i don't have any tools etc for doing kit building so it would be a very expensive business for me to start up in.

Keep up the good work though Doug i am looking forward to your updates.

Regards
Paul
 

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The chassis for the most part is self aligning thanks to the turned brass spacers and the slot and tab spacers. But care still has to excercised as mis-alignment can still happen. Not all the DJH chassis used these turned brass spacers some just use the slot and tab type spacers. Kits like Comet and Southeastern Finecast just use spacers that you have to determine the correct position for and solder in place, then use your chassis aligning tools to correctly align the other side then solder that side to the spacers. It's a more long drawn out method that requires a bit more patience. I haven't tried a PDK or a Brassmasters kit but I would assume they use the same method as Comet and Southeastern.

Garret chassis water tank end


Garrett chassis bunker end

Charles Emerson
Queensland
Australia

QUOTE (Lancashire Fusilier @ 3 Nov 2008, 12:05) <{POST_SNAPBACK}>Just a query here and by the way thanks for sharing the photos and progress notes. I see that there appears to be no springing or compensation on the axles and you hadn't mentioned how you made sure everything was square in terms of axles in the chassis etc. How did you ensure it is all square and aligned?
 
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