OO gauge J94 Austerity Tank locomotive

[Signaller69]

I would say the lner/br J94 ran with red coupling rods but trying to find a colour photo of one clean is difficult so trying to decipher through the grime like on this one which I won't say more about this loco.

 

https://www.flickr.com/photos/knoxrj/8869652040/

I know this is b&w but certainly suggests red rods with grime cleaned off? http://farm9.static.flickr.com/8290/7787532702_2872f7aff6.jpg

 

Hth

Martyn.

[bertiedog]

What were they thinking of, trying to run without any chimney? presumably the skirt is still in place above the blast pipe, but the draught through the smokebox must have been way down. I suppose just before scrapping, so nobody bothered to repair it. The red rods have been reproduced on many previous models of the Austerities, so there must be a definitive answer out there, or are people confusing the "private" owners with BR on this point.

Stephen.

[PMP]

 

 

I don't quite understand the comments in the review quoted about not being able to disassemble the chassis etc., as I have taken it apart and examined all the parts, which are typical of most FE productions in mechanical terms. The screws are all removable with the correct type cross head screwdriver,

 

Mine runs through Peco code 75 points, and Peco code 83, and handmade points, no striking of the frog, and for the life of me I cannot see how the rods would influence the flanges,

 

 

Coreless motors.....buy a modern controller, do not expect to run on a 40 year old design controller.

 

 

 

Overall the loco is fine, I am not going to comment on details like steps etc., fitted on a Thursday afternoon 50 years ago in the works shop.

 

Stephen

 

Stephen

The reason I can't undo the chassis is explained in the review.the screws are overtightened so they will not undo. I provided a picture of the poor quality hardware used as fittings on the review, I used to supply F1/Le Mans and other racing teams, aircraft manufacturers/repair organisations with hardware, so I do know what a good screw is. You appear to have assumed I would use an incorrect tool for the job.

 

The frog strike occurs on two points, a curved radius streamline electrofrog point where the frog strike occurs on every movement fore and aft, (more noticeable travelling forwards) and a medium radius point on occasion when travelling forwards. The back to backs aren't correct (marginally too tight). Other stock and motive power works fine, which implies the fault is likely to be somewhere with the chassis of this J94. Its quite simple regarding the crankpin issue. There is such limited clearance on it that when it moves laterally it pulls all the other wheels sets across with it, due to the fixed coupling rod. It's of note that the frog strike occurs primarily on this wheelset with the restricted crankpin clearance.

 

Controllers, I have a Gaugemaster 'W' it works just fine on this, I made this quite clear on the blog post. No one that I'm aware of has made any mention of coreless motors being unsuitable for DCC use ... 

 

As far as detail vs the prototype depicted, there are a myriad of examples on this site alone of RTR manufacturers across the scales that have products that do not match the prototype, either in livery, detail configuration or both. Try the Dapol 08 thread for a start. It's not unreasonable to comment on a review whether the product matches images of the real thing.

[Porcy Mane]

Not very good for after-market chimney sales either.

Dunno about that. If you want the prototypical J94 gap between the top of the tank the DJM chimney has to go and a replacement fitted but here's me repeating myself.

 

Steam Locomotive 68078 Widdrington Disposal Point 19.9.87 by cigcardpix, on Flickr

[Signaller69]

I'm glad controller type has been mentioned, do the instructions say anything regarding analogue feedback controllers as they are what I use; I seem to recall in the distant past that coreless motors should not be used with this type of controller?

 

Can a J94 owner clarify please?

 

Thanks,

Martyn.

[Bernard Lamb]

Interesting reading.

On taking the link to the review I immediately noted a familiar "house style".

I shall follow the instructions of AY and say no more.

Several of the points raised were covered in my earlier post and as I wrote others were mentioned by several people.

Regarding the use of an ancient controller. Would it be legal to sell one of these without a current test certificate? I am sure it would cause comment if it came up at an auction. Or have I been watching too much day time TV where they remove the wiring from old electrical items.

As for the big hole in the coupling rods, That was new to me. You can see it if the loco is doing less than around 10mph and then for about 25% of each revolution. Not a big deal for me.

I have come across several rather more expensive German locos that do not like Peco curved points so nothing new there.

I also first came across German locos with coreless motors around 1992, so nothing new in there.

The idea of all wheels driven and a lower weight does seem rather novel. What affect it has on haulage capacity remains to be seen but mine seems to be adequate for the class of load that the original version was designed to handle.

A big machine with full outside valve gear built on the same lines might be interesting. As long as I don't have to put up the money for the development.

My only real issue after all that is the lack of under tank steps.

As for the red rods. Take a look at 65469 around 1960.

Bernard

[Les1952]

Red rods?

 

There aren't all that many colour photos of J94s in BR service but those that do exist show rods that filthy it isn't easy to tell whet what colour they were originally.  Red is less likely as they largely seem to be the same shade as the wheels.  On the other hand there are a lot more photos of J94s (real and pseudo) in PRESERVATION with red rods than otherwise, and the ex-BR loco at Widdrington Disposal Point definitely had red rods.

 

When it comes to industrials there are an awful lot more with red rods than black, with a couple of yellow or amber thrown in for good measure.

 

Hornby's 68062 is being used by some as a comparison with the DJM 68023, and this has red rods!

 

Hope this rubbish helps.  Again, rods can always be repainted/weathered if you want to change them.  We ARE supposed to be modellers after all.....

 

Les

[Izzy]

It has always been the reccomendation, (coreless motors have been around for many decades - used to be called 'instrument motors' - and often fitted by select modellers well before they became more commonplace in the late 1980's with the arrival of the Portescap motor/gearboxes), that coreless motors need simple/non-feedback controller DC current ( DC feedback is mostly low frequency), due to their efficient nature/fast response, which means they over-react to low frequency output i.e 'jittery' performance. Basically the low frequency feedback 'hammers' them - a good technical term - overheating being a common occurance. Modern DCC decoders provide high frequency output - some provide a choice of frequency - to overcome the issue which can also effect efficient 'normal' motors in the same manner, and allow decoder motor parameters to be tailored to each individual motor.

 

I am surprised at the comments regarding the fixed coupling rods and the loose fit around the crankpins - except it would seem with the review sample. The fitment of these is I feel a natural consequence of a chassis with all-geared axle drive, and the gearing backlash that results. Basically the coupling rods are just there for cosmetic purposes and go along for the ride, so need to not affect the gearing, but the challenge - which N gauge users have had to put up with for decades, coupling rods going along at 'funny angles' - is getting the coupling rods to appear mostly straight and level, and fixed rods help with this, for using pivoting coupling rods with loose pivot joints - as many RTR locos are fitted with - can make it seem as if the rods are going in wierd directions and angles to each other and just look 'wrong'.

 

Izzy

[Flyingscotsmanfan]

I've got two DJM J94s and three Hornby ones and I must say the running is so much better with the DJM ones than the Hornby. The ex Dapol ones were very nice for the day but have been crying out for replacements and finally we have some from a new manufacturer and as a first model I am very impressed. There are of course refinements that can be made but can anyone tell me of any model that doesn't need any refinements? Personally am looking forward to more from DJM in the future. So well done Dave for an excellent first model!

[railroadbill]

 

On performance it is very good, it handled 30 wagons plus brake van, and could have taken a few more, but I am using four foot radius track, not setrack curves, or massive inclines. The max incline is about 1:80. All the stock has pinpoint axles in brass bearings, with RP25 or near profiles.

 

Coreless motors.....buy a modern controller, do not expect to run on a 40 year old design controller. On expense, use the old controller to supply AC to a rectifier and regulator board, about £4/5 or so from Ebay, or build one for about £2/3. I would agree that you should not use a Relco unit on coreless motors.

 

It is no problem on DCC to run coreless motors.

 

Thanks for conducting a proper test on the haulage capacity of the model.  30 wagons should be more than ample (it will be up to hauling my long 3-link coupling rake).  I always find it useful in reviews, indeed vital,  to have the running of the loco tested and all the factors commented on.  Tells you what to expect when it's on the layout. There are some youtube vids showing J94s running well.

 

 

Re DC controllers  and coreless motors, the issues have been well covered above. However I'd like to say that I've got   H&M Commander and Clipper controllers. These are "pure" dc and just vary the voltage.  I've had  them since the 80's to run kit built locos that had RG4 (coreless) motors fitted. So nothing new of course with the coreless issue.  Still in use (when layout not in DCC mode).  Other DJM locos with a similar motor, such as BWT work very well with these controllers, from very slow crawl  to reasonable running speed. The BWT has run well over 20 hours so far with no motor problems.

So in my experience, older control equipment can be satisfactory provided it's the right spec in the first place.

[Vistisen]

Quote from my future brother in law "I did think about buying one, but I own a real one" it turns out that he has bought shares in the Bodmin railways J94

[The Black Hat]

68023 of 51A has arrived here in the land of 51F. On first inspection the model looks very nice. Lovely appearance and character that's been captured well. Very much a fan of the extended bunker to look that bit different. 

 

Just waiting to sort Wilbert now. 

[bertiedog]

By older controllers, I meant half wave types, not straight DC, although even these DC types may have poor rectifiers and smoothing, (if fitted at all), which gives a 50 hertz wave to the DC, and this is enough to make a coreless motor noisy. The early HM controllers can be modified to add modern rectifiers and smoothing capacitors, but they will not then pass testing for shows.

 

With feedback controllers with PWM the frequency of operation must be higher to get the system to work with coreless, they will run, but can behave oddly.

 

Plainer PWM types will work, but coreless motors are noisy due to the pulses.

 

The best type of controllers for coreless motors are plain voltage regulators, with added capacitor smoothing. Little or no noise making wave is transmitted to the output.

 

Stephen

[Edge]

As I've said in the Hattons thread - very impressed with the engines themselves and the finish on them is exceptional.

 

My sole comment on something to be improved actually relates to the foam insert of the box - it's too close at the bottom and the engines cannot be put away with their couplings in situ.

[Brian Hawkins]

I've purchased J9406 a week or so ago and now in the last few minutes have added J9409 and J9404 by phoning a certain retailer in Liveroool, stunning Models, if Dave Jones reads this posting I think you owe me a very large pint of Carlsberg me old mate :-) top work Dave and thank you for a truly stunning model.

[alexl102]

Question: As someone who is intending to purchase one or two of Dave's models once funds are availble, what is classified as an 'old' controller which is not suitable for use with these models? I currently use the standard Hornby train set black single controllers with the red control knob (https://hattonsimages.blob.core.windows.net/products/R965_1.jpg); will I need to invest in a newer controller to run one of these?

[Hilux5972]

I'd say yes that is classed as an old one but I don't imagine that the newer version is any different internally.

[AJ427]

As I've said in the Hattons thread - very impressed with the engines themselves and the finish on them is exceptional.

My sole comment on something to be improved actually relates to the foam insert of the box - it's too close at the bottom and the engines cannot be put away with their couplings in situ.

I actually rather liked the foam insert - snug but secure and it also works as a loco cradle.

[DJM Dave]

Hi everyone,

The reason that the couplings are not fitted in the loco on delivery but in the box, or a groove cut into the foam to allow for the loco, fitted with couplers to go back into the box is a simple one.

 

It's to comply with drop testing.

 

It was found that if fitted with couplers the foam could distort slightly bringing damage to the loco. By removing the couplers and filling the gap left for the couplers with foam, drop test certification was passed.

 

Cheers

Dave

[bertiedog]

By old controllers I mean 1960's 1970's HM with half wave control, or equivalents from other makers, or plain designs using selenium rectifiers and no smoothing capacitors, but these are only identifiable by test opening and running on a scope to see the wave form.

I have never checked the Hornby as to operation internally or the circuits used.

[Broadway Clive]

I'm puzzled by some of the mechanical choices that were made with this loco. As the coreless motor cannot cope with normal analogue feedback, HF track cleaners, or older DC controllers, this loco will have a handicap on many analogue layouts. With DCC it is possible to fine tune the feedback to suit any motor so surely there is then no performance difference between this and the latest conventional motors, so why have coreless?

 

The drive to all axles when the wheels are linked by side rods is unnecessary in '00' and stops any vertical movement that can otherwise help with electrical pick up and surefooted-ness over pointwork. On trials of 68023 on my layout it repeatedly derails on a Peco Streamline code 100 3 way point that has uneventfully been in situ for over 25 years, so I'm wondering if the gear drive is the critical factor here.    

[Porcy Mane]

With DCC it is possible to fine tune the feedback to suit any motor so surely there is then no performance difference between this and the latest conventional motors, so why have coreless?

 

Whilst I understand the point you're making  and have sympathies for those that still use older and less sophisticated controllers,  the fitting of  coreless motors has to be a forward step. With the visual improvements to detail and accuracy that modern design and production techniques have brought to models over the last couple of decades surely we should expect the same improvements to the unseen prime mover and drive train. I've never heard of anybody wanting to fit an engine from a Model T into a Ford Focus.

 

Whether the unconventional motor and drive train design DJ models has chosen for their 4 mm steam models is a success or an improvement, only time (and sales) will tell.

 

A bigger worry for me is that, should a spare motor be required a good few years down the line, spares will not be available.  I guess, the motors are currently being mass produced in China with their model rail use being only secondary. Once the primary use for these motors is lost and production moves on, will spares still be available? Unlike the old X04's and bulldogs the modern generation of motors cannot be re-magnetised and rewound but does anybody do that anymore?

 

P

Edit to correct un-predictive text.

[RedgateModels]

Unlike the old X04's and bulldogs the modern generation of motors cannot be re-magnetism and rewound but does anybody do that anymore?

 

Erm, yes

 

www.redgatemodels.co.uk

[Butler Henderson]

Thought I had posted this this am but seemingly not:

 

Postie arrived with mine yesterday 

 

On the subject of oiling would a light labelle grease be better on the gear train?

 

The instructions are pretty slim - no explanation for example of the inside valve gear moulding, how to fit it and which way round, for example.

 

A new query - where does the harder foam cradle fit when its repackaged?

[No Decorum]

Thought I had posted this this am but seemingly not:

 

Postie arrived with mine yesterday 

 

On the subject of oiling would a light labelle grease be better on the gear train?

 

The instructions are pretty slim - no explanation for example of the inside valve gear moulding, how to fit it and which way round, for example.

 

A new query - where does the harder foam cradle fit when its repackaged?

I think what you refer to is the piece of foam, the legs of which make contact with the sides of the front of the smokebox. Its purpose seems to be to protect the delicate smokebox handles.