7mm: A Tale of Two 40s

[ZiderHead]

Coincidentally, I have a DJH 40 to refurb - that one is far too heavy for comfort.

Hi Richard

Any idea how much it weighs? Ive been looking at the DJH kits and the body castings look very hefty indeed. When you say refurb I assume its not one you built yourself, I'm trying to find out how they are to build up and haven't managed to find any online builds apart from Christian Cresswell's Tower/DJH warship which appears to need quite a lot of work just to get the body sorted.

 

[Phill Dyson]

Hi Richard,

the pony truck dictates that the smallest radius is 6' 6" I had a great time getting things sorted. Getting the pony truck right was the key.

Cheers

Mike

Any further details on your pony trucks Mike?......would also be useful to the WT Peak builders

 

[Steph Dale]

Hi Richard

Any idea how much it weighs? Ive been looking at the DJH kits and the body castings look very hefty indeed. When you say refurb I assume its not one you built yourself, I'm trying to find out how they are to build up and haven't managed to find any online builds apart from Christian Cresswell's Tower/DJH warship which appears to need quite a lot of work just to get the body sorted.

Jon,
I've got a DJH Deltic on order with much the same concerns in the back of my mind...
Steph

 

[Ressaldar]

Any further details on your pony trucks Mike?......would also be useful to the WT Peak builders

Hi Phill,

nothing specific I'm afraid, just a lot of filing and polishing to get the truck running freely really. A few general photos taken during the build which might help.




cheers

Mike

 

[Dikitriki]

Hi Richard,

the pony truck dictates that the smallest radius is 6' 6" I had a great time getting things sorted. Getting the pony truck right was the key.

Cheers

Mike

Hmmmm, that will be a problem. I really need a comfortable 5' 9''. I'll have to see what I can do.

I must say your 40 looks really good.

Hi Richard

Any idea how much it weighs? Ive been looking at the DJH kits and the body castings look very hefty indeed. When you say refurb I assume its not one you built yourself, I'm trying to find out how they are to build up and haven't managed to find any online builds apart from Christian Cresswell's Tower/DJH warship which appears to need quite a lot of work just to get the body sorted.

Hi Jon.

No, I didn't build the DJH 40, though I have built (nearly finished anyway) 2 warships, and I do think they look really good. Indeed, Brian Hanson gave one of them the once over and couldn't find much wrong with it. There are a lot of mould lines to get rid of, and on the warship they were in the most inconvenient positions around the cab windscreens. There was a hell of a lot of preparation before I got building for real. I took lots of photos, but they must be on an old drive as I can't find them at the mo.

The DJH 40 weighs in at a whopping 8 lbs. It really is too heavy for comfort. Indeed, at the moment there is no movement in the bogie (ie it no longer clears the body round curves) as the mounting points (white metal) have, I assume, sagged over time. I shall have to strengthen/rebuild the mounts at the very least.

Cheers

Richard

 

[ZiderHead]

The DJH 40 weighs in at a whopping 8 lbs.

Blimey!

 

[Ressaldar]

Hi Richard,

many thanks, I built it for a fellow Club member, since sold on to swell his coffers.

I'm sure that it should go down to at least 6' - but that is some wheelbase.

cheers

Mike

 

[Dikitriki]

Hi

I have amended the thread title as here seems an appropriate place to consider the refurb of the DJH 40. I remember when the DJH 40 first came out - I thought it was fantastic and had a huge presence about it. Our paths never seemed to cross until I picked up a well-built one off Ebay; well-built but poorly running. Not a problem, as I reckoned I could deal with that.

I must confess I wasn't expecting the weight of the thing. It only had one motor, the gears were well-worn and the bogies didn't have clearance to swing under the body.My initial intention was to keep the bogie sideframes as they came and just rebuild the innards - hopefully a quick job I could get done in a week so Tim could chip it this coming weekend at the next Heyside workday. No chance.

I already had 2 of the big DJH motors in stock, and I reckoned this would be a good use for them, especially as the kit was designed around them, and I reckoned 2 of them would have the grunt to shift an 8lb lump of Pewter.

So, I removed the bogies from the body, and the inner chassis from the bogie sideframes. No problems until I had a critical look at the inner frames.



The leading unpowered axle is not in a truck. It just runs in the inverted 'U' at the front. Worse, the height is such that the leading and middle driving axles were not taking any weight. I am for the moment leaving this design as is, but have filed the top of the 'U' so that the leading axle is not taking any of the weight at all. Instead it is free to move laterally and go with the flow. Tests have shown that it should take my curves, but it's a bit early to be happy.

The middle driven axle was very slightly lower than the outer 2 driven axles, so the bearing was filed to a very slight oval so that all driven axles rested on plate glass without rock - I did actually use a chassis jig; see below.

And finally, one of the rear axle bearings, the ones directly driven from the motor, was, how shall I put it, somewhat of an agricultural fit.....



No wonder the gear mesh was all over the place.

I managed to extract the bearing using a microflame without disturbing the cast white-metal brake shoes, and replaced it. This is when I used the chassis jig so I know it is square. I tidied up all the brake shoes, sorted out the paint blemishes and resprayed...



I have ordered some more delrin cogs, and I am going to make it a proper 1 Co Co 1, with all 3 driving axles driven. It should have amazing pulling power, far more than I need, but we shall see.

Richard

 

[Steph Dale]

I have ordered some more delrin cogs, and I am going to make it a proper 1 Co Co 1, with all 3 driving axles driven. It should have amazing pulling power, far more than I need, but we shall see.

Richard,

I shall be interested to see how you get on. In previous models I've been a bit wary of sideplay on Delrin driven axles - it doesn't seem to take it very well, but you may well be alright providing you're not allowing too much sideplay.

One other quick thought is that with that much weight to haul around you might be better off running with fewer axles driven; the adhesion and mass is going to put a tremendous load on the motor and that first driven axle. Keep an eye on the motor(s) too (assuming you've got the Buehler motorising kit*) when you get the chassis running; it may look a thug, but it's not much more powerful than a Canon 1833...

Taking those two things together I'd be using nice, simple four-axle drive I think, but I admire the approach you're taking and look forward to seeing the (positive) outcome.

I also wonder if the loco is supposed to use the same approach as my Deltic, which comes out the packet with a set of oversize bearings to allow the middle axle to float in a slightly half-ar$ed fashion. I wonder if the original builder put the bearings in the bogie frame in the wrong order...?

Steph

* I note that DJH are now recommending use of the Slater's/Mashima 1833 drive for its diesels; that must be somewhat underpowered in a loco of that weight.

 

[Rob Pulham]

I also wonder if the loco is supposed to use the same approach as my Deltic, which comes out the packet with a set of oversize bearings to allow the middle axle to float in a slightly half-ar$ed fashion.

That would be the same as the tender axle boxes on my A3 and not knowing any better at the time I used them as is. - But I did get them in the middle

 

[richard carr]

Richard

I bought and built a DJH 40 when they first came out. Mine is powered by 2 RG7 motors (the 23:1 version) with delrin drive to the other main axles. It runs very well, albeit a bit slowly.
You can get plenty of side play so getting it go round 5'9'' curves shouldn't be too much of a problem. I wouldn't worry about the brake shoes you cannot see them on the finished model, you don't even get any in a JLTRT kit.

Richard

 

[Dikitriki]

Hi Richard

Thank you for that information. What did you use for pick-ups? It's a bit of a pain finding an appropriate location and route for the wiring bearing in mind the necessity of keeping the sides clear to attach the bogie sideframes to the inner chassis, and the fact that the chassis bottom plate can't be permanently attached as access to the bogie screw is needed.

Richard

 

[TheSnapper]

Hi Richard

Would it be possible to use the "American" system, with each bogie live to one side of the rail?

Tim

 

[richard carr]

Richard

Mine is battery powered using Red Arrow so it doesn't have any pickups.

I tried using the American system on an MMP 40 but inthe end I added wire pickups to the insulated wheels and it did improve performance. They were just connected to pcb glued to the top of the inner chassis.

Richard

 

[Steph Dale]

Richard,

I tried posting a while ago (android-related fail), but was wondering about using copper clad to replace the keeper, or perhaps just stick some on the top of the bogies (or keeper-plates) and use springy wire pick-up?

Nice and simple. The neutral chassis arrangements are good for DCC too.

Steph

 

[Dikitriki]

Tim, Steph

I'm inclined not to enliven the chassis for 2 reasons. First, the movement of the pony wheel, being linear, is likely to be more than one would like, so the risk of a short is higher. Second, the pony axle ends extend through the bogie sideframes, and again, there is a risk of shorts.

I had already considered wire pick ups on top of the chassis, and think that that is going to be the easiest, if inelegant, route, and will be mostly hidden behind the bogie sideframes. The concern here was that they might get too close to the bottom of the body with the swing of the bogies. I just wondered what others had done....and Richard's radio control is a real cop out in that respect. His 40 must weigh a ton though with all the batteries and RC gear .

Richard

 

[richard carr]

Richard

Yes it is very heavy even without the batteries so make sure your track is strong enough to carry it.

It works though and as there are no pickups there are no risks of shorts.

The MMP one is pretty heavy too as it needed plenty of lead in it to get the necessary traction, the same goes for my JLTRT one.

Richard

 

[Dikitriki]

Hi Richard

Since you have the DJH, MMP and JLTRT 40s, would you care to say which you think is the best model? Being primarily a steam enthusiast, they all look pretty impressive to me.

Richard

 

[Dikitriki]

Hi

After some more ordered destruction on Heyside (will someone take that bl**dy Lancashire mill book off Allan), an update on the DJH 40.

A review of the bogies showed me some niggles I couldn't accept, so the decision was made to strip them - Nitromors followed by a cellulose bath - and they came up well.







The bits I really don't like are the jaunty angles of the sandboxes, the sand pipes and brackets (the brackets I will straighten, the pipes I shall get from David Parkins as his come with the traps), some springs are askew, and the footsteps need straightening out/resoldering. Everything is of soldered construction, the components are nicely cast, so it's really a case of quietly going round and adjusting.

I also think the design of the bogies is flawed. Surely there should be a box of etched brass/nickel silver for strength. I have no objection to soldering on detailed white-metal overlays, but the whole thing as is lacks rigidity. Also, part of the body framing is cast into the bogie sideframes, along with the etched brass detail. It looks odd, but I don't propose doing anything about it.

The jury's still out about stripping the body.

Richard

 

[mickoo]

Looks nice but I hate saying this, but your side frames are too wide, they should not line up with the side of the buffer beam, they are inset by roughly 1.8mm You might need the extra width for wheel side play in S7 for 60" curves but I doubt you'll need it in FS for 72" curves



However if you don't do that, then I beg of you, please please please at least remove the casting flash from the top of the bogie side frames.