7mm Diesels

[HealeyMills]

Oh dear, its finally happened - I took the plunge and purchased one of the JLTRT 7mm diesel loco kits. As you will have seen from the title this is to be 40118. I have never built anything in this scale before and its a little daunting to say the least.

The details so far: 40118 xb LO BR Blue circa 1981, disc headcodes, with no frost grille, Long-short-long boiler grills, two brackets either side of the door catches. I initially thought that 40118 had its number on one nose end but after trawling photos it seems I must have been mistaken for either 40012 or 40058! If anyone knows anything I've missed or have a correction to the aforementioned please feel free to add to the list.

After posting here before, trying to research the ins-and-outs of the kit and how to build it (JLTRT Class 40), I've been busy purchasing components:

[squeaky]

I would love to build something like this, but can't seem to find the time or money!

 

Keep us posted on this one looks to be an interesting build and good luck.

[brian daniels]

Oh good, caught another one You got to admit that cab just screams at you, 40! Hope you enjoy it and needless to say any problems the combined knowledge on here should sort it out.

[the penguin of doom]

Looking forward to this one......

 

I'm going to have a JLTRT Peak as soon as I can afford it.

 

Cheers.

 

Sean.

[two tone green]

Will be keeping a watchful eye on this as I'm on the edge of getting one as well.

[Gazza]

Take your time it will be worth it in the end Im on my second, if get stuck talk to Brian Daniels

[gronk the shunter]

The JLTRT 40 looks to be about the best you can get (to my eyes at least) in any scale. Please keep us posted with your progress - I'm getting one of these for Christmas - and will be following your thread closely!!

[iploffy]

got one of those myself excellent

 

Ian

[Ark Royal]

Shame JLTRT don't venture into the 4mm market that looks absolutely fantastic.

 

Watching with interest on your progress

 

Good Luck

[HealeyMills]

Ok, so far... erm not very far actually. I have decided to start with the bogies and running gear so I folded the gear boxes, inserted the brass bearings, gears and test fitted the motors with their worm gear:

 

 

A test fit with the motors attached (I know they are upside down I was just trying to ascertain how much room I needed to the gearbox and how to fit them) and I ended up with this:

 

 

Having looked at the alignment of the brass gear (the fact that I needed a few washers as spacers), I thought that turning the left hand bearing around would help alleviate this and provide space along the remainder of the axle for the 10T sprocket. With a little bit of re-soldering (now it looks a little untidy at the moment) and filing the brass gear sits nice within the gearbox and turns very smoothly with very little sideways movement:

 

 

With the Delrin chain in place (ignore the files holding the gears/ sprockets in situ) it seems to be coming together:

 

 

However, I have now hit a stumbling block as to how I will fit the motors. I appreciate that one way would be to cut away all the plastic/ resin from the bogie directly above the gearbox for the motor to attach to. This would be simple but would allow the motor body to rotate about the axle. So I was pondering whether to put a spacer between top of gearbox and bottom side of the bogie frame, drill out any excess plastic prohibiting the screw and worm gear alignment then try to attach the motor through both spacer and existing bogie plastic to the gearbox

 

Any suggestions???

 

Cheers

Lee

[brian daniels]

Cutting a hole out of the top of the bogie is fine to put the motor through. So long as the hole is not too big, for and aft, the motor will only move until it hits the frame which so long as the hole is not over size will be ok to support it.

[HealeyMills]

Hi Brian,

 

Thank you for your words of wisdom - I was a little reluctant to just use the bogie bodies to provide stability to the motors against the turning force. Obviously it is the best way forward.

 

Whilst busy scratching my head I decided to do a little brass folding and soldering:

 

 

Hope to start cutting tomorrow, I will then be able to fit the motors to the gearbox.

 

Cheers

Lee

[boxbrownie]

Lee.......don't forget to wear a mask when cutting/filing the resin castings......that powder is nasty stuff!

 

You probably already know, but well worth reminding peeps every so often.

[HealeyMills]

Hi David,

 

Thank you for the reminder/ warning.

 

Cheers

Lee

[Michael Delamar]

great stuff, I cut mine away, just so it fits snug as Brian said

[HealeyMills]

Had a productive day yesterday as I managed to fit both motors to the bogies. Following Brians words of wisdom I decided to start cutting away at the bogie mainframe to allow the motor to be fitted to the gearbox. It took a little while to do and I soon became skilled at drilling holes in succession :

 

 

 

Finally after lots of filing, testing, re-filing and re-testing they both fit very snuggly indeed with no hinderance to the axle motion and no movement in the motor about the axis of the axle. Both gearboxes run smoothly but I have no doubt that some adjustment will be needed at some point:

 

 

And now for something, well not completely different, but nonetheless I need to start trying to put the pony wheelsets together. I had to use the JLTRT Class 45 build instructions (excellent they are too) for guidance. I'm just missing two pieces I think????

 

 

I understand that the white metal curved sections hold the axles/ bearings. These as a whole should (but don't and need a considerable amount of filing) fit inside the brass box type castings with the pins(?) holding them underpressure from a spring. The cover fits on the brass box holing it all together.

 

The question left to be answered is ..... where are the small round collars that afix to the pins? I did wonder whether it may be better to use a couple of small nuts and bolts rather than the cast brass pins, adjust as necessary then loctite them??? Hmmmmmm

 

Cheers

Lee

[ian@stenochs]

Hi,

 

There are no collars, they are not needed as the plungers are retained by the whitemetal axlebox which is itself held in by the brass cover to the guide. Just check that the springs are reduced in length so that the poney does not carry too much weight and lift the front of the bogie.

 

Happy modelling,

 

Ian.

[HealeyMills]

Ian, thank you for your reply. You are quite right that no collars are needed - once I put the unit together I realised that the springs are help in place as there is no room for the pins to retract totally into the pony axle casing.

 

However, once assembled I'm not sure that there is sufficient movement in the pony wheels. The photo below shows how I have filed the whitemetal axle retainer to allow it to fit inside the pony axle casing:

 

 

There is movement about the vertical as the springs allow the axle retaining box (whitemetal) to move. But there is little if any movement fore-aft of the pony wheels/ axle. It's as though they are rigidly fixed about the horizontal axis.

 

When fitted to the bogie the unit seems to sit well and fits like a glove but I am not sure whether the lack of movement will de-rail the loco. I haven't permanently fixed anything yet as I'm now back at the head scratching phase!

 

 

Any comments please feel free to post

 

Cheers

Lee

 

PS Brian - I have to work this weekend so it is very unlikely that I will make Warley

[brian daniels]

Shame you can't make Warley

 

You WILL need side to side play on this axle as the 40's are a very long wheelbase. I must admit I have never seen a whitemetal part like yours with those "wings" stopping it from sliding from side to side. Hopefully you can see in the attached pictures that mine have not got those bits on.

[HealeyMills]

Brian - thank you for your swift response. The white metal parts were very similar to those you have pictured but they were rather large and I had to file away (both concave and convex sides) a lot of metal to get them to fit. As a result of all the filing I was conscious that there was a chance of weakening the ends that hold the bushes for the axles. Hence in order to retain the axle I had to reduce the amount of filing towards the ends.

 

Perhaps I can file a little more away making a more abrupt transition to the ends so that the axle retaining unit is free to move within the brass retaining box. This will give the pony wheels more side to side movement.

 

Do you fix the bushes in with superglue or do you leave them free?

 

Hope Warley goes well - if my circumstances change (as occasionally they do) I will turn up... I'm sure I will find you if that is the case

 

Cheers

Lee

[boxbrownie]

Hi Lee, thats odd your white metal castings, mine like brians are just parallel (albeit curved ) with the brass pony truck "runner" casting and slide completely freely, in fact if the wheel assembly isn't installed the WM casting just slides straight through. Which of course gives plenty of side play.

 

I did it cockhanded naturally by assembling the brass casting first with the top plate fitted then installed a pin and spring one side held with tweezers and just slide the WM casting in, this held the spring/pin assembly one side while I just did the same with the other spring/pin and slide the WM casting all the way in, sounds hard but in fact was such an easy way to install the springs and I could fine tune the length of the springs until I had the pressure correct very easily.

 

No warley for me either I am afraid, as "dan'ear" we have the Shoeburyness MRC event this weekend.......never mind at least its a good show at an easy venue to access!

[brian daniels]

If I were you Lee I would give JLTRT a ring next week and ask for the correct whitemetal bit as It looks like yours are from something else. The correct part is numbered MM 414501

 

I did put a spot of glue on my bearings so the axle goes round in the bearing and not the bearing going round in the whitemetal!

[boxbrownie]

 

I did put a spot of glue on my bearings so the axle goes round in the bearing and not the bearing going round in the whitemetal!

Me too, and when totally dry and secure I reamed the bearings inline to give a lovely smooth action, but I am still playing around with motors gears and delrins tonight, stuck out in the freezing shed fuddling around......might look for a different motor g/box combination this weekend not that there is anything wrong with the set up I have now, its just I have to fuddle and in pursuit of a chassis that will crawl slower than walking pace I am forever tuning, tweaking and easing.

 

I should be happy with what I have now....but hey ho, thats the fun of this hobby!

[HealeyMills]

Wow, great service from JLTRT. Ordered part Nos MM 414501 yesterday and they turned up today. Unfortunately I've just discovered that I don't have any spare time this week (thanks work) but next week I shall have plenty to make some headway with this kit.

 

I was thinking of soldering the brass cast lid to the box section - as opposed to using one of the JLTRT adhesives. I'm assuming that because its brass I don't need anything special in terms of solder (145 deg) and its not likely to melt like whitemetal parts do. Is this correct?

 

Always questions, questions, questions from this thread, people will stop tuning in!

 

Cheers

Lee

[boxbrownie]

I used a thicker cyano for the brass pony truck (after all there is no real load involved), I think if you solder it and at a later date ever needed to dismantle it, it would be much more of a pain than just popping it into boiling water for a while, or even dare I say use one of the "glue buster" concoctions.

 

And as I said previously there is no need to fiddle with two springs and pins in position with the WM casting while you glue/solder the lid of the pony truck into place, you can assemble the pony truck first before installing the springs and pins very easily.