...and upgrading too

To my mind, Bachmann's Jinty is one of the best of it's kind.  It looks great and runs even better.  It's perfect for shunting and out of the box will provide quite reliable slow running.




There's not a lot wrong with it, but because I am what I am, I will still find an excuse to make it even better.  I've had Brassmaster's upgrade kit for quite a long time on my roundtoit shelf.  I love their stuff, it's exquisite in execution and always well researched.




The kit also comes with a DVD containing dozens of pictures of the prototype and not just 3/4 views either, lots of lovely closeups.  I'm not sure at this point just how much of the kit I will use.  Another good source will be Tim Shackleton's article in MRJ 160 "Building a Better Jinty".  This article goes into P4 conversion but, more useful to me, it also contains tips on improving the detail.

Now to grab MRJ 160 and have a read.


Oh and one other thing, I plan to utilise a Comet chassis kit.  I will use the frames sandwiched with plastic card to increase the width of the chassis.




There is overlap between this and the Brassmaster's kit.  Details haven't gelled in my head yet.

John

This is interesting John.
Some of the P4 converter,s have also used lead sheet as a chassis sandwich. Both to add weight and as far as I know lead is an electrical non conducting material?
Of course plastic card maybe easier to work with.
Best of luck with this project.
My brother did not turn up today to do the lighting and power sockets in my workshop build.
So a little delayed on the lathe work for those Jinty axle spacer,s I plan on making.

regards,

Derek.

Spooky, I had a premonition that you'd be here

Hmmm, I think lead does conduct, it's used in batteries.  Finding lead in the small quantities I would need (and I'd like some for general ballast work) is difficult I think, since it's considered hazardous.  TBH I haven't made much effort to look. 

This morning I started the teardown and wheelwork.




For completeness, the chassis.  Note the hardwired decoder.  This model is from an early batch before being DCC ready.




Wheels off.  I used the wheel puller (right) and to my disgust the bushes stayed on the axle.  I got these off using a gearpuller (left) and special adapter plate that I cobbled up.

My next job was to measure up and compare to Markits wheels.

                    Markits          RTR

Width            2.44mm     2.72mm

Flange            ~0.6mm     ~0.7mm  (EM calls for 0.54mm, this is critical)

Flange depth      1mm         0.9mm

For a control, I mounted a set of wheels on an EMGS axle as is.  The wheels did go through the test point but I could feel that there was very little clearance at the crossing, which is the critical location.

Next I made a couple of gentle passes on the back of the wheel with a grinding attachment on my Dremel.  I then rubbed the back of the wheel on a wide coarse file.  This was then refined with a fine file, knocking off any sharp edges from the flange.  I repeated the filing until I got a thickness of about 2.6mm.  This gives me an effective flange of about 0.6mm.




The picture shows the reworked wheels on the crossing.  I can "feel" that there is good clearance now.

John

Nice experimental work their John.
Looking at those gear and wheel puller tools.
Reminds me of cycle chain breaker tools for pushing out the rivets on chain links, Hmmm?
Regarding getting lead.
Go to a builder,s hardware supplier and look for lead sheet roof flashing. I have a load from previous building jobs, It comes in rolls.
Or ask them if they have an odd spare length left over?
Of course old church roofs were a happy hunting ground for some people. Not suggesting that route of course.
regards,
Derek.

So, I've reworked all the wheels now and assembled the first wheelset.  It took a bit to get my head around the dimensions but I think we're there now.  I don't think the EMGS axle takes full account of the plastic bush, so that has to be thinned but it must still insulate.

Both my B2B gauges measure 16.3mm, should be 16.5mm so that's a bit of a nuisance.

John

Hi John, Good progress,
The plastic bush, Do you mean the flange of the bush on the inside of the wheel needs thinning?
After the Christmas break, I am going to order some 1/8th axle steel rod from Eileens Emporium, Plus some 3mm and turn some axles to the Bachman profile to suit EM gauge and the Bachman wheels. May save a lot of fiddling.?
regards,
Derek.

Yep, you got it.  The 3mm part of the axle measures 16mm long, so the total thickness of the plastic bush flange can't be more than 0.5mm or 0.25mm each.

Very enterprising of you to make your own axles, but you do know that EMGS axles aren't dear, ~ 1.00 each.  Now making one's own axles for those locos designed with 2.14mm axles may be necessary - I haven't seen any EM ones.  I have a piece of steel rod somewhere (if I could ever find it) that is just a bit larger than that.

John

I have a confession to make John.
I am not a member of the EMGS.
I am a member of the Scale 4 society.
Typical Derek back to front.
If things turn out well with the axle,s ?
If I make a small batch of those 2.14mm ones you will be welcome to a set. I will use silver steel rod.
Oh Eileens Emporium do lead strip for model,s 1.3mm thick in various lengths and widths.
They are a great source for all sorts of things modeling.
regards,
Derek.

For shame Derek! :It's a no no 

I've used Eileen's in the past, very good indeed.  I shudder to think what the postage will be for lead!  Still, I did do a search and found that lead is still used for flashing, so I will have to check around.

Thanks for the offer on the axles, I'd better check to see what I've got with that size.

John

I think I've missed something here John ……………:???::???:

The figures you quote give Markits wheels with a flange of 0.6mm and EMGS calls for 0.54mm.  Does that extra 0.06mm on the wheels make all that difference to the clearance ?

If so, then you're working to much tighter tolerances than I thought ………… :shock::shock:

It was also interesting to see your DCC installation.  I have a pre-DCC ready Jinty to chip at some time but following the trials and tribulations I had with a V2 (even though I was only following John Dew's tutorials), I'm a little reluctant to tackle it ………..:roll::roll::roll:

Hi Peter, I wouldn't get all hung up over the second decimal place, when talking mm's that is really small.  I was simply quoting the spec and was quite happy to get where I am.  Running clearance in 00 and EM is ~0.5mm (this is the difference between the gauge (16.5 or 18.2mm) and the sum of the Back to Back + 2 x Flange Width) and that is what I'm trying to maintain.

eg, for 00 the latter sum is 14.5 + 2 x 0.7 = 15.9 vs a gauge of 16.5mm.  For EM we get 16.5 + 2 x 0.6 = 17.7mm vs a gauge of 18.2mm.

I think Derek and myself are trying to understand the principles here which is why we're doing these experiments.


In the picture above, I think you can see that if the B2B is too small and/or the flanges too thick, the wheels will ride up on the checkrails.  When having derail problems, the first thing to check is the wheel B2B, in my experience, resetting this usually corrects the hproblem.

I really like the engineering aspects of this but I suppose it can get a little tiresome.

John

Thanks John - it was the fact that you ground the wheels down that got me hot around the collar ……………  I'm guessing these were Markits wheels and not the original Bachmann set ……:roll::roll:

The engineering aspect also interests me but my engineering was done with big hammers and not tweezers …………..:???:

Actually Peter, Markits wheels are good to go.  These are the original RTR set and are (I think) to the RP25 spec which includes too thick flanges.  My goal here is to try to make the RTR wheels acceptable and save 30 pounds on Markits wheels.  I actually have Markits wheels in stock and 3mm EM axles for them so if it all goes pear shaped I have a fallback.

I've never actually read about or seen anyone do this before so I want to know whether it's feasible.

John

Ah - that's where the confusion was John.  I had assumed these were the Markits wheels.  Now I understand what's going on. :thumbs

Without looking at my Jinty, do these wheels have that "pick-up rim" for the pick-up wires to run against ?  If so, are you going to replace it or just rely on the wheel itself for power ?

Right Peter.  The wheels are all metal, nickel silver rims and mazak centers (as far as I can tell).  They are insulated by a plastic bush at the axle.  Pickup is by a phosphor bronze strip on the backs of the wheels.  I will need to modify this since the PB strips won't be long enough - something to mull over.

Cheers

John

Hi Derek

Ultrascale do a conversion set of wheels including gears etc. The link below is to the PDF instructions, according to them you should be able to bend the pickups out far enough to reach the back of the wheel sets.

also suggests you may have additional work on the brakes.

Comet also do EM frame spacers - LS10

Peter -  the DCC conversion for the Jinty is soooooo much easier than your V2. from memory - it is liable to muddle things

1. remove body
2. remove capacitors etc.
3. disconnect connections to motor - you may need to remove motor to make this easier
4. wire up the decoder
5. test it
6. refit body - if you cannot fit the decoder you can remove the weight in the boiler - I did this to place my stay alive capacitor

Go on you know you want to do it

Paul

Hi Paul, I am aware of Ultrascale and their stuff is superb.  The big problem is that there is a leadtime of weeks or even months.  I actually have a set of their wheels for my 3F conversion using Brassmaster's Easi Chas.

My preference for wheels for kits is Markits because they are robust and easy to quarter.

New Jintys come DCC ready.  I have installed sound in my BR liveried Jinty (I just need to get rid of the lining that never existed in life).

This exercise is really an exploration of a few things that have been going around in my head, from RTR wheels to laminating Comet frames and plastic card to produce the chassis.

John

 

Today's progress was to prepare the Comet frames.  I am grateful to Tim Shackleton and his article in MRJ 134 for lighting my way.




The idea is to attach the frames and brakes along with all the other gubbins to the keeper plate.  This necessitates making slots so that everything can slide over the wheels.  Not as easy as one might think since the frame would have been impossibly weak without the reinforcing plates - these took quite a long time.

I also made the springs double thickness for looks and strength.

John

This is looking very interesting and showing the way John.
Neat job on those frames.
Tell me, How are you going to handle those sand boxes on the original chassis?
The loco will look superb if it all comes together.

regards,

Derek.

Hi Derek.  I will reuse the old sandboxes and glue them to the frames.  It is a policy of mine to pin whenever I glue, that is, I will drill and solder a brass wire and use that to anchor the boxes.  I'll probably do the initial fixing with cyano and reinforce with epoxy.

I did some more frame prep today, soldering spacer pieces to the inside frames and putting pins in for the gluing to the keeper.




The two main chassis pieces.




Upper chassis fits very snugly between the frames.  They're something slightly over 13mm wide now.  To my surprise the axle holes in the Bachmann chassis didn't quite match those in the frames so I had to do some additional filing.

I did a trial fit to the body and that's looking good too.

John