Glen Ogle

[tedp]

It's quite a good result - I remember the teething troubles you had with the circuit at the beginning of your R/C experiments. The finish on the 3d printed shell is very smooth as well. I have a body shell on order from Tom - I hope I can achieve the same finish you have.

The only thing that still bothers me is the funny chassis still necessary for an R/C controlled loco, but obviously these are early days. The advantage is considerable however. Probably it will be possible to use rod-coupled chassis for an R/C loco some time in the future.

[Graeme Dunbar]

Trail-blazing work there Brian! Hobby and I were discussing RC last time he was in Aberdeen. It certainly has potential. If it was not another project for me to start and not finish I'd give it a go as it would take me full circle to my radio control (glider) days.

For suitable donor chassis I think the key elements are:

1. low current draw for maximum run time.
2. low voltage to reduce the number of cells in a battery and so reduce the size.
3. ease of conversion, though applies just as much to converting to DCC so is no great problem.

In that respect the Kato tram chassis is nice not particularly remarkable. The gearing is pretty crude, just a single stage worm reduction. The most sensitive loco I have is the new-ish Farish 08 which starts on just about half a volt and trundles along on a nice low voltage. I've forgotten what current it draws but it is low. Other good candidates would include Nigel Lawton or equivalent micromotor powered chassis with a good high gear ratio. Crudely put, for electric motors voltage = speed and current = torque. For maximum efficiency the motor should run at rather less than half the stall current and rather more than half the no load speed, i.e. "high revving" and large gear reduction. (For maximum power transfer it is half the stall current and half the no load speed.) Every motor will have graphs like this:
http://www.namiki.net/product/dcmotor/curve.html

Finding the characteristics for a motor is one thing, but estimating the gearbox efficiency and load is another.

It would seem that  many chassis are undergeared for maximum efficiency and possibly undergeared for maximum power transfer. I assume this is (or was) for commercial reasons in that it cost more to put gears in and less for an oversized motor running inefficiently. Old chassis with chunky motors and crude gearing  possibly run nearer stall conditions than maximum power transfer most of the time. Now with cheap low torque micromotors it makes sense to improve the gearbox.

The main thing - avoid old chassis!

[Frank]

Hi Brian,

Good to see you are making such excellent progress.   The loco is looking very good and the performance is good as well.    The Kato chassis are naturals for radio control, they combine low voltage and low current requirements and the low profile makes for useful spare space inside the loco too.

The 08 chassis looks promising too as Graham says.   Older chassis can be more difficult though not impossible, but seem to work better when well and frequently maintained, which can be a chore.

Keep up the good work.

Frank

[gtmspyder]

More pictures of the Kattie loco.

I have now fitted the Narrow Planet engine name plate and makers plates I had made, and I have lined it out using yellow electricians tape cut into strips.



The results as you can see are very poor, despite my care in not stretching the tape before cutting, the tape has shrunk away from the corners making a right pigs ear of the lining.

The other side is better, but does not stand close scrutiny.  Some of the paintwork is poor, especially around the red skirts, and the safety valves are not in line, very annoying.



Over all, I had hoped to do much better, and I am disappointed with myself, I know what is required to produce the model of a standard I would be proud of, but my patience and skill level no longer matches my aspirations, and I don't like having to resort to the two foot rule, and pretend that all is well when I know full well that it is not.

Before trying to assuage my feelings with generous replies, which we are all guilty of to some degree, think on this.  If I was to put this loco up for sale, at a price that covered my materials build cost, how many of you would be prepared to buy it?

Regards,

BrianT.

[DeadHorse]

I submit that all amateur modelling is a learning curve and that we learn by the mistakes made by others as well as those we make ourselves.
You have made some decisions in your modelling that I would not have done - some of them producing results that are much better than my own efforts could have achieved.
You have learned that your painting skills need more work, and that attempting to line out a 4mm model with electrical tape is a bad idea.
So think of what you have gained (experience) compared to what you have lost (time).
Providing that you have not varnished over the lining tape it will be easy to remove and no harm done.
Otherwise it will need a rub down and start again.
You will find that taking time over painting & lining is well worth the effort. The 'quick way' usually proves to be time wasted.
And we all have our ups and downs, so dont despair :-)

[Krizzy]

Brian

Using tape to line out a loco is something I have never thought about. My first attempts at lining was to use my old draughtsman's ink bow compass with enamels. A failure but it was so long ago acrylics were then becoming popular and my problems were solved. Then the quality of some acrylic paints was lost so what was I to do. I turned to FOX TRANSFERS and have used them now for many years. Their range is large covering BR. the big four and many of the old companies. They also do corners, curves and straights long enough for coach sides all in various colour combinations. On many of my models I use BR Express Loco lining in either 4mm scale or 2mm scale on some small locos. I even cut between the orange lines in the black for single orange line edging with the black similar to the old L&B original simplified loco painting.

Using waterslide transfers make the art loco lining so much easier.

Roger 

[gtmspyder]

Hello again,

I have had another setback, while waiting for some lining decals to arrive, I decided to do some work on the Chris Ward double Fairlie 3D print loco.

This was already painted the same livery as the Kattie  tram loco, but still had the various bits of fancy brass to be fitted, handrails, smoke box door darts, number and nameplates etc, and the new lining decals when they arrive.

So I decided to strip the linings I had fitted to the Kattie loco, and give both loco's a dose of spray matt varnish.  I had purchased a new spray tin of Humbrol matt varnish, heated the tin, and shook well, the models were at room temperature as the varnish was sprayed on.

This was the result.



I have only shown the Kattie tram loco as I have all ready stripped the Fairlie back to it's base as this was the easiest to do as it had no brasswork bits attached.

The Kattie loco is at present dunked in a solution of spirit as I type, as this has had to have the Kato chassis removed and the electrics disconnected and photographed to show on here.

I know this phenomena has occurred to others on here, but having read of others misfortune, I thought I had covered all the bases, clearly not.

Your collective commiserations and recommendations are awaited.

I am truly fed up, and it doesn't take much. :(  >:( >:(

Regards,

BrianT.

[Krizzy]

Brian

Have you used a solvent based varnish? I am not one for these 3D models so has there been a reaction with the paint or with the plastic used in the manufacture of the model. Maybe acrylics are better.

If you are going to apply waterslide transfers a gloss finish is advised with matt varnish after.

Roger

[gtmspyder]

I noticed today that the shoebox I used as a spray booth had a white'ish powder where the overspray had landed, vey like very fine flour, and it could be swept into little piles with my fingers.

I have finished cleaning up the 3D loco prints, so I cleaned the powder from my shoebox spray booth, and set too grey priming the two loco's again, and I am currently awaiting there drying.



I have also sprayed a piece of spare black Plasticard with the grey primer, and as I spray the other colours, I will spray a test strip onto the Plasticard.



When I get to the varnish stage, I will test spray onto the Plasticard test piece and see what happens.

There's nothing like a photo to show up cruel imperfections is there?



I thought I had made a good job of preparing the two loco's, clearly, more work needs doing if I am to continue with this magnification of photo's.



Regards,

BrianT.

[clayliner]

Sorry to hear of your varnishing misadventures, Brian, but I am sure you will manage to retrieve the situation and teach us all something useful in the process. Also, your shoe-box spray booth is a useful idea which I will bear in mind, so it wasn't an entirely wasted exercise!

Hoping 2014 starts on a brighter note for you (how's the hip progressing?)

David.

[gtmspyder]

Good new years morning to you David ;D

Thank you for your felicitations regarding my Kattie and Fairlie construction, oh and the hip is going on quite well, still a bit of a struggle with my pants, and the right sock application is a lost art at the moment, but I can get about unaided, and I have done a walk from Baslow to Chatsworth house, a round trip of about four miles so things are on the up. :laugh:

Kind regards,

BrianT.

[tedp]

The loco is looking rather better than last time I saw it, Brian. Only a few marks to be corrected. The spray booth is a good idea although I prefer doing it outside to get rid of the fumes.

I use spray only for the priming stage. Finishing and varnishing is done with a brush - I like the better control it offers, although I always have to be on the look-out for brush marks.

Good to hear the hip is progressing!

[gtmspyder]

More work done on the Kattie and double Fairlie Chris Ward 3D print loco's.

Having stripped off all the previous paint, done a little more smoothing, and added the detail handrails and smoke-box dart handles, I started to re-spray the two loco's with several coats of Grey primer, before starting the masking up ready for the first coat of Blue.



I masked off the smoke-box, which will be black, and the skirts and buffing beams, which will be red, and the cab interior, colour as yet undecided, but possibly green, on the Kattie loco.





With the same treatment for the Fairlie except it does not have skirts.
Three coats of Blue were applied over a period of time, and left to harden, before the initial masking was removed for inspection.



Then the Fairlie was denuded of masking tape.





Then the new sprayed sections were masked ready for the next colour to be applied, the smoke-box black.



That's about it for tonight.

Regards,

BrianT

[gtmspyder]

I recorded this as a Christmas greeting to you all, but could not post it at the appropriate time, perhaps now?

If you click on the picture, and give it time to load, you should see the result of what was supposed to be a Christmas greeting, I did say Merry Christmas at the end, but I have spent a lot of time trying to post it to several friends before the due date, and in doing so, I have chopped off the second verse and greeting, so I will add, " Have a Happy New Year Everyone."



Regards,

BrianT.

[gtmspyder]

The Kattie was the first to have it's blue masked off.



It is a fiddly game doing the masking, and is best undertaken by cutting strips of different width and length of masking tape, and with small pieces of cut tape, mask off the detail first, then apply the larger pieces of tape to just overlap the edges of the detailing masking tape and roughly cover all the exposed areas that do not want painting.



Having sprayed the black, I removed all the remaining masking, before masking again to just leave the to be red area, and back to the spray box for a coat of red around the buffing beams and skirts.



A final gentle rub of the originally applied Brass number and nameplates with the fibreglass pencil.



The roof is only placed in position at the moment as I have to paint the cab interior, which I will probably do with hand painted acrylics, and fit a driver.



Still a bit to do yet.



Regards,

BrianT.