chris251

Thank you Ian, Phil, and Simonmcp, I'll buy a jar of maskol, that does sound much better than masking tape, and leaving black all over the back except windows to reduce light bleed is a good idea. and yes makes sense to paint a layer of white in between the black and yellow so the yellow doesn't come out too dark, I'd have been kicking myself for forgetting that! will try to remember to post some pictures to show how it goes...

I'm (slowly) building a Bratchell Models class 150, painting it in the new Transport for Wales livery. I'm stuck for how to paint the cab fronts - they're a 1 piece clear plastic moulding including the glazing, gangway, windowframes, and all the other detail. I plan to use Revel enamel paint. Picture showing the cab end, though its hard to see the detail because its clear plastic (there is a cutout for a lighting board in the back, and a few moulding pips on the back) My guess as to how to paint it is: drill out the headlights (I'd like to fit working LEDs anyway) mask off the window glazing and back then airbrush in mat black, allow to set for a few days, then remove masking tape mask off the window glazing and window frames, and mask gangway connection airbrush with yellow paint I'm worried that I'm likely to make a mess of the paintwork, it's going to be very difficult to get all the masking neat particularly around the curved window frames. Has anyone got any other suggestions for how to do it? Any ideas would be appreciated.

Thanks for the advice I tried Isoproponol alcohol, and it does lift the acrylic varnish, but was worried it can also lift transfers, so avoided using it on the transfers leaving some acrylic varnish being over-coated with enamel. I'd already painted over the acrylic varnish with enamel gloss cote (thinned with white spirit) before seeing these answers, and it's not lifted anything - hoping it won't gradually start to lift and ruin things at a later date! When you mention enamel solvent lifting acrylic, do you mean white spirit, or acetone/xylene as the solvent? - acetone/xylene seem to thin and lift almost any paint and I hate using it, so always use water or IPA for acrylic and white spirit for coach enamel. Some enamel spray paints include acetone thinners, but Humbrol gloss cote from a jar uses white spirit.

I made the mistake of airbrushing Humbrol acrylic varnish to some models today. The problem is that the varnish I used was number 135, satin finish, and it made the models all cloudy and greyed/whited out, and yet being modern prototypes, they need to be shiny. The satin varnish is much duller than the satin Pheonix paint below it. This might be caused by a matting agent, but enamel gloss cote varnish doesn't dissolve it completely, and I would like to replace the acrylic varnish for enamel gloss cote Does anyone know how to strip acrylic varnish without damaging paintwork and transfers? (Paintwork is all enamel apart from the black door seals which are acrylic), and the precision labels transfers which are coated above and below with acrylic varnish - I'm not so bothered about ignoring the varnish on transfers as a slight difference in finish on the transfers won't be so noticeable. Also, would it create a weak-spot if the acrylic varnish can't be removed completely and so lies under enamel varnish in corners?

Yes I tried mixing the darker blue from Humbrol paints, and found they turned out too grey (not impressed with the quality or colours in this range recently). Also on that RMWeb topic, I read that Rail Blue is a fairly good match, and (I wished I could go out to see the train but that would mean a long trip, it was lockdown then and no guarantee of seeing Arriva colours because most are now Transport for Wales livery - was lucky to see some ready for re-painting in a rail yard from the train on the way to work), rail blue does look right to me - a dark turquoise. (assuming the Mk3 coaches use the same dark blue as the 158s). A dark turquoise can be mixed by mixing Vallejo turquoise and a black, but I was painting the rest with enamel so I decided to use Pheonix rail blue.

I originally tried Vallejo turquoise but found the shade too dark, but I've just tried again at mixing Arriva turquoise from Vallejo paints, and it is possible to mix a very good shade by mixing Vallejo turquoise with Vallejo light turquoise and yellow. (the turquoise is the base colour, the light turquoise lightens it slightly (and makes it more blue) and the yellow lightens it and turns it turquoise again, without 'greying' it out, the result is a lighter shade of turquoise without 'greying' it out.) Annoyingly just adding white tends to 'grey' colours rather than making them lighter, which is why I added yellow today. Maybe I'm just being picky, but I'd say that Vallejo can be used to make a good Arriva turquoise, but it's a good idea to mix several colours not just use one. The darker blue I've used is Pheonix rail blue, and that seems to look about the same as your choice of MA087. For the doors, I've used Humbrol number 47 ('sea blue') not sure if this is available as acrylic but their paint colours are not accurate to the colour chart or the tin, and their colours can differ between batches, so a different supplier might be better.

I've just bought some of Nigel Lawton's square belts, and run a simple test with the same mechanism just swapping the belt, and measuring the electrical current going into the motor at various voltages: with the o-ring (6.7mm diameter by 0.7mm cross section), the motor runs at 30mA, (at 6V) wheras the square belt (6.5mm diameter by 0.6mm cross section) runs at 20mA, (also at 6V) and from the pitch of the sound of the motor, it also runs faster and more freely with the square belt fitted. Result - Nigel Lawton's square belts seem to perform better than o-ring belts.

Ever since I discovered flywheels, I've always thought they made a wonderful difference to running. I'm not able to afford some of these brand new RTR items for sale now, so I've always been looking for ways to improve my existing locos. However, I'm inclined to agree about the importance of a good motor and suitable gearing: All my attempts to the Hornby railroad 0-6-0 chassis never worked very well. I tried simply modifying the motor to double-ended shaft and adding a flywheel, this improved things, but wouldn't start smoothly or run very slow. I tried replacing the motor with a 5 pole Tenshodo 19mm motor, but again, not very good without a flywheel, and a bit jerky with flywheel, but crawls better. Older-tooled Bachmann class 158s run very well at a decent speed, but cannot crawl very slow - they are fitted with a centrally mounted large 5 pole strait wound motor with 2 flywheels, gearing is single-stage 1:7 gearing, gears are coarse, the pickups are quite high friction and the trailing coach has plain bearings not pinpoints. The motor is good at slow speed, but I think the gearing should be at least 1:14, and the split axles could have brass bearings instead of wiper pickups. Their new 158 seems to use pinpoint bearings, and split axle pickup. I motorised a Dapol railbus kit, and with 1:50 gearing, and a motor with flywheel, it is quite loud, but crawls beautifully, and rolls about 12 inch or more when the power is cut from a scale speed of about 50mph. I've also been modelling 009 and found that a flywheel is often hard to fit in, but again the important thing is free but not rattly gearing, good pickups, and a good motor (often the only motors that fit are tiny 3 pole motors, some of these are very good and run very slow). Generally, flywheels work much better at higher speeds. If you're building the mechanism, by doubling the gearing, the motor has to run twice as fast to achieve the same same speed, so the flywheel will have 4 times the stored energy (stored energy is proportional to the square of the speed, 2 x speed = 4 x energy, 3 x speed = 9 times energy). A tiny flywheel which just smooths the engine across dodgy pointwork seems to crawl much better than an enormous flywheel which keeps the engine rolling when the power is cut. Also, don't assume a 5-pole skew wound motor will be the best - some cheap ones are worse than 3 poles and won't run slow at all. As for an analogue keep-alive, I've tried without much success - it needs so many electronic components to make it work well (including a tiny computer chip) and the capacitors need to be about 0.5 Farad at 10V to have an effect on a newer motor, they'll do almost nothing for an X04. My opinion is to fit in a small flywheel if possible but also make sure everything else runs smooth and free.

Thanks for the quick replies, I was thinking if I should use the spur gears instead. by round and square belts, am I right in assuming you mean when located on 'V' profile pulleys? The pulleys I'm trying here are 'V' profile and round profile belts.

I've recently bought a set of pulley and drive belts to fit into a 009 model engine I've been building. Because of space constraints, the motor (8mm x 16mm 5 pole coreless) has to drive a layshaft, which then drives another layshaft with a worm gear, which drives a coupled axle. The belt drive is located between the 2 layshafts, and I also have a pair of gears which can fit in the same space as an alternative to the belt drive. For some reason, the belt drive causes about twice as much friction as the alternative gears, is this normal for a belt drive? - lots of people seem to fit belt drives directly off these motors without trouble, but this seems to be causing far too much friction. The belt is 6.7mm internal diameter x 0.7mm round cross section, the pulley root diameters are 1.75mm and 5.2mm, and the spacing is 6.0mm, calculating this gives an 11.1% stretch to the belt. Does anyone have any advice on how to reduce the friction caused by a belt drive or am I best to just use the alternative gears?

Did anyone ever produce replacement glazing strips for the older tooled Bachmann class 158? I like to fit interior lighting to my models, and the original glazing always looks too black (and LEDs have to be very bright to be visible then they leak light), so was wondering if anyone has heard of a replacement glazing - moulded or laser etched.

I might be interested in a coach (can't have more than a 5 car train on my layout but got 2 centre cars so far) if there's any still left for offers

For Dapol models, look on dccsupplies.com, they're Dapol's official spares dealer, so you can find pictures of the motors for certain models, if they're a flat-can type they're likely a 5-pole iron cored motor, if they're cylindrical, they're possibly coreless - coreless motors are a cylindrical can because the static magnets are located in the centre, not around the outside, with bearings in the centre to house the shaft. Both the Dapol 73 and 121 are flat can motors, so likely 5 pole cored, the GWR streamlined railcar is a flat can motor with flywheel too (I had the club one to pieces once to repair a broken pickup wire). The earlier batch of Heljan Garrets are coreless motors (about 13mm diameter by 30mm long, one motor in each coupled end) Newer Marklin z-gauge pacifics use coreless motors.

I'm exited to see that the new Kato tram chassis includes a coreless motor and flywheel, but just how is it put together I'll have to buy one some day, but not had an excuse yet... Are the axles running on the metal block, or are they attached using pinpoint ends to the pickups,? And are the pickups the typical very thin 5thou phosphor bronze or are they structural in the bogie? I'm wondering because if the axles run on the metal block, and the pickups just pick up current, or if the pickups are actually thick enough metal to support the weight of the train on top without the sideframes fitted, then I could modify one to make an outside-framed steam or diesel shunter for 009 gauge.

Thanks for the reply, I hadn't even thought of Railmatch. Not so sure what would happen if I airbrushed Railmatch enamel onto Pheonix enamel though - most likely nothing problematic. Out of interest, what colours have you used for the turquoise and the doors? I've not yet reached the doors, was wondering whether to try Humbrol number 47 (a pale gloss blue), but might have to buy a new tin anyway if mines dried up, so might as well buy a better shade if a better shade exists.