RobjUK

I use PLA for everything - I got a reel of ABS originally, thinking it may be needed, but I've never had reason to try it. With PLA I've drilled it, files it, reamed it etc. with no problems, it is very tough. However most parts are made hollow, with a honeycomb internal reinforcement - if you try and put holes in at random, you will not have structural locations where you drill. You must build-in the holes in your design, so the 3D-to-print conversion program (a "slicer") can allow for them and include the appropriate structures where needed. Just design the parts to be a direct fit together, with mortise joints / holes / recesses / counterbores for fixings etc. at the required sizes. A decent printer used with a properly set up slicer program will make the parts to exact size. I made a height gauge for something a few days ago and over several versions, the main block was coming out consistently to no more than 0.001" off the design size. I also made a replacement battery box cover for a young relative's toy, complete with locking pegs at one edge and a spring latch at the other, and the first was an exact fit. I use "Designspark mechanical" to create the 3D models, as that's one of the few programs that allows you to set absolute sizes for dimensions as you work. That is free, here, and I'd highly recommend it for precision designs: https://www.rs-online.com/designspark/mechanical-software Some examples of parts with fastening positions and & joints built in - this is a 3D scanner from a Kickstarter project, so someone else's design, but printed on my machine. The nuts are and exact push fit in hex recesses and all the holes and countersinks for the screw heads are printed in. The swivel joints for the laser line modules just push together then clamp with screws and the "cable chain" elements are all identical and just snap together. You can also see the internal grid inside the shell in the thin crossmember in the first photo - that's all done by the slicer, you just design the parts you want and the slicer software adapts them so the printer turns them out correctly. I did not really bother cleaning anything up much before assembly & the slight gaps with a couple of covers are due to them only resting in place.

I agree, print with holes in place. I can get reasonable results down to 1mm holes, I've used them as pilot positions for slightly larger drillings when I've not been sure of the final size required. eg. The large holes in this are 5mm, the small ones 1mm:

There are a few 1:43 trucks in die-cast, but the prices are a bit steep! eg. https://www.ebay.co.uk/p/IXO-Model-Trucks-Ford-Thames-Et6-1953-British-Railways-1-43-Scale-Tru018/8028535702 https://mclaren-models.com/index.php?main_page=product_info&cPath=762_765_1583&products_id=14875

That is exactly right, the tip will be at the set temperature. Think power, not temperature. With a non-TC iron, you start trying to heat a sizeable workpiece and the the tip cools down as there is no more heating power available. With a TC one, the element power has backed off to a low level once it's at the set heat and idle. As soon as something tries to to cool it down, the element power ramps up to compensate and try and maintain the set temperature.

If you mean these - http://www.gaugemaster.com/item_details.asp?code=GMC-PM1 The switch part is electrically separate from the solenoid "motor" connections, so you can run the point control and track from two different power sources without any problems. The switch can be used to direct power to the frog, control signals or whatever you like - even on yet another separate power system, if appropriate.

Once you get above a certain size of parts, it gets beyond "soldering iron" practicalities, if you also want neatness. I have a 150W monster, which I tries to use for some chassis work on my first brass kit - it was slow and very! messy. There is just not enough heat transfer through a small contact area between a bit and a large area of brass sheet. The Antex can get large pieces hot enough for small area joints, given time; the big advantage I find with a TC iron is not so much the heat setting as the fact the power ramps up to full as soon as you touch the bit to anything that draw heat from it. Even that is still messy in some circumstances though, as an area the size of the bit is the smallest that can be used to transfer heat. For small parts or low temperature solder on any size part, it's unbeatable! For brass edge joints or trim parts where I don't want any externally visible solder, I now exclusively use solder paste applied very carefully on the back or along the end of the butt joined part, plus a blowlamp to provide the heat - the joint is flowing within 5 - 10 seconds, with virtually nothing visible away from the joint line.

I use an Antex TCS240 for a lot of varied work, both electronics and brass/white metal etc. - and I never change the setting, it's at about 2/3 scale on the pot.. The printing wore off a decade or more ago, I don't know what the actual temperature is. With low melting point solder or white metal, the time the bit is in contact with the solder varies the amount of heat transfer. I find that the tip being very hot allows the surface of the parts to get heated enough for solder to flow well, without heating the bulk of the pieces. With a lot of smaller parts I can do them whilst holding them in the correct position. I do use a lot of flux (6% phosphoric acid, made from 75% rust remover diluted 11:1), which probably also helps regulate the heast as it starts to boil away. For electronics or small to medium brass parts, I use 0.7mm tin-lead flux cored solder. For larger items or assembling sheet brasswork, I use a miniature blowlamp and solder/flux paste.

Polyurethane wood glue - there are many brands, including a Gorilla one. (Look for the translucent brown stuff). It expands slightly as it sets, so use very sparingly. Also make sure you can clamp parts solidly while setting. Or, "Mitre fast". Thats a cyanoacrylate plus activator kit. You mist one part with activator spray, apply the glue on the other and hold them together for a short time. You can apply a run of glue inside a joint angle and mist with more activator to instantly harden it, to add reinforcing fillets if needed.

There is also an 0-4-0 Ruston-Hornsby with a sloping cab, quite similar to the PWM in the earlier post See the second photo in this link: http://ukrailways1970tilltoday.me.uk/Lincolnshire_Wolds_Railway_2011_three.html?LMCL=PJgmpN Still differently proportioned to the matchbox one though.

Hi, there is a recent thread on the subject of glues suitable for polystyrene, here:

I'd highly recommend the Antex Gascat 120. If you buy it in the kit you get multiple sizes of soldering bits, hot air, blowlamp etc. I've had one for probably around 15 years & some of the original bits are still good, though I have replaced a couple of the smaller ones. Example: https://cpc.farnell.com/antex/xg12pkt/gas-soldering-iron-kit-120p/dp/SD00866

Hi Dave, that same place does miniature motors down to 4mm diameter, or a motor plus worm gear kit for building in to other things. eg. https://www.sol-expert-group.de/1zu87modellbau/Motor-und-Getriebe/Motoren:::48_66_67.html https://www.sol-expert-group.de/1zu87modellbau/Motor-und-Getriebe/Getriebebausaetze/Universalantrieb-fuer-Mikromodelle-1-20-bzw-1-30-Untersetzung::1103.html

That's why I also said:

If you want to be safe, just put a bit of reasonably thick flat steel against either side of the magnet itself, so they bridge the top and bottom plates. That will provide a decent magnetic circuit if you do need to remove the armature from the polepieces.

In principle, if your layout works as it is with a conventional controller, everything powered and no shorts, then connecting a DCC controller to the same wires and putting a DCC loco on the track should "just work".. It should need less isolation and section switching than with a conventional system running two or more locos, as with DCC they run on exactly the same power connections, rather than different sections & controllers as with DC / conventional power. I'd suggest you first decide what style of controller/throttle you want - eg. a desktop / console unit or hand-held throttles, plus how many locos you want to run or control at the same time.

The most fundamental difference to traditional control is that the track is permanently powered and the speed control is done within each locomotive. Think of it a bit like a TV remote control system; the command in that is sent by rapidly turning on and off an infra red LED. In DCC, the track polarity is rapidly reversed to send the coded commands. The loco decoder both rectifies the track voltage and monitors the timing of the reversals to decode what commands are being sent, and if they are addressed to itself or not. All the complex stuff is taken care of by the DCC controller / "command station" and the loco decoders and at a minimum all you need to do with a new loco or decoder is set it to the address you want, often the loco number. A lot more info here: https://dccwiki.com/DCC_Tutorial_(Basic_System) The hardest part is probably deciding what make of controller setup to go for! (I use a Digitrax Zephyr, and all-in-one controller / command station / throttle, but I'm more interested in the mechanics and engineering and do not have a fixed layout at all, so the limit of I think 20 locos does not bother me..)

If it's purely a digital data connection and not a current-carrying cable, anything up to tens or even hundreds of metres should make no difference. Using a shielded twisted pair will reduce the possibility of interference. If you use Ethernet cable as WIMorrison suggests, that should work fine - but make sure you use one pair for the data and a separate wire (or pair joined together) for the ground/common connection. I have seen people parallel pairs in multi-pair cable, thinking that will make it work better; it does not... A single pair RS485 type cable could be smaller and neater than Ethernet. If you need a lot of the stuff, a reel of this would be appropriate - it's purpose made data cable, rather smaller than Ethernet and stranded core: https://www.ebay.co.uk/itm/VANDAMME-GREY-SERIES-1-PAIR-100M/351543309187?epid=1139229544&hash=item51d99d3383:g:dgYAAOSw1JVaG~iC (That's cheaper than we have been paying from trade suppliers...) Or, If you only need around 3 - 5m, you can have an offcut for the cost of a stamp.

Anything like these any good? https://www.hannants.co.uk/product/ML80134 http://www.langleymodels.co.uk/acatalog/Shop_Front_OO_Cranes__Heavy_plant___Road_Machinery___RW1_RW21_36.html

It's a Loksound V3.5 - see the photo at the bottom of the page here: http://www.esu.eu/en/products/former-products/loksound-v35/ You need a 100 ohm speaker for that one.

I'm using this style in my 7mm deltic: https://www.ebay.co.uk/itm/Gdstime-2507-25mm-25x25x7mm-Micro-Cooling-Fan-DC-5V-PC-Computer-Laptop-Cooler/222323580268 The fan outer body can be removed to leave the blades and motor. Do you have enough space to remove the blades as well, and add a scale fan on top, with eg. motor hub painted matt black or spaced down slightly? Or, something like this - a miniature motor and configurable gearbox: https://www.sol-expert-group.de/1zu87modellbau/Motor-und-Getriebe/Getriebebausaetze/Universalgetriebebausatz-G243-mit-Motor::1096.html Or any other miniature gearbox they sell? https://www.sol-expert-group.de/1zu87modellbau/Motor-und-Getriebe/Getriebebausaetze:::48_66_68.html I've not used that first one, but to put the sizes in proportion, this is the top left type from the second link: [Edit - just realised that plastic kit one is the odd one out on that page, it's massive compared to the others..]

I think you have a typo there - 500V not 5000V!

They look promising, I hope everything works OK!

Interesting - I'd not seen that one, only the MERG stuff and other that did not support 8 pin PICs. I'll give that a try, thanks. (Though designing and programming electronics is both my main hobby and profession).

Thanks Michael. I'm not totally happy with some bits, but I think it will clean up OK and look reasonable when painted. It is the first brass kit I bought and I have learned a lot in the process of building it! Plus doing bits on the Deltic in between times, with quite a bit of back & forth between the two model as I've found info or discovered different methods & sources of info or materials.

Indeed, that's why I like them, no surface mount needed! You can even get a 16MHz PIC16 in a eight pin package now, eg. PIC16F18313. I've been messing about with those to make an absolute minimal accessory decoder, but not finished yet due to other higher priority stuff. The debugging status LEDs and connector for ICD3 take most of the space on my test rig board: