What would you do in my situation enclosing cab unit

[bc6]

I'm working on a kit and basically done with it however I want to add LEDs to it and possibly a DCC decoder. My dilemma is whether I permanently close up the cab after installing the lights and possible decoder. What would you do after painting and detailing the cab going forward, Are there temporary adhesives I can use. Below are pics of the chassis in question. 

 

 

[cteno4]

Hmm I guess screws from underneath are out as truck in the way. Going to be a lot packed into that cab!

 

the usual removable glues I use on plastic are plain old PVA (white glue) glue and E6000. PVC is a stiff joint that with some pressure just pops off most plastics and then bits sticking can be easily scraped/rubbed off. You can also loosen it with some moisture, but on the cab with motor I’d say just pop it off with some pressure. E6000 is sort of like a stiff rubber cement. It doesn’t bond completely with most plastics and can be pried apart and excess bits scraped/rubbed off. Using a small wood stick works well to rub off excess glue bits. Fingernail art supplies call these “orange sticks” they work great to clean bits of glue off without much potential of gouging into plastic that a metal tip can.

 

pairs of small neodymium magnets in each corner could also work. 2mm dia x 1mm thick ones hold pretty well to each other. Would be some work to get the ones on the cab mounted well.

 

with this the way to get access at the motor I would definitely not permanently glue the cab on.

cheers,

 

jeff

[bc6]

Thanks Jeff you've given me some great alternatives to permanently securing the cab to the chassis. I really like the neodymium magnets option as it seems like the cleanest and strongest solution I am going to look for some on eBay. 

 

I just ordered some 1x1 neodymium magnets to place in the cab and on the chassis, Thanks again. 

Edited September 13 by bc6

[cteno4]

1x1 may be a bit small. Might also look for 1mm dia x 2mm long for small footprint instead of wider flatter ones. 
 

best way to mount magnet to magnet sets like this is to pop the two magnets together and glue the magnets at the top end in place so that the unglued bottom ones are as flush as possible (actually a tiny bit recessed). Once the glue is dry then take off the unglued magnet and add good fillets of glue around the sides and top of the glued magnet, but don’t get any on the bottom end that attaches to the other magnet or would interfere with the other magnet’s attachment. Once that glue is dry replace the other magnets onto the glued magnets and put a small dab of glue on the bottom of these magnets and place the piece in the correct placement. Let the glue dry. Once dry you can pop the piece off and add some reinforcement glue to the areas that don’t interfere with the piece placement. The trick doing this with small magnets is first just doing a very small glue bond then reinforce in the second phase. If you start with a lot of glue when first gluing either top or bottom magnets you run the risk of gluing them together!

 

I’ve used the dual magnet trick like this to attach structures to modules for easy removal and to hold lots of small things in place. works well.

 

cheers

 

jeff

[Kamome]

I agree with @cteno4 Personally I wouldn't glue the cab if it can be secured in another way or use something easily removed. I added some Cedar models light kits to the Tenshodo Kumuru static model in HO. The cab space was tight but nowhere near what you will need to contend with.   Despite my best efforts, on occasion, the tiny LEDs have worked there way free of their position and I'm forced to reopen it and re-glue the LEDS in position. Thankfully the chassis and body clip together.

 

Alternative to PVA would be the Tamiya multipurpose cement clear. This stuff is semi-permanent and doesn't melt plastic or eat into paint. It's designed to apply parts like aircraft canopies and has a tacky gum consistency. You can pry off parts if there's an issue and clean up any residue without damage to plastic or paint. I use it to apply metal etched parts to locos and it works very well. Actually the Kato Uni cleaner works well on the clean up.

[bc6]

@cteno4 Thanks for the tips on using the magnets, You may be right about the 1x1 magnets as they are really small but that cab is really cramped for space. There are some protrusions on the rear of the cab that I think will give me space to mount the tiny 1x1 magnets or I can make a faux toolbox to mount a larger magnet. I was looking for rectangular magnets but really didn't see much in the smaller size but I'm not sure if that would have worked in this situation.

 

@Kamome I agree permanently mounting the cab would be a bad ideal because of the motor access and light access. What did you use to glue the LEDs to the cab body is it the Tamiya multipurpose cement you mentioned. It's funny you mentioned applying etched details because I need to do the same thing with this locomotive. Thanks for the advice on the cement I will be picking up some.

[Kamome]

I think i ended up having to use some quick setting CA glue to mount the LEDs in the end. Wasn’t worried about any frosting as the LEDs were very bright. The issue was mounting 2 headlights and 2 tail lights per cab, the taillights being quite low, close to where the chassis clips in place. 

 

Im sure the next project I would construct light boxes to avoid the light bleed nuclear cab light issue when running forwards. 

[bc6]

Oh ok thanks, I'm afraid of mounting anything permanently thinking I may need access to it. I wish I could find that train pictured it's a favorite of mine. 

 

The engineer and conductor must wear sunglasses to drive that train lol. 

Edited September 14 by bc6

[cteno4]

Another thought popped into my head, but may be too bulky to do. You could use a tiny 1mm pitch 8pin connector to hold the cab in place and also avoid a lot of extra wire needed if everything is hard wired from the chassis to the cab. 
 

 

all and all this one will be a challenge!

 

cheers,

 

jeff

[bc6]

Jeff that seems like an interesting way of dealing with the electrical nightmare Im thinking I'll encounter and something I'll leave on the table for consideration thanks.