Hello from a modeller in Birmingham, UK

Hello all.

I'm a complete newbie with this technology, but I'm wondering if I can use it to make part of my hobby a little easier. I build a lot of railway wagons from plastic kits, and to introduce some variety, I would like to prepare alternative components for van sides and ends. It looks like I can do that (I have to learn to use the software, of course) - but I'm wondering how to bond my 'new' components to those of the plastic kits. The plastic I'm working with is either styrene or ABS, and I use a liquid solvent known as MEK (Methyl Ethyl Ketone). Would the same solvent be suitable for bonding 3D-printed components?

Welcome,

We have a very large train community here. You may want to check out the post production section for your glue question. Some may effect the 3D printed materials

Thanks for your reply.

I did look through the post production section, but didn't really find any answers to the questions I had in mind.

Of course, using a solvent to bond the components of a kit, I expect those components to be affected. A layer of plastic (the thickness depends on the amount of solvent applied) of each component is dissolved, and then when the solvent evaporates, the material of the affected components solidifies and the components are bonded. If the plastic material used in the 3D printing process will dissolve in the same way, and I can then rely on it bonding to the material used in the original kit components, that's exactly what I need.

So - if my use of MEK (or some other solvent) 'affects' the material of the printed part, that's a GOOD thing!

May be worth ordering some test pieces to try. At least with the Nylon prints, the material is very porous, so even a tiny bit may get sucked in and cause issues. You can always ask in the post production section what others experiences are. I'll also ask our resident train expert.

Hi,

What could go wrong with gluing them together ? You can use 'foam safe' CA (Cyanoacrylate) in case it dissolves the plastic too much or regular CA that will work for almost any materials.

Arnaud

Thanks for the replies.

I'd rather steer clear of cyano, at least for some of the parts I'd like to produce. Cyano grabs a bit too quickly, and doesn't give me the chance to adjust a component into the correct position. Using solvent, I can get the component where I need it, then apply some solvent to the joining faces using a small artist's paintbrush, and capillary action will then take the solvent into the joint. Using cyano, I'd have to apply the glue on one of the mating surfaces, then place it into position precisely, and if I've got it wrong, it's too late!

Also - well, as I said earlier, I'm thinking about preparing alternative components for plastic kits, where the assembly is almost exclusively going to be using the solvent technique. OK, there are some kit upgrade components available in other media - whitemetal or etched brass - which need a different kind of adhesive, and I'm OK with that for my own modelling, but I have one eye on the possibility of making these components available to other modelmakers through a Shapeways shop, and perhaps they'll just want to assemble a collection of plastic components using the regular solvent technology.

I'll give you an example. My first project using Sketchup (it took me just 4 hours to produce the artwork for this, having never used the software before), is for an alternative component for a kit made by Parkside Dundas. Built without any modification, the kit makes up into a Great Western Railway ventilated van (diagram V11), which had a wheelbase of 18' (72mm in the scale of the kit). The axles are held at that distance by 2 w-irons molded as part of the 2 solebar components. (Apologies if you don't know UK railway terminology - a solebar is a length of 9" channel on its edge, running the length of the van on each side, so 2 are required, and they are the main structural components of the chassis.) The axleboxes and springs are separate components, and have to be glued to the outside faces of the w-irons. I'd like a model of a V9 ventilated van, which was almost identical to V11, but had a 20' wheelbase. It's not really possible to make one of these by cutting the w-irons off the V11 solebar and then reattaching them further along, at 80mm centres. The joint would be far too weak. So I'd like to 3D-print a new solebar and w-iron component, attach that under the floor of the van, and then attach the existing axlebox/spring components to the face of the new w-irons. For this assembly work, solvent is ideal - providing that it does the job when applied to the Shapeways material, of course.

Check your local hobby store. There are many formulations of cyanoacrylate, some of which set up quite slowly. (Some are so slow as to have catalyzing sprays available.)

You should try using CA the other way it can be used. First place the parts, second apply the glue to the joint sides. It will spread by capillarity along the (microscopic?) crack, then solidify. Use mid, or better low, viscosity CA.

+1, watch the spray can turn the glue into a white color

+2

W irons might be interesting.

In general, I've noticed that not much model railway stuff appears on SW lately. too inconsistent in quality i think, SW could never guarantee a quality print. it is a pity they could never get it together as it might have been a good partnership and lucrative too. but that has been the consistent story among those i've discussed it with.

B.