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nick_bastable

Whats on your 2mm Work bench

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Any ideas how the speed of production compare to filament extrusion?

 

I'm afraid I don't have any direct experience using a filament extrusion printer. However, the speed of production on an DLP is dependent on the slicing thickness, exposure settings and the orientation of the part. The coach I posted above took around 13 hours to print but was angled up at 30 degrees, sliced to 20um and had an exposure of 11 seconds to ensure warping was eliminated. This may (or may not) be longer than an extrusion machine but I think the quality of the surface finish is far superior to any prints from an extrusion machine that I've seen to date.

 

Hope this helps. 

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The two unpainted wagons in post 2172 have now been finished off.

The Dia 24 open will be departing soon with its load of some mining machinery for a customer in the south west of England.

 

post-25077-0-28162100-1543530236_thumb.jpg

 

Jim

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At Wakefield this year my Raithby Etch built 4F started acting up. Inspection has revealed serious wear of the rear axles. Curiously, the worn section is both tapered and eccentric. The bearings seem to be quite OK. So the job to replace the axles with steel, rather than the turned brass of the original starts. The key points here are that he turning tool needs to be necked to pass the closing nut for the collet holder, the final axles before fitting are shown as wellpost-14910-0-42815700-1544962599_thumb.jpegpost-14910-0-95018700-1544962933_thumb.jpegpost-14910-0-64837500-1544962987_thumb.jpeg

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Well a hour or so after we have replaced the wheel axles. The pictures are largely self explanatory, the key thing is that the part that is inserted into the wheel was deliberately over length, so that a short taper could be put on to help center the wheel in the staking tool , before pressing it home. All that remains is to re- assemble the engine.post-14910-0-43733100-1544970035_thumb.jpegpost-14910-0-77220600-1544970087_thumb.jpegpost-14910-0-42463000-1544970140_thumb.jpegpost-14910-0-85372300-1544970211_thumb.jpegpost-14910-0-74022200-1544970266_thumb.jpeg

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Great work there Richard!

 

The fact you'd had to remove the crankpin to do this reminded me - when I had a snapped crankpin, I tried to remove the remains of the broken pin that I'd soldered on, but had absolutely zero luck using my soldering iron and a pin to try and push it back through its hole, and ended up distorting the wheel and having to replace it.

 

So it has crossed my mind to maybe use Araldite in future, rather than soldering?  But I've noticed that most people do seem to refer to soldering their crank pins.

 

How do you get a soldered crankpin out?

 

Justin

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Great work there Richard!

 

The fact you'd had to remove the crankpin to do this reminded me - when I had a snapped crankpin, I tried to remove the remains of the broken pin that I'd soldered on, but had absolutely zero luck using my soldering iron and a pin to try and push it back through its hole, and ended up distorting the wheel and having to replace it.

 

So it has crossed my mind to maybe use Araldite in future, rather than soldering?  But I've noticed that most people do seem to refer to soldering their crank pins.

 

How do you get a soldered crankpin out?

 

Justin

I don’t solder them in to start with. I simply push them in with a drop of super thin cyano. They then just pull out.

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I don’t solder them in to start with. I simply push them in with a drop of super thin cyano. They then just pull out.

 

Boiling water will usually weaken cyano. I did some test for Xpelair some years ago and found going above 95deg C the bond seemed to weaken. Loctite Brush on is rated for up to 82deg

 

Don

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Boiling water will usually weaken cyano. I did some test for Xpelair some years ago and found going above 95deg C the bond seemed to weaken. Loctite Brush on is rated for up to 82deg

 

Don

 

Given that the wheel rims are themsleves cyanoed on, I wonder about the wisdom of heating a wheel to solder your crankpin in.

 

Chris

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Indeed Chris. Although the brief time of heating to put the crank pin washer on seems to leave the bond reasonably secure.

Edited by RichardW1

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Given that the wheel rims are themsleves cyanoed on, I wonder about the wisdom of heating a wheel to solder your crankpin in.

 

Chris

 

Best not to dunk the wheel into boiling water then.

 

Don

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Great work there Richard!

 

 How do you get a soldered crankpin out?

 

Justin

Very hot iron, well tinned tip, lots of liquid flux. Quick in and out.

 

Tim

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Given that the wheel rims are themsleves cyanoed on, I wonder about the wisdom of heating a wheel to solder your crankpin in.

 

Chris

 

I have always soldered crankpins in, never a problem - follow Tim's advice above.

 

Jerry

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I've far less experience than those commenting above, but I solder mine chiefly because of problems in the past with crankpins coming unfixed and revolving in their holes in the wheels. Not ideal but not the end of the world on an inside cyclindered loco, but a bit of a disaster when it's a Walschaerts fitted loco and the loose crankpin is one with a return crank on it!

 

Simon

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Very hot iron, well tinned tip, lots of liquid flux. Quick in and out.

 

Tim

 

How do you actually get the pin OUT though Tim?

 

This was a flanged pin where the whole projecting part beyond the pin had snapped. However much heat, its surely going to need some kind of leverage or pushing from behind to get the flange away from the wheel face while the solder is molten. But using a knife blade on the front, or pin from behind, seemed to act as a heatsink - and also made it much harder to try and be "in and out" quickly. 

 

J

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How do you actually get the pin OUT though Tim?

 

This was a flanged pin where the whole projecting part beyond the pin had snapped. However much heat, its surely going to need some kind of leverage or pushing from behind to get the flange away from the wheel face while the solder is molten. But using a knife blade on the front, or pin from behind, seemed to act as a heatsink - and also made it much harder to try and be "in and out" quickly. 

 

J

 

I'm surprised a knife blade could act as more of a heat sink than the brass wheel centre.

If I was in your situation, I would try using a bigger tip on the soldering iron, and make sure it is tinned.

 

I always countersink the back of the hole before soldering crankpins in. If I want to get one out, pushing from the back with a soldering iron bit will move it as soon as the solder melts. That would be enough for something like a knife (or the end of a cocktail stick) to get in behind the flange.

 

Nick.

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I'm surprised a knife blade could act as more of a heat sink than the brass wheel centre.

If I was in your situation, I would try using a bigger tip on the soldering iron, and make sure it is tinned.

 

I always countersink the back of the hole before soldering crankpins in. If I want to get one out, pushing from the back with a soldering iron bit will move it as soon as the solder melts. That would be enough for something like a knife (or the end of a cocktail stick) to get in behind the flange.

 

Nick.

 

Well with that particular wheel, I'd ended up distorting the centre with my efforts to get the pin out, but luckily when I spoke to the shopkeeper, he had an odd number of 9mm wheels and was able to send me an odd one as a replacement :) So the original has been junked.

 

But on the basis of that experience, I was a bit reticent about soldering again. I suspect I'd used too much solder that time - some had crept onto the front face around the flange, which must have made it even more difficult to get it out. 

 

The countersinking tip seems like a good way to solder without risk of the problem I had before - thanks Nick :) How deep do you tend to go - just a turn or two, or as deep as the drill is wide? If the hole is 0.5mm, I guess a 0.8mm-ish diameter drill for the countersink? 

 

Justin

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 I suspect I'd used too much solder that time - some had crept onto the front face around the flange, which must have made it even more difficult to get it out. 

 

 

Justin

 

It does sound as if you've used too much solder if it appears at the front. A small dab of solder on the rear of the crankpin should be all that is needed to fix it in place. I've also used Nick's tip of countersinking the crankpin hole (I think it was a couple of turns of a 1mm drill) and that works well.

 

Andy

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Just occured to me that the 3-112 Frame Bushes (the large ones)could be used to make a dog clutch. They can be mounted on a 1.5mm shaft, clamped together then drilled for the pins and slots.

 

Mark

Hadn’t seen this post before- like the dog clutch

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I built one of these some 30 years ago (

Must have been as it was before I moved to Market Harborough) follow the instructions, and be very careful with the steps!!

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How do you actually get the pin OUT though Tim?

Another way would be to drill a 1 or 2mm diameter hole in a piece of plywood or hardboard. place the wheel face down with the pin over the hole, apply the iron to the rear and when the solder melts. push the pin into the hole with a fine point.  Tim and I would use an old dental probe, but a pin in a pin vice would do just as well.  The iron needs to be plenty hot, no point in using one which is only a few degrees above the melting point of the solder.  That way you won't need to dwell too long with it.

 

Jim

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A quiet moment near Fujioka station on Gakunan Railway.

 

post-6716-0-14863700-1545504934_thumb.jpeg

 

A sneak peak of my GJLC comeption enty.

 

Pix

Edited by Pixie
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A sneak peak of my GJLC competition entry.

 

Pix

 

That's looking fantastic Steve, but I hope you mean DJLC entry - you're about 8.5 years too late for the GJLC!  ;)

 

Andy

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There was a rather strident thread on the 2mm email list ("VAG") over the last few days about the virtues of the current design of etched axle boxes and springs, which take quite a bit of assembly, versus looking for new approaches like 3D printing. 

 

I tried building some of etched axle boxes and found they produced a great result, and despite being easier to put together than many included on chassis kits, they were really more time consuming than I think is perhaps worth it for an axlebox. So, inspired by the "theoretical" VAG discussion, I decided to try out actually 3D printing some axleboxes. 

 

I wasn't going to aim for the absolute scale dimensions possible on the etched version, but I spent a few hours drawing up a design that more or less matched the dimensions of the last of the very old white metal RCH ones I still had. It's very much representative, rather than dead scale, especially on the springs.

 

post-3740-0-09747800-1545590021_thumb.png

 
I printed three sets of four, each at slightly different orientations, on my Anycubic Photon this afternoon, which took about an hour. To my surprise, they all came out!
 
post-3740-0-54645300-1545590029_thumb.jpg
 
I might still beef up the springs a bit further, and the bearing hole designed at 1.05mm still needed some opening out with a 1mm drill, but overall I'm very happy. I'll experiment with reducing the number of supports - or at least ensuring they're at spots where they're easier to remove - was very tricky on the ones that were most "upright" - but even the springs survived some gentle cleaning up with a file. 
 
post-3740-0-25391500-1545590037_thumb.jpg
 
It looks like with a small amount of tweaking to the design and supports, it would be possible to knock out a good number at a time, and then save a lot of time on wagon chassis builds!
 
Justin
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