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That's a different approach, what is the motor your using there?

Hi Has anyone modelled working hydraulic rams / cylinders in HO scale? I was looking at a chute for a coal loader, I've seen a working models but nothing that shows the workings. What I would like to do is to be able to raise the chute up and down to allow the loco to pass through then lower for the wagon. I guess if the control for let the coal out is higher then a servo could be used, then another servo to rotate the chute out of the way for the loco to pass. Hope that makes sense. Cheers

Here is the molding box I made from 10mm acrylic it's a 100mm high by 100 x 300mm in length. I used a PVC priming fluid it join it all up. I use clamps to hold it together, so now I can have any size box I need. When I made the two part mold I just brushed on vaseline on the silicone before pouring the second half on the mold, which worked pretty well. I'll give the double sided tape ago, I guess there will be a little bit extra to sand off from the model due to the thickness of the tape.

Thanks, it makes it easier when you see it being done. I had another go, I took a vid but at 500Mb just a tad too big, so I took a screen shots to the best quality but the idea is there. I also asked the supplier of the resin and they recomended using industrial talcum power to line the mould to help with reducing an static electricity and realeasing any air bubbles, however I'm thinking its the chemical reaction between parts A and B that creates the air bubbles. I tried being gentle on the mixing but I'm not sure. When casting the mould how do you stick the master down, I used super glue on some xray film, but it doesn't come off very well when I seperated the xray film, it left a residue on the master and I ended up cutting into the master. Tried bee's wax that didn't work very well either, didn't stick the baseboard. So any ideas would be great.

Thanks that's pretty informative, the plastic sheet is that about 1 to 2mm thick can it be anything.

That makes more sense, it seems you need to have a method to do this, from making the mold to pouring the resin. In regard to the resign, what type are you using? I'm using a product called Procast, it only has a pot life of 5min, the guy at the shop also said to try Easycast pot life 2min. I think this is too fast, I could not even put it in a vacuum chamber (if I had one) to get the air bubbles out. Is there a method to mixing so as not to introduce air bubbles. I might butcher my mold to be able to pour the resign in rather than plunging the top part of the mold into the bottom.

One thing I do not seem to get is, we are told to put the model on an angle to reduce the surface area being printed to avoid suction issues, yet the model sits on one big flat raft with a bigger area than that of the model. How much of an issue is it really?

By the sounds of it you have the supports within the wagon, I have been printed open wagons so that the supports are on the under side that way you don't have to worry too much about pitting since it's underneath. I have also found that if I print at 30deg all the supports are on the underside and nothing on the sides or ends that way they are all clean. Post a pic of the supported wagon will make it easy to provide a comment.

Agreed, this was something I thought I could add to the tool bag, to increase production. I too have a graveyard of almost there but no cigar prints, was thinking about using them as a train wreck I have also learnt that everyone has something to contribute, it's whether you choose to take that on board or how you take that is another thing I shall crack on, maybe with both methods running parrallel.

I have gotten better results with 3D printing, however at 9 plus hours per print, I thought casting would yield quicker models, plus I want a lot of wagons and didn't want to hammer the printer. So same mould, slow pour and let the plug slide in with a little pressure, a better result but still lots of air bubbles. However when I first pour the resin in I do not see any air bubbles so I'm not sure what's going on there. The sides feel rough even though the mould doesn't. The photo of the end has two bubbles that seem to be in a very odd spot. I would expect to see air bubbles trapped against an overhang. I used a toothpick to open up the smaller openings abit more so my side steps can out better (well one side). I guessing it's developing a technique when pouring. Phil, thanks for the advise it is really helpfully, hopefully the penny will drop soon. When you do an open mould what to you stick the master down with so it doesn't move when you pour Cheers

Hi Trial 2, I decided to go for a piece hoping that the buffers won't break on the way out, after de-moulding the buffers didn't come out. I think it's an air bubble issue, I'm also a bit gutted that there was a big air bubble just near where the bogie is attached. I was thinking I could fix that by using either wax or plasticine. I'm suprised that the air tank came out, thought that was going to fail for sure. I didn't bother to clean the model up as it wasn't very good Fastening the model down I used a piece of exposed x-ray film and glued the the model down using super glue, peels off easy after the inital pour, however the excess super glue needs to cleaned off, which more than likely caused me some issues. I did see somone use bee's wax, but a slight touch and it came loose. Is there another way to hold the model down? The sides, for some reason, came thicker is some spots, maybe because I used a book to hold the top piece down and squashed the mould a bit, shall try with rubber bands next time. Also the clean up on the excess glue my also be a contributing factor. How you push the two halves together may have a effect on the outcome the casting, I think I did it a bit too quick, maybe a slower approach required. The instructions say you can de-mould from 1 to 3 hours, I did it after 1 as the left over resin was hard, but when the model came out it felt soft, next time I'll leave for 3 hours So what did I learn don't mix for too long, less time to pour, choose the time of day, the warmer it is the quick it goes off. Holding the casting up the light shows up all the air bubbles and lack of resin. The master needs more sanding also.

This is what I was thinking, if I split the ends off then it's just a matter of gluing them back on. No doubt there will be a mtach line but a bit of filling, sanding and paint should cover it up. My only concern is the coupler box, maybe it would be better to keep that as one piece, even though it is an overhang (not sure if that's the right word).

Thanks for that, I hadn't come across that method. I guess that each method would have it's own benefits. I'm not sure about splitting the body and the chassis because of the buffers, maybe I can split the ends of the wagon as well so there would be 4 pieces. Could I create one open mould rather than four separate ones?

Hi Well it's taken it's time but I have done my first casting, needless to say it will be a labour of love before I get it right. Apart from air bubbles, need to make a vacuum chamber (new topic I assume). So here are few pics sorry about the focus hence the 3D versions. I'm using pinkysil to create the moulds and procast for the resin. Issue number one - I do not have a bottom or a top of the mould, as I have the half at the buffers so they would not break off when taking it out of the mould. Which means I can't get enought resin in before it starts to overflow and panic sets in. I'm thinking to place the whole model so that the bottom is up, the split line is at the top of the wagon and the top part of the mould becomes a plug that gets pushed into the bottom part. The only concern is the buffers breaking off when trying to seperate the casting. I've been playing with the mould that creates the sides to see how much give it has and I'm half thinking the casting may come out without breaking the buffers. Issue number two - I want to include the steps and air tank as part of the model. I can place a small infill in the steps and break them out later, which I did for this mould but found out that air gets trapped (I considered this to be the top part) and the hole I put in to let the air escape is too small so the steps did not come out very well. With the air tank I have made it part of the underside so there's no air gap, I'm just not sure how much to fill the gap without making it look to out of sorts. I can 3D print these and get a reasonable print, but I would like something a bit less brittle and being a iron ore wagon I would like just a few without killing the 3D printer. The more I stare at it the less I see the negative space that I need to create so I can get the resign in without it going all over the place before I bring the two peices together. I guess I can break it apart and cast it as parts then glue it back together, but I don't know how to cut the ends off to make it look clean when you glue it back together. Any thoughts would be great. Cheers

Hi I'm going to embank on a stick build project and my search for plastic I Beams and Universal Columns have have yielded and few products from Evergreen, Kit Kraft and Plastruct. However this seems like an expensive way to go. Has anyone made their own structural members, I also thought about 3D printing a few and casting the rest. Or is this a lost cause and I should just save up and buy the "off the shelf" ones instead. Cheers

So what country or time zone are you in? Cardiff - should have looked at the video first.

Thanks for those suggestions, I'll have another go at. However prior to reading these posts, I ended up doing the following making the handrails 0.2mm dia the stairs and landing 0.25mm thick made the C-sections just a solid member Here's the result on an Anycubic Photon, layers where 0.05mm, with default light supports. Removing the supports was the issue, cracked a few of the handrails at the supports (handling issues, too small for my fingers) but easily fixed using resin and a UV light. What I would do different, in my excitement I UV cured it before removing the supports and I should have dipped it in hot water first then removed the supports. Then maybe the supports would have come off cleaner on the handrails. Also I need a support beam where the stairs connect to the building to make it easier to glue, didn't see that until a test fitted the stairs. The photoetch looks interesting

Hi I want to print these stairs in N scale, the first attempt was a failure mainly due to using a true scale version and scaling down. The thickness of the model was too thin, especially the handrails. I gather that modelling structural members at this scale will have to made bigger as the strength will not be there, it's just the appearance that I was after. I'm tempted to just to model the structural members as square sections to give it a bit more thickness. Is there a min thickness before it looks out of scale or in the end It just doesn't matter. Cheers

A bit more work on the warehouse, from 3D modelling to cardboard. I think I'll 3D print the exhaust outlets, since I'm print the stairs, my effort a scratch building at this scale needs work (as well as HO). Are there any thought's on modelling corrugated sheeting in N scale, finding heaps on HO scale.

Dowel Push Rods for Manual Point Control I didn't find much infomation but this is how I did it after I saw it on another layout and thought it would be good try, plus the kids like the idea. The wire is 1.25mm tie wire (photo #2), you would use it tie mesh fence to star pickets. Dowels are 6mm in dia. This is the basic idea, it doesn't matter what angle the point is relative to the edge of the base board, I wanted the rods to be perpendicular to the edge of the board, you could do it so that dowel is parallel to the tie bar if you like. I drilled a hole about 3 sleepers up from the tie bar (photo #3), bent the wire to fit into the hole of tie-bar and bent so it would go through the hole in the base board. I used eyelets so the dowel had a support (photo #4), once under the board bend the wire so its perpendicular to the dowel drill a hole through the dowel and feed the wire through.

Well it's starting to take shape, I have used 6mm dowel rods and 1.25mm tie wire to change the points. The wiring is done, turned out one on the points was an electrofrog and kept shorting out until I put in some insulated joints, trap for young players, now for the buildings

Thanks, well I ended up rotating 30deg and placing the supports on the bottom and it came out much better. Not sure what happened with those tiny holes, just might be somethin in the resin, a little bit of fine turning and should be ok.

Maybe like this

Thanks for that, I was going for an Australian feel, those links are interseting. I guess I was more focused on the timesaver layout and use it for shunting, I do have a HO version which I enjoy, but you do make some intersting points. So if I had a main line "running" through then that would give the potential for a train to arrive and depart. I could flip the silo, lose the road to the north to give more room for a main line, add a point where you could come of the main line and into the timesaver. Sure the rakes won't be long, but 'm putting together an iron ore layout, so I have the 260 long rake coverd

Yeah, I used that link to get this layout, some good ideas there. I was hoping to add a extra dimension to it. Well one has flagged anything majorly wrong with the layout.