O Scale HSS – IV

e-Clip Pin Swivel
e-clipLooking closer at the print – and especially the pocket formed between the two body halves, I think there may be a better way. The problem is that at some point the two halves need to be cemented together. When this is done – that is that – the swivel pin, handle and .. realistically, the connecting rod are basically fixed in place. I got to thinking about it and realized that an ability to dissemble everything would be much more useful.

So. The idea is to use a small pin and e-Clip. These e-Clips are used – in the size I am looking at – in watches and can be ordered online.

The 1.2mm e-Clip shown in the drawing fits nicely on a 0.040″ dia shaft as shown. The pin iteself can be made on a small lathe .. setting up with collets would make it relatively easy once one figures out the tools and setup.

body5aWhat’s nice about this beyond the ability to assemble/disassemble after the Harp frame is cemented together is that it actually looks good. The little e-Clip doesn’t look outsize at all .. even with the idea that when used .. if possible – I would slip the pin into the Harp Switch Stand so that the flat head shows and the e-Clip would be on the side not seen.
body5bFinally, exploding the model to show how this would work. The only problem I see is that machining the pin will possibly drive me stark raving mad.
Version 5
body5Last night I realized that since I had decided to modify the design for a pass-through pin there was no need to have the stand in two parts – so I merged them into one body.

Current dimensions – The connecting rod hole is 0.040″. The 0.028″ holes are for NBW and anchor pins to secure the stand to the layout. The swivel hole is for a 1.5mm pin.

Control Rod Linkage
control_rod_linkage_1Caboose 202S HO Caboose ground throws have a throw of 0.190″. In the graphic the red handle is centered, with Green and Blue showing that total 0.190″ throw. With Green and Blue shown centered .. the pivot arc means that the center of where the handle and connecting rod join drops about 0.020″ in the center.

That will cause a problem .. I think .. as shown. What I am thinking is that if that hole in the end of the handle was elongated by that 0.020″ it would work.

Another problem is .. if yo look at the end of the handle .. that is close to the legs of the stand. That is perhaps .. around 0.020″ .. which means that isn’t enough space for a 0.040″ control rod to twist around to fit through the end of the handle. A clevis *might* work .. but that adds to the complexity .. and difficulty. I had thought to bend the end of the connecting rod into a hook that would fit into the end of the handle .. but no room for that. Thinking .. would need to widen the space between the feet.

control_rod_linkage_2Here’s a way around bending the control rod and having room for it not to hit the foot. I elongated the hole in the end of the handle to allow for vertical movement.

The control rod is 0.040″ dia. which means it would be perfect for the 1.2mm e-Clip to hold it in place.

A Render
render2Just for the fun of it I just knocked out a little rendering. I stuck in NBW on both the stand pads (theoretically to bolt the sides together) and the nuts and washers for the anchor bolts ..
render3A closer look. What sucks about this is that if I were doing this in FUD I could get darn well close to this level of detail. Printing in WS&F is not nearly so nice.


O Scale HSS – IV — 12 Comments

    • yeah .. thought about a little notch or somesuch. That is part though depends on the design of the operating handle. I still think that I need to get into photoetching.

  1. Any chance these will be available soon?

    These are looking fantastic, and a FUD print would be ideal for what I need. I am looking for something like this to use just as a scenic element. My turnouts are activated by pushrods under the table and I would love some harp stands that can be tied to the points as indicators, not actuators.

    • Printing them in FUD would be easy enough. I put this on a back burner as I had given out samples in WS&F to a group with the expectation that I would get some feedback .. which I am still waiting for. I will take another look at them today and see if I can make that happen.

      • Thanks for thinking about it. FWIW, I am more than willing to pay the Shapeways bill for 10-12 of them. I need 7 right now, but I don’t think a few spares would hurt.

        • I uploaded a copy this morning to Shapeways – http://shpws.me/HFvq .. and as I say in the ‘blurb’ .. it wouldn’t make any sense to order ‘as is’. If you have one part in a mesh or a hundred you pay a $5 handling fee (subtract $5 from the price you see) and $5 shipping. It makes MUCH more sense to put those 10 or 12 or more in a single mesh which means that handling and shipping is spread across the order.

          Here is what I will do. I will add this to my next order to Shapeways .. basically ‘tuck it in’ the other mesh. I will then send it to you so you can decide it it is ‘good to go’ or needs more work.

          • That sounds like a great plan. I am not in any hurry, so just let me know when the time comes.

            Given that I will be using the wire only to actuate the handle/flag, I expect that .025 will be fine, maybe .032 to bulk it up a little for looks. The jog in the handle base is a good solution to the interference.

            As for the pivot pin and e-clip… Um, no.
            I plan to ream the 1.5mm hole to 1/16 and just use a scrap of wire slipped in and retained with a micro dot of thick CA on one end. Thick so it doesn’t capillary through the hole and freeze the flag. Or even a piece of styrene just pressed in place.

            Given your pricing structure, it sounds like a dozen would be about $2 per which seems more than fair to me.



  2. I added the FUD version to a group to be printed .. I had intended to add NBW to the model but this was before I had my coffee and forgot. See how they come out. If good I will send you (Thayer) the ‘prototype’ for suggestions for a ‘production model’ such as enlarging the pivot hole and such. Sometimes I can’t see the forest for the tree and can use such suggestions. 🙂 .. you can just see it peeking from behind the group in the linked pic


  3. Excellent to know it is moving forward, thank you so much! One thing I noticed though is that the model it is not attached to the main cluster when I spin the 3D image. I just want to make sure that was intentional.

    • It is there now. I updated the original mesh group by adding the switch stand. Sometimes it takes a while for the servers at Shapeways to update

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