Plow progress, couplers, and mods

 photo Plow-17_zpsbb46c518.jpg

I’ve made a bit more progress on my Ambroid snow plow kit. As the photo above shows, I’ve added the headlight casting (fitted with an MV Lens – catalogue number “L 228″). And I’ve added the kit-supplied handbrake to the roof.

I’ve also installed Sergent couplers at both ends and should share some notes on this…

The front coupler required the most work. To position it correctly, I had to shorten the shank and then devise a way to pin it into the coupler pocket casting. I removed the back part of the coupler shank using a cut-off disc in my Dremel Tool. I then filled the slot where the spring goes by securing a piece of 0.060″ x 0.080” styrene strip into the slot with CA, then trimming it to size after the CA had cured.

Finally, I found a small brass screw in my collection to mount the coupler. There’s a pilot hole cast into the coupler pocket – I drilled this out and tapped it for my screw. I then drilled a clearance hole through the coupler shank – partly through the metal, and partly through the styrene. I then assembled the coupler as instructed by Sergent Engineering (and as described elsewhere on my blog).

Since this coupler no longer has an alignment spring, it tended to flop about a bit in the box. I solved this by adding layers of masking tape to the underside of the shank until it created a fit tight enough to stop the flopping but not so tight to prevent the coupler shank from moving when coupled in a train. Two layers worked for me in this case.

I then worked on the rear coupler…
 photo Plow-19_zps08c7a7a2.jpg

Here, I was able to use a standard Kadee coupler box, but I had to widen the recess in the body to accommodate it. I used a handy micro-chisel from Mission Models (whose website has now disappeared, it seems) to widen the recess. I also had to add some blocking to lower the coupler box to the correct height. This, I made by gluing up some scrap strip wood – I had several large sizes used for bracing models – and then sanding the block to finished size.

With couplers installed, I gave the plow a test-run on the layout – and almost immediately discovered a problem. The plow wings have large, triangular wedges to help lift and throw snow, and the bottom edge of these would connect with the ties that form the edge of the St. Williams station platform, causing the plow to lift and derail.

I thought about modifying the platform – and did a little bit of carving at one end to help solve the issue. But to do this properly would’ve required tearing out the styrene sheet that forms the base for the gravel platform – a sheet that also helps align part of the mechanism for the working train order board. So, I opted for a less aggravating solution, and filed back the bottom of the wedges to clear the platform. Once painted, the modification is barely noticeable. Compare the photo below with the lead photo on this post and judge for yourself:
 photo Plow-18_zps404487e6.jpg

Since some prototype plows have a rolled-under body side – known as a “Tumblehome” on British railway carriages – I’m comfortable with my modification.

Next up: Some more testing on the layout, plus grab irons and other details. But the plow is getting closer to completion.

Finally, a bit of housekeeping: I’ve now added a separate category to collect all posts about this project, to make it easier for those of you who are interested in the plow to find every post in one place. It’s called “Ambroid Plow” and you’ll also find it in the “Categories” drop-down menu on the right side of the home page.

5 thoughts on “Plow progress, couplers, and mods

  1. Thank goodness that something went wrong during your otherwise flawless assembly of the Plow. I was beginning to feel very unsure of my own skills since most of the time I foul up the simplest tasks. This effort has been a real inspiration, Thanks

    • Hi Tom:

      Yer a funny guy…


      Actually, I have surprised myself that the plow project has been as painless as it has been. I’ve just tried to take things slow – think twice before doing things. I’ve still made a few mistakes – for example:

      – I spent a lot of time fussing with the positionable wings, only to realize I would never position them and that the whole thing would be more robust if I simply glued them in place.

      – As designed, there’s no way to get into the plow once it’s constructed. I remembered to glaze the windows before adding the roof and sealing things up – but forgot to add weight. I ended up adding some underneath the nose and between the wings, where it doesn’t show.

      – Making today’s modification to the wings would’ve been easier if I hadn’t yet installed the wings. I should’ve mounted them without the hardware – even double-sided tape would’ve worked – and then tested the plow thoroughly on my layout before proceeding. (Now, I’ll use the plow as a one of my clearance testing cars when I do things like build the platform at Port Rowan.)

      I think anybody can do a good job with these kits. A few people – not me – can do a great job. The hardest part so far is overcoming the fear of messing up something. Those fears have so far been unwarranted.


  2. Hi Trevor. Great job on the plow. Have really enjoyed watching it come together.
    Coincidentally, just watched a show on CN snow plow operations in the ‘80s. Included footage and story about a snow plow wreck told by one of the crewmen in the plow. Horrifying and interesting.
    Concerning the Sergent S scale couplers. How similar are they to the original Sergent S scale Couplers? Would the new ones mate with the old ones?

    • Hi Bill:
      First, thank you – and I’m enjoying watching it come together too!
      As for Sergents, I’ve added a new category to the blog so that all posts about these couplers will appear in one place. I’ll write more about them as I make progress building and installing them in different pieces of equipment.
      That said, they’re superior to the original S scale Sergents in several respects. The castings are much crisper, with a lot less fussing to do to make them work, and yes – they should mate with the original ones (although I haven’t tried that).
      I’ll have more observations in future postings.

Leave a Reply

Your email address will not be published. Required fields are marked *

Please prove you're not a nasty spamming robot thingy * Time limit is exhausted. Please reload CAPTCHA.

This site uses Akismet to reduce spam. Learn how your comment data is processed.