Mack AC

edited July 2015 in O Scale Builds
I've been following this forum for the past year and have been a fan of SierraWest Scale Models for many more. I've been collecting most of the O scale Deer Creek kits including the Sawmill which just came this week. I'm anxious to get started building so I thought I would start small and begin participating in the forum. I've never participated in a forum before and while I've modeled on and off for several years I'm certainly not up to the level of the many fine modelers on this forum.

I've decided to start with the Mack AC. The pictures below show once again the excellent castings provided by Brett



  • This is going to be fantastic to follow along. I know there are a lot of these sitting on shelves around the world just begging to be built!
  • As you can see above, there are numerous castings in this build. I've organized them in containers to match the various subassemblies in the build process.

  • Instead of using 3" x 8" styrene strips as called in the instructions, I used 5/32" styrene channel. Most of the older trucks used a steel channel frames. I can't say for certain with a Mack but I know my Model A has a channel frame.


  • Welcome Steve, great kit to get started with and I will be following your build. Glad to see you joining in. Ken
  • I notched the channel for the rear cross member and the inverted frame end at the front. The channels also have to be notched for the cross member.

  • Great to have you joining us Steve, I'm really looking forward to following you build and getting a few tips from you.
    Brett mentions there are plenty of these sitting on shelves around the world and I have to admit that I am one of the guilty (lucky) ones.

    It's going to be a pleasure to follow your build.

    Welcome to the forum.
  • The front suspension is next. The leaf spring mounts to the brackets before mounting the brackets to the frame. The front leaf spring can be differentiated from the rear leaf because the rear has shackles cast with the leaf spring.

    The spring mounting brackets can be a little tough to identify but hopefully the pictures will help. It is important to keep the brackets square to the leaf spring. If you use super glue gel to attach the brackets to the spring, you should have enough time to set the assembly on the frame rail so it dries square.


  • Thanks Karl and Ken. I'm really excited to join the forum and start building my Sierra West kits. This is the only Mack I own but I've been on the look out for more. There is a tremendous amount of detail in these castings and I would love to build more.

    The next step was to start on the rear suspension, drive sprockets and brakes. The rear leaf springs mount to the sides of the brackets instead of the tops as the fronts do. I ran a #62 drill through the holes in the sides of the brackets so the pins on the leaf spring fit the brackets easier. Again, the brackets mount to the springs first. Use the rails to hold things square. After the spring assemblies dry, use the brass rod rear axle to keep both sides aligned when gluing to the frame. You have flexibility spacing the rear spring rear bracket from the frame end.

    Also, I failed to mention earlier that you can cut the frame rails to match the overall length of the truck you're building; typically 204', 225' or 249'. I'm building a 204' truck.


  • The brake assemblies are glued on the rail by temporarily using the brake spreader and chain assembly to locate their position.


    Then again using the rear axle for alignment the brake spreader and chain assembly are glued in place. You'll also see I notched the rails to add a couple of cross members.



    Finally the front axle was glued in place


    Now the frame is ready for paint and weathering.
  • Welcome aboard Steve, you will find the group super friendly and helpful...Joe CCCModOn30
  • Steve, this is very interesting. I admit I don't model with styrene and metal very much, but please show us what adhesive you are using that you call "super gel".

    Also, I'm confused about the length of the truck. You mention: "typically 204', 225' or 249'. I'm building a 204' truck." I assume this is inches, not feet?

    I really like how neat your construction is. I'm looking forward to how you are going to paint and weather your model. And thanks for doing a thread on this kind of model building.
  • did this build complete?
  • Nick,

    No response from the builder yet.
    Does anyone have a link to a build of the SierraWest Mack AB? Or have an unbuilt AB or AC kit for sale?

    Later, Dave S.
  • I think Steve's completed Mac was featured on one of his award winning dioramas a year or so ago, but maybe I'm confusing him with someone else.
    Hopefully Steve will 'pop in' soon and enlighten us.

  • Karl,

    Thanks. I be tuned-in hoping to see Steve F's reply or a link to the build you recalled.

    I did find Steve F's Railroad Camp Office build but there was no completed diorama and there were no Mack vehicles.

    Later, Dave S Tucson, AZ
  • I have noticed that the white metal parts were not blackened prior to the assembly. Is there a reason for this ?
  • Robert,

    I noticed that the frame was not blackened prior to assembly as well. I looked back to see when Steve started this build and found it was in July of 2015. I am quite sure blackening metal parts prior to assembly and painting was pretty common by then. I also checked to see when the last time Steve checked in was. His last time on the forum was May 21, 2018.

    Later, Dave S. Tucson, AZ
  • Steve,

    Any updates on the build?

  • I just discovered this build. Looks fantastic. I'd want want one of these too. :smiley:
    Anybody ???
  • I had to wait a while to get mine.....every once in a while they come available....and with the advent of the Truck Repair in "O" ….Brett might be charmed into an eventual run of them again.....
  • If you are looking for some great trucks, Keith has just release a line of new 1/48 vehicles. They are great.

  • Keith's trucks are awesome. In fact I have one of the wreckers on my bench right now that I'm building for the truck repair diorama.
  • Brett,

    Can't wait to see it. I have two trucks on their way to me as well. One open cab and one closed cab light duty trucks.

  • Yes wiseman came out with a bunch of O scale trucks last month.... Copied all the HO ssltd trucks. We definitely needed some different vehicles in 1/48..... I wish someone would do the same thing with all the old HO Jorden line
  • The problem is nobody has the legal right to copy the Jordan vehicle line. It would be an infringement upon their copyright ownership. Even though the family chose not to carry on the line or sell it they still retain the ownership of the line and copying it is wrong.

    Keith in contrast legally owns the old SS Ltd. line in HO Scale and thus the copyright privileges - so he can upscale it as desired.
  • Brett,

    Any pics of the truck you have been building?

  • Not yet Frank, just wish I had more time so I could finish it! I will take some shots with it once complete...
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