Traverser Manual Mode

We returned home earlier than expected thanks to an early start and great weather encouraging the cottage mob to stay late. I used my extra time to build character by installing the traverser slides. I did not have a failure of orientation error but I think I committed just about every other one except setting things on fire. I will summarize by stating that there is more than one set of holes in the table slide mounts and leave it at that. I may have indulged in an expletive or two as well.

I pressed on and made reworked things until I have something that seems like it will do, at least in manual mode. My plan to drive the table from a single screw in the middle may not work due to the tendency for the table to rack as the various stages of the slides are reached. The two slides cannot be counted on to behave exactly the same so I may have to resort to either two stepper/screw pairs or some sort of single motor pushing on both ends drive system. I have some ideas. I may just try it with the single screw and see how it goes since I have the one motor and motor driver already in hand.

Table at right extent puts the traverser center track in alignment with the runaround track.traverserright

Getting that reach required me to employ a trick I learned somewhere. I bent down the stopper tabs on the slides so that the slides run both ways. In this particular case the dual direction capability wasn’t necessary except for one of those previously mentioned errors. I located the baseboard slide supports based on bad assumptions about the travel of the slides relative to their footprint and ended up a half inch short on the right extent. Folding down the tabs fixed that with minimal fuss. Here is an underside shot of a bent down tab.traversernotab

Left extent puts the center traverser track on the back track and extends the table beyond the back of the layout. I have yet to decide if this will be useful for fiddling cars on and off the layout or not.


The big question is how well does it fit. The gap I ended up with is quite narrow, perhaps too narrow. If it turns out to be too close, I can shave things off the layout side.traversergap

Looking at the level of the two meeting edges shows the work left to do. The table is level but the matching roadbed is floating unsupported and is not level. The final step will be to attach a support to the end of the subroadbed and torque things into alignment.traverserlevel


4 thoughts on “Traverser Manual Mode”

  1. I have arrived mid way on your Meanderings, and have not seen a reminder of what scale you are modeling…O? Or perhaps S?

    Do you have a large basement to contain this large scale and layout?

    And you do seem to be making decent progress…are you retired? Even though I have been retired for twenrt years, progress has been very slow….I model in N and using code forty rail.

    Thankyou, Ian


    1. Hi Ian,
      Comstock Road is 1:48 O scale with the trackwork built to P:48 finescale standards.

      The layout is 2’x12′ all in and built to be portable in the manner of a British exhibition layout. I have more basement than that but previous more ambitious projects have died in the early stages due to taking too long to complete.

      I am not yet retired. I just keep plunking along as I am able. This blog is in part a motivational tool for me. There is only so much to write about without actually doing something. I find getting set up so I can do a few minutes at a time helps me get something done even if it is only spiking a few more tieplates down.


  2. Dear Mark,

    A single motor + worm-drive system should be capable of overcoming any stiction + train-loading you might submit it to. Google “Brooklyn : 3AM traverser” for one example, using a MicroMark “SwitchTender” gearhead motor to drive a 1/4″ threaded rod. On said rod is a pair of wing-nuts, oriented “ears facing each other”, keyed into a short piece of conduit to form a “traveller” which runs LR along the threaded-rod as it’s turned. A stiff piece of spring steel (NWSL HO driveshaft) anchored thru the traveller conduit, such that it’s parallel to the threaded rod, pokes up thru a slot in the benchwork, and engages with a hole in the centre of the traverser. In “Brooklyn”s case, the traverser was Foamcore, and the engagement hole was re-inforced by some Code 100 rail, strategically placed and weathered to look like “cast-off relaid/worn-out jointed-rail lengths”.

    Point being, it’s well-doable, can be driven and controlled just like a “stall-motor” turnout drive,
    (esp if you only need the traverser to be a “2 position/ X tracks” affair, use the “555 stall-motor control circuit” from Rob Paisleys “Model Railways and Misc Electronics” website), and provides a slow, powerful, smooth, reliable hands-off traverser motion.

    Happy Modelling,
    Aim to Improve,
    Prof Klyzlr

    Liked by 1 person

    1. Hi Prof!
      Thanks for the advice. My concern is not for power to move things. The slides are ball bearing ones rated for 75 lbs. Even entirely loaded with Atlas diecast locos I won’t exceed that. My motor in hand is a NEMA23 stepper which probably has enough torque to tow the entire layout across the room.
      My concern is that the slides have “stages” which telescope. There is a bit of a hitch when the next stage’s stop is hit and with that table measuring 38″ end-to-end a hitch might cause a misalignment at the business end. Initial experiments with pushing on the center of the table makes me hopeful that my concern is unfounded. I will proceed with collecting empirical data and report my findings.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s