Body Mounting Kadee 830’s onto an Aristo Dash 9 Locomotive
Moving beyond factory couplers.
By: Keith Stratton

  This installment is the fourth in a series of ‘How To’ articles on body mounting Kadee 830 or 930 straight shank couplers.  To find out why I decided to go with body mounted Kadee couplers in the first place you can read my first article, which appeared in Issue #130 (November – December 2012).
In the Kadee catalog on the ‘Conversion’ page it calls for Kadee 789 couplers to convert the Dash 9 locomotives.  This a number of years back and, being new to garden railroading, I went ahead and did the install.  I remember at the time being not to thrilled with the post the coupler needed to be mounted onto as it was prone to flexing and would not likely hold up hauling long/heavy consists.  It was; however, considerably better than the original, and very wobbly, Aristo coupler that protruded way too far out from the end sill, as can be seen in the locomotive on the left in picture #1.

Picture 1

Picture 2

  Before and after shots can be seen in pictures # 1 and from the underside in picture #2.

Picture 3

Picture 4

  The trucks and side-frames are removed from both ends of the locomotive to permit better access to the coupler pocket areas.  Picture #3 shows the Aristo coupler still installed.  First thing you have to do is remove the screw for the centering spring then pull the spring out and discard.  Now remove the screw holding the Aristo coupler to the mounting post and pull the coupler out through the end sill.  Next, take a Zona or Atlas saw and cut out the cross brace that held the centering spring in place as it is no longer needed, as can be seen in picture #4.  This is a good time to tape the step light wires off to the side to prevent them from getting damaged.  Also, depending on how, or if, you use the battery pigtail you should also pull it out of the coupler opening in the end sill as it can be put back into place at the end of the install. 

Picture 5

Picture 6

  The post needs to be removed in order to build-up the coupler-mounting pad.  A pair of side cutters can remove the bulk of the post but the bottom area needs to be flat and square to build upon.  Pictures #5 and #6 shows both ends of the locomotive, mounted upside down, on the table of my vertical milling machine, which makes for a quick and accurate job.  (On my first install I didn’t have the mill yet so I used a very sharp chisel to get the base prepared.  It was a bit awkward but it can be done.)

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Picture 8

 In picture #7 you can see the freshly milled base for the coupler-mounting pad and in picture #8 you can see the first piece of the mounting pad installed.  The material used is Evergreen Strip Styrene, Item No. 404 that is 0.188” thick x 0.625” wide and cut into 1.0” lengths.  You will need three for each end of the locomotive.  A hole is located above the round base of the pillar and a pilot hole is drilled with a #30 drill.  A ¼” drill is then used to drill a pocket for the screw head of a #4x3/8” pan head screw to fit into.  This is to recess the screw head flush with the top of the mounting pad.  A #54 drill is used to drill the pilot hole for the screw in the base of the pillar.  The first piece is glued in place with CA adhesive, flush with the front of the inner sill and then screwed in place for a very solid foundation.

Picture 9

Picture 10

 The opening for the coupler draft gear box will have to be widened as you can see in picture #9 and as you can see in picture #10, this was easily accomplished with a file.  You will also need to file the top of the box opening to match the height of the Kadee height gauge that you should have used to verify the height before taking the trucks off (of this I speak from experience…).

Picture 11

Picture 12

 Now you will have to complete the buildup of the base by gluing in place the next two pieces of styrene for the pad build-up, as seen in picture #11.  Before you start, scrape the paint off of the backside of the end sill as these two pieces will be glued right up against it.  Use CA adhesive all the way around for a secure bond.  You will find that the three pieces of strip styrene used for the build-up results in exactly the right height for the coupler draft gear box to be mounted to… things like this seldom work out so nicely, so just smile and move on to the next step!
Before mounting the coupler, you will need to shorten the draft gear box by ¼” which corresponds to the end of the coupler shank inside the gear box as shown in picture #12.  Also, cut off the small half-round tab on the end of the coupler shank.  These modifications are necessary for clearance between the trucks and the back of the coupler draft gear box as the trucks to swing from side to side on curves.  Also, the un-coupling pin will have to be cut off due to the coupler having to be inserted in place from the inside and the un-coupler pin prevents this.  I don’t use magnets to uncouple cars so this is not an issue for me.
Now mount the coupler by positioning the draft gear box in its final place and then take a scribe and mark the center hole.  Push and twist the scribe point into the center mark to create an indent for the drill.  A #54 drill bit is used to drill the pilot holes for the mounting screw.  Screw in a #4 pan head screw into the pilot holes and then back it out.  Trim flush the extruded / raised ring of plastic that forms around the hole.  This raised edge must be cut, shaved or chiseled off otherwise the coupler draft gear box will not have a flush fit against the underside of the mounting pad.  Now take a #4 x ¾” pan head Phillips screw and secure the coupler in place.  I usually paint the screw heads brown or black so they blend in but have left them unpainted in the pictures so you can see them better.

Picture 13

 Reinstall the side frames and trucks and check the coupler height against a Kadee height gauge.  It should line up just right, but have a couple of 1/32” shims handy for final adjustments… just in case.
Now my friends… you are ready for the ‘long haul’.  This coupler mount is very solid, doesn’t flex up or down when hauling heavy loads and also works well on small radius curves… it just doesn’t get any better than that!  I hope you have found this information helpful, even if you don’t run Kadee’s!!!  Stay tuned for more articles on how to install these wonderful couplers on our 1/29th scale treasures… *