Kato SD70ACe assembly issue?

[R L Smith]

I recently purchased two of the Kato Heritage SD70ACe's and decoders from my LHS.  Finally got around to taking them out of the box, and as soon as I did, the rear truck assembly fell out - on both locomotives!



I need to take the shells off anyway to install decoders, so I assume I can fix these without too much difficulty.  My reason for posting here is to ask two questions:

1) Did anyone else have this problem with recent Kato units?  (Perhaps my LHS received a box that saw "extra handling".)

2) Are there any other surprises waiting for me when I remove the shells?

Thanks in advance,

Ron

edited title. -gfh

[johnh35]

Received a new one a year or so back that had the same problem. Not too fond of the design.

[peteski]

I think that I read about this problem back on the A-board.  Is is possible that the truck detached during shipping?

These locomotive are very delicate but  they run like a Swiss watches and pull quite well (I've seen them in action on friend's layout.

[Bob Horn]

About 50% of mine arrived in the same shape. Not hard to repair, just make sure you get the driveshaft lined up correctly. Kato insists it is due to rough handling. Bob.

[Teditor]

I have the full Heritage collection of these, the chassis halves are just held together by the chassis/body (not screwed together), the trucks come out 'very' easy, as stated by another, make sure the drive shaft seats in the flywheel and just push the truck back in.

The extended under loco packing piece is to help in the handling of these locos and also help keep the trucks in place.

The trucks feature (for want of a better word) a sprung centre axle, for this to work, there are very fine toothed gears, the most minute particle of ballast etc can jam them up (a clunk, clunk and hopping of the truck is a dead give-away that this has occurred).

I place a strip of Tamiya Masking tape on the bottom of the truck to help avoid this happening.

These are a great running loco, but need constant TLC.

[wazzou]

I don't own any of these or any recent KATO power for that matter, however If I remember right, this was a widespread problem with the redesigned SD40-2 and newer KATO produced locomotives.

[jereising]

I don't own any of these or any recent KATO power for that matter, however If I remember right, this was a widespread problem with the redesigned SD40-2 and newer KATO produced locomotives.

I think the SD40-2 Mid Production and SD70ACe are the only two with the "sprung truck" chassis design.  I believe Kato has taken their sophistication a bit too far with this design. 

Because of this, I'm very much looking forward to Fox Valley's pending SD70ACEs - when they come out in other than the NS Heritage schemes, and will most likely replace all my Kato ACes with the simpler, more reliable FVM chassis over time.  Given Kato's notoriously poor long term parts support, there are gonna be a lot of 40-2 Mids and ACes sitting on the shelf in coming years.

[R L Smith]

Thanks for your input everyone.  The SD70ACE's are too modern for my era, so I guess I wasn't paying attention to any previous discussions about the issue.

RLS

[mu26aeh]

Yes, and now you have to get some stacks and racks to pull with those Aces 

[GaryHinshaw]

I have ~half a dozen ACe's and the lead truck on one of them (a KCS Belle) refuses to stay in place, whereas the rest seem to be fine: the trucks are easy to remove, but not so easy that they just fall out.  I haven't figured out why the one is the way it is yet…  The thing that bugs me more about the new design is that the truck side frames don't sit level to the rails because of the way the spring mechanism in the phosphor pickups is designed.  When viewed at eye level, they look a bit silly, and I don't see an easy way to fix that. 

I too am curious to see how the FVM ACe's stack up.

-gfh

[Bob Horn]

Gary, drop the frame as per the instructions for the SD-40-2 mid-pro on the Kato site. Then assemble the truck and gear tower and re-install. Bob.

[GaryHinshaw]

Thanks for the tip Bob.  I did what you suggested and I have gotten to the point where the trucks don't fall out freely -- which is progress!  To satisfy my compulsiveness, I looked at the loco some more and can identify three separate mechanical issues which bug me about the ACe's.  This photo illustrates two of them, and might be useful to others:



1. The first issue (noted above) has to do with the tab circled in green at the top of the truck tower.  That tab is supposed to rest on a shelf inside the frame and you push them in to release the truck.  The problem I am having is that the slightest bit of inward deformation of these tabs causes them to barely contact their shelf, making them prone to just falling out.  I verified that my frame assembly was fine by swapping trucks and having the problem stay with the truck.  (I did take apart the frame too, with no discernible effect.)  My only solution so far is to force the tabs back out a bit so they engage the shelf better, but it's not a very satisfactory solution.

2. The second issue has to do with the sprung truck design as a whole.  There are two sources of springiness in the design: a) the phosphor contact strip along the under frame pushes down on the contact above the centre axle.  This is basically fine, except that the support tabs noted above are inboard of the centre axle, so this causes a torque on the truck that is counterclockwise in this photo (two black arrows).  b) The axle cup pickup assembly has a sprung arm to support the centre axle (red lines indicate the outline of the assembly, schematically).  This makes the rest position of the centre axle lower than the outer two, producing better tracking and  adhesion, in theory.  (Note, you can kind of see that the left wheel is not in contact with the rail in the photo above.)  The problem for me is that the pickup strip is not very well secured to the sideframe, so it can rotate a bit relative to the frame.  The net result is that there is a strong tendency for the frames to sit askew relative to the wheels, e.g.:



It's not a huge deal, but it looks dorky and it bugs me!     I think it would help to attach the pickup strips more securely to the truck frames, but I'm not sure how to best do that yet.

3.  This last one is a minor issue, but I seem to be having a bit of a fit problem with the shell and the under-skirting.  Here is an illustration of the issue:



With Kato's new screwless design (what wrong with screws?), the skirting is the device that holds the frame halves together when the shell is off.  It snaps on to little tabs on the frame halves at the front and back (and around the fuel tank).  When attached properly, there should be no gap between the green lines in the photo above.  However, when I put the shell on, it presses down on the skirting causing it to sit too low.  I think I need to file away some shell and/or skirt material to relieve the pressure there.  In the shot above, the little spacer (black arrow) that keeps the frame halves separated is almost entirely out of the slot... 

Sorry to ramble on...
-gfh

P.S. I should add that these locos run beautifully (of course) and that the tooling quality of the shell is second to none.   Paint quality is variable and their lack of detail is already well documented.

[Bob Horn]

I got another today, Lackawanna since I grew up with the Lackawanna in Chatham, NJ. This was another problem unit with the truck contacts out of place and the contact for the frame caught under the nub on the gear case. Also the underframe was not installed properly. These problems are not caused by rough handling in shipment. It was just not properly assembled to start with. The repairs took less than 3 min. Still the best out of the box locos on the market. My fleet is at least 75% Kato out of some 150 locos. Bob.

[GaryHinshaw]

FWIW, my fleet is ~90% Kato, but that is mostly due to the prototype and era I model.  I like their fundamentals - mechanism & tooling quality - and I'm happy to take care of the detailing myself. But the ACe is a case where their design got a step or two ahead of their execution, IMHO.

-gfh

[MichaelWinicki]

Nice write up Gary!

I don't own of these, but I learned something in case I ever do.