Anyone have experience with Accucraft K-36 derailing frequently. Mine does. Need help!
Hi Howard,
Welcome aboard.
Can you tell us a little more, like which wheels derail first and is there a situation where it happens? Do you have other locos that don’t derail where the K does?
I’m with John on this one…
First things to always ck.
Wheel gage… Are all the wheels properly gaged, and running true on the axels?
Track gage… Is the track in gage, and if the derailment happens at a turnout, is it in gage, and are the guide rails “in Gage” with the proper spacing for “Back to back” size?
Track radius… Are you trying to get it to go around to sharp of a corner. Big engines need big curves.
Lead or trailing truck causing the issue… Check for clearance when they pivot, and or are electrical wires causing binding.
All these things are the most common reasons for de-railing… on almost any engine, and need to be verified first.
Dave
Howard
I saw your comments in chat last night. 10’ radius track is plenty big. You said #6 trunouts which should also work as they diverge rather than curve. This is exactly the combination I use. Assuming your track work is not damaged then the locomotive is the culprit.
I have the K27 but two members here in the NMGR own the K36 both electric and live steam versions. One of the members runs on Code 332 with no problems and the other on code 250 also with no problems. That said all Accucraft engines will pick the points of a turnout if they are not closing completely.
My thought is bent axle or damaged flange. This could be so slight that you do not see it on the track. Check it on a stationary roller or turn it over and look down the drivers for wobble effect. This will also give you the chance to see if their bind from being slightly out of quarter.
You might also check the end swing over the pony truck. Run slowly through a curve and see if it is causing the front driver to lift up on one side.
Howard , I purchased a k-36 new several years ago and it would not run 6 feet without derailing . When I inspected the wheels I found 2 problems . The first problem was
one that the stainless steel wheel flange was not centered on its hub and caused a severe wobble .The second problem was back to back spacing on both front and rear trucks .
Fixing both was not difficult . The flange is a pressure fit and could be pressed on the hub without removing the driver . I used channel locks with a pad . The flange slid into place .
It has not moved again . Problem # 2 required disassembling the trucks and setting standard back to back . I hope this helps .
Earl
Thanks for the input. I inspected the drivers and found them to be in gauge with almost imperceptible wobble. I suspect sharp flange maybe the problem or the side play is almost non-existant; stiff frame is a common cause of engines derailing
Howard, my first live steam engine is a K-28 and while it did well on the club’s portable layout and the Stavers elevated layout in Portland, it continually derailed on my garden layout. For years, I blamed my gravel based tracks with its grades and descents, and slowly rebuilt and put in larger radius tracks. After doing that, this year the layout was in best condition…it still derailed. And only then, I must say to my disgust, did I check the springs on the drivers. There was virtually no movement. As a matter of pure chance, I attended a HO layout open house one night in the spring, and had been asked to bring the engine to show its size. The host was a retired mechanical engineer who immediately saw the problem and with pages of measurement shown afterwards, both unfroze some springs and replaced others that were too strong. The engine has not derailed since on my layout. My gratitude to him knows no bounds as I would never have had the skills to do same.
Myron Claridge
Each driving box on the K-36 is carried on three coil springs. They seem very strong (stiff). Would it help to remove one spring from each box? Any thoughts on this? I think I can do it one axel at a time.
Howard Hoy
Howard, do a google search for Accucraft K-28 issues, there were some threads on the engine’s issues when first brought in and the spring issue was discussed in MLS steam section and maybe here, and even websites other than these. Some people did suggest either shortening the springs or removing a spring or even two leaving the middle one in each driver…Mine were frozen, no movement whatsoever and thus, removal of one or two would not have worked, they and boxes had to be freed, then springs replaced or shortened.
un-Level track side to side and @ switches … (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-wink.gif)
