Large Scale Central

Bachmann K 27 Tinkering

OK folks we’re closing in on Spring Fix and Repair time, one of the things I want to do this year is lock the front and rear drivers on my K to solve some issues its having…problem is , I haven’t been able to find the prcedure anywhere…anyone can give me a rough blow by blow and or even better some pics would be appreciated!!!

What do you mean by “lock the front and rear drivers”? Side to side play?

Ken,

it’s purpose is to eliminate the side play in driver 1 and 4. Toc told me about it when the “K” first came out and it has helped with track side clearance. It really does not affect the ability of the

“K” to negotiate curves. It prevents overhang coming into and out of curves and switches.

I used vinyl washers to lock mine. and it seemed to even help with tracking of the pilot.

Use care not to get the drivers locked too tight and that the hole for the axle is of a size not to bind…

Well worth the time to do it.

Frank Bailey said:

Ken,

it’s purpose is to eliminate the side play in driver 1 and 4. Toc told me about it when the “K” first came out and it has helped with track side clearance. It really does not affect the ability of the

“K” to negotiate curves. It prevents overhang coming into and out of curves and switches.

I used vinyl washers to lock mine. and it seemed to even help with tracking of the pilot.

Use care not to get the drivers locked too tight and that the hole for the axle is of a size not to bind…

Well worth the time to do it.

Gotcha. I do seem to recall now a mention of this from somewhere in the past. I just wasn’t sure what Bart was talking about.

This might help Bart,

Modification #3: Eliminating excess side play By Dave Goodson
Out of the box, the locomotive I have has about 11/16" side play at the pilot beam. This is to allow all 4 drivers to move 1/4" on their inner axles. It was a little too much for my tighter clearances, as a load could cause it to not make the clearance.

To fix this, I removed the #1 axle, took out the cranks and springs, and made some nylon washers to test. I installed the washers between the wheel and frame. Replace the cranks but not the springs. Now the locomotive has less than 1/4" play, but it still traverses 1600 curves without problem.

Next, I did #4 axle in the same manner. The K-27 still runs smoothly through LGB 1600 curves and switches (old ones, too), still has about 1/4" sideplay at the pilot beam, and the locomotive does not “rack” when backing a load.

This is less diameter than the 8’ diameter specified by the manufacturer as minimum.
For anyone with tighter clearances on their railroad, this could be helpful. Since this is a screwdriver modification, it’s easy to remove the washers.

Good Luck.

Thanks Frank, exactly what Bart is looking for.

OK thanks Frank I think that answers my question…

Bart, I found the material at Home Depot. They were spacers that I cut down. They didn’t sell a nylon washer that size.

Here’s what I did to mine. http://largescalecentral.com/forums/topic/19896/a-little-b-mann-k27-help-please/view/page/1

I have some of the spacers left, If you want I’ll bring them to York.

Terry

edit because I can’t spell.

I’m glad I could help!

I have the 2nd generation and it runs well but not a lot. No issues at this point.

Nicky

Locking some drivers on the K27 will reduce the side to side play on curves.

If you are going to lock drivers I would recommend doing the 2nd and 4th rather then the 1st and 4tth

Why?

On the prototype the pilot’s purpose is to guide the locomotive around curves. In the model the pilot is simply pushed along the track. It does not exert much force to help guide the model.

When you lock the 2nd driver rather then the 1st driver the result is that the 1st driver with its axle springs will help glide the frame around curves.

I have several K27s. They are my favorite locomotive. Only one has locked drivers. It is the one that can operate DCC or RC and is the only one I take to other railroads. I have adequate clearance on the SJR&P so I have not bothered to do this step with the other Ks on the railroad.

Hope that Helps

Stan

I don’t understand. Is this modification for tighter curves than 8’ dia?

I have 15’+ on my layout and have no problems. And heaven knows my track ain’t level or perfect. I did re-gear it with Rodney’s motor and gearbox.

I believe all will be made clear soon. Stand by for edification.

Greg

One thing all you Gentlemen need to note is that you need to check your RR clearances. Get the D&RGW clearance diagram and atart checking your own RR clearances. I found a diagram in an old Fine Scale Modeler of several years back. Might check the WEB to see what you can find. I know that my own K has problems on the CCRy due this very problem. I have made a number of changes on my own SVRR so I now have fewer problems. Other than a BBT drive I have done nothing to the K, so far!

Paul

I’m consulting the master, and will be adding to a web page on all tips on the K:

http://www.elmassian.com/trains/motive-power-mods-aamp-tips/bachmann-motive-power/k27/improving-the-k27

Greg - For us more faint of heart, could you possibly include pictures ore better yet a complete “How To”?

Thanks Greg.

Bob C.

Thanks Greg, Your site is one of the best and most helpful to a lot of people. It’s great that you invest your time and knowledge to help others out,This is another reason why our scale is starting to move forward again because of people with knowledge of the products and helpful fix’s when there’s some issues.

Thanks.

P.S. We do like pictures…

OK guys,I’m not have a clearance issue…I’m haveing a yawing that makes the front pilot truck derail at a certain switch issue…when the locomotive is straight on the track…its not an issue…after several laps around the loop its significantly pointing off to one side and the pilot truck picks ont the switch everytime…thus to need to lock the driver…

Bart Salmons said:

OK guys,I’m not have a clearance issue…I’m haveing a yawing that makes the front pilot truck derail at a certain switch issue…when the locomotive is straight on the track…its not an issue…after several laps around the loop its significantly pointing off to one side and the pilot truck picks ont the switch everytime…thus to need to lock the driver…

Bart

The pilot truck derailing is a common issue. We generally use the K’s pilot truck to find track problems on the layout.

Which turnout brand and model is your K derailing on?

Stan

Ummmm all my switches are hand laid…