K-27 Counterweights

[JLyans]

Dear All,
As reported here, some (many? all?) K-27s have loose counterweights that can bind from time to time. Dave Goodson has examined the locos and made a suggestion, which has been independently corroborated by a couple of other Large Scalers.
We have been in contact with China, and shim sets are being prepared. A call to the service department will get you a set. I'll post here when they arrive; please hold your calls until then.

Bach Man,
Wow, I had hoped for something better than that. I don't think that this is the best solution.  I am a relatively experienced modeler and this is a task that is not for the faint of heart.  I have placed brass shims in four counterweights so far and they have varied from .004" on the drive axle to just under .008" on the fourth axle. They don't go on real easy and some of the axle ends have to be filed down a little.  Also, a lot of people are going to end up with those little plastic retainers broken.  The thicknesses of the needed shims vary some from model to model which will make for a difficult fix unless a variety of shim thicknesses are provided.  There are a lot of folks that won't mind taking this on but I don't think the majority of your customers are going to want to be filing away on the axles.

I think a better, but admittedly more costly solution would be to make up new counterweights with the correct fit at the axle and a little bit thicker so that the axles wouldn't have to be filed. I wouldn't even mind paying for better fitting counterweights.

Sorry to make this observation because this is a beautiful model, perhaps the nicest looking 1:20.3 model I have ever seen.

Thank you.
John

[glennk28]

Pardon the double post on this--but I didn't realize this thread had started.

At what point should a problem become evident with the counterweights?  Does it take time and miles to develop, or should it happen right away?  Exactly what happens?  Is it only on certain number locos (assuming that each variation was done as a batch, and that at some point the problem was seen?)  So far I have only run my loco back and forth on the bench, about 12 feet.

[the Bach-man]

Dear Glenn,
I haven't had one here to check, but evidently you should be able to tell immediately.
I just got one to display at the Amherst Show in Springfield; I'll check it there.
Have fun!
the Bach-man

[JLyans]

Glenn,
Here is a link to a picture of what happens. Most of the problem seems to be too much slop in the rotation necessitating the shims on the flat part of the axle. But there is also too much lateral play hence the need to very slightly file some, (but not all), of the axle ends.

When I first ran my K-27 it locked up only twice when I would  reverse the direction. But the problem will only worsen with time if there is any play at all. Of the two metals that make up the axle and the counterweight, the counterweight is the softer of the two and eventually as it "works" back and forth the opening will enlarge.

John

http://www.elmassian.com/images/stories/motivepower/bachmann/whoops1.jpg

[glennk28]

Thanks--mine hasn't shown any problem yet--but as I used to tell clients as an Inspector--"the operative word couild be "yet".  gj

[Greg Elmassian]

I don't want to add any fuel to the fire, but there are "counterweight" issues even running forwards that will, in my opinion, cause excessive wear and eventual failure between the axle and counterweight.

You just cannot have all this free play when you are transmitting power through the connecting rods.

I have a video of this, but I will have to check with the person who took it first.

Suffice it to say, it needs correcting, but the fix is pretty simple, and not all that hard, in my opinion again.

Regards,

Greg

[glennk28]

Viewing the picture--that crank is definitely out of quarter!  It definitely should lock up!  I'll keep an eye on mine.  I agree that perhaps Bachmann should use the returned warranty cards as a mailing list to send out the shims when they come in.

[JLyans]

I would fix it before it becomes a problem. The longer it is run "loose," the more wear there is in the counterweight.

John

[locoron]

 A friend and I each have K27's and of course they both had floppy counterweights.
We shimmed, or rather he did, both of them with .015 styrene. This is a real tight fit but worked perfectly.  Should last as the only load on the styrene is compression and it ain't going anywhere. Took about 45 minutes per K
Both K's run very smooth and look great double headed.
   Locoron

[Kclassbuilder]

Hi all

I used .005 brass shim stock on the No. 4 counterweights.  This worked out great with no movement.   They are on has they should have been from the start.  The orange LED's have to go.

Best regards to all

Kclassbuilder

[Jeepersinco]

Bachmann,
Since I can't run my K-27 because of the counterweight issue I have an expensive mantle piece. I can't return it to Bachmann; it already has sound and DCC controls installed. Even if I could I would not want to wait the 3 or three months to send it to Bachmann and get it repair and sent back but I have not seen any offers from Bachmann.

If I take it locally to be fixed I have to pay to fix a manufacturing defect that I think Bachmann should be responsible for. I don't want to make the modifications myself on such an expensive piece of equipment.

What are K-27's owners to do? I'm not trying to be bitchy but I have $1000 invested in something I can't use. I don't want my money back I want a working model.

Sincerely,
Jim

PS I tried to PM this directly to the B Mann with no sucess.

[paultorrey]

Jim,

I am with you.  I have a very nice engine that I'm afraid to run.  I'm a little intimidated to take the side rods and counter weights off to try and shim them.  I would just assume send this back to them and have it fixed properly except I'm sure that would mean a flood of engines coming back and waiting weeks to get it back.  I'm hoping Bachmann will come up with several options for customers depending on their level of expertise and comfort in taking engines apart. 

Examples-
Option 1 - send out shim kits for all those that email Bachmann asking for them.  Customer to do the swap out.

Option 2 - send out new counter weights (that have been properly machined) for those that ask for them.  Customer to do the swap out.

Option 3 - for customers that want a warrantied fix, send them back to Bachmann for the permanent fix.  (Shipping to be paid by Bachmann both ways).  Higher extra staff if needed to do the work quickly and turn engines around in 1 wk or less.

I know from working with customers you need to satisfy them quickly or suffer the chance that future business goes elsewhere.  Just having the customer do the fixes themselves is not the best solution in my opinon.

I like the Bachmann products, I just want to see them step up to fix this issue so it's behind us.  A recall may be necessary.

Thanks,

[Carbine]

I have now shimmed the counterweights on both of my K-27's and inserted packing ABS "washers" on the 1st and 4th axles to reduce the amount "sideplay".
I found that all of the axles required some shimming under the counterweights and while I was at it, took some measurements.
I found that all the counterweight holes, measured from the flat of the "D" appeared to be the same. The issue is the machining of the flat at the end of the axle, they all verried to some extent, hence the need to shim.

In my opinion, replacing the counterweights would not solve the problem, the axles would have to be replaced with accurate machined locking flats.
Not an easy option.

Wayne

[glennk28]

How about option 4--Bachmann contract with "Authorized Service Stations" like Lionel used to have--send out "repair authorizations" for warranty repairs.  With all the customizing we have been doing on our locos, we need to be able to get our own loco back.  gj

[the Bach-man]

Dear All,
Please know we are actively pursuing a solution, and we will stand behind the locos.
Thanks!
the Bach-man