K-27 Counterweight Link

[lqdsky]

Sorry I'm obviously over looking it.  Can someone point me to the link that has the details on how to tell if I have have the previous run with the faulty  counterweights.

I had received my K-27 a few months ago and it did not have a sticker on the box stating new counter weights. I had completely forgot to check, yep that busy.

I think I remember that one of the test was to hold one counterweight and move the opposite weight and that if their was allot of movement, then it's bad. Mine only moves slightly, less than 5%.

[Tony Walsham]

"I think I remember that one of the test was to hold one counterweight and move the opposite weight and that if their was allot of movement, then it's bad. Mine only moves slightly, less than 5%."

They should not move at all after being replaced.
Any movement at all would eventually end up being a lot of movement resulting in a lock up situation.

[Jon D. Miller]

No movement, i.e., slight rotation on the axle is not necessarily so.

Having replaced counterweights on eleven K-27 locomotives I've noticed that on some of the counterweights, when properly installed there could still be a very slight amount of rotation of the weight on the axle.  This slight rotation, certainly not 5%. however that is measured, will not cause a problem. This slight rotation, hardly noticeable, can be determined by holding the opposite counterweight and trying to rotate the counterweight.  Remember these weights are not a press or interference fit on the axle.  Not all replacement counterweights will have this very slight rotation.  Most, if not all weights replaced will not have any rotation. Now I realize that replacement of just eleven sets of couterweights probably does not even come close to all those replaced by TLIHOM, however eleven does seem a reasonable sample.

The old counterweights had two slots in the mounting face where the screw and washer set against the counterweight. If your counterweight does not have these two slots, that is, the mounting face is smooth with no slots then these are the new counterweights.

Look at one of your counterweights. If it does not have the slots in the mounting face, as described above, then you have the new weights.  On all the weights replaced, the originals had these two slots in the mounting face. Replacement weights had no slots with the mounting face of the counterweight being smooth.  This is the mounting face where the washers and mounting screw attach the weight to the axle.

       (Just one of the "enthusiastic children")

JD

[lqdsky]

Thank You guys for taking the time. I know this has been beaten over & over.
By your description, these seem to be the replacements, correct?

So the slight movement is alright?
Looks like I'm good to go.

[the Bach-man]

Dear All,
There is always counterweight play in part because of the axle design
where the wheel floats back and forth on the axle.  So if you only try
to rotate one side you will see some play but that is normal because it
is the axle that is moving and not the counterweight.

The best way to check is to hold one counter weight in one hand and
then try to rotate the counterweight on the other side. Movement then
is counterweight movement and not axle movement.

If there is play in excess of 1/4 inch the counterweights need to be
replaced.  If there is only a slight movement then the counterweights
are the new ones.
Have fun!
the Bach-man

[grayfitz]

Mr Bach man,Am I the only one to make a point about the counterweight crank pins being a different length on the new weights to the old weights.? If we were to replace four on each side it wouldnt matter,Regards Graham,

[Tony Walsham]

"Mr Bach man,Am I the only one to make a point about the counterweight crank pins being a different length on the new weights to the old weights.? If we were to replace four on each side it wouldnt matter,Regards Graham,"

Graham.
I have here examples of both old and new replacement counterweights.
Yes, you are correct. 
The shaft does appear to be slightly longer than the old one.
Well, not the shaft itself. 
The actual bearing surface of the drive rods are the same length.  It is the thickness of the spacer that stands the rods proud from the actual counterweight that makes the rods sit further out than the old version.
I guess it could be possible for tight fitting rod bearings to wear a bit more than they otherwise would.
I have done  a number of replacements now and so far the fact that the sides rods are not exactly parallel along the length of the wheelbase has made absolutely no difference to the performance.  There is still enough side play of the rods to allow for the 1/2 mm difference in the spacer thickness compared to the old counterweights.

[grayfitz]

 ThanksTony, It looks as though no one else is worried about the difference including The Administrator.I wonder why the difference, was it a mistake ,or is there a reason,If it was intentional ,a note in the pack of new weights would have explained. I suppose we will never know, SO I will complete my replacements and hope all will be OK,  Regards Graham (Australia)

[FordcvP71]

I just checked mine that i got back in May, 3 out of 4 counterweights on either side have alot of movement

The third one back i think it was didnt move at all but the rest seemed veeeery loose and hardly felt like anything was connecting them to eachother 

Where do you get the new counterweights from? 

[jimtyp]

Yes, the #3 axle is normally fine.  You need to send a request into Bachmann Service department.  I sent in a FAX with a copy of my original receipt.  Got the replacements about 10 days later.   If you don't want to do the work yourself they will pay to ship the loco both ways and do the work for you.  However, it is a fairly simple procedure, follow this link for the detailed steps on replacing the counterweights.

http://www.bachmanntrains.com/home-usa/gallery/album49