Micro-Trains Wheelset Question

[VonRyan]

Point to point is the same on the wheels...inside of cone to inside of cone on the side frames is the same. All we did was restore the sideframes to their original thickness, point dimensions stayed the same.  Over the years, to combat flash, grinding was done on the hot half to the point we could not keep the sides from flexing.  Assembled trucks with and without couplers are roll tested but I cannot speak to how old stock works with new given all the variables regarding shrink, expansion or flashing that may have happened in the past. 

Joe
MTL

Hmm... so basically the change in thickness of the truck-frames is only outward?
I found it odd since in some not-exactly-old-nor-new trucks i could put the rib-back wheelsets in and they would roll just fine, but with the newer trucks it's a no-go.
I'm satisfied.
(plus it is kinda hard to argue with the guy that makes the stuff.  )

-Cody F.

[JoeD]

Hey Cody,

Not to the outside but to the inside, but the position of the cone point was the same.  Hard to picture this and me describe it without my second cup of coffee    I think shrinkage may be the issue you are having, I know we try and maintain dimensions but there are so many variables in manufacturing to such hight tolerances.  When you see how they are made (nicer than seeing sausage made) you see that as the side frames come out of the mold they are pushed over the point inserts...so the side frames are splayed out a bit and then, in theory snap back to position.  If something is running to hot, potentially you could get the inside dimensions a bit wider than normal.    Oye...my head hurts.   

Joe

Hmm... so basically the change in thickness of the truck-frames is only outward?
I found it odd since in some not-exactly-old-nor-new trucks i could put the rib-back wheelsets in and they would roll just fine, but with the newer trucks it's a no-go.
I'm satisfied.
(plus it is kinda hard to argue with the guy that makes the stuff.  )

-Cody F.

[NYC1956]

Joe, if you are talking about a run of the original 1008 lo-pros - I would be in for a couple thousand or so myself!
I was converting everything I had to lo-pros and was dismayed to discover the design had changed part way through the process!
The second iteration (with the sharp flanges and flat tread) just doesn't cut it.

[VonRyan]

Hey Cody,

Not to the outside but to the inside, but the position of the cone point was the same.  Hard to picture this and me describe it without my second cup of coffee    I think shrinkage may be the issue you are having, I know we try and maintain dimensions but there are so many variables in manufacturing to such hight tolerances.  When you see how they are made (nicer than seeing sausage made) you see that as the side frames come out of the mold they are pushed over the point inserts...so the side frames are splayed out a bit and then, in theory snap back to position.  If something is running to hot, potentially you could get the inside dimensions a bit wider than normal.    Oye...my head hurts.   

Joe

That would explain it. especially since the old wheelsets have metal axles so the shrinkage would be less than the delrin.
though comparing the sides of the newer truck frames to the sides of some oldish ones by eye, the newer ones are thicker, and i think it extends inward and outward, but luckily I haven't had an issue with the low-pros yet, and once tuned up they roll just as good as the older ones.
All-in-all I'm just glad that there is more wood-side reefers. 



-Cody F.

[bbussey]

Point to point is the same on the wheels...inside of cone to inside of cone on the side frames is the same. All we did was restore the sideframes to their original thickness, point dimensions stayed the same.  Over the years, to combat flash, grinding was done on the hot half to the point we could not keep the sides from flexing.  Assembled trucks with and without couplers are roll tested but I cannot speak to how old stock works with new given all the variables regarding shrink, expansion or flashing that may have happened in the past. 

That may be, but the original LoPros definitely will not spin freely (if at all) in the current truck frames.

[peteski]

That may be, but the original LoPros definitely will not spin freely (if at all) in the current truck frames.

 I suspect that just like decreasing sexual performance of aging males, this can be blamed on ...shrinkage... 
At least that is Joe's way to explain any incompatibility between different versions of the trucks and wheelsets.

[VonRyan]

That may be, but the original LoPros definitely will not spin freely (if at all) in the current truck frames.

Good to know i'm not the only one noticing things. 


-Cody F.