A.F. Standard steam wheel axle hole & rod screw hole size ?

Hi Harry, sorry to take so long to get back to you, I had to clear a place to set a ladder up on the layout to get to the top shelves, you can tell I don't run these too often.

So I looked at 4 Flyer Wide Gauge steam locomotives. 

4672 cast iron loco; sold with the 4671 tender it was called the 4672.

4694 Ives type loco with the "Golden State" tender

4696 brass piper loco, sold with 4693 oil tender

and the 4692 large loco (but not piper) sold with the 4671 tender as 4675.

Flyer's numbering system was absurd.

I did not pull off wheels or anything, but the Flyer drive axles caliper at:

.186

.1865

.185

.1875

which seems to be normal variation.

For the drive rods, two of the engines (4694 and 4692) were obviously 6/32 thread.

The other two, I think they are 6/32, but when I threaded a new 6/32 machine screw into the hole, it would go in a couple turns then bind up. Comparing the threads on the Flyer screw and the new 6/32 screw, it appears that the Flyer screw might be slightly coarser threads.  However, I am not aware of a 6/24 standard thread.  When I put a new 6/32 nut on the old Flyer screw, it went on fine.  The threads were definitely NOT size 4 or size 8, they are #6, and 6/32 seems to be it.  All 4 Flyer locos appear to have original drive wheels.

I know Lionel on some applications used a 4/56, which is finer than the standard 4/40, and 4/56 is basically impossible to find today; so the popularity of thread sizes does change, and it may be possible that there was a coarser thread #6 that Flyer used?  or it may just be that the threads in the wheel were old and hanging up. Maybe another forum member could shed some light on this?  As I say, a new 6/32 nut spun on the Flyer rod screw easily.

I also looked at two Ives 1134 steam locos: the 1928 version and the 1930 version. I was not able to get in to caliper the drive axle, without disassembling the engine. However I was able to caliper the inside of the hole in one drive wheel which was not all the way on the axle. I got .192, which given the difficulty of getting a good reading I would say is probably the same as the Flyers.  The Ives drive rod holes are definitely 6/32. However, both Ives engines have MEW replacement drive wheels on them.

It makes sense that Ives and Flyer steam wheels would be the same. Flyer did not have a wide gauge steam engine; it got the rights to the 1134 when Ives and Lionel bought Ives in 1928. So the Ives 1134 was then the Flyer steam engine... and when Flyer developed other steam engines from there, it would have made sense to carry over the same steam wheel specs. 

david

For the most part, David is spot on(as per usual!).  I measured 24 axles and its my vernier caliper they all measured between .182" and .1875" with the majority being .186".  I prefer a .003" to .004" press fit for the wheels.  Some recent MEW electric loco wheels are reamed to .182" I have no more replacement steam wheels but an original with a short axle measured .182".

Some original AF Steam wheels are tapped for 6/36, most are tapped for 6/32, Remember that 1931 had press fit stakes on the eccentric crank. I don't know how many are out there (it was a failed attempt at cost cutting?) and that mics out at .110".  

Ives wide motor driving wheels mic out at .205" (MEW Replacement).  The wheels are quite different than AF... serendipity on the rims.

Thanks Rob, good info.   6/36, that's weird.

d

hojack posted:

Thanks Rob, good info.   6/36, that's weird.

d

Not if you make your own fasteners!  Lionel did this early on as well.  Ever wonder why 6/32 some times just don't seem to fit? But will go in if you work hard enough?  Or the screw made of brass that all of a sudden snaps at the shoulder?

Model engineer threading standards were implemented (but not fully accepted) in 1912.  My guess is that as the threading machines got replaced in the 20's, they went to the "new" standard.

Thank you all.  My original notes from MEW call for .182 axle ream, & 6:32 screw thread.  Variations in screw pitch was not noted anywhere ( in my notes )., but when we tapped the Lionel std. & "O" gauge holes, I went slightly deeper so that the screw did not bottom out in the hole, but rather when the shoulder met the wheel.  Braking off a nickel plated brass screw is not the way you want to finish a wheel job.  

I am still looking for more info on the Ives std.   Harry