Kato Mikado driver diameters and cutting TT grooves

[rogergperkins]

Clarification about Kato 2-8-2 with DCC; I did not intend to imply that Kato announced a new release.
I read between the lines on what MBK posted online.
May have miss understood.
Concur traction tires greatly improve the Kato 2-8-2; have them on all five of my engines.

[Rasputen]

I'll try to see how deep of a groove I can cut in a non-TT driver without ruining it.  If someone has a few
spare sets, I would be interested in them - I think I only have two. 

Perhaps if I cheat a little and leave the OD larger than 0.455, the traction tire would still stay on,
but still be useable?  There shouldn't be a lot of stress on the remaining metal during operation,
but if there is only .006 left then there will definitely be some scrap.

[mmagliaro]

Great photo, Peteski.
My original post had the wrong values.  My first digits should all be "3", not "4".  Thank you for correcting that.

To answer Chris's question, I did this by just running a fine diamond jewelers file against the tread.  It is a pretty gentle way to go,
more gentle than an actual "cutter".  I have serious doubt about being able to cut that groove down until there
is only .005" of metal left, and not destroy the rim while doing it.  If you have a good lathe and you are really good at using it,
maybe. 

I don't (have) ... and I'm not (that good) 

Some other metal wheel  band that is the right size and already has a traction tire on it... hmmmm

Another EDIT:
Something struck me about your comment about Kato "over engineering" the driver.
It seems to me that they didn't have a choice.  The Mikado came out, and they must have quickly realized that its
pulling power wasn't cutting it.  The driver rim was too thin, so what else could they do?

And in retrospect, if they had not introduced that TT driver as an option, the Mikado would probably have
been a big flop because of its pulling, even though it runs so well.


-- M

As others have mentioned, Kato Mikado without a traction tire driver is pretty much useless (which is too bad for such a smooth running and well designed loco).  For few years traction tire drivers from the last run were worth their price in gold! After years of modelers pleading with Kato USA (and after years of Kato USA pleading with Kato Japan), around last December another batch of those drivers was produced. But they are all gone again so either Kato again misjudged the demand or speculators bought them all out.    That is really too bad. There was a mention of Kato producing yet another batch but I'm not so sure about that.  Funny thing is that another small batch of (never to be seen) Mikados (Kobo version) showed up again at MBK.  But going back to traction tire drivers, I was lucky enough to buy 8 of them from the latest run at a discount from MBK.

As far as the drivers go, I measured (using digital caliper) couple of my Mikados and my results were quite different from Max's. All the drivers have consistent diameter.  Here are the measurements:
                                          Driver          1               2               3                4 no tire        4 w/tire
Dia. of the driver's metal tire   ------- 0.372"     0.373"      0.372"      0.372"            0.374" with tire, 0.363" metal rim, 0.352" groove
Dia. of the drivers flange  ------------  0.424"     0.424"      0.424"      0.424"            0.424"
Dia. of the drivers insert opening  -- 0.340"     0.340"      0.340"      0.340"            0.323"
Dia. of the insert.    -------------------- 0.335"     0.335"      0.335"      0.335"            0.320"

I was also very surprised that Kato produced a whole new metal wheel and spoke insert just for the TT driver. But then again, Kato likes to over engineer things (no that there is anything wrong with that).  I'm pretty sure that they did that because otherwise the thickness of the wheel at the groove area would have been very thin.  The groove is 0.0055" deep. that makes the metal in the groove area 0.0145" thick.

If they made the TT driver using the standard driver then the thickness of the metal in the groove area 0.006"  That would be pretty darn thin! Too thin. I expect that the would have problems reliably turning their wheels without the outside of the metal tire tire breaking off.

Lemosteam:   I would look at this from a different perspective. I suspect that if the traction tire driver wasn't an afterthought, Kato would have made all the drivers with the same dimensions as the TT driver (to simplify production). But of course only the TT driver would have a groove in it.

Here are some photos of the difference between standard and traction tire driver. The difference is quite obvious.  In case it isn't, the TT driver is on the left.



In this photo I splices quarter of the standard driver on top of the TT driver. I aligned it by the edge of the metal tire (the difference of the flange depth on the right side is caused parallax error of the camera (it wasn't perfectly centered and perpendicular over the driver).

[mmagliaro]

Had to toss in just one more

I measure the Spectrum 2-8-0 TT driver at .374" over the tire itself, which seems like it should be a dead-on
match to the Kato driver.

Has anybody actually tried to just swap the wheels?   Ideally, you'd want to press out the centers and just use
the Spectrum rims so the drivers really match up visually.

[SkipGear]

If they are made like the Model Power drivers, there is no pressing anything out. The plastic is molded in the rim. There is a rib cut on the inside of the rim that fills with plastic when molded to lock the rims to the centers. I've tried to swap the rims on a model power driver after damaging a center section. Lets just say I did more damage in the effort.

The Kato centers may push out because the center hub on the revised wheels is the same piece as the rim. On the older wheels the hub and metal spokes were a seprate piece than the rim and I think those may have been molded together. The Bachmann wheels are copies of the revised Kato except that they have a solid back instead of spokes.

[mmagliaro]

Ugh.  Thanks for the update Tony.  Well, that kills that idea.  I wouldn't want to use the whole Bachmann wheel.
It doesn't match.

[Lemosteam]

But wait Max, what if you pressed Bachmann drivers onto ALL the axles so they match... (Ughh.  Trix driver conversion all over again....)

[OHCR 4218]

I have been watching E bay for a while, the traction tire drivers are fairly rare, I haven't managed to get a set yet. As for Bull Frog Snot, I can give you a good example of what not to do. I applyed what I thought to be a small amount of BFS. A day later I attempted to run it and to my suprise the siderods where stuck to the drivers. Thinking like Tim the Tool Man I applyed more power.  Turns out the BFS is stonger than the axle keys.    The good news was that I was able to find a new used mikado for 30 bucks.

Brandon

[peteski]

But wait Max, what if you pressed Bachmann drivers onto ALL the axles so they match... (Ughh.  Trix driver conversion all over again....)

But the Bachmann drivers (with the blind spokes) are so crude and ugly!  Why ruin a perfectly presentable Kato locomotive with drivers which look like they came from an old child's toy?!  Just to get a traction tire?  I would rather spend the money on the real thing.

[Chris333]

What about first run drivers? Are they just as thin and the newer ones.

[mmagliaro]

But the Bachmann drivers (with the blind spokes) are so crude and ugly!  Why ruin a perfectly presentable Kato locomotive with drivers which look like they came from an old child's toy?!  Just to get a traction tire?  I would rather spend the money on the real thing.

Right.  That's the rub.  I just wanted the metal rim.  I wanted to keep the Kato centers, but it looks like I can't.

[robert3985]

After reading this thread, and looking at the photos...IF the proper depth TT groove will leave a bit of metal at the bottom of the groove...even only .006", that should be enough for the tire to remain on the driver center, IF it's done on a lathe, at the correct speed, with the correct, sharp tool, and only if the driver is mounted securely with ZERO run-out at the tire surface..taking miniscule cuts to not overly stress the driver center or overheat the tire...causing it to dismount from the driver center.

Because of the tiny amount of "meat" left on the bottom of the cut, attempting to make this cut by using a diamond file and a cordless drill will ALWAYS fail because of the precise concentricity required.  It's just not possible attempting to do it "by hand" if the proper depth TT groove only leaves such a small cross section of metal.

Since you don't have a lathe...and are not versed in machine-work...maybe you could see if your buddy with his Sherline could do it for you! But only if he's experienced machining parts before. 

You DO know a model railroader with their own lathe and mill, right??

Cheers!
Bob Gilmore

[kelticsylk]

FYI...

http://www.ebay.com/itm/KATO-11-604-Pair-of-N-scale-Mikado-4-driver-with-traction-tire-NEW-/350569793821?pt=Model_RR_Trains&hash=item519f96891d

They are out there on a regular basis...

Just looked at this auction...
A) The bid is at $20 plus. A bit more than Kato would charge but OK.
B) Shipping is $12! For two driver sets? NO WAY!

I have used Plasti-Dip on the drivers. It's the stuff they dip tool handles in. It works great and cost A LOT less than BFS ($25 an ounce!). I have heard folks frantically tell me NO! You must use the Kato drivers because... (insert favorite reason). I had no problems.

I did notice that after I removed the Plasti-Dip the locomotive (with GHQ kit) had more traction than a blank driver. It would pull 15 cars up a 1.5% grade. I think the minute scratches created from scraping the stuff off may have caused the change. Apparently roughing up the driver surface may help somewhat.

The Plasti-Dip can be purchased at Home Depot or Lowes. It does a great job and there is no noticeble if applied correctly. Only a very thin coating is required.

My 2 cents worth...

[central.vermont]

But the Bachmann drivers (with the blind spokes) are so crude and ugly!  Why ruin a perfectly presentable Kato locomotive with drivers which look like they came from an old child's toy?!  Just to get a traction tire?  I would rather spend the money on the real thing.

Think it was meant to be a tounge in cheek answer and not a viable solution Pete! 

Jon

[SkipGear]

Big 4 Man.....

Hows that deal on Kato TT drivers now? Are you ready to buy?

http://www.ebay.com/itm/350569793821?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

Still 5 hours to go for the insanity to continue.