Arnold SW-1 Parts source?

[peteski]

I guess I concentrated on the first part of Max's post. 
Now I'm curious how he will handle insulating one of the Kato wheels, because the plastic sleeve is designed for a thicker Arnold wheel. I suppose he might turn some new ones out of Delrin.

I also haven't figured out the reason Arnold turned a groove in the axle where the insulating sleeve is installed.  To keep it from going out of gauge?

[johnb]

So Max, you will still end up with the Arnold insulated wheel and a "new" wheel electrically connected to the axle?  So you can only make as many replacment wheelsets as you have the old Arnold S2 locos?

what about the NWSL S2 wheel sets?

[nkalanaga]

NWSL also makes insulated bushings for various axle sizes, so one can probably special order wheels with whatever size you want, within reason.  I doubt that you could put a 3mm axle in an N scale wheel, but who'd want to?

[Ed Kapuscinski]

I'm really curious about the full replacement option. That's intriguing.

Although I don't know if I'm about to pull out a lathe to achieve it.

This reminds me, next time I do a Kato parts order I need to order a bunch of wheelsets for general replacements.

[mmagliaro]

To answer everyone's questions:  (slight correction on the drill size)

I drill out a Kato wheel to 1.45mm, and press it on the non-insulated side of the Arnold axle.
I drill out another Kato wheel with a #43   #44 bit, pop out the Delrin insulator from the Arnold wheel and press it into the Kato wheel, and then put that on the other side of the Arnold axle.  The insulator does not appear to be any different in fit in the Kato wheel, thickness-wise.  Yes, I can only do as many of these as I have Arnold SW-1 wheelsets, but I don't see why that's a problem, since the whole point is to replace all 8 wheels with Kato to get a new, matching set of 8 wheels with no traction tires. 
This means I end up with a few spare Arnold wheels with no traction tires (the ones without the insulating bushing)

The slightly larger Kato wheels just clear the brake shoe detail on the side frames.  I was a little worried about this when I put it back together.  But there was enough extra clearance there to allow for the wheels which are indeed .006" larger than the Arnold ones.

I have all 8 of these on an SW-1 and it seems to run fine.  I have had some things come up with work, so I haven't gotten any video done.  I have some photos.  I'll post this process as soon as I can.

One good thing about this was that it forced me to get around to meticulously aligning the tailstock of my lathe to the spindle.  It was "close" from the factory, but was about .005" off, which is way too much when you start talking about boring a hole that is .059" in diameter (1.5mm).

[Ed Kapuscinski]

So a dumb question... is it possible for the stock Kato geared wheelset to work?

[randgust]

I only got to 'play' with one of these SW1's at Altoona T-trak a couple years back and was very impressed.   Up until that model was announced, I was doing a number of custom-built SW1's based on the Kato NW2 chassis.

But looking at the parts supply situation over time, suddenly my Kato NW2 conversions with a resin body to an SW-1 are looking a whole lot better; that Kato NW2 drive has really proven to be a honey.  Yes, I know there are reports of cracked gears on those but I've been through about 15 of them and have yet to see it in the wild.

If you really wanted punishment, you made an SW1 out of a Life-Like SW chassis and redrilled new frame mounting holes after grinding the frame halves down.  Did that once.  Never again.    But there's a tiny bit of an evil smile looking at trying to put Kato wheels in the Hornby mech here to get around the traction tire supply problem and/or 8x8 pickup.

Doing the customs on these was fun while it lasted, but if you get frustrated enough, I still think it's feasible to stuff a Kato mech in there.

[johnb]

I only got to 'play' with one of these SW1's at Altoona T-trak a couple years back and was very impressed.   Up until that model was announced, I was doing a number of custom-built SW1's based on the Kato NW2 chassis.

But looking at the parts supply situation over time, suddenly my Kato NW2 conversions with a resin body to an SW-1 are looking a whole lot better; that Kato NW2 drive has really proven to be a honey.  Yes, I know there are reports of cracked gears on those but I've been through about 15 of them and have yet to see it in the wild.

If you really wanted punishment, you made an SW1 out of a Life-Like SW chassis and redrilled new frame mounting holes after grinding the frame halves down.  Did that once.  Never again.    But there's a tiny bit of an evil smile looking at trying to put Kato wheels in the Hornby mech here to get around the traction tire supply problem and/or 8x8 pickup.

Doing the customs on these was fun while it lasted, but if you get frustrated enough, I still think it's feasible to stuff a Kato mech in there.

after the crappy performance of my SW1, I  might be interested in your kit...

[Mark5]

No idea what Hornby was thinking when they put traction tires on these ...

Did anyone here do the no-traction tire swap on one of these while they were available? I'm curious as to how well they pulled without the rubber.

[tehachapifan]

I don't know what keeps the traction tire thing alive either. Maybe it's the crowd who thinks their tiny switcher should be able to move 30 cars around.

[dem34]

I don't know what keeps the traction tire thing alive either. Maybe it's the crowd who thinks their tiny switcher should be able to move 30 cars around.

There's always going to be that one guy.

But from what I gather with Hornby's 00 offerings it just seems like something they do as S.O.P.

[mmagliaro]

I guess I concentrated on the first part of Max's post. 
Now I'm curious how he will handle insulating one of the Kato wheels, because the plastic sleeve is designed for a thicker Arnold wheel. I suppose he might turn some new ones out of Delrin.

I also haven't figured out the reason Arnold turned a groove in the axle where the insulating sleeve is installed.  To keep it from going out of gauge?

To keep this together with Peteski's photo...  that Delrin insulator turns out to not be too thick to use in a Kato wheel.  I drilled out the Kato wheel with a #44 bit, and just pushed the Arnold insulator right into it.  It doesn't stick out on the outside face of the wheel.

[mmagliaro]

So a dumb question... is it possible for the stock Kato geared wheelset to work?

Probably not, since the Arnold Axle is 1.5mm and the Kato and Atlas stuff is smaller, so it won't ride in the truck slots correctly.  And on the Kato/Atlas wheelsets that have a plastic axle tube in the middle with the gear molded on it, the axle tube is bigger than 1.5mm so that won't work either.  For my money, the surest way to make something like this is to preserve the axle and the gear, and bore out wheels to fit on the ends.  But I realize that is a very hands-on solution that requires precision drilling and pressing, which doesn't make it a "drop in" solution.

[Rasputen]

I'm interested to hear how you got your tailstock aligned.  My Sherline is off by about .005 inch.

[mmagliaro]

I'm interested to hear how you got your tailstock aligned.  My Sherline is off by about .005 inch.

There are a million ways to do this.  I watched a lot of YouTube and read articles on machinist forums, and settled on a simple, somewhat home-brew "good enough" method that I think got my tailstock about as good as this Grizzly lathe is capable of (about .001" error between spindle and tailstock over a 12" length).

So... you have a spindle, probably with a lathe chuck on it., and a tailstock.  My tailstock has a precision drill chuck in it at the moment  (precision is key... a chuck with .0002" runout).
 I used a piece of 1/2" precision ground drill rod, checking it's position left/right with a dial indicator, chucked in the precision chuck in the tailstock   I adjusted the tailstock left/right with the adjustment set screws until I got no change in the left/right readings when I clamped the opposite end of the rod into the spindle chuck.  The vertical adjust was trickier, since my tailstock has no vertical adjustment screws on it and I bet yours doesn't either.

First, with the drill rod only clamped in the tailstock chuck, I ran a dial indicator, magnet-mounted to the carriage, along the top of the rod.  I found that it pitched down slightly (about .005") as it moved away from the tail toward the spindle.  This COULD be error in the actual lathe bed or in the tailstock itself.  But since I'm not about to start tweaking the lathe bed, I figured I'd just assume the rear end of the tailstock is slightly higher than it's front, and adjust accordingly. My tailstock is 2 pieces - the top part with the quill in it, and the bottom part that rides on the lathe bed.  I took them apart (just a couple of bolts).  Then I ran the top part over some 400 grit sandpaper, but only on about the rear 3/4 of it.  I did this several times, each time re-mounting the tailstock on the lathe until I could run the dial indicator over the drill rod all the way with no variation (well, .001" or so).  At least now, I knew  the tailstock itself was level.

Then I slid the free end of the drill rod into the main lathe chuck at the spindle end, and noted how the vertical height of the rod changed as I tightened the lathe chuck.  In my case, the spindle end forced the rod down by about .008" relative to the tail.  So I took the tailstock off, and again ran the base over a whole sheet of 400 grit sandpaper mounted on the flat concrete floor.  I'd do this maybe 10 times in each direction, then put it back in and check again. After about 5 rounds of this, I got my end-to-end error over 12" down to about .0015".   Good enough for me.  Then I double-checked by mounting and remounting the drill rod in the chucks at spindle and the tailstock, rotatinfg the chucks and the rod, loosening and re-clamping the tailstock, to make sure all of this was repeatable, or at least, within a consistent amoung of error.

Remember, .001" is a mighty precise amount to expect from a hobby grade machine.  And with all the variability in all the pieces on a lathe, it will be tough to always guarantee that.   There is always going to be deflection of the drill bit, and the drill is always going to somewhat follow the existing hole in the wheel.  But getting the tail aligned to within .001 or .002 is WAY better than .008".  At .008", I could visually see that the drill bit wasn't positioned in the center of the hole in the Arnold wheel.  After aligning, I can no longer see that.  Also, the drill bit used to obviously deflect a little as it went into the hole in the wheel.  It doesn't do that anymore either.  I'm already using screw-machine drill bits to minimize the bit deflection.