Bachman SD9

[Mark5]

While I had things apart, I noticed that there was a fair amount of gear lube sprayed around outside the gear box. So, I took an alcohol-soaked mini-brush and cleaned the wipers and wheelbacks (the brush wound up pitch black). It seems to run quite well now, so perhaps that was the magic bullet? I'm going to try running it around in circles on and off throughout the day, so we'll see.
-Mark

Great info - this might end up saving a few of these from the scrap heap. 

Mark

[Ed Kapuscinski]

Watching a video and looking at your pics... has anyone measured the hood width? It looks kinda wide.

Either that or the angle on the ends is off.

[Chris333]

Even though those are old style wipers. They bend around the axle hole so that the axle also rubs on them.

[spookshow]

I'm not sure what you mean, Chris - the wipers don't come anywhere nears the axles (not long enough).

Ed, the hood measures a little under 16 mm wide.

-Mark

[wcfn100]

I'm not sure what you mean, Chris - the wipers don't come anywhere nears the axles (not long enough).

I think he's talking about at the top of each axle hole there are pickup 'fingers' that are bent into the hole which would rub on the  top of the axle.

Jason

[thomasjmdavis]

I'm not sure what you mean, Chris - the wipers don't come anywhere nears the axles (not long enough).

Ed, the hood measures a little under 16 mm wide.

-Mark

Is that over the radiator on the long hood? The drawings I have show the hoods as 6' wide, somewhat wider over the radiators- but would have expected a dimension more like the 11.5 mm (+/-) of my Atlas GP-9 (not SD, but happens to be sitting right here) plus maybe a mm for the radiators.  My caliper needs a battery, so maybe I am just reading the measurement wrong (?)

3 or 4 mm in N scale is a lot of mm's.

[peteski]

Here you go -

Thanks for the photo Mark. These appear to be designed differently from the older wheelsets prone to cracking the plastic axle tubes.  Or not . . .
Do you know if the metal half axles are pressed into  the plastic axle, or are the metal half-axles hollow  and the plastic axle is pressed into  them?

I also noticed that the electric wiper design (specifically the fairly uncommon little dimple which is supposed to be the pint of contact with the wheel) looks like the design used in the IM's Cab Forward wipers.  I wonder if those were designed or manufactured by the same company?  Don't mind me - I'm always trying to figure out how the various model train companies are interconnected through their Chinese manufacturers.

[peteski]

I'm not sure what you mean, Chris - the wipers don't come anywhere nears the axles (not long enough).

If you look at the top of the axle bearing opening you'll see that the metal pickup plates seem to be bend under the plastic truck frame. So when  the wheelset is installed, the metal axle will be in contact with the metal pickup plate (contact point at the top of the axles).

[tehachapifan]

Judging from the photo, those wheelsets sure look a lot like the earlier Kato blunt-end ones.

[Chris333]

[peteski]

Judging from the photo, those wheelsets sure look a lot like the earlier Kato blunt-end ones.

They sure do.

[spookshow]

I think he's talking about at the top of each axle hole there are pickup 'fingers' that are bent into the hole which would rub on the  top of the axle.

Ah yes, thanks. I never noticed that before.

-Mark

[spookshow]

Is that over the radiator on the long hood? The drawings I have show the hoods as 6' wide, somewhat wider over the radiators- but would have expected a dimension more like the 11.5 mm (+/-) of my Atlas GP-9.

Sorry, I was looking at the wrong numbers (I don't use a caliper very often, lol). It's 12 mm.

-Mark

[spookshow]

Thanks for the photo Mark. These appear to be designed differently from the older wheelsets prone to cracking the plastic axle tubes.  Or not . . .
Do you know if the metal half axles are pressed into  the plastic axle, or are the metal half-axles hollow  and the plastic axle is pressed into  them?

The plastic axles are hollow and the metal half-axles are press fit into them.

-Mark

[spookshow]

Things were looking good until a derailment at a turnout caused one of the trucks to melt 

But in any case, it does look like the pickup problems were due to a "lube where lube shouldn't be" situation (since it ran flawlessly once I cleaned it up). I'll have to get another one to test, but the solution appears to be to take the trucks apart and clean the lube off of the axles, wheels and wipers.

-Mark