Athern Rubber Band Drive Problems

[Telegrapher 10]

I am trying to refurbish my father's Athern SantaFe freight locomotive.  I have overhauled the motor and cleaned it.  I am having 2 problems

1. rubber band continues to run off the end of the drive shaft
2. locomotive will run well in one direction but not the other ... very jerky and then stops.

Problem #1 - The drive shaft supports have considerable wear on them.  My solution is in photos I will try to upload ... a brass sleeve that keeps the drive shaft at the height it is supposed to be at.  The hole had become elongated over the years and as a result they pitched down. This seemed to allow the rubber band to run off the end of the drive shaft.  The brass sleeve has helped some but not 100%.  I also put a couple plastic stops on the ends of the drive shaft to stop the rubber band as it travels to the end.  Please ignore the fuzzies around the post ... was cleaning up with a paper towel at the time.  Does anyone have any ideas as to why this is happening and what I can do to stop it?

Problem #2 - The locomotive runs perfectly in one direction but is jerky and stops in the other.  I noticed that the brushes are worn when compared to the Bud car I am also working on.  I am planning to replace the brushes with new ones.  I'm not sure that this will solve the problem though since the motor runs well in one direction.  I thought the plastic stops on the ends of the drive shaft could be acting like a brake but I would think it would behave the same in both directions.

[MisterBeasley]

Congratulations and thank you for keeping old equipment running.

This may seem !Ike a silly question, but are all the drive belts mounted the same way?  Are they all new drive belts?  As I recall, the motor is only connected to the drive shaft with a small piece of rubber tubing.  If that's worn out, the shaft might turn on the bench but not do much on the track.  Can this engine pull a short string of cars?

You may be right about the tilting driveshaft.  One belt would be looser than the other, and that would cause performance issues.

Some modelers who rehab these old Athearn engines completely replace the motor, and also the drive wheels to get better electrical connectivity with the rails.  I have two old drive belt engines, but I ended up buying new engines to replace them.  I removed the motors and drive components and now run them as dummy engines.

[dknelson]

The problem with the rubber bands running off the drive shaft was common and usually caused when the rubber bands got stretched a bit.  Also common was putting on a "stopper" at the end of the shaft. In fact I recall it being pretty common to put pieces of a tight rubber tubing on the shaft to increase friction with the rubber band and get more pulling power, although when new engines with the Hi-F drive did pull surprisingly well.  You have to allow the shaft to move a little horizontally when reversing direction, for whatever reason, so you can't put the rubber tubing tight against the vertical shaft support. 

And yeah it was very common to get one rubber band on exactly wrong back then especially for us raw beginners who were attracted to the shockingly low price of an F7 with Hi-F drive: I think AHC wanted $3.99 for the kit.

There were also some who wanted tighter rubber bands than Athearn supplied and sold and found them as a dental supply - the braces of that time involved rubber bands that needed to be replaced regularly.  I tried using them (my sister wore braces) but the rubber bands were too small and too tight and I think I overheated and weakened the motor in my Athearn Hustler as a result.  The motors were not top notch and prone to be short-lived.

Dave Nelson

[rrinker]

 I'd be surprised that there was actual 'wear' on the metal motor shafts from the rubber bands. A rubber band could scrub a piece of steel for 100 years and not wear it away. It may be well-polished, which could cause clippage - in that case, roughing the surface might help.

 Adding a bushing on top could be a problem - the larger the motor side 'pulley', the faster the loco will go, and those rubber band drives already run pretty fast. Part of the problem with grip was keeping that motor shaft tiny and putting as big a drum on the axle as could fit based on the wheel size.

                             --Randy

 

[BigDaddy]

to the forum.  Your initial posts will be delayed in moderation. 

There is a sticky on how to posts photos,    it is not like other forums you may be on and you simply can't skirt the rules.

http://cs.trains.com/mrr/f/88/t/249194.aspx

Never owned an Athearn rubber band drive.  I can tell you that when we have a discussion of what happens to our trains when we are called to the great station in the sky, there is not a lot of sentimentality and the word dumpster comes up frequently.

It wouldn't be a sin to put a more modern drive in it.

[Shock Control]

I have long wanted one of these engine's nostalgia's sake, but have heard nothing but bad things about them.  Are they viable if they are modified?

[Overmod]

Sounds to me as if the "bushing" has done what happens to pivot holes in brass clock plates over the years: dirt gets between the steel pivot and the brass and cuts the brass progressively into an oval.  

With clocks, you can butcher a temporary fix by hammering and shaping to force brass into the hole and then redrilling and reaming it smooth.  Technically you could do the same sort of thing to the bushing, but in practice you'd be better off replacing or re-making it.  Note that they do make special ball bearings for repairing this kind of clock damage, and those would be a permanent, if somewhat expensive and 'overkill', fix.

Putting a cap on the end of the shaft would be like putting a cap on the end of the vacuum-cleaner motor stub when the roller belt tries to walk off the end.  You won't get smooth performance out of that arrangement without more work than it's worth -- fix the shaft to run straight, or make a support for the outer end of the shaft, or align the motor correctly as Mel and others have recommended mounting them.  

If the shaft appears worn, I do NOT recommend mechanically roughening it with sandpaper or other abrasive.  Some sort of gentle etch by dipping the shaft in and promptly cleaning/rinsing the end off, without involving the motor bearings, is about as far as I think I'd go.

DO NOT use overly short or higher-tension bands in these -- you will not get measurably better 'adhesion' but you will assuredly wear bushings out faster and perhaps even bend shafts.

[MisterBeasley]

Shock Control

I have long wanted one of these engine's nostalgia's sake, but have heard nothing but bad things about them.  Are they viable if they are modified?

Modified how?

The ones I had were probably from the late 1950s.  They ran for about 10 years and then I boxed them up when I finished college.  After 40 years in the same boxes, they ran hesitantly if at all.  I suppose I could have replaced the motor and the wheels, but by that time I was looking at more cost than a far better, well-detailed new engine, which was the course I took.  The motor and drive train came out, the wheels stayed and the horn-hooks gave way to Kadees.  I put a cheap Sound Bug sound only decoder in one and a sound-and-lights decoder in another.  It keeps my old friends running.

[mbinsewi]

rrinker

 I'd be surprised that there was actual 'wear' on the metal motor shafts from the rubber bands.

I think he's talking about the little post, that supports the drive shaft, and the notch in the post that drive shaft spins in.  

I'm looking at the instructions and parts list on HO Seeker.

I have 2 Athearn RDC that have that drive.  Haven't done anything to them yet.

As far as running good in one direction, and not so good in the other, the 70's and 80's BB locos would do the same.  I think that's a motor problem.

https://hoseeker.net/assemblyexplosionAthearn/athearnf7ahifitowerdrive.jpg

If the link works, it's the one on the left.

Mike.

[Overmod]

Problem #2: you are probably going to have to 'stone the commutator' to get all the little segments flat, smooth, and true at the time you change your brushes.  I think Mel and Ed, in particular, can help you with best ways to do that.  Be sure to run the locomotive a while, reversing every couple of minutes, when you first change the brushes, to get them to seat properly in both directions of rotation.

And be sure the 'end-shake' of the armature isn't making it bind if the belt tension tries to pull or push it sideways against the thrust washer as the motor turns.  Some of the places that bind might be 'interesting' and a bit unexpected...

[Shock Control]

MisterBeasley

Modified how?

Read upthread. ^  

[mbinsewi]

If the OP is going to modify this loco with a new motor, trucks, and drive train, than whats the point.

I think he just wants to get dad's old loco running, for the sake of it. It was his dad's.

If he's doing this to make an everyday running loco out of it, there are many other options.

I'd say, get dad's loco running, as is, completely restored with original parts, and use it for a seldom used display, or a tourist special, knowing it functions as it once did.

Mike.

[Shock Control]

mbinsewi

If the OP is going to modify this loco with a new motor, trucks, and drive train, than whats the point.

I think he just wants to get dad's old loco running, for the sake of it. It was his dad's.

If he's doing this to make an everyday running loco out of it, there are many other options.

I'd say, get dad's loco running, as is, completely restored with original parts, and use it for a seldom used display, or a tourist special, knowing it functions as it once did.

Mike.

You can improve a rubber band drive, as detailed in this thread, without replacing everything.

[zstripe]

Picture of an original Athearn Hi-F drive F-7 from the early 60's. I was speaking to a forum member about what I used to replace the rubber couplings on drive line. I still have two engines with this original drive system still running and probably will still do a scale 200mph:

Take Care! 

Frank

[mbinsewi]

Shock Control

You can improve a rubber band drive, as detailed in this thread, without replacing everything.

I'm not seeing the thread your talking about. 

Mike.

[Shock Control]

Read upthread. ^

[mobilman44]

Hi,

I had a number of these in the early '60s.  On the plus side, the motors were terrific (for the time) and the prices were very reasonable.  While you couldn't get great "slow running", they could run awfully fast.

A friend and I set up a long "dragstrip" in his basement with a pillow for an end stop and we raced various ones several times.  

When the "belts" became ineffective, we ended up using rubber bands from the local news vendor.  They worked, but didn't last long.  Oh, make sure they are all "facing" the same way.........

 

 

[Telegrapher 10]

Thanks for the response.

1. Yes.  The drive belts are new.
2. Yes.  They are mounted correctly ... all the wheels turn in the same direction when it runs and when I manually operate the drive shaft.
3. Haven't tried cars yet ... did twist some wire around one of the rubber tubes on the drive shaft.  I just posted some pix and a video.
4. Also ... I swapped the brushes to see if that made a difference between forward and reverse ... no change
5. lightly sanded the wheels as part of my overhaul ... seemed to help connectivity with the track.