ER Shark pickup problems

[Maletrain]

I have 2 A-B pairs of N scale ER Baldwin Sharknose models, and while cleaning wheels, noted that I am not getting electrical pickup on one of the trucks in 3 of the 4 units.  On 2 it is the front truck that does not pickup, and on the other it is the back truck.

Reading Spookshow's review of these, it says that all wheels pickup and transfer power directly to the split frame via wipers  - no wires involved.

So, I am thinking that the wipers are either bent or there is some crud in the contact points.  These are second (at least) hand units that I have never taken apart, but have no idea if others did before I bought them.

I would appreciate any pointers for solving the pickup problem.  I am not sure how these units are supposed to come apart.  I can see the wipers, but am not sure where the contact is failing.  Wondering if squirting some contact cleaner into the wiper areas would do any good - or damage.

[peteski]

Not 100% sure but I think those are similar to what Bachmann used on other models of that era.  The electrical pickups were just thin phosphor bronze shapes which were loosely fit behind the wheels.  They rubbed on the backs of the wheels and the upper part which was bent out was rubbing against the metal chassis.  Loosening the split frames and letting the trucks fall out would allow you to just pull those wipers out and clean them and also clean the wheel backs and the contact points on the chassis. 

[Maletrain]

Looking at the upper ends of the wipers, as best I can without disassembling them and using a 10x loop, it looks like they might not be making contact with the frame. On one of them, I can get intermittent contact by derailing one wheel of that truck, and on another by pushing down gently on the fireman's side of the body over the truck.

I would like to see an exploded view of these before trying to disassemble one.  In particular, I want to know how the motor is isolated from the frame halves, so I don't end up providing a solid contact just going to a new short circuit induced by clumsy reassembly.

[peteski]

All Bachmann split-frame diesels from that time period has the motor's metal body "wrapped' into a clear plastic cover to isolate it from the frames. Again, I'm again assuming this is the case in this model.

[Maletrain]

Using magnification and strong loops, it looks like the bronze phosphor "ears" that carry current from the wheels to the frame halves are designed to be bent outward at the top and rub on the bottom of horizontal surfaces on the frame halves. It seems that the bends are too sharp to keep the ears in contact with those frame surfaces.  I am not sure how they got that way, but I now think I will have to take the trucks out of the frames and bend those ears back upward to make contact consistently.  With the ears resisting reinserting the trucks to their proper depth into the frames as I reassemble the split halves, and 2 trucks needing placement at the same time, I am trying to think my way through reassembly without accidentally rebending the ears too flat, again. 

I'll let you know what happens.  Right now, there are too many other things demanding my attention and work space to try this.  I don't want to have to rush it.

[peteski]

Steve, as you found out, this pickup design is not the best, and it can be tricky to reassemble, but 20 years ago when these were current models, I have managed to be successful at it many times.  The pickups are fairly flexible and can be re-bent if needed.

Now as I jog my memory, due to the truck design (with integral worm), the trucks do not just drop out like in Kato diesels.  The frame halves have to be fully separated.  Leave the frame half which is holding the motor down on the workbench withe motor facing out.  Remove the trucks and drive shafts, service the trucks and the pickups, then insert the driveshaft in the worm and slip the truck into the frame half with the motor. You will have to make sure that the pickup wiper is properly installed so it contacts the bottom of the frame half. You also have to make sure that the drive shaft slips into the universal coupling on the motor. Once both trucks are sitting in that frame half, you will have to ease the other half onto the half with the motor/trucks in it. Then you will have to wiggle the pickup wipers to get under the frame, and align it all so the frame sits down over the motor and the frame fasteners.

[Maletrain]

Thank you Peteski. Will let you know what I find and whether I succeed.

[wm3798]

I have a B unit that suffers the same malady.
The pick up ears are very small and very thin, and you have to be very finicky when reassembling as @peteski describes, or you'll bend it right back out of contact again, making the whole exercise a waste of time.
I'm not sure if it's possible to bypass it with a hard-wired solution, or if that would even be durable as much as doable. 

I wonder if it was an "innovation" that ER brought to the design, or if Bachmann used the off-brand model to let the consumer do some quality testing of something they weren't sure about...  Sort of like the '64 Corvair...

Lee

[peteski]

I wonder if it was an "innovation" that ER brought to the design, or if Bachmann used the off-brand model to let the consumer do some quality testing of something they weren't sure about...  Sort of like the '64 Corvair...

Lee

I believe this was all Bachmann's design. All the white-nylon-gear diesel locos of the time used that pickup design.   It is extremely simple, even clever.  Just a pickup strip loosely inserted between the gear case and backs of the wheels, and the thin bent part of the strip provides pressure against the wheels and against the chassis.  If ER Sharks have black gears that would indicate that they were produced later, when Bachmann started using black plastic (which still cracks).

I found my set of the Sharks.  The pickups are similar, but not quite what I thought.  They should actually be easier to adjust without taking the chassis apart.  I'll try to post some  photos later today.

[peteski]

This is what I found out:

There is no need to take the frame apart.  Those wipers can be accessed right at the trucks. 

Remove the shell and place the chassis upside down on the workbench.


ER_Shark_Truck01.JPG

Unlike other similar truck designs, the wheelsets are not retained by the sideframe/bottom cover.  They are snapped into the gear case.  Sideframe/bottom cover is just cosmetic.  To remove it grasp the chassis in one hand and with the thumb and index finger of the other hand grab the sideframe/bottom cover at its center (where the leaf spring molding is).  Then start pulling it up. The bottom cover will start bowing up. Don't worry, it is very flexible. Keep pulling it all up until the bottom cover bows up enough to unsnap from the 4 hooks at the ends of the gear case.  Do not try to pry the ends of the bottom cover like it is done for other similar trucks. Also do not try to unlatch the hooks by pulling them outward.  They are very stiff.  The method I described works the best.


ER_Shark_Truck02.JPG

Removing the sideframes/bottom cover exposes the gear case and the electric wipers.  Unlike the wiper system Bachman used on other diesels of that period, these wipers are actually fastened to the gear case with screws.


ER_Shark_Truck03.JPG

To gain full access to the wipers the wheelsets have to be removed. As I mentioned earlier, they are snap fit into the bearings molded in the gear case.  Just pull them out.


ER_Shark_Pickup01.JPG
This photo shows the loose screw and pickup strip removed from the other side of the truck, and also the wheelsets I pulled out. The loose pickup strip can now be shaped until its top loop makes positive contact with the bottom of the frame.  This will likely be a trail-and-error process done few times. That is not a problem since the pickup strip can be easily attached and detached from the gear case. Once the loops are adjusted correctly and the pickups are screwed back into the gear case, using pointy tweezers adjust the wiper's fingers which will rub against the back of the wheels.  The should be spread out  far enough to make contact with the wheel backs even when the wheelsets shift laterally.

Next, snap the wheelsets back into the gear case making sure the pickup fingers slip behind the wheels.

Last thing left to do is to snap the side frames/bottom cover back onto the gear case. Because the 4 hooks at the ends of the gear case are very stiff, the bottom cover will not just snap in.  We have to employ the bowing process again.  The way I do it is to slide the bottom cover under the inboard latching hooks. While that side is latched, using my thumb and index fingers I again grab the inboard-latched sideframes/bottom  cover and place the index finger of my other hand over the outboard end of the bottom cover.  That allows me to again bow the bottom cover up far enough to push the outboard end of the bottom cover under the latching hooks.  Once the front and back are latched, you might still have to wiggle the bottom cover slight to snap it down over the alignment posts in the center of the truck.


ER_Shark_Pickup02.JPG

I discovered that one of the pickup strips on my B unit was deformed, not touching the frame.    Here it is before and after it was fixed.

I also noted that even though my model has black gears, one of the wheelset gears has cracked.  But overall it is a pretty decent model.  I also noticed that unlike other Bachmann models from that time period, the motor sits in a plastic cradle, similar the ones used by Kato and Atlas in their split-frame models.

[Maletrain]

Thank you Peteski!  (I had tried to remove those truck side frames a couple of ways, but was afraid they would break.)

I can't give you more than one up vote, but I could buy you a beer in Springfield next month. 

[wm3798]

Thanks for that synopsis, @peteski .  I checked mine against a Spectrum F unit from the same/similar vintage, and the ER wipers are smaller and more finicky.

That's the ER wiper, and this is the Spectrum:




You can see the contact point is much bigger.
The problem with mine is the wiper is bent down like yours, and when I went to straighten it back up, I could feel the phosphor bronze start to split at the fold...  So if you're flexing it to restore contact, be vewwy vewwy careful.

I haven't torn down the trucks to see if the bigger wiper will fit on the shark, but it might be worth a try. 

With all those cracked white gears from the Plus version, parts should be plentiful.
Lee

[Maletrain]

To finish this off, thanks to Peteski's extensive efforts to provide clear guidance, I was able to service my Sharks and get all 4 of them ready to go for the club open house events these next 2 weekends.

The trickiest thing seemed to be getting the truck side frames back in place without putting much downward force on the trucks (for fear of rebending the bronze contact strips I had just adjusted).  The technique that eventually seemed to work best for me was as Peteski described - to inset the end near the fuel tank first, and then hold the center with my fingers of one hand and use the other hand to push on the other end, with the already inserted end of the side frame contacting the fuel tank for support.

My original pickup problem was that the bronze strips were bent, but there was also some black stuff on the backs of the wheels as well as the bronze strips where they contacted the wheels and also the frames. My problem bends were different from the pictures of Peteski's.  Mine were just bent too sharply where the OEM bends are, and did not have additional sharp bends like in Peteski's left photo.

Fortunately, none of my gears showed any cracks, both white and black gears.

Fingers crossed for another 18+ hours of running.

And much thanks again to Peteski for going out of his way to provide such excellent guidance here on TRW.