Heisler Drive Problems?

[gbbari]

I have a brand new 1:20.3 Bachmann Heisler (actually purchased it 3 months ago from Star Hobby but never had it out of the box until today).  I watched the DVD, performed the lubrication as specified, and placed it on a test track.

On the track with low voltage, the loco moved slowly OK with no binding in the actual motor drives - in either direction. Increased throttle yielded a comensurate increase in loco speed.  All seemed OK, except.....

In forward motion, there is a minor binding/hesitation of the linkage/piston mechanism with each revolution. The mechanism hesitates despite the engine's steady forward motion and then quickly catches up. I canot see where the "bind" may be occuring.  Going backwards, it does the same thing.  There is also an audible "chuk....chuck" sound that coincides with each wheel revolution but that seems to come from the rear truck (i'm not sure - ears aren't very good.

I turned the loco upside down and laid it in the foam packing top.  I took some wires from a small LGB power pack and touched them to the wheels. The motors ran but with each revolution of the wheels the front truck shudders significantly for about 1/4 to 1/2 turn. In reverse, the rear truck has a similar but less noticeable shudder.  I can still watch the linkage to the steam pistons / crankshaft bind and release on every revolution.

Are these mechanical issues normal for the Heisler?  Never having been inside one of these before is this something I can resolve or does it need to go to Bachmann? 

Al
Sykesville, MD

[the Bach-man]

Dear Al,
The loco should run in. It sounds like the valve gear is pausing to take in slack and then flipping over.
If it doesn't smooth out you can send it in.
Have fun!
the Bach-man

[Curmudgeon]

When these came out some referred to it as "lopping" (sic).
There is as part of the design considerable slack in the gearing to the driveshafts in each truck.
The contacts in the top of the cylinders (worthless for use, as they only close when the rod is fully up, and it is a 90° crank, giving chuff-chuff-blank-blank-chuff-chuff) are springy, and as the crank passes over TDC (Top Dead Center) the crank falls against the slack in the driveline.
The crankshaft is split, valve gear running off front truck, crank off rear truck.
Personally, I remove the contacts completely.
But, if you can pop the round top cover and catch both, and bend them up out of the way, see what that does for you.
I also remove the main caps and file any casting parting lines off the journal, and then grease it before re-assembly.

Done a lot of them, do the same to all, and they work much better.

TOC

[gbbari]

Bach-man, thanks.  I will try TOC's suggestion first and if that does not resolve the issue then I will look for some warranty repair help.


TOC - Thanks very much for the advice.  I will try that today. Hopefully that won't void my warranty in case this is a more serious mfg. defect issue inside the power trucks.  I will post the results here.

Al

[Kevin Strong]

One thing that I did with mine was to wrap a small bit of masking tape around the end of the square driveshaft where it fits into the coupling coming off of the truck. This removes some of the slop and smoothes the motion out nicely.

Later,

K

[Perry Ottoman]

I had the same problem, I dont use sound so I take out the chuff switches, ditto on Shays and Climax. Solved it fo me to. Dave has the nail on the head, trying to activate a pressure sensative device (contacts) off a floppy bunch of loose drive mechanisms is ludicrous IMO.

[gbbari]

Kevin -
How did you gain access to those couplings?  I can see them but they are rather buried up close against the trucks and I cannot reach my stubby fingers into that space to wrap tape around them...

Al

One thing that I did with mine was to wrap a small bit of masking tape around the end of the square driveshaft where it fits into the coupling coming off of the truck. This removes some of the slop and smoothes the motion out nicely.

Later,

K

[gbbari]

I did the chuff contact modification per TOC and it did reduce some of the hesitation in the central crank shaft rotation. Thank you sir!

For anyone interested who has not done this - be careful when handling the Heisler and especially around the cylinder heads.  Don't ask me how I found this out.      All is well now thanks to Faller plastic cement... 


I gently pried off the cylinder caps....


And v-e-r-y carefully bent the contacts upwards out of the way of the piston at TDC


I wanted to get into the drive blocks to check the issues TOC mentioned but did not see an obvious way to remove the bottom covers. The screws in this pix did not release the cover (without exerting more prying pressure than I was willing to use...) so I stopped there.  I popped the round cap and could see grease on the pinion gear, but that was all I could see from that little opening.


The shuddering in the rear truck is still present on every revolution of the wheels. It does not seem to be present in the front truck.  It seems to run on the track OK so I may live with this for now. 

Otherwise....what a neat and beautiful locomotive model.  I can see why many guys get into 1:20.3 narrow gauge geared steam with logging and similar themes on their RR's.  Just watching this engine is a joy.  Can't wait to convert to battery/RC and get some sound onboard.  Yeah I know it ain't easy.  Already got a doctor lined up...

AL

[Curmudgeon]

What he's talking about is the square slip-shaft.
Some have a black square vinyl piece inserted, some do not.
Simply rotate the shaft stop to stop.
You ain't gonna fix it.
I've been into it, requires unriveting of the gearboxes (once the truck is fully disassembled),  fabricating new shafts with tighter fit to gears.
Ain't worth the effort.
I have seen anywhere from about 70° to 130° of free rotation in those gearboxes to the driveshafts.

Also, check the review on them in GR.
Find the lube port in the bulkhead shown in the manual.

BTW, the manual that comes with the locomotive discusses opening the trucks and lubing.

And, on the vent that broke-
They all do it once in a while.
If you lay the unit on it's side, on a hard surface, they break.
Drill out the cylinder with a small drill and pin vise, glue the stub in, it will be JUST enough further it it won't hit anymore.

[gbbari]

Also, check the review on them in GR.
Find the lube port in the bulkhead shown in the manual.

BTW, the manual that comes with the locomotive discusses opening the trucks and lubing.

TOC - I cannot find your review in GR.  Searched extensively thru the garden railways forum but no luck.  Could you post the URL to it. 

I did not get a paper manual - only exploded parts/assemblies  diagrams and a warranty card.  Since the bag was obviously factory sealed I assume they intended the DVD to be the "manual".  The DVD does address lubrication details, and the 25 hour service part of the video shows removing the motor covers (I missed that earlier - duh!). 

Except the video completely omits showing the small noise suppression PCB attached to the inside of my engines covers and the pain-in-the-butt connecting wires snaking around one axle and barely mising the offset pinion gears.  Video must have been made on earlier (pre-production?) version that did not have this PCB.  The PCB's wires also look like they could easily rub against the central drive shaft universal joint which connects to the drive  (the one Kevin & TOC discussed earlier).
.

I lubed everything per the video and got everything re-assembled again and the engine seems to run OK.  But...still has the noise - very apparent at slow speeds - but runs fairly smoothly at slow speeds.  I think I'll let it be. When the doctor installs the battery/RCS/Sierra system    I'll let him perform any corrective surgery he may recommend. 

Thanks to all for their advice and comments.

Al

[Curmudgeon]

It can be anything, even the rollers on the pickups.
But, since those go away anyway.....

The booklet that came with mine showed the oiling.
Shows a neat oil port in the bulkhead on the end with the bevel gears.

When they leave here, they have that lube port.
One per truck.

TOC

[gbbari]

Sounds good!  I am going to ask Bachmann for a replacement owner's manual.  Apparently the one that came with mine was nicked out of the box prior to my buying it at the store.  When the shop owner and I checked, it looked like everything was still sealed in poly bags inside the box so we didn't take a full inventory.  Live and learn... 

Al

[gbbari]

Postscript -
I finally found TOC's June 2004 Heisler review. Was looking in the wrong place (the GR forum) and finally looked in the GR magazine online product review archives. Good review!

Al

[wslogger]

I am also having problems with one of the trucks on my Heisler.  Since I am installing onboard battery power I disassembled them to remove the "suppression" pcb's, the wheel electrical contact rollers, modify the wiring and do TOC's modification to provide lubrication for the brush end bearings.  After re-assembly I tested each truck to make sure they ran properly.  The rear truck was smooth as silk but the front truck Sounds like a coffee grinder.  I disassembled that truck again to make sure I got everything back correctly and all was found good.  This truck made the same noise before I made any modifications so I know it is nothing I did.  Sounds like a gear problem.  I tested the trucks before I installed them back on the loco so it has nothing to do with the drive line slop or triggers.  Has there been problems with the gears as they came new from the factory?