Ernst + Hustler = trouble

[Anonymous]

So I'm installing the Ernst kit in a Hustler.

Yes, I know. Stop laughing.

I think somewhere along the line Ernst either didn't react to a change, or let their molds and machining slip. The flash on the gears was expected, like every other kit of theirs I've used (5 or 6 so far). The brass worm and flywheel looked good, even if the worms were a little rough at the end opposite the flywheel.

The instructions are very explicit about how to apply the flywheels to the worms (press in a vise or press), and the worms to the motor shafts (oil shafts, then press). There is supposedly a shoulder inside the worms that prevents the shafts from being overinserted. I did as the descructions requested, but after I pressed the second worm/flywheel assembly onto the motor shaft, I was horrified to discover that the first worm/flywheel (at the comm end) had gone beyond it's limit, and the motor was now locked due to the compression. Ack!

Let me take a moment to say that I am mose definitely mechanically inclined. Let me also say that the problem of removing, or at least repositioning, the worms without damage has so far escaped me. There is NO space between the worms and the bushings, and I fear that the worms may have dislidged one (at the comm end) slightly.

The lesson: If I can rebuild the drive in a 1962 brass articulated and have it run better than my Protos I should be able to handle this, right? Wrong.

Anyone have any ideas about how to fix this...er....fix that I'm in, without destroying the motor or the worms?

-dave

[nfmisso]

gear puller

[Anonymous]

I thought of that. Unfortunately, the gear puller would destroy the worms. Ask me how I know [;)] I did make some progress by pulling the flywheel and sandwiching the worm between two pieces of poplar in a vise, and then beating the snot out of the shaft with a drift (punch). Now all I have to do is figure out how to re-place the bushing that got knocked out of alignment by the compression. Ugh.

And where'd the motor mounts go? sheesh. This is just getting silly...

-dave

[Anonymous]

Can't offer any suggestions to your problem other than saying if you do get the kit properly installed it might not be worth the bother anyway. I installed the Ernst kit many years ago in an Athearn Hustler with less than satisfactory results. If I recall correctly, the instructions said the way to properly me***he worm on the motor to the wheel gears was by adding layers of masking tape to the inside of the body shell. When the body is installed on the chassis, these strips of tape are supposed to pu***he motor down so the gears mesh. This compresses the motor mount in the process. I tried for a while but lost interest in this flaky method.

I think I later tried to add an insulated screw up through the motor mounts so I could snug down the gears. This didn't work to well either, so I set the model aside, where it still sits.

Either way good luck!

Bob Boudreau

[Leon Silverman]

The industrial method for fitting bearings onto shafts is to heat the bearings slightly befor sliding them onto the shafts. The tight fit develops when the bearings cool down. Your solution might be to apply some heat, either from a blow dryer or a soldering gun to the worm gear to expand it. This might loosen it enough to slide it down or off the shaft.

Former Bearing specification writer.

[Anonymous]

Well, it's still vexing me. I got the worm bashed back into place to eliminate most of the binding, but It seems that the bushing that was dislodged (due to the compression of the frame) is rather reluctant to be re-lodged. This may be the end for it's prime mover. I have an NWSL can that would fit doing temporary duty in a brass steamer, but it's out for paint and won't be back for a month. And I was hoping to run this guy today at the show. GRRR!

Bob-

This will be my 3rd install on a Hustler, so I'm not too worried about the results (or maybe I'm just lucky? All mine turned out fine once tuned), but this is the first time I've ever had trouble with the worms. I'll know for sure when I talk to Ernst tomorrow.

Leon-

I'm familiar with the joys of termal interferance fits, slip fits, press fits, and all the rest. [:D] This one looks like a simple press fit, with the clearance being between 0.005 and nil, given the amount of force required to get the worms on the shafts. The worm/flywheel fit is much more open, just a hair tighter than a slip fit I think.

OK, lunchtime. I'll keep y'all posted.

-dave