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Greg Procter wrote:


big snip

At least you were progressing in the right direction.
If mark doesn't give up on things, there is always hope that he can traverse the same general learning curve and become one of us 'old farts' that answers questions too.
Chuck D.
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Charles Davis wrote:

<snip>

No, guy, I check voltages with one of my multimeters. If you read what I wrote, I was talking about trying to light the headlight bulb, by itself, with a 9v battery, so I'd have a constant intensity.
mark
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mark wrote:

My mistake!! Sorry, that idea never occurred to me as there are easier (and cheaper) ways of getting 'constant lighting'.
Chuck D.
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David Starr wrote:

*sigh*
Honest, guys, I wouldn't have gotten this far if I didn't have a clue. Let's see, I think it might be getting some pickup on the trailing truck, and it gets it off the two drivers. The leading truck has, I think, plastic wheels.

All I'm trying to insulate is the side that supposed to be insulated by the two insulated driving wheels and the insulated trailing truck. Where I soldered the wire that goes to the tender for the other side, it may stick out a bit, which is why I was insulating the body from that. I also noted that if the drivers have some sideways play, as they need to, the insulated wheels' conducting tires contact the frame, which is why I put the plastic there. I'm also seeing play in the tender wheels, so that they sometimes contact the frame; ditto with the insulated trailing truck.
Have I now covered everything that I've covered? <g> <snip>

Right, and if I'd had the insulated wheels mixed up, it wouldn't run at all, and I'd have the breaker in the power supply popping all the time, not just occasionally. <snip>

Yup, runs nicely. Starts and stops as I touch the wire to the other track.

Yes. Esp. after the 52nd time I took it apart, this time to trim the wire that comes out of the crosshead, and the casting, which seem to be slightly longer that the one from 45 years ago, and were butting up against the cylinder every rotation. Now it's smooth.

Found that out. One washer, in the cast indentation, so that it's about level with the top of the rest of the frame, and it seems right - I can spin the motor with a finger, and the wheels rotate without binding. A second washer, btw, lets the motor spin all it wants... above the worm. <snip>

Thanks!
mark
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Why not clip off extra wire, or re-solder it?

With only four drivers, you don't NEED side play. In any event, the driver tires should not touch the frame, with or without side play. Same with the trailing truck wheels. The wheel hubs should be raised enough that they touch the frames before the wheel rims even get close to touching anything.
Are you missing some washers that should fit between the hub and frame, inside the wheels for drivers, and outside for trailing truck?
--
Bill Kaiser
snipped-for-privacy@mtholyoke.edu
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snipped-for-privacy@mtholyoke.edu wrote:

We're talking about a mm or two, here, I s'pose I could file it.

Hmmm... maybe adjusting them on the axle might help with fitting the track. The tender - the wheels keep jumping the track (and it's code 100, btw).

Can't really put any inside the drivers - they were supposed to be permanently on, and I had to pull one (on the axle w/ the gear) and use Loc-Tite on it, so there's no way for that. I could try washers on the trailing truck, or, as I noted above, seeing if I can just push them further onto the axle.
Thanks. Right now, I'm still pushing the thing. I've got it on a curve (getting the tracks up will take a *while*, esp. since I have to put covers over to keep the large cats off <g>), and I note that if I push on the side of the engine that does not have the insulated wheels, it moves a bit easier. I've tried tightening and loosening the plate under the axles, so any other ideas?
mark
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mark wrote:

At this point, I'd say your 'trouble shooting' has covered most of what I can think of. The only other thing would be excessive wear of he axles in the frame. This would be allowing the worm gear to mesh too tightly with the worm. (making for VERY touchy adjustment.) Chuck D.
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Charles Davis wrote: <snip>

Great. And given that it came "partly assembled", which in this case meant the drivers and leading truck were on, and almost nothing else, I'm thinking that this was an estate sale of stuff from someone's late parent that had never been run, so worn shouldn't come into play.
mark, frustrated
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mark wrote:

Hi Mark,
I've not had time to follow this thread properly. 1) remove the motor and gently push the chassis/mechanisim/frame along the track, feeling for binds. Fix the binds. 2) install the motor, block up the chassis and apply power directly to the brushes. Reduce the voltage until it either slows to a smooth halt or binds. Fix the binds. 3) turn it over (onto blocks) and apply power to the wheels which have pickups. Sequence (say) left front + right front, left front + right second etc until you've covered every combination. That will show up any bad contacts. 4) Now try it on the track, without body. It should run nicely. If not there's something wrong. Post description here. 5) replace the body with screws. If running is different to 4) then something is touching inside the body.
Regards, Greg.P.
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mark wrote:

I follow your reasoning, and would come to the same conclusion! So --- Back to the beginning --- Take the bare frame, drop the two driver sets into the axle slots, attach the cover plate on the bottom, and make sure there are NO problems rolling along the track (NO side rods at this time, no leading or trailing trucks).
IF there are any rough spots, holler, we'll think of things to check/ adjust. It needs to be free enough to roll down the track, by itself, with NO pushing, if you raise one end of a 3' section of track a couple of inches. (A single inch would be best, but lets start with an easier challenge.)
Same aim --- free rolling on a SLIGHT incline.
Someplace along here you need to check the drive gear for roundness. This is an 'eyeball' check --- to be done with the frame UPSIDE DOWN, so that the axle is riding in the same place it will be when things are assembled and running properly. You don't have to stand on your head and look at the gear where the worm will be riding, any 'out of round' condition will be visable watching the bottom side. [I don't expect there to be a problem here, but now is he time to check.]
Next add side rods (cylinders & main rods are the next step --- you already mentioned curing a problem with the cylinder rod on one side.)
Re check for free rolling [This is where I would expect to find a problem. the driver that has been 'off the axle' may NOT be exactly quartered any more.]
If this is where the problem rears it's head, there ARE 'shade tree' fixes that will allow you to get the thing running 'sorta', to be able to make a decision later as to whether or not you want to invest the $ to do a proper fix of the quartering problem.
Note No leading , trailing trucks, no motor to this point.
Let us know results to this point.
Chuck D.
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Charles Davis wrote:

One other check that you should do along here someplace.
Frame upside down, drop the drivers in their slots, (easiest if you have TWO straight edges) lay a straight edge on the tires of the drivers on one side of the loco. straight edge on the other side of the loco, how do they compare??? They SHOULD be visibly parallel, IF the frame is 'Tweaked' /bent, you will be able to notice the difference in the lack of parallelism for the two straight edges.
IF that shows up, it MAY be fixable with some gentle 'tweaking' of things. (Be aware that the ZAMAC frame is liable to be on the brittle side. So don't just grab hold and start twisting.)

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Ok, someone asked me to take it apart *again*, so since I did ask for help, I took the motor and the trailing truck off, and tried that. The results are this:
* if I push down a little, and run it along the rails, it seems to go ok. * sliding it down a tilted track, the drivers don't turn * if I hold it in my hands, and turn the gear, it seems to bind in one direction; if I push front and rear drivers, it seems to be ok.
Analysis?
mark
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mark wrote:

It does need to be free enough to 'Roll' down an incline track. I presume your recent test was with the 'cylinders. main rods, and side rods still attached. Try removing them, and see if 'just the drivers & axles will roll freely.
IF 'just the wheels' shows up as having a problem, the first thing I would check for, is if your 'locktite/ crazy glue' joint may have a 'fillet' of glue on the back side of that particular driver, interfering with the smooth rotation of that driver set. [If it does, a sharp razor blade' will handle removal of the excess glue.]
Chuck D.
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Charles Davis wrote:

The binding in one direction when you turn the gear suggests that one driver is slightly out of quarter. Just enough so that the slop in the siderod bearings isn't enough when turning one way, but is enough when turning the other. The siderods displace forward/backward when driven by the geared driver.
HTH
--
wolf k.

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mark wrote:

That sounds like either the wheel wipers are sprung against the drivers too hard or something in the valve gear / coupling rods / connecting rods is tight.

Different action in different directions probably means that the piston rods are sticking / wheel out of quarter / coupling rods of different length

Definitely something wrong. ;-)
Is the hang-up/restriction continuous or just for part of a turn of the drivers? If it's continuous the restriction is in the wheel wipers (assuming it has them) or in the axle bearings. If the restriction is for part of a turn only, and for the same part of the turn, then the problem is in the piston/valve gear/connecting/coupling rod area. You check this by: - remove the valve gear and check wheel rotation. - remove the connecting rods (wheel to piston) and check wheel rotation. - remove coupling rods. (between wheels)
(remember to put the bits in a small tin or zip top bag) (remember to look how it all goes together and where each bit goes in relation to the others - draw a picture / photograph)
Remember, your finger is more powerful than the motor.
Greg.P.
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Greg Procter wrote:

Neither. I *think* I've found what's hitting: the ->top<- cylinder has this rod that comes back about a quarter or a third of an inch. the rivet that attaches the rod that goes into the cylinder - not the piston rod, but the one above it - anyway, that rivet seems to be hitting the cast-on piece. Should that cast-on piece be holding the rivet beyond its end, or do I need to file it down some?
left side: ----- * ------------------------ (radius rod) | | ===* <- this rivet, this cast-on piece - the = signs | |_[crosshead]
Still a little resistance from the wheels - sort of like moving under oil, rather than rolling free.
mark
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mark wrote:

<snip> And after taking it apart for the 57th time... one of the damn microscopic rivets popped, and I can't find the *one* spare that came with the kit, and I'm not spending $5.50 for that. So, either I use a piece of wire, or I try to solder a piece of wire to the head of the rivet, or maybe I'll find a microscopic brass nail....
mark, unbelievably pissed
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I avoid using rivots and prefer steel sewing pins: 1: insert pin through hole in part A 2: stick through a small piece of paper 3: insert through hole in part B and solder pin to back of same 4: snip off excess pin, tear out paper and file away any excess solder that may be present
The paper not only functions as a spacer between the valve gear parts, but, prevents them being soldered together. This idea is by no means original. I believe I came across it about forty years ago in MR. HTH.
Jerry
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mark wrote:

A sewing pin or a tiny brass nail should do the job. You can put the nail in an electric drill and apply a needle file to it to shape a replacement pin. Remember to file to shape from the end away from the chuck and wear a leather gardening glove so the file doesn't get pushed into your hand - nasty/painful.
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mark wrote:

That rivet shouldn't hit ANYTHING. The "piston" of the upper part is the "valve". It should jiggle back and forth when the lower piston (the actual piston) reaches each end of it's travel.
Actually that rod/rivet shouldn't move very far at all, so (without seeing it) I'm suspicious that the excentric crank , which screws to the driving wheel, is mounted on the rong angle. (too far out) The connecting and coupling rod screw holds the eccentric that drives the valve gear should drive the vg at 90 degrees out from the connecting rod/piston. Until the screw is tightened it can flop about at any angle, but there should be a stop so it sits at 90 degrees and gives a through some where about half the connecting rod/piston throw.
The purpose of all those levers and rods is so the valve moves back and forth in the opposite sequence to the piston but pauses at each end of it's movement.
Regards, Greg.P.
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