I'm getting to this project that has been on the back burner. I see I will need to uses several screws to assemble the loco. I plan to assemble and test the mechanism in DC mode to see if I need any (motor, gears) upgrades. Then disassemble, paint, add decoder & sound, etc.
The can motor to motor bracket uses 2mm screws (nylon ones on the way from China, but I have the 2mm steel screws if they can be used to force the threading).
The motor bracket is attached to the frame with a 2-56 screw. I have the tap for that as I bought some typical ones such as that, 0-80, etc).
The bottom gear cover plate is to be attached with two "2 x 3/16 inch" screws. I'm not sure if they mean a 2-56 or a 2-xx???
I have the supplied machine screws. So the first question is can I just force the 2-xx screws for the gear cover plate into the pot metal frame? And ditto the 2mm screws into the can motor housing? Or should I get a 2-xx tap for the one and a 2mm tap for the other? Will they have these at my box store or HF or do I need a MicroMark order? And, should I order a tap set?
Thanks for any help This project may be a stretch for me.
Paul
Modeling HO with a transition era UP bent
MDC kits came with 2-56 self tapping screws, so they would force tap the holes as you turned them. If your screws aren't self tapping, it would be best to use the screw tap to make them fit.
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Oh, no no no no. Don't force a machine screw into metal. Among other possibilities is you can crack a casting. Or distort it. Use appropriate taps. And, if it's zamak, be sure to put a bit of oil on the tap, because zamak sort of likes to jam up taps.
Taps broken off in holes are REALLY IRRITATING. So be careful not to let that happen.
Ed
I hadn't thought of the self-tapping screws that Darth mentioned. They should work, though I'm still a guy who likes to run a tap through anyway.
Ditto for me! I almost always tapped the holes for self-tapping screws--unless they looked too coarse, which was seldom the case.
Deano
Always tap. I have used kerosene in the past. Read about that many years ago in a MRR magazine.
Few times I used a 2-56 bottoming tap if the hole did not go all the way through but that was kind of rare.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
I got to this today. It turns out I should have looked more closely. The can motor version came with the less common 2M screws for which I don't have a tap, but fortunately the motor can holes were already threaded, two 2Ms to hold the can to the support plus a 2-56 to hold the motor/support assembly to the frame.
The other holes so far have been mostly untapped 2-56, with "self tapping" screws provided, but in some cases are tapped already. Since I do have the 2-56 tap I used that.
That's the good news. The bad news is that I assembled the drive mechanism, wheels, rods, etc in steps. It works but the (brass in this case) driver wheelsets are in lousy shape. The loco would hop down the track. One driver on one side is toe'd out (not parallel to the rail). And I think at least one has the axle off center so the wheels, even if on the same horizontal plane, go through a hopping cycle. It's not the rods binding, but maybe I have to check closer for a quartering mismatch, if that can make a wheel hop relative to the others. Maybe I can make a video to demonstrate. I'm assuming I cannot obtain new replacement wheelsets. Not at all sure I want to continue, paint, add a decoder and speaker as I doubt I can get this to run right without new drivers.
Yikes, Paul. That doesn't sound good at all.
I recommend putting it down for a couple of days and letting that brain thing you have contemplate the problem.
You quite likely can get drivers and other parts on Ebay. That's how I've been assembling parts for a loco project.
Darth likely has some advice on the matter, too.
7j43kYikes, Paul. That doesn't sound good at all. I recommend putting it down for a couple of days and letting that brain thing you have contemplate the problem. You quite likely can get drivers and other parts on Ebay. That's how I've been assembling parts for a loco project. Darth likely has some advice on the matter, too.
Ed, you are wise to recommend taking a breather. Nothing like a good night's sleep to help the attitude.
I have other commitments today but just looked at the frame and mechanism and a couple of ideas arise.
On the toe'd front driver, it's the one on the non-pickup side, so the axle is inserted into the plastic (vs. metal) wheel (it has a metal rim for looks). Rather than bend it into alignment parallel with the track and its mate, I'm thinking to gently use my heat gun to warm the plastic before doing that. It won't take too much so that might work. The risk is making the axle hole elliptical and loosening the driver.
On the hopping, what occurs is at some point in the revolution one of the drivers moves upward relative to the other two, causing a hop. I can think of three possibilities. If a quartering mismatch with limited slop in the side rod holes, a semi-binding could make a wheel hop (need to move vertically) before totally binding the mechanism. I doubt this is the issue. A similar cause could be the side rod holes on each side are not identically spaced, causing the same effect.
I think the most likely issue (before checking further) is that one side of the (middle) drivers has it's axle hole slightly off center, so the axle has to move vertically relative to the other two wheelsets. That could mean the siderod hole(s) need to be large enough to take the axle moving off center. But I'm guessing the holes are large enough for that. I think more likely is that when the offending wheel needs to move vertically, it is raising the frame (at the simple U-shaped journal) at that point, making the frame lift at a slight angle (resting on the high wheel and one of the others. If that is the case, filing the frame journal to make some vertical room may be helpful.
Just guesses at this point. But perhaps some troubleshooting can be successful. I don't find the drivers (or mechanism) on EBay currently, but perhaps it will show up.
Paul,
Some good thinkin' there. Don't DO, yet. 'Cause some of that you may not be able to undo.
I read that you say one of the DRIVERS hops up. That gets me wondering how it can hop "up" unless there is a lot of slop in its axle bearing. And if there is, perhaps some shimming might be in order. Either by itself, or, more likely, along with some other "stuff". Remember, all the axles should be in the same plane--meaning you should be able to sight down each side and they all line up (easier to say than to check).
I am wary about heating up that plastic. It seems like a sort of thing that can go wrong fast. But, on the other hand, IF it doesn't........
I recall back in my steam loco kit-building days thinking that if I just filed the side rod holes bigger, everything would be better. I'll just leave it there.
Thought about this at the gym. Here's a quick video. It may be one problem, versus two.
https://www.youtube.com/watch?v=yK-yoQPwJbQ&feature=youtu.be
Here's some additional thoughts.
Troubleshooting this kit mechanism. The left front driver is toe'd in and will need straightening or wheelset replacement (if attainable). The "hopping" is perhaps related or a separate issue. It may be that the toe'd driver flange hitting the rail, certainly causing a wobble) is also causing the hopping (one driver lifting and tilting the frame from horizontal) if the flange is climbing the rail slightly.
The toe'd front driver has its axle into the plastic (other than brass rimmed). Whether the toe-ing can be straightened without loosening the driver connection to the axls the question. I'm assuming the axle end is not bent and that the driver is on crooked.
I think the next step is to remove the motor and rods and see if the independent wheels roll smoothly without hopping (one lifting the frame). If ok, it is likely that the toe'd driver is the sole problem. If not, maybe the journal areas need attention if one driver is a little out of round vs its axle (needs to move vertically).
Pretty darn neat and useful video. Well, as far as it goes.
Besides the first axle, I can also see a problem with the wheel on the second axle. In particular, when the camera is down low and steady towards the end, I can see a reflection off of it's flange that should not be "wiggling around" like that.
Oh, a thought: Get yer NMRA gage (my favorite spelling) and apply it all over those drivers. Another bit of information.
It's awfully hard to believe the axle itself is bent or crooked. But if it is, it is. I think the odds are going with it got shoved into the plastic crooked. That is, if it IS crooked, and not an illusion generated by some other problem.
One thing you might try. AFTER seeing how sloppy the front axle is in the frame, have the motor run it and only it. Disconnect the rods and turn it upside down. If the problem goes away (somewhat unlikely), THAT will certainly tell you something. Of course, if the bearing is real sloppy, that might be causing the problem. The NMRA gage, applied around various positions, should also indicate if the one driver is cocked.
I'm not quite sure how I'd set it up, but my inclination to fix (or try to fix--ya sort of have nothing to lose) a cocked driver is to build a fixture (jig) for it and apply a small measured repeatable pressure in the direction I want. Leave it for a day (because plastic creeps, this might work) and check again. Each day apply just a little more measured pressure. That measure pressure thing is tricky. Maybe a weight that you can keep increasing. Anyway, that's the slow-and-easy approach. This, by the way, I would likely only try on a plastic driver center. As opposed to metal. BUT. I will say I used this EXACT technique to straighten the walkway on a Varney metal switcher body. It bent JUST A LITTLE. Just enough. And did not crack. Which Zamak loves to do.
Now, designing and building this fixture is a project, itself. Fun? Perhaps. There's "always" Ebay.
I could be seeing things wrong, but near the end of the video where you had the top down view, was the right-center driver disconnected from the siderod? If so, that would cause an immediate bind.One other thing to check is that the drivers are all properly quartered. If one wheel is off even a little, it can cause a bind like this. Sometimes, it's possible to see if the wheels are quartered by lining them up perfectly and seeing if anything is off at all.
Thanks, guys. Darth is correct, the right side main rod pin fell out so only the left side was cranking when I took the video. (The pins are inserted loosely as they need to be disassembled for painting, etc.) I took and posted the video in some haste today. I think it will behave similarly if I correct that but there are other things to do first and it will be a few days away.
- I will reconnect the pin and take as close as possible a visual look at the quartering.
- I then will remove the motor and rods and see how the frame and drivers in the journals roll as is, especially concerning any vertical rocking and which driver(s) cause that by needing to go higher (i.e., if out of round).
- I see I need to address the piston rods holes into the cylinders and/or slightly trim at least one as the right one starts binding there when is needing to go max into the cyinder. A problem but not the only one.
- I'll check the drivers lined up and judge which (certainly the left front) are not perpendicular to the axle. And put the NMRA gauge to each around the circumference to confirm. I'll try the suggested plastic bending technique to see if less than a sledge hammer is the place to start.
- Along the way and as I progress with the above, I'll try to better determine whether the journal areas (U-shaped grooves in the frame) need any adjustment. It strikes me that, for instance, any out of round driver axle needs to have a journal top height (relative to the other two) that would let that driver move upwards slightly (allowed by sufficient side rod hole slop) so that that driver axle does not bump the frame upwards.
I could go on, but this will have to go stepwise. Thanks for the suggestions.
Sounds like a good plan. With the motor removed, you should be able to roll the loco easily by pushing it on a flat surface. Looking at the video, I suspect a bind. Check the rods and the brackets that support the pistons to make sure nothing rubs against the other components. It is unlikely that the grooves in the frame are the problem, unless you filed them too agressively during assembly. Good luck!
So. I just broke a tap. Not as bad as it could be, because I can easily make a replacement for the piece of steel featuring a newly installed broken part of a tap in it. It's ART! Am I bid $10,000 for this piece? Free shipping!!!!!
It wasn't model trains. I was doing some work around the house. I'm so used to just running a 10-32 through electrical boxes that I tried "just running" a 6-32 through steel that's twice as thick. Without lube, mind you. Why? you ask. 'Cause I like to avoid cleaning lubricant off the part.
So, it's back to the workbench; and this time I will use oil. And be a wee bit more conservative with my wrist.
This is not NEARLY as upsetting as when I broke a 2-56 tap in a coupler box hole in the frame of a locomotive. That would be the somewhat expensive-to-replace frame of a locomotive.
Do NOT do this at home, kids!!!
Just for info, I'll add a followup note on the 4-6-0 driver problems.
I did some checking today on a number of things. The bottom line is that the final problem seems to be the left center driver being axle'd off center, so it runs more like an ellipse than a circle. While other concerns were able to be solved or reduced, the mechanized frame simply wobbles, hobbles, hops too much. The problem can be seen when running it (slipping) on a short piece of track, observing it from the side, and then gently lifting the left side slightly. When slightly raised, the left front and rear drivers are still slipping atop the rail, but the center driver noticeably goes above the rail and then down firmly into the rail. That makes things move around unacceptably due to the cycling vertical force. Perhaps increasing the journal groove would let it move upward without tilting the frame, but the push down into the rail still makes the frame jumpy. Plus some of this eccentricity is doubtless transmitted laterally throuch the side rod which has the other drivers attached. In technical terms, it's a mess.
I've decided that this is not solvable, at least by me, with the current driver(s). Frankly, all three of the wheelsets are iffy at best. And given the brass wheel rims, this may hardly be a good running DCC loco anyway.
So I'll see if eventually I can find a good set of drivers (including plated rims) on Ebay. Meanwhile, this project is back in the box, on the top shelf of the closet, and other fish will be fried.
A wise move.
I suspect the only way to pull this one off is get a couple more of these, hoping you can assemble 3 good driver sets out of 9. Which may or may not be worth your time/money.
Another possibility: turn this think into a hulk outside the engine house. You could take some parts off, and such. You could pull the tender off for use elsewhere--maybe a water car for MOW. Could end up being the better choice.