I agree, Simon. In fact, most of my locomotive purchases over the past few years have been older brass unique to my prototype (NYC); some at very reasonable prices with very good detailing. It's been fun to convert them to DCC and wire them for SMD LED headlamp lighting and occasionally sound. And it's the only way I'd be able to procure those particular models since they will - more than likely - never be made in anything other than brass.
I've only had one brass locomotive that has been a disappointment running-wise. All my other acquisitions - steam or diesel - have been very smooth runners. The disappointing road switcher I plan to replace the gear towers with Stanton drives.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
I'm glad to hear that the results are satisfying. And thanks for sharing the picture: I like brass - inside and out!
Simon
Tom, I am glad motor is good for your locomotive. But, can you test this locomotive for minimum flat DC voltage required for locomotive to move on flex track? I am curious, because most of my locomotives move at around 1 - 1.5 VDC, or even less.
Hrvoje
Thanks, Kevin. I'll be sure to post photos when I get 'er done. I may still purchase a couple of inexpensive but quality can motors to play with for comparison (Minebea being one) before buttoning this one up.
tstageAlso zero spikes
Tom, this is all very good news to hear.
It is always good when a brass steamer is made ready for the fleet.
Good luck with the lighting and decoder installation. Even though I do not do this, I would love to see your work.
-Kevin
Living the dream.
The replacement motor arrived this afternoon and I installed it onto the original bracket that I pre-drilled 10mm x 2mm OD spaced mounting holes to accommodate the new motor. I also opted to use Du-Bro silicone tubing for coupling the gearbox & motor shafts, which worked well for my previous NYC brass boxcab project:
Most importantly, the new motor is working quite well and smoothly - especially at slow speed. (Thanks, Hrvoje!) Current draw is extremely consistent and low: At speed step 030 it fluctuates between 0.04 & 0.06A. Also zero spikes and it's operating cool as a cucumber.
As with my previous setup, the LokPilot is only temporarily soldered in place for testing purposes. The 18 x 18mm motor housing will give me more headroom for the decoder inside the boiler. Like my other DCC brass installations, I'll be adding front & rear headlamps. I'll also be adding another SMD LED to the backside of the backhead to mimic firebox flicker. The brass casting for the backhead has the firebox door open.
My one disappointment is that I won't be able to use/add the supplied lead weight to the front part of the boiler because someone (I'm guessing the manufacturer) soldered the front boiler plate on enough that I fear damaging it trying to get it off. Sometimes the boiler plates are just press fit in. However, I can see at least 3 or 4 small solder spots along the boiler plate seam. Even cutting along the seam with a sharp X-acto knife to score the solder doesn't open them up. I'll find other ways to add the weight.
I also believe flexible tubing is the best way to connect the two shafts. I even doubt whether you can fit the universal in the limited distance.
Universal joints are very good at accepting radical angles of drive. That's not needed here.
Universal joints are very good at transmitting power across a goodly distance. That's not needed here.
Ed
And considering the difficulties involved with pressing that coupling on an assembled coreless motor's shaft, I cast my vote for the tubing, with fallback to a close U-joint if the tubing 'fails to thrive'.
I've used silicone tubing and NWSL u-joints for driveshaft couplings and both work well. I've never seen this particular design before and would agree that it looks less forgiving and less flexible than the other two options.
snjroyI would suspect that the problem is associated with that odd coupling system.
Agree, many of the NWSL U Joint kits come with a close-install "dogbone" that should work.
If this was my engine, I would change the coupling component. These motors are of good quality and I would suspect that the problem is associated with that odd coupling system. I've used tubing on 3 or 4 brass engines and they all work very well at all speeds. As for the motor connection, I would remove the brass bracket and build a new base with plastic, and use caulk to hold everything in place. I see no advantages in keeping the original coupling system, but I see a lot of "smoke" suggesting that it burned your motor, and might do the same with the next.
Anyway, that's my worth.
Tom,
I think it is not necessary to drill new holes - just make a "groove" from existing holes 1-1,5 mm towards the center. It seems to me, after looking to picture you posted that motor holder is held with two screws to loco chassis, so it is not difficult to remove it and work on it. My idea is that these grooves intentionally enable some movement of the motor to fine adjust motor into perfect position.
My proposal is to solder wires to motor contacts, and connect them to DC power pack after you temporarily install motor in its position with screws not fully tightened. Then, with minimal possible DC voltage that enables motor/wheels to rotate try to find "sweet spot" where motor works without any resistance within hex coupler. When you find it, tighten both screws fully.
Another thing is very important - pressing back hex coupler to motor shaft. If fit is too tight, you could practically destroy the motor if you press this part too hard on motor shaft. Unfortunately, this motor does not have dual shaft, so there is no shaft on the other end of the motor that can be used as support while pressing hex coupler on.
Therefore, if necessary, widen the bore in hex coupler wide enough to be able to press it on without excessive force. If you widen it too much, then you can first use anything to make tight fit between motor shaft and hex coupler (e.g. piece of paper towel or piece of sewing thread) to test how motor works when installed. After you are 100% certain everything works fine, you can glue this part on motor shaft with some glue (e.g. 2K glue with at least 5 minutes of working time). I would avoid AC glue (especially fully liquid one), because it could penetrate to motor bearing, and in some cases, fix the hex part before you slide it in wanted position (happened to me several times, because AC glue is very fast).
Do not get me wrong - I do not have the impression that you are not capable, but I know how many "surprises" I had during remotoring of my locomotives (at least 40 until now), so I just want to pass on my experience which I think can be useful to you, or any other member of this forum.
Just one note on general design of coreless motors - their rotor is in fact a bell made of wire windings (without any iron core - therefore very fragile), and it rotates AROUND stator (cylindrical magnet) that has a bore in the center (for motor shaft). Longitudinal movement of the rotor is prevented only thru metal ring usually pressed on motor shaft outside of motor casing. At motors with just one shaft, shaft is not supported at all on the other side (there where commutator is located). Nice picture explains better than words - here a comparison between iron core and coreless motor design (Citizen motors).
Confirmed from the seller that the mounting holes are 10mm apart and take 2mm screws.
Overmod But note that he HAS tested the motor outside the chassis, and HAS verified the issue to occur in the isolated motor precisely as it appeared when installed. And he said he roll-tested the chassis for binding when the motor was out. I don't think it's 'worth' trying to fix the motor, other than to do some forensics on what's causing the observed issues. Replacement -- ideally improved replacement now that that famous mother, necessity, allows for invention -- is the sensible track to follow going forward.
But note that he HAS tested the motor outside the chassis, and HAS verified the issue to occur in the isolated motor precisely as it appeared when installed. And he said he roll-tested the chassis for binding when the motor was out.
I don't think it's 'worth' trying to fix the motor, other than to do some forensics on what's causing the observed issues. Replacement -- ideally improved replacement now that that famous mother, necessity, allows for invention -- is the sensible track to follow going forward.
Spalato68Btw, mounting holes on motor I linked above are 10 mm apart, and accept M2 screw (there is a drawing in technical specificaation part). If your motor has the same design (except for motor shaft), then mounting holes should be 10 mm apart. I think your motor has mounting holes that are 12 mm apart (I conclude this from drawing that can be found here). Ok, this is all guessing, because you will know exactly only when you receive the motor. I am sure you will find the way to install new motor in correct position.
You are absolutely correct, Hrvoje. The holes on the Mashima motor I have are indeed 12mm apart.
I decided to contact the eBay seller to ask them if they can tell me that information. That way I can have the bracket holes drilled out and ready for the new motor when it arrives.
Tom, I am glad that you found this motor, I completely forgot that recently I also saw this version, with 2 mm motor shaft. This version came out after I already bought several pieces of version with 1,5 mm shaft, so it had priority in my mind. 2 mm shaft is even better, especially now when you managed to remove hex coupler from old motor.
If hex drive coupling does not work from any reason, I would rather use NWSL universal u-joint over silicone tubing.
Btw, mounting holes on motor I linked above are 10 mm apart, and accept M2 screw (there is a drawing in technical specificaation part). If your motor has the same design (except for motor shaft), then mounting holes should be 10 mm apart. I think your motor has mounting holes that are 12 mm apart (I conclude this from drawing that can be found here). Ok, this is all guessing, because you will know exactly only when you receive the motor. I am sure you will find the way to install new motor in correct position.
In any case, I am looking forward to read and see about new motor when you install it. If this is the same motor as I used in my locomotive (it seems so), then you should be very happy about it.
If the mounting holes on the new motor don't precisely match just drill new ones in the bracket at 90 degrees, which preserves the ability to 'restore' original if ever desired.
I look forward to see how this runs, and I'm tempted to see how the various alternative types of drive might perform with this motor...
LastspikemikeI'm betting it's pressed on. Should be feasible to try pulling on it a bit to see if it budges.
You were correct, Mike. The hex nut was press fit onto the motor shaft:
I used one of my beefier Wiha flathead screwdrivers to slowly pry it off the shaft. I'll try doing the same with the gear box but will need to be a little more careful since it's still connected to the chassis.
Unsure whether I'll stick with the original hex-drive coupling with the new motor...go silicone tubing...or use a NWSL universal u-joint.
Spalato68 Tom, if you are seeking a new motor, which seems unavoidable, then you could consider this motor: link. It is 12 V coreless motor, 17 mm in diameter, 24,5 mm long, 12000 RPM - so it fits in your locomotive (with some adaptation to motor seat). I bought several motors from this seller and never had an issue, but there are many other sources for this motor... Regards, Hrvoje
if you are seeking a new motor, which seems unavoidable, then you could consider this motor: link. It is 12 V coreless motor, 17 mm in diameter, 24,5 mm long, 12000 RPM - so it fits in your locomotive (with some adaptation to motor seat). I bought several motors from this seller and never had an issue, but there are many other sources for this motor...
Regards,
Thanks, Hrvoje! Using your link I was able to find a similar 12V coreless motor for the same price and it looks like it has identical (or nearly identical) mounting holes to the Mashima I'm looking to replace:
It also comes with a 2mm OD shaft, which matches - as best as I can measure it - the shaft on the gear box.
[Update: Ordered 1 and one extra. Should be here by mid-August. Looking forward to trying these out - Thanks, Hrvoje!]
OvermodBut note that he HAS tested the motor outside the chassis, and HAS verified the issue to occur in the isolated motor precisely as it appeared when installed. And he said he roll-tested the chassis for binding when the motor was out.
Just to be clear: I removed the shaft coupler (that connects the motor to the gear box) only and operated the motor mounted on the bracket and connected to the chassis, as shown in the photo below:
This way the motor shaft was more easily observable, as I monitored the current draw with my Power Cab at the same time.
I didn't recollect the shaft moving axially when the current spikes occured so I ran the test a 3rd time. While I didn't observe any axial movement of the motor shaft as the current spiked, the motor shaft did bind and completely stopped rotating.
Interesting note: After shutting down the Power Cab (to preserve the decoder) and restarting it again, the bind in the motor shaft was still present when I set the speed step to "30" and the current draw remained at 0.01A - as if I had not applied any current to the motor at all.
I did roll the drivers last night on my cutting mat and I did not observe or feel any binding with the linkage so I think we can rule that one out of the equation.
So it looks like a replacement motor is the direction I'll be going. Thanks all for the suggestions and ideas.
Dumb question: does the shaft 'shift visible length' at the moment the straining starts? If the armature moves against, say, inadequate thrust bearing capacity or excessive clearance, the internal resistance might go up substantially, perhaps including brushes hanging up on the edge of the commutator's structure.
Perhaps this could be kludged by restraining the shaft motion externally: the end of the shaft in the direction of shift could be pointed, and a plate of hard material on a bracket of some sort provided...
But replacement would still be the preferable choice...
tstage 7j43k It sounds like you have a bind. That is why your current draw goes up. I suggest you find the bind and fix it. Ed Ed, Wouldn't a bind occur at regular intervals of rotation? The higher current draw happens sporadically and for short periods of time before dropping again. As a test to rule out any mechanical binding though, I disconnected the motor from the gear box and ran the motor alone with the decoder at speed step 030. (I believe that someone may have suggested that earlier.) The overall current draw was lower - i.e. in the 0.1 - 0.25A range. However, after a minute or so the motor whir changed noticeably (as if it were straining) and the current draw shot up to 1.0A and > before I shut the Power Cab down. I ran the same test again and got similar results. So, I think that confims the motor is indeed bad and the binding is occuring inside the motor housing. Tom
7j43k It sounds like you have a bind. That is why your current draw goes up. I suggest you find the bind and fix it. Ed
Ed,
Wouldn't a bind occur at regular intervals of rotation? The higher current draw happens sporadically and for short periods of time before dropping again.
As a test to rule out any mechanical binding though, I disconnected the motor from the gear box and ran the motor alone with the decoder at speed step 030. (I believe that someone may have suggested that earlier.) The overall current draw was lower - i.e. in the 0.1 - 0.25A range. However, after a minute or so the motor whir changed noticeably (as if it were straining) and the current draw shot up to 1.0A and > before I shut the Power Cab down. I ran the same test again and got similar results.
So, I think that confims the motor is indeed bad and the binding is occuring inside the motor housing.
Well, since you put it that way......
Yup. Good sleuthing.
snjroy Hi there. Before doing anything on the drivetrain, I would eliminate all other possibilities. Now that the motor has been removed, you can check for binds by rolling the engine by hand. There should be no friction. You can also benchtest the motor separately. Simon
Hi there. Before doing anything on the drivetrain, I would eliminate all other possibilities. Now that the motor has been removed, you can check for binds by rolling the engine by hand. There should be no friction. You can also benchtest the motor separately.
I agree - if worm is removed, and locomotive positioned on a track, or even glass sheet, when pushed, locomotive should roll without any hesitation or binding.
SeeYou190When you get the new motor, find a brass metric machine screw with the needed size hex head. Cut the shank off the machine screw, and then drill a hole in the center of the head to match the diameter of the new motor's shaft.
Be careful that the hole is at right angles to the hex as well as centered inside it -- again something that is facilitated by using the shank as a guide.
if you are seeking a new motor, which seems unavoidable, then you could consider this motor: link. It is 12 V coreless motor, 17 mm in diameter, 24,5 mm long, 12000 RPM - so it fits in your locomotive (with some adaptation to motor seat). I bought several motors from this seller and never had an issue, but there are many other sources for this motor.
I have used this motor for my locomotive, its performance you can see on this video. It is virtually silent, has no cogging at all due to its design which is completely different from iron core motors.
This motor has 1,5 mm shaft, so if you want to use the original hexagon connector, you need a tubing (ID 1,5 mm to OD 2,00 mm). I think such tubing (brass, stainless steel) is available from NWSL, or it can be found on Amazon or even at nearby hardware store (like Home Depot). Or you can buy universal joint set from NWSL if you want to remove hexagon coupler completely, but this requires much more work.
This motor is more than strong enough for this small locomotive. It performs beautifully with ESU decoders. I do not recommend using TCS decoder with it because I noticed that with 2 out of three different coreless motors, TCS WOW sound decoder had issues in lower speed range. But as you have both at hand, you can test both.
7j43kIt sounds like you have a bind. That is why your current draw goes up. I suggest you find the bind and fix it. Ed
Tom, the hex-drive coupling is actually pretty easy to adapt to a new motor.
Just use calipers to measure the outside hex of the nut. It should be metric. One millimeter is pretty close to 0.040" for conversions.
When you get the new motor, find a brass metric machine screw with the needed size hex head. Cut the shank off the machine screw, and then drill a hole in the center of the head to match the diameter of the new motor's shaft.
I mount replacement motors with Kneadatite epoxy putty, so centering the drive nut to the hex coupling is no problem.
If it were mine, I would seek out a double shaft motor and put a flywheel on the end, but you will lose the backhead detail if you go that route.
It is easier than it sounds.