JTC NSC 17-post well car coupler & etch issues

[Bob]

Hi all - I finally started running my new JTC 17-post well cars, and find that they easily uncouple, most often in an undesirable location like a helix!  Anyone else having issues with these cars?  Some of the couplers don't seem to be as 'springy' as they ought to.  The couplers are attached to the car with what has got to me the smallest screw I have ever seen, so I can't take one off/apart to investigate.  Reaching out to see if anyone who has experienced this has some advice!

[GaryHinshaw]

I haven't run mine enough to experience uncoupling, but some of the couplers on my cars have issues as well, with some boxes being too tight and others too loose.  Alas, the screw for the box is put in from the top - presumably for axle clearance reasons - so to do any kind of service on the coupler, you have to remove the end walkway etch.  I haven't been successful at removing these etches without deforming them beyond repair.   

I don't have a solution yet, other than a plan to convert mine to LEZ couplers and beg @JaxTerminal for (more) replacement end walks.  Otherwise, these are outstanding and much-needed cars for us modern N scalers.

[Bob]

THanks Gary - I found a review that noted, as did you, and the screw comes in from the top, and it stated that 'great care' must be taken when prying the end walk off!  I'll try with one of the cars and see if slight loosening of the screw does the trick.  RIght now I have had to sideline 5 of my 7 cars as they uncouple so frequently!

[Englewood]

I've got two that like to uncouple. I haven't had time to look at them yet with all the hustle and bustle of the holidays.
Aren't these Microtrains couplers?

[Bob]

Yes, they are MT couplers so you would not expect to have this problem.  My guess is that they are tightened too much.  I had a couple of locos where I installed MT couplers that tended to uncouple, and it turned out I had just tightened the screw too much.  When I backed it off just a touch, the couplers then worked perfectly.  So, I surmise that is the issue with the JTC cars.  Unfortunately, they are screwed from the top or this would have been easy to adjust.  Tomorrow I will see if I can get an end walk off without destroying it.  Even if I do destroy it, I can at least test this hypothesis and I'll report back.

[turbowhiz]

I’ve had very good success removing the walkways on these cars without destroying them. I’ve done it on 3 cars both ends and have not destroyed or even substantially damaged one. I just pulled out another from my recent order from the 2nd run to take pictures for this post, and removed that one without trouble either. Notably I've had quite a few cars come with damaged couplers, including the one I randomly picked for this demo. I don't care as I'm replacing them, but its notable. (In my first batch of 3, two car had deformed couplers on one end that someone might not notice, and this most recent example is just plain broken).

There is no good reason for the screw to be installed from the top... There are way too many times you need to maintain a coupler. Its a royal pain when manufacturers do this. When replacing the couplers I tap the hole for a 0-90 screw and screw the replacement box assembly in from the bottom and don't have any axel clearance issues.

My trick:

1. Remove the truck
2. Drop a little CA De-bonder where the platform bends into car on the end.
3. Push the platform from below with something that distributes the load. I had a servo horn lying around and I trimmed it down to fit. You want to push on the platform close to the edge. You will have to use a fair bit of force, but be judicious. I removed a few before I started using the CA de-bonder, and I was successful even without it, but its a whole lot better if you use it. Work one side at time... Now be careful, once you have released one side, the platform will fly away on you when you release the other side... You've been warned.

Now once that platform is off, its a great time to paint it... Mask the walkway and airbrush the steps and the railings... Makes a huge difference. And its way easier to paint off the car.

See pictures below (K I can't do pics properly cause I guess I've not posted enough, but they're attached )

[peteski]

Turbowhiz,  what brand of CA debonder are you using?  I ask because some debonders can contain acetone, which might affect the paint.

I agree that placing the screw head on the top is not a good design.  The draft gear box needs to be easily accessible for when the coupler needs to be worked on, just like in your example, when the coupler head get damaged.  Good example of what appears that the model's designers are not really hobbyists who would know better than design the draft gear box this way.

[Bob]

Turbowhiz - this is so helpful - thank you for taking the time to post such helpful pointers.  I am going to give this a try today, but will see if I can get some CA de-bonder from my local shop.  But, as Peteski asked, the brand you used would be useful to know as it is clear that it worked for you.  Also, I think I'll write to JTC about this issue as I imagine they will do additional runs - I wonder if they just drive the screw in from the bottom?

[turbowhiz]

I'm using Bob Smith Industries un-cure. (Well its technically labeled "Hobby Craft Canada" but yeah.. Its an ancient bottle of the stuff, and its most definitely BSI OEM)

Now I'm using a VERY small amount... I dispense a little pool from the bottle and then use a fine brush to apply it only into the platform end support area. All you want to do is to fill the little channels in the car end that the platform pokes in to. I find it runs along the platform edge often too...

The paint seems to be holding up ok against the CA de-bonder, but I wouldn't be applying it directly from the bottle and getting it all over either. In any case, touching up that part of the car would be easy enough anyhow, but I've not had to do that at all.

As I said, I've removed the platforms without the de-bonder too using the same technique; But its a LOT better to use the debonder, they come out a whole lot easier with a lot less force.

The other trick is as you push the platform, you might find the back end will raise up but the tab won't release... try and keep the platform level as you push on it... Sometimes its useful to push the the platform back down on the top to keep it level (the "back end" being the platform edge without the tabs facing the inside of the car) while also pushing at it from the bottom at the same time. The tabs won't release well if they are being pulled at an angle.

[peteski]

Thanks turbowhiz.
My local hobby shop used to buy unbranded BSI CA products, and stick their name and address on the blank area of the label. Or maybe BSI did that for the hobby shop.  Manufacturer info on the label still shows BSI.

Anyway, BSI is my favorite brand of CA adhesive products - I just never had reasons to pick up the debonder.  I also like their accelerator.  I have tried about a half a dozen brands of accelerator and BSI is the best.  Low odor, doesn't evaporate too fast, and it and it doesn't cause the CA to bubble due to the fast setting reaction.  Good stuff!

[turbowhiz]

I don't go through the stuff very quickly... This bottle I'm using here has to be 10+ years old. But from time to time, it does come in handy.

I'm with you Peteski, the BSI stuff is my go to CA product line.

[Bob]

You must have hands of gold, Turbowhiz!  I tried removing one end walkway without CA debonder as I don't have any on-hand, and I promptly bent the walkway rather badly.  I am going to cease and desist until the debonder shows up on Wed, then I will try once again.

[GaryHinshaw]

Great tip Whiz!  Thanks for posting.  As it happens, I did have some BSI Un-cure on hand and it worked well.  Here is a shot of the part after removing it:



There is a very slight bit of deformation near one of the tabs, but that is easily rectified.  Here are a few additional notes:

* I applied a very small pool of the solvent into the slot with a white Microbrush and it pooled nicely without running out.  Let it sit for 30 secs or so before trying to remove the part.  I had no issue with the paint stripping off.

* Put a single container in the well and get a short piece of 1/8" square stock to put on top of the walkway, then turn it over and press on the bottom of the walkway with another piece of flat-end stock while holding the top (now bottom) piece in place:



You'll hear a pop when the bond has broken. 

* Once you've broken the bond in both tabs, you can easily remove the walkway. But note there is also a tab on the back side of the part that does not appear to be glued.  You'll have to twist the walkway up and out from under the upper etch to remove it, but that is straightforward.

I'm going to replace the couplers with LEZ couplers and printed pockets, but for those that want to keep the stock couplers, the easiest fix is just to tighten the existing screw appropriately and re-glue the walkway with something less permanent, like canopy glue.  However, it does look like you might be able to tap some 00-90 threads in the existing hole and re-screw the box from underneath.  Not sure how hard the metal is, or if the screw head would interfere with the outer wheel axle though.

Now about that brake wheel and those end grabs...

[turbowhiz]

You can tap the hole with a 0-90 tap. There is enough there to work with.

There is no issue with screw clearance at all, as the screw is far ahead of the axle anyhow.

[Bob]

Thanks guys - I will try again once the un-cure shows up!