BLI Mikado-BullFrog Snot

[Teditor]

I have one of the BLI Heavy Mikados that keeps tossing the traction tires, I have BullFrog Snot that has basically cured in the jar, does anyone know if the BullFrog Snot can be re-activated please.

Teditor from the Land Down Under

[MK]

Unfortunately you can not but I read somewhere, I think some other MRR forums, that earlier batches had bad caps and didn't seal correctly, leading to premature drying out.  The new jars supposedly don't have this problem and the stuff can last 2-5 years in the jar.  I don't know if a time period was mentioned as to when they switched to the newer cap.

If yours is fairly recently I would contact the manufacturer.  People have reported replacements if your purchase was before the switch over.

[mmagliaro]

Have you tried retrofitting with a different tire, perhaps from this place?

https://lovetrainhobbies.com/N-scale-traction-tires-locomotive-engine-replacements-steam-diesel-N-scale-traction-tires-lovetrain-hobbies-mm-N-MAIN.html

You could measure one of the existing tires with a caliper and then order some that are the same and some that are a size smaller.

[Teditor]

I have looked at them, but being in Australia can be a problem, BullFrog Snot was an easy way out when it wasn't a gluggy blob, BLI do supply two spare traction tires with the loco, but I'm wary about pulling the pin (Nut/screw) from the rear driver to do the change and would rather not have them.

Teditor from the Land Down Under

[w neal]

People don't understand about being an N scaler in Australia. Its like craving mangos in Montana (my band's name).

[randgust]

Looking at how this is put together, you can be legitimately concerned.

http://www.spookshow.net/loco/bli282.html

Good shots, thank you Mark.

OK, so I just had to change out two rear traction tires on my Kato/GHQ L1, and was equally freaked out because re-inserting them in the gear train means they can get out of quarter, and on the BLI, the only thing moving the rear drivers is the crankpins.   So yeah, it needs thought out.

But if you're got BLI replacement traction tires, I'd still try those first.   If that fails, well, BFS.    Getting anything like that smooth and even is the challenge and if you're afraid to pull the drivers, makes it a lot harder to work around the rods and body.

So here's how I'd do it.   First, don't try to remove the rear driver.    Work on one side and then the other but not both at once.   It looks like a tiny round-headed plated pin in a cast plastic driver.  Not sure if it is threaded, but I doubt it.   So if it is press-fit round pin, work tweezer points under the rod and pry gently to see if the pin works out; get it out far enough to grip the head with tiny longnose pliers and work it out.  You may want to do that step inside a plastic clear ziplock bag to make SURE that pin doesn't go flying.  If it is threaded hex-headed screw, you can use the longnose to gently back it out if you don't have a fitting hex-head jewelers screwdriver.  (some brass even comes with the right-sized one).  With the pin out, you can remove the old tire remains and put on a new one, then replace the pin.   Then do the other side same way.   

If it is a threaded hex-head screw, probably a good time to fish around and look for the right tool - the open-end hex-headed wrench.   I got a set of these a while back and it was worth it.  Even in Australia you can probably get one of those, and I'll guess BLI is metric?

Loosing crankpins out of drivers is one of the scariest things out there, I understand your concern.    The trick here is to minimize the risk on either messing up the quartering or loosing the pin.   I like working on a pad of clear small bubble wrap now even better than a foam cradle.  It captures parts better.

[nickelplate759]

If you pull the pin, follow the process that randgust described - but in addition, put your work pad inside a smooth plastic box or tub.  Then if you drop the pin (in my case, when I drop the pin), it will be in the box.

[peteski]

I use ends of my pointy tweezers for prying out crank pins. I insert them under the side rod (not directly under the pin's head. If there is not enough space to insert tweezers, I pry them out with a hobby knife.  Yes, it is very important to do this somewhere  where the pin will not shot off and be lost.  I would even recommend doing that in a transparent plastic bag.



A hobby knife blade can also be used (inserted between the wheel face and the siderod.  This way the siderod is what actually lifts the crankpin. This allows  much more control over the lifting process so the crankpin should not go flying out of the tweezers.

Randy, doesn't the GHQ L1 use Kato Mikado mechanism?   In that one the rear (TT equipped) driver is geared and it doesn't even have crankpins.  The traction tire can be slipped out between the wheel and the crankpin-less siderod.  And regardless, why is getting out of quarter a concern when neither the wheels or the wheelset is  removed from the chassis?  Also Kato Mikado axles are hexagonal shape for super-easy disassembly and reassembly without worrying about perfect quartering.

Same with the BLI Mikado - I don't see why quartering would even come into play since the wheels do not need to be removed from the axle for TT replacment.

[mmagliaro]

The 2015 NTrak Steam Annual, Page 48
Article:
"Removing and Reinstalling Siderod Crankpins on Steam Locomotives"

Shameless plug:
https://www.ntrak.org/Sys/Store/Products/58690

The article is a fully photographed and explained, step-by-step process on doing this.  The photos and comments thus far posted are similar to the process in that article ( using Xacto to pry out the pin from behind the rod,
using fine point tweezers to wedge it out the rest of the way, and how to get it pressed back in, all without having the crankpin
fly off to the Island of Misfit Loco Parts).