Greetings!
Quite a number of years back while at one of the local swap meet/flea markets I picked up a package of silicone tubing cut to about 2" length in three differend IDs and packaged as motor coupling tubing. I figured that I might need it someday and, sure enough, someday came about six months ago when I needed a length for a Westside B&O Q4d.
The original coupling tube had turned to a coal like brittleness and was completely shorn from the gearbox input shaft.
Fast forward to yesterday, another Westside engine, B&O, this time a T3a and the very same crusty, rotted motor coupling. I spent two hours looking for the package of tubing to no avail!!! It surely IS somewhere amongst my junque but do you think I could find it?!! So, no worries, just jump on the www and order another package... not so easy!
Googling silicone motor flex coupling comes up with lots of near misses, Caboose Hobbies has a nice page of hints and tricks for tuning up a brass engine but no mention of a supplier of the tubing.
Greenway products shows it available but they have a caveat about not taking orders due to medical problems.
IF I could remember who marketed the first package I bought it would sure help... that's why I'm asking here. Any ideas? Aquarium and medical tubing has a thinner cross section so that's out. The stuff I'm looking for has a pretty beefy wall thickness.
Any guidance would be appreciated... Thanks, Ed
Go to your nearest drug store and look for oxygen tubing. Take a piece with you to compare the inner diameter, because oxygen tubing comes in different sizes.
As simple as this: Go to a Hobbytown store or other retailer that sells RC airplane stuff. The fuel line tubing I purchased was a slight force fit onto a 2mm motor spindle shaft on one end. There are several diameters of this stuff- if your motor has a 2.4mm diameter spindle shaft, you might want to bring it along to test fit it. The plastic tubing is highly flexible and should remain so for years, although I don't run the diesels I used it in as much as other modelers might (in terms of hours of operation). You purchase this tubing bu the foot, so get several feet for future applications.
Remember, the straighter the "line" from the shaft to the wheel gearing tower, the better; however, I have one where there is about 3/16" drop from the motor shaft to the gearing and it runs flawlessly.
Cedarwoodron
Hey Ed,
Is the tubing used for the drive shaft, like the one below Walthers used in their early 90s SW1 switcher?
Do you know what ID/OD tubing you need? Would a NWSL U-joint replacement kit work instead? That's what I ended up using for my SW1 and it's been working great.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
Tom is also on target, but why spend extra money for something that is cheaply-purchased alternatively, as I suggested. I bout a couple of the old "Hobbytown of Boston" (as contrasted with the national franchise Hobbytown stores of today) universal u-joint replacement kits a few years ago, but found the cost was greater than just getting the right size of flexible fuel line. Be frugal!
Ed, when you find your tubing, check out www.clag.org.uk/ and on the right hand of the page under "construction" there's a topic on universal joints. Our cousins across the pond have realized the right size of steel ball bearing inserted in the tubing halfway makes for a "necked" section on either side that greatly reduces the force required to bend the tubing as it works. All the technical details are in the article mentioned but it ends up pretty simple. Small bearing balls are available from www.mcmaster.com where a couple of bucks will get you hundreds!
Lou
You can also check with eBay seller "denalm". He puts up some good drive tubing somewhat regularly, and the average is $7 for 30". I got some from him, and it fits shafts from 1.5mm to 1/8" or so.
http://www.ebay.com/usr/denalm?_trksid=p3984.m1439.l2754
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Wow, Thanks for all the quick responses fellas!
Here's a pic of the Q-4b I did back in June. The T-3 is nearly identical but that sleeve is even shorter in length than the one in this pic. That concerns me a bit since any universal is dependant on a nice length of shafting to keep it aligned and from eventually wobbling. The silicone tubing is much more forgiving and some have stated that it helps to reduce noise.
The motor shaft is 2.00mm and that little sleeve soldered on is 2.42mm OD. The gearbox input shaft is 2.18mm.
I cannibalized a few Athearn BB SD-9s a while back and saved the U-joints from them. I could ream the Athearn parts and press them on with a bit of Loctite. Athearn has a 3mm motor shaft and a 1.5mm drive shaft to the gear tower.
Thanks for posting the great pics, Tom. In my case the shaft alignment is practically straight-on, what I read about universals is that they're great for off-set shafts but that might be overkill in my case. The Athearn U-joints "snap" together thus take some lateral forces. IF the U-joint can slip apart I would have to add a "torque arm" to the gearbox since it can spin with the driver axle.
I will definitely look at that Ebay seller Darth. Cedarwoodron, I'll be near a Hobbytown on Monday and I'll check out the fuel line selection. That might be my fasatest option! Cacole, I have a friend in the medical field. I'll ask her to keep a look out for some breathing tubing. Someone mentioned the face/nasal tubing to be just the right diameter and thickness for motor shafts!
Thanks again for all the great suggestions! Can't wait to get this 40 year old beauty pulling trains again!
Ed
gmpullman,
Jerry
Three other sources: Fish tank supplies for tubing, Intravenous tubing and Sears that sells weed wackers, it is used for the fuel tank sump. They all come in different sizes. One more, RC model air planes and cars, used for fuel line.
Frank
Ed,
It might be worth contacting NWSL anyhow and seeing what they suggest. They responded quickly to my e-mail inquiry and were quite helpful. I think the conversion kit was only a few bucks. Maybe something one of the vendors has at the upcoming NMRA train show @ Lakeland in March.
I picked up a pack of fuel line tube at the local Hobbytown (finally, something they are good for - they have very little train stuff) to fix up the brass RS3 I got. It already had been remotored, but whoever did it glued the universals in the short hood incorrectly and there was almost no flexibility. The fuel tube is better, but still not good enough, it handles curves OK but since there is no fore-aft give in it, it doesn't do well if the track is less than perfectly level. I suspect I have aome more work ahead of me. The motor is a good Sagami can motor, but for whatever reason it was ofset back to the short hood, so there is a nice long drive shaft built up from square brass and some Athearn universals on the long hood, and the short hood end is about the distance fromt he truck worm shaft as on the picture above.
I'd think for a steam loco, the tubing would work better. Even with sprung drivers, all you really are contending with is up/down movement. On the diesel trucks, at least ones mounted the way these are, any change of grade significantly tilts the worm shaft and increases or decrease the space between it and the motor shaft.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
In some situations, a combination of tubing and universal couplings works extremely well. For instance, a piece of tubing on one end of the motor connects to a universal shaft, which then connects to a free ball and socket joint on the truck (such as NWSL's). This gives it the flexibility it needs while keeping a very sturdy, yet quiet setup.
Darth Santa Fe You can also check with eBay seller "denalm". He puts up some good drive tubing somewhat regularly, and the average is $7 for 30". I got some from him, and it fits shafts from 1.5mm to 1/8" or so. http://www.ebay.com/usr/denalm?_trksid=p3984.m1439.l2754
Thanks, Darth! It arrived today and I have enough to do 60 locomotives!
I looked at Tygon, Jerry but it is a different material, not quite as flexible (although there are dozens of formulas of Tygon, the most common one available seems to be a bit stiff)
I never did find the original package that is somewhere among my junk... unless the cat ate it!
Thanks again to all who wrote! Ed
Never put anything past a cat, Ed. Yea, the Tygon would be stiffer and slippier than the silicone and not a good choice.
Well, now you have enough to do 60 locomotives, Ed...until the cat eats that, too.
Ed, once that T3 is ready to run the rails, "Murphy" will show you where all that tubing is...
Modeling B&O- Chessie Bob K. www.ssmrc.org
gmpullmanThanks, Darth! It arrived today and I have enough to do 60 locomotives!
You're welcome! The stuff is pretty tough, and can drive even the heavy duty trains. I found that it can be a little over-flexible for very long lengths (like 3" or so), but a fixed mid-shaft (as in, motor shaft, mid-shaft, then flexible universal) takes care of that. I'm currently using a setup like that in my Bowser Challenger, and it's now running the best and quietest that I've ever been able to get it going!