Author Topic: So is there a fix out there to improve the Walthers Berkshire anemic pulling?  (Read 5980 times)

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victor miranda

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mmmmmmm

I am thinking the adhesive is the trick.

the vinyl electrical tape will walk off because that adhesive is mobile/creepy.
and then you will have the adhesive to remove.
the masking tape.... will erode into the adhesive...
and then you will have the adhesive to remove.

thin wall vinyl tubing....

hmmmmm

CNscale

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Quote
I still wonder how much of the adhesion to the rail is due to the substrate of the tape rather than the adhesive itself.

I suspect it's not the substrate, and not the adhesive, but rather all the crud picked up by the adhesive that effectively turns the tape into a sheet of very fine sandpaper.

jdcolombo

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Victor's last post made me wonder:

Do they make heat shrink tubing large enough to go over a driver?

If they do . . . cut a slice of the tubing, put it on the driver and apply some heat.  Tubing shrinks to the driver.   Almost like doing a real steam driver tire!

John C.


peteski

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Victor's last post made me wonder:

Do they make heat shrink tubing large enough to go over a driver?


Yes they do (and even much larger). But even un-shrunk it is way too thick to be used as a traction tire without a groove in the thread.

Victor has me confused again. The tape in question has adhesive on both sides. On one side the adhesive holds the tape to the metal tire's surface - the other layer of adhesive is in contact with the rail.  I wonder how long that outside layer of adhesive stays on the wheel (before either being totally contaminated by drud or simply wearing off the tape). Either way, that still leaves the tape substrate with the other layer of adhesive still holding it to the metal tire.
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Lemosteam

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Victor's last post made me wonder:

Do they make heat shrink tubing large enough to go over a driver?

If they do . . . cut a slice of the tubing, put it on the driver and apply some heat.  Tubing shrinks to the driver.   Almost like doing a real steam driver tire!

John C.

Issue with this is the heat shrink tubing shrinks unevenly, and gets thicker as it shrinks. Then, what keeps it attached to the tapered driver?

CNscale, I think you are on to something.

Peteski, the tape is 0.003 thick and even though the pictures on the Mike crud are alarming, the hour that I ran th Berk on the more used track, did not look like that, it looked mor like metal micro shavings were embedded in the tape.

I wonder what would happen if the driver were not totally smooth (save for micro finish)?  What would happen if just the tire surface were sandblasted with an air eraser using Aluminium Oxide powder?

I've asked this before on th A forum, but no one ever responded.

Max, curious, did you catch my response regarding you earlier questions?

mmagliaro

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Yep, I got your answers, John.
I am not convinced that adding a heavier weight than the engine normally has doens't skew
the results, even if you run all the tests with the same weight.
The pulling power increase from the tire is the product of the weight and stickiness of
the tape.  i.e. You get a higher and higher coefficient of friction as you increase the weight.

If you add 5g of weight, a stickier tape will cause your pulling power to increase
more than a slipperier tape that has that same 5g weight on it.    Put another way...
Let's say a stock engine with no weight could pull 10 cars.
You put traction tire 1 on it, and it pulls 20 cars.
You put traction tire 2 on it, and it pulls 25 cars.

If you then double the weight of the engine, I'm not convinced that the two
traction tires will increase the pulling power in a linear way.  In other words, if the pulling
went up to 40 and 50 cars, respectively (both doubled), then we could say that
the weight doesn't matter as long as it's the same in all cases.   But I suspect
that the stickier tape might pull, say, 55 cars, and the slipperier tape might pull only 40, or 37.

I am not so sure that the pull increases the same for all the tape types as you add weight.
-------------

Whew...
Now, having gone through all that, what I'm getting at is that if you weigh the engine down
more than the standard Berk weighs, you might see more dramatic increases in pulling from
sticky tapes that won't really happen with the real engine.  For 4 different types of tape,
you might see increases of 10, 20, 30, and 40% respectively, whereas with the real
Berk weight, you might see increases of 10, 18, 25 and 28...  or... something.

I don't think the two factors are independent.

////////////////////////////////////////////
And at this point... I doubt any of this long winded winging makes any difference.  The
2-sided tape worked for you and it pulls the train, so who cares?    :D

Oh... and about needing the tools to cut that groove properly...
yeah, I don't have them either.  That's why I cut mine IMproperly, and I just got lucky that
it worked. 



Lemosteam

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But that was the point Max. That the only thing that changed in all three tests was the driver. The weight did not shift or change place from test to test to test. Each driver saw the same vertical load, so each driver set had a different coefficient of friction resulting in different pull values for each driver.

But I agree, it works and surprisingly well IMHO.

The next test will be to run the PE on an NTrak setup at a local show to see how the tape holds up and for how long in that environment.

peteski

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Actually by adding the "tape tire" the weight distribution over the drivers has changed quite a bit. Since the taped drivers have a slightly larger diameter now, they carry more weight on them than before (they carrytheir weight, plus whatever the middle drivers carried). The front drivers also carry good portion of the weight (this all depends on how the loco is balanced in the first place).  The middle drivers now do not carry much weight since it they are floating between the front and rear drivers.  That is on level track of course.

John, a great majority of model RR wheels is made of brass (seldom nickel-silver) which is then plated to appear sliver.  Some older Arnold locos I have (like a GG1) actually use plated steel. I have seen the plating wear off after long-term running and you can clearly see the golden brass color where the plating wore off.  Ot in case of Arnold, rust will can form where the plating was worn off (of the loco sits unused).

You could sandblast the tread area (either just lightly so the plating is blasted, or all the way to the whatever is the metal under plating.  That might increase traction but I think that the blasted areas will quickly polish out from running on the track.  I'm simply speculating since I have not tried this.
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Kentuckian

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I am talking way out of school here but several years ago I read somewhere that Athearn HO locomotives used to use sintered bronze for their wheels.  This process is when a powered metal is put into the wheel mold, and fused into a wheel.  Because of the rougher texture, these wheels had more adhesion than the wheels that were machined from metals discs.

Could this be used in N scale?  Is it a more expensive process?
Modeling the C&O in Kentucky.

“Nature does not know extinction; all it knows is transformation. ... Everything science has taught me-and continues to teach me-strengthens my belief in the continuity of our spiritual existence after death. Nothing disappears without a trace.” Wernher von Braun

mmagliaro

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It already has been.  The Lifelike diesels from the 90s, like the GP and the F unit, had roughened
blackened wheels that sure seemed like sintered bronze.  And those engines do pull like a dinosaur,
even without any traction tires.

victor miranda

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I suspect that n-scale sintered-bronze steam engine tires would be affordable.

I doubt the would be worth much in terms of traction.
Kato's Mikado drivers were treated to get much the same result.
.... and traction tires are now available.

the issue is as simple as weight.
weight is how traction is created....
HO has room for weight.

n-scale wants for weight.

victor

SkipGear

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Coming into this late but yes, heat shrink works very well for a traction tire. I do it all the time. The hardest part is cutting it uniformly wide. Uneven shrinking is not a problem if you go slow and I usually start with a size smaller than will fit on the wheel anyhow and stretch it to fit.

The important part is to get good heat shrink. Radio shack is not the place to buy heat shrink. The best I have found without heading to the electronics suppliers comes in a package from the RC company, NOVAK electronics. It comes with an assortment of sizes that work well for N scale and it is a soft rubber, not that hard plastic junk sold at Radio Shack and most home improvement stores.

I have a dozen or so loco's that have tires replaced with heat shrink when the originals were no longer available.
Tony Hines

peteski

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I have a dozen or so loco's that have tires replaced with heat shrink when the originals were no longer available.

I thought the discussion was about improving traction without having a tire with a groove cut in it.
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victor miranda

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forumers,

the groove for a traction tire is not a difficulty in that is can be done a number of ways.
the problem is the tire.

we could use a rubber band for the task....
that will require a deep deep groove and that is the problem.

depth for the tire or what tire
Atlas/RR uses vinyl tires which are pretty thick
the same tires will not work on a ll/w berk
because there is not enough metal to make the groove deep enough.

one fellow here has said he uses Kato Mike tires.
for the berk driver, I am sure a groove for that tire will be ok.

so that is my plan for the loco.... along with a tungsten weight in the nose.

it seems if you get traction, the nose of the loco will lift.
all the detail to attend to get a good runner.

victor

« Last Edit: January 30, 2015, 06:18:16 PM by victor miranda »

peteski

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OK, since we are talking about regular traction tires now, one shoudl not forget that there is a large selection available for European steamers. There is a wide variety of steam locos produced by Fleischmann, Minitirx, Roco, Brawa and others. Many of them use traction tires. Granted, it is more difficult to obtain these in U.S., but it should not be impossible.
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