I shake my head at people who keep so much slop in their rods that precise (note the word I use) quartering doesn't matter.
SOME of the reason for not needing accurate 90-degree quartering on models that aren't live-steam is that they move the main driver with a motor, and the main pins drive some of the rods rather than the other way around, and do it with relatively constant torque (or at least with torque dissassociated with nominal rod position or pin angle). Discussion of anything involving main-rod and piston drive or admission/exhaust characteristics does not matter much to such models.
On the other hand, the specifics of rod drive can become VERY significant if you're relying on the side rods to transmit traction power to the other driver pairs, or reduce slipperiness/add tractive effort to a given model. At that point getting much off 90 degrees for typical 2-cylinder prototype (or 60/135-degree Swiss-drive for three-cylinder setups) is going to start having torque-transmission problems, exacerbated if there is slop in the rods or binding in knuckle setup, etc. If you have 180-degree "quartering" setting of 2-cylinder rods with slop you might easily get binding or even the beginning of reverse rotation, so yes, even with gear-driven wheels the arrangement of pins isn't fully optional.
The take-home message about quartering is that you SHOULD use a jig, even if homemade, and it SHOULD give consistent angle for all driver pairs, and it doesn't matter at all if you are even a few degrees 'off' an exact 90 degrees on a model, where you won't even see both sides at once to tell if things are off, and it almost never matters if the mocked-up valve gear is off time on one side relative to the other. Too many modelers don't even bother with implementing practical reverse, which is like a poke in the eye to a steam tech fan even worse than visible screw slots in the rod pin ends.
If the axle isn't splined or keyed, requiring absolute quartering, our models can have their drivers at any place on the clock one wishes...won't make a difference. What counts isn't quartering, except for looks, but alignment of all the cranks. When one is out by more than one or two degrees, the offending crank will want to sieze around the tiny hole in its side-rod. This, in turn, will draw the other rods in that direction and make them bind a bit, but the biggest bind will be at the one out of alignment.
There are two problems with not having quartering on a real steamer:
a. getting the maximum piston thrust on one piston while the other is at its furthest extreme inside its cylinder where it can offer slight thrust against its crank; and
b. you always want one of the two valves, one above each cylinder, in such a position that it will open an inlet port and to admit steam and make it work against one of the two piston work surfaces. With quartered drivers, one of the two valves will always be in a position to admit steam since it will be linked directly to the main crank on that side, which is linked directly to the piston rod via the crosshead.
Jim,
Absolutely with real steam. For a two cylinder locomotive, 90 degree quartering is IT.
But for a model, where the power is delivered continuously to the main driving wheel, I am not seeing the need for quartering.
If someone cared to do the experiment: try removing one side rod on a model. Will it move reliably? If it does, then obviously quartering means nothing, since there is none.
As you point out, it is required for a steam locomotive, because the power delivery is not continuous. With our models, it is.
Ed
7j43kI expect a 180 degree "quarter" would work, too.
Yes, on a model, I suspect any consistent spacing should work, but 90 degree spacing would probably make for optimal balanced friction loads and smoother movement. (I'm getting way out of my pay grade here.)
On the real steamers, since the pistons were pushed from both the front and rear, if the side rods were set at 180 degrees apart, there would be two positions in wheel rotation from where the loco could not be started from a standing position as both pistons would be at top/bottom-dead center. So, I presume, the obvious solution was to split the difference and use use 90 degrees as the standard.
Jim
SeeYou190 As Doctor Wayne said, quartering does not need to be perfect. The most important thing is that it is consistent among all the driver axles. I have a home made jig that sets the quarters just a little tight, say 85 to 88 degrees. Using this jig results in smooth running. If all the divers are at 87 degrees the locomotive will run great. . As with many things, consistency is the key. . -Kevin .
As Doctor Wayne said, quartering does not need to be perfect. The most important thing is that it is consistent among all the driver axles. I have a home made jig that sets the quarters just a little tight, say 85 to 88 degrees. Using this jig results in smooth running. If all the divers are at 87 degrees the locomotive will run great.
.
As with many things, consistency is the key.
-Kevin
The locomotive will also run great if all the drivers are quartered at 95 degrees. Repeat: all.
I expect a 180 degree "quarter" would work, too. Or 0.
But that would be sorta weird-feeling. Nope. I won't do it!
Yeah, sorry, I should have mentioned that. If the wheel is loose enough, it might be worthwhile to pull it free from the axle (depends, too, on if the side rods will allow this without further disassembly), then clean both the inner hub of the wheel and the end of the axle. I find that a little lacquer thinner on a small brush will take care of any grease or oil, then use the same brush, cleaned-off, to apply some alcohol to remove any residue.
Re-install the wheel, but don't push it home until you have the driver quartered. Then you can apply a minute amount of ca into the wheel's hub (the tip of a #11 blade works well as an applicator), then press the wheel into place.
If your locomotive doesn't have wheel wipers (f'rinstance, if it's a brass locomotive) this fix may insulate a driver that's intended to conduct current.
Wayne
doctorwayne While I have, and have used, the NWSL Quarterer, I generally find it just as easy to do it "by-eye", especially if only one driver has slipped on its axle....simply line-up the counterweights on the non-slipped side of the locomotive, then manually twist the out-of-sync one on the other side to match the position of the non-slipped ones. I usually place the counterweights at the bottom on the good side, then it's a simple matter to adjust the errant one vertically. This can often be done without any disassembly of the locomotive. Once everything is properly aligned, apply a little ca to the wheel/axle interface, then allow it to fully harden before running the locomotive. There's enough slop in the siderods to allow you to be a few degrees off. Wayne
While I have, and have used, the NWSL Quarterer, I generally find it just as easy to do it "by-eye", especially if only one driver has slipped on its axle....simply line-up the counterweights on the non-slipped side of the locomotive, then manually twist the out-of-sync one on the other side to match the position of the non-slipped ones. I usually place the counterweights at the bottom on the good side, then it's a simple matter to adjust the errant one vertically. This can often be done without any disassembly of the locomotive. Once everything is properly aligned, apply a little ca to the wheel/axle interface, then allow it to fully harden before running the locomotive. There's enough slop in the siderods to allow you to be a few degrees off.
doctorwayne, before applying the CA, should the area be cleaned with a degreaser to remove any trace oil residue? Thanks for the reply in advance.
YIKES... I'd rather keep my steamers in on peice. I have neber drawn and quartered a locomotive before, Thos some of mine would look good that way in a scrapper's yard!
I suppose a band saw would do it if you really wanted to quarter your locomotives.
LIONS only run SUBWAY TRAINS, electric traction does not need to be quartered.
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Living the dream.
TrainMasters TV, part of MRH, has a video, but you have to "subscribe", as in pay, to watch all of it. I think a 3 month subscription is one of the options.
https://trainmasters.tv/
Mike.
My You Tube
Really? Didn;t find anything? I just types HO scale driver quartering in Google and selected videos. 344 results.
https://www.youtube.com/watch?v=Rzj9d4OOX1w
https://www.youtube.com/watch?v=pNQsa9CGCzA
https://www.youtube.com/watch?v=4fqSbez-9Tk
A few examples that talk about and/or show quartering.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
nickyb Also, is there a good video on quartering ?
Also, is there a good video on quartering ?
Since you must have tried Youtube, and found nothing useful, I'm gonna say no. I've never heard of something like that.
The quartering tool most often mentioned is the one from Northwest Short Line. It's tool number 44-4 in their online catalog. The company's website is http://www.nwsl.com/
Mark P.
Website: http://www.thecbandqinwyoming.comVideos: https://www.youtube.com/user/mabrunton
I need some info on a good quartering tool.. what do some of you recommend.. Also, is there a good video on quartering ?
NickyB