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| wheel and pin pressing https://www.rypn.org/forums/viewtopic.php?f=1&t=1932 |
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| Author: | Jack Anderson [ Sat Jul 21, 2001 12:11 am ] |
| Post subject: | wheel and pin pressing |
Some time ago there was an inquiry about pressing drive wheels off their axles, and the fact that a new axle must be necessary. Based on a recent project, we pressed off a 44" main driving wheel. We also pressed out the large crankpins on the same wheelset, to re-machine and press back in. I am happy to say that both pin and wheel press jobs were successful. Everything presses back together with some loss of gripping power, but not much. Quartering was left up to the 1" square key on the main driver. This was a necessary job because there was a cracked eccentric needing repair, so the wheel had to come off. By putting the main crank pins in the lathe we were afforded the best set-up for re-machining the pins. We had no problems with quartering. The locomotive trammed nicely and no sign of binding of the side rods was found. This was on a 1910 Baldwin 2-6-2T. Jack Anderson steamrr@mashell.com |
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| Author: | Dave [ Sat Jul 21, 2001 12:27 pm ] |
| Post subject: | Re: wheel and pin pressing |
Thanks Jack, another example of why we don't need to make simple jobs complex. Could you be a bit more specific as to how the setups were made for the pressing on and off? Horizontal or vertical, where the wheel center and axle were supported, etc? Dave irondave@bellsouth.net |
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| Author: | Pete [ Sat Jul 21, 2001 4:48 pm ] |
| Post subject: | Re: wheel and pin pressing |
> Based on a recent project, we pressed off a > 44" main driving wheel. We also pressed > out the large crankpins on the same > wheelset, to re-machine and press back in. I > am happy to say that both pin and wheel > press jobs were successful. Everything > presses back together with some loss of > gripping power, but not much. Quartering was > left up to the 1" square key on the > main driver. How did you measure the fit? A recording pressure gauge? |
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| Author: | Jack Anderson [ Sat Jul 21, 2001 7:06 pm ] |
| Post subject: | Re: wheel and pin pressing |
> How did you measure the fit? A recording > pressure gauge? We use a horizontal wheel press which is hydraulically powered. A 500 ton pressure gauge tells us about pressing off and on pressures. Watching the needle tells the whole truth. Jack steamrr@mashell.com |
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| Author: | HKA [ Sat Jul 21, 2001 10:48 pm ] |
| Post subject: | Re: wheel and pin pressing |
I understand that the D&S does this all the time, since with their outside cranks, it is virtually impossible, or at least very difficult to machine the axle journals with the cranks in place. They report, as you do that it doesn't reduce the press tonnage enough to matter. In pressing out, returning, and pressing back in crankpins, everyone should be aware that if their crankpin had been previously turned on a quartering machine, the journal surface could be eccentric to the wheel seat, and center holes on purpose, in order to have the crankpin in quarter, and stroke. In a case like that, they would have to be careful to note the orientation of the crankpin in the wheel, set up and turn the crankpin concentric to the old journal surface, and then press the crankpin back into the wheel in the same orientation as it came out. I am just stating this so people will be aware of this possibility, since once it is apart, you canÂ’t tell if the job is done right until the rods are going back on, and then one overlooked detail could result in profanity. Two questions. In most locomotives, the backside of the wheel in countersunk around the crankpin hole, and a lip on the circumference of the crankpin is riveted into this countersink in order to secure the crankpin. It is usually possible to press out the crankpin only when that riveted area is removed by grinding, chipping, or whatever, in which case it wouldnÂ’t be there to do its job in the future. How did you deal with this? Did you lubricate the wheel seats with anything? |
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| Author: | Jack Anderson [ Sun Jul 22, 2001 12:02 am ] |
| Post subject: | Re: wheel and pin pressing *NM* |
steamrr@mashell.com |
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| Author: | Jack Anderson [ Sun Jul 22, 2001 12:12 am ] |
| Post subject: | Re: wheel and pin pressing |
> I understand that the D&S does this all > the time, since with their outside cranks, > it is virtually impossible, or at least very > difficult to machine the axle journals with > the cranks in place. They report, as you do > that it doesn't reduce the press tonnage > enough to matter. > In pressing out, returning, and pressing > back in crankpins, everyone should be aware > that if their crankpin had been previously > turned on a quartering machine, the journal > surface could be eccentric to the wheel > seat, and center holes on purpose, in order > to have the crankpin in quarter, and stroke. > In a case like that, they would have to be > careful to note the orientation of the > crankpin in the wheel, set up and turn the > crankpin concentric to the old journal > surface, and then press the crankpin back > into the wheel in the same orientation as it > came out. I am just stating this so people > will be aware of this possibility, since > once it is apart, you canÂ’t tell if the job > is done right until the rods are going back > on, and then one overlooked detail could > result in profanity. > Two questions. In most locomotives, the > backside of the wheel in countersunk around > the crankpin hole, and a lip on the > circumference of the crankpin is riveted > into this countersink in order to secure the > crankpin. It is usually possible to press > out the crankpin only when that riveted area > is removed by grinding, chipping, or > whatever, in which case it wouldnÂ’t be there > to do its job in the future. How did you > deal with this? Did you lubricate the wheel > seats with anything? We removed the riveted-over portion of the main pins with a torch. After the pin was eplaced we welded onto the pin enough new metal to rivet into the wheel's counterbore. The pin was not welded to the wheel. I am working with small locomotives. This one was built by Baldwin in 1910. I have seen no evidence that quartering machines were available that early in the century, but that they were developed and used later in the history of steam locomotives. As locomotives grew not only in size but also in technology where more was expected from them, the quartering machine became a necessary machine. Jack steamrr@mashell.com |
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| Author: | Pete [ Mon Jul 23, 2001 11:48 pm ] |
| Post subject: | Re: wheel and pin pressing |
> How did you > deal with this? Did you lubricate the wheel > seats with anything? Last I heard (about 8 years ago): White lead (lead acetate) in linseed oil, which also goes under the name AAR Wheel Mounting Compound, or something like that. I believe this is the last industrial use for white lead. The lead lubricates the metal to metal surfaces in just the right way. You best bet is to get ahold of a copy of the AAR wheel and axle manual, preferably a copy from around 1960-1965 Watching the pressure gage won't really give a good indication of wheel/axle fit because the it's the shape of the graph drawn by a recording gauge which tells you this. It must be a certain shape or a mis-fit has to be declared. And pressing the same wheels off and back on the same axles isn't really a very good idea because this increases the chances they will come loose. As far as that peened-over part of the driving pins, why not make all-new pins, press them in, and then peen them over just like the originals? |
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