hoppercar wrote: ↑Tue Nov 19, 2019 3:02 pm
You are always better off to have wheels keyed to the axles at 90 degrees. ..over time, without keys, any slip in the press fit between wheel and axle will result in a lame engine
Even then, I've seen many posts here where builders have to file a key some thousandths of an inch to get them to dial in correctly. Now that I think about it, this is called "quartering"?
If you've got a spoked wheel, you could probably chuck up the wheelset between centers and use a mallet to tap one around like I've done when putting bearings and rod in a two stroke engine (conn rod pin is pressed into two crank halves and then put between centers and tapped so they run concentric). After that, hit it with a couple small TIG weld tacks so it doesn't move.
Glenn,
Without keying, the usual method was to use a quartering jig (there I go with the "jig" thing again) to align the press. Seems that these aren't used much any more in large scale work which relies on keying instead. Now that we have anaerobics the quartering jig might make a comeback.
I had purchased an unfinished project pacific. The machine work was just awful. The drivers were loose on the axle, and keyways filed loose to allow the drives to fit the rods etc. To fix the mess, the drivers were broached larger keyways, larger axle bore, and redo the crankpin holes. The drivers were bolted back to back per axle when machining. The axles were keyed at 90 Degrees.
I agree, keyed axles are the way to go! Broach both wheels for that axle at the same time with a dowel in the crankpin holes so the quartering is true. Also, use woodruff keys. Ive seen square keys work loose and start eating into the back side of the siderods.
Thank you all for the interesting replies. My questions have been answered and with multiple solutions. That is one thing I am learning about this hobby. There are multiple ways to perform machining tasks.
dampfmann wrote: ↑Wed Nov 20, 2019 8:00 am
That is one thing I am learning about this hobby. There are multiple ways to perform machining tasks.
I worked as a machinist/toolmaker for 26 years. What you say is true, but one thing to keep in mind is that there is usually one way that is superior to all others. It, typically, offers fewer chances of making scrap, the best possibility of producing high quality, and offers the safest possible way to accomplish a given task. The hard part is having enough experience to understand that, and how to determine which one is the best option.
H
Wise people talk because they have something to say. Fools talk because they have to say something.
Soot n' Cinders wrote: ↑Tue Nov 19, 2019 10:26 pm
Also, use woodruff keys. Ive seen square keys work loose and start eating into the back side of the siderods.
+1. I refuse to use that continuously slotted axle shaft material for that reason. Nothing like having a key work it's way out into somewhere it's not supposed to be and wipe out a bearing, seal, or other moving part. I mill all my own keyway pockets in the location needed only.
if your concerned about keys coming loose in the axles....after there fitted to the axles, drill thru the key into the axle and press in a small pin to keep them in place before pushing them into the wheels
Hello all,
What about this method (exerpt from my topic in Build Log 'A with Timken Running Gear')?
Works as intended within different locomotives, by the way .
Hi All
As you well know this subject has been covered numerous times on this board.
I disagree that the cranks don't have to be exactly 90 from each other. Yes it is true that it will work if all of the drivers are the same say 91 degrees apart but your timing will not be square so that is the reason that i am saying exactly 90 degrees.
I made a video years ago about my method of quartering the drivers the 45 degree method. Here is the video just consider it.
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