TWO CYLINDER SLIDE VALVE STEAM ENGINE CRANKSHAFT: VIDEO #2

This video completes the machining of the crankshaft disks, including the mounting of the billet in the 4 Jaw lathe chuck to offset the billet so that the center of the valve timing eccentrics now run concentrically in the lathe. It finishes with the parting off of the first complete crank disk, one of the two which carry the eccentrics machined as an intrinsic part of the crank disk itself.
The next video will continue the final assembly of the crankshaft proper, thw pressiing of the crankshaft and crank pin parts, as well as the bearing bronze bearing bushes. This stage is critical, so wish me luck! Unless all goes well, and I can make an assembked crankshaft that runs with all three crankshaft portions truly concentrically, there won't be another video!

Category:

Science & Technology

Tags:

• Steam
• engines
• live
• model
• engineering
• machining
• lathes
• four
• jaw
• chucks
• metal
• working

[DoctorHerbert]

Hey John that's some great stuff. Is that a new lathe you've got yourself? I was expecting to see the Taig. When I set up my 4 jaw chuck for odd things I use a wiggler mounted in the tailstock drill chuck, it really helps speed up the setting up.

Looking forward to the next bit.

[johnsimmance]

@DoctorHerbert Hi DH! Yes, it is a 7x12 mini lathe. I still use the Taig - it is very handy if i have something set up in the mini lathe and I suddenly need to turn something else! That's a good tip about the wiggler - thanks! The next bit will take a little while, the assembly and pressing in of the shafts and crankpins is critical! I'll take it slowly! Cheers - John.

[johnsimmance]

I first used an indicator, then made many very small adjustments to the 4 jaw chuck, eyeballing it with a 2.5X clip-on magnifier! Remember that there were no adjustments to the tail stock - as soon as i could see no wobble of the center drill mark that precisely located the true center if the eccentric, I knew I was there, Putting the dead center very close to the drill mark makes any wobble easier to see. But now will come the difficult bit! Cheers! John.

[bcats171]

wow john thats quite the setup, how did you figure out where to set the tailstock.... did you just eyeball it or did you use an indicator somehow?