Which Lathe Should I Buy?

Red Lathe: SIEG SC4
Blue Lathe: Weiss WM 250V-F
Sherline: Sherline 4100 (Metric)
(Retired Green Lathe: CQ6125)

Sherline Thread Cutting Attachment: https://sherline.com/product/3100-thread-cutting-attachment/

Tubalcain Tailstock Alignment videos:
https://www.youtube.com/watch?v=WLXL3cdnbpM
https://www.youtube.com/watch?v=tqjO4yPvhQs

Lathe Leveling:
TOT: https://www.youtube.com/watch?v=THkb-x35fwc

Amazon Affiliate links:

Cameras: 

Panasonic GH5 - https://amzn.to/2rEzhh2 
Panasonic X920 - https://amzn.to/2wzxxdT

Tools & Shop Products:

Dormer A190202 Jobber Drill Set, 1.0 mm - 6.0 mm x 0.1 mm Size: https://amzn.to/2DR5fdb
Dormer A190203 Jobber Drill Set, 6.0 mm - 10.0 mm x 0.1 mm Size: https://amzn.to/2ITfeTa
Dykem blue: http://amzn.to/2plmLlx
Sherline Lathe: http://amzn.to/2pnXM19
Sherline WW collets: http://amzn.to/2FYZ7F8
Generic Dial Indicator 0.001": http://amzn.to/2FOFTyF
Interapid Dial Test Indicator: http://amzn.to/2FPInwH
Optivisor Headband Magnifier: http://amzn.to/2HFg1FU

Books:

Watchmaking: http://amzn.to/2FH3cyh
Wheel & Pinion Cutting in Horology: http://amzn.to/2HI6ca9
Clock & Watch Escapements: http://amzn.to/2FIEaic
Practical Watch Repairing: http://amzn.to/2tUyThX
Practical Clock Repairing: http://amzn.to/2HCey35
The Science of Clocks & Watches: http://amzn.to/2HIyuBA
Watch and Clock Making and Repairing: http://amzn.to/2pfdT0U
Casting Practice - The Ten Rules of Castings: http://amzn.to/2HF3VfL
The Model Engineer's Workshop manual: http://amzn.to/2G43VsV
Model Engineer's handbook: http://amzn.to/2FPxwmq
Workshop practice Series: http://amzn.to/2DyPs2D
Machinery's handbook: http://amzn.to/2pi7XE5