FWIW,
The spindle sleeve in different materials;
Note: I figured these mathematically by material volume and material density;
Stock Steel ones should weigh ~72 Grams Each
If made from
6-4 Titanium = ~40 Grams Each
7075-T6 Aluminum = ~26 Grams Each
6061-T6 Aluminum = ~24.5 Grams Each
The TI ones could be lightened further by upsizing the ID in the middle to 12 or 13 MM for the center 2-2 1/2". But that will up the cost of machining due to the tooling requirements and still would not change the volume enough to get close to the Aluminum weights.
P.S. I just ordered enough 6061-T6 tubing to make 16 sleeves for about $50 shipped. (They need to be cut to length, ID drilled to 10mm, deburred, and then sent out for hard Anodizing)
If your heart is set on Titanium there are a couple options, stack three of these (
http://www.hrpracing.com/brake-pedal-spud-titanium-0-625-inch-od-x-0-375-id-1-00-long)
across after opening the ID up to 10mm. $60.00 per sled. (**NOTE** the description has it as 1" long but the drawing claims 1 1/4", I sent them an E-mail for the actual length, I'll update when they reply, 1" is what we are after, ~3" total length)
Or use two of Alts ski bushings with one of those between them and shorten the stock spacers the 1/8" for the Ski bushing flanges. (See above **NOTE**)
If one were to look, one could likely find a couple Delrin washers / spacers the correct size to replace the factory Aluminum spacers.
