spoke length can I get away with 1 length?
 

I used the DT spoke length calculator to arrive at spoke lengths of 293mm & 294mm for the two sides of my rear wheel. Miche track hub on Open Pro with 14/15 double butted spokes. I'm wondering if that 1mm is crucial, or can I get away with using 1 spoke length either 293 or 294.

Yes you can get away with it. There is always a little variation in the rims and hubs anyway. Some of the old calculators like Blue Pig used to let you put the measurements you got for the parts in every time you measured and kept a running average.
I would go with the 294, you might have just a little hangout, but with the boxed rim it won't matter and you will have a full thread engagement .

hey chuck, is there an online database with proper spoke lengths for rims and hubs combinations?

Dt Swiss is great but you need to be able to measure your rim and hub.
http://www.dtswiss.com/index.asp

If you do much building you can get the DT wall chart calculator pretty cheap.

Take a look at http://home.earthlink.net/~mike.sherman/bike.html#WHEEL
The full version of Spocalc has a reasonable hub/rim data base but requires Microsoft Excell or the freeware substitute listed on the above site/link. The data base does not include Mavic Open Sport or the Trek "no-name" hubs that I am working with......dig out my metric calipers/ruler.
Happy building!

If faced with that choice go with the 293's, better to be 1mm short than to run out of threads on a long spoke.

Al

Do a google search for spocalc.xls - it's got a huge dBase of lengths and dims

This online calculator has some hubs and rims in its database or you can just enter the measurements.

SPOKE LENGTH CALCULATOR

Dogbait

I just measured up a spoke and nipple. Both Dt, 14g spoke, 12mm nipple. The spoke can protrude 1.25mm past the nipple before it bottoms on the threads. The groove in the the nipple measures 1.3mm. The threads in the nipple start 3.6mm from the lip.
In theory a calculator tries to give you full engagement, that is to the bottom of the groove in the nipple. So, in theory, you have 2.55mm before you bottom the spoke in the nipple. I still say go 294, if you used the Dt calculator. If it bottoms out I will paypal you a dollar. :)

They bottom out? Huh?

When I rebuilt my wheel, I noticed that the spokes were pretty far past the nipples. No problems though. I think the threads are taller than the diameter of the spoke.

"They bottom out? Huh?"

Depends on the spokes and nipples. I have had some you could thread the spoke all the way thru and the nipple would slide up and down the spoke, not often tho.