Scopes - 10" Meade LX200, Coronado 90mm, Vixen ED103, Orion 80mm Guide Mount - AP1600GTO Std (Encoders.... someday) Cameras - Atik 320E, Atik 314L+, Atik Titan, Mallincam Xtreme X2, Skyris 274M, Orion StarShooter, Canon 7D Instruments - L200 Spectrometer (300,600,1200 gratings), SA100 Diffraction Filters - LRGB,OIII,SII,Ha; J/C UV,B,V,Ic,Rc Way too many computers....
AT10RCF, TMB SV105 F6.2, C11, Obs 15, DS solarmax 40 AP900GTO QSI 683 & 640wsg-8 12' X 15'6" BYO http://www.astrobin.com/users/jaddbd/
Quote:FWIW.....You realize you don't need V-Groove rails on both sides and in fact if you only put them on one side, it will prevent any binding you might get from differences in the distances between the rails for the 70' of travel. It does require that the flat rollers be larger and/or have a piece of flat stock to ride on so the height is constant but it completely eliminates any binding.
Quote:I ended up doing a little bit of both - mostly 'cause I got sick of breaking drill bits trying to drill holes thru the rails....
Quote:As far as the alignment, I just lined them up and put them together. I have one joint to rollover and you barely notice when it goes over the joint -no issues. We were extremely careful to make sure everything was very square and level with the walls and rail supports and it has stayed that way.... But I just noticed you are talking about a 70ft run of rail (wow!) so not sure if that presents an additional problem.
Quote:Here's a third option:Weld flat crosspieces to the bottom of the track at appropriate intervals. Predrill oversize or oblong holes in the flat cross-pieces. That allows for easy installation and future adjustments. A lag screw with washer makes for a robust fastener.Shimming under the unsupported areas of track will probably be required.Welding lengths of track together is easy and strong. A proper weld won't distort the track. You don't have to weld them in place. Weld them near the observatory, grind as needed, and then lift into place.I like to keep one section of track fastened down solidly and just snug down the 'follower' track to allow for seasonal changes, etc.dan k.
"The object in life is not to be on the side of the majority, but to escape finding oneself in the ranks of the insane." Marcus Aurelius (AD 121-180)
m1OASYS automation system
NW Mass, inches from Vermont
(well....it used to say that.....)
Quote:I have a small sawmill, that has a bandsaw head that rolls on rails, over the log to be cut. It runs on rollers same as a roll-off, and the angle iron track stands up in an L-shape. Much easier to drill and fasten down that way.Russ
8"ACF, AR152, ED100, ST80, EQ6Pro, Duo-T, AZ3, EQ1
AP900GTO, AP1200GTO, DM6, Tak Epsilon 160, 12.5" F/3.8 AG Optical Newtonian, C9.25, 8" LX200GPS, 18" Starmaster w/Zambuto F/4.3, ES ED127mm CF, FS60C, SV80 FLI ML8300, QSI640WSG-8 SX Lodestars Some Uncle Al's glass hand grenades www.doghouseastronomy.com
Dark Arts Observatory - Brockport, NY - Skyshed POD XL5 with iOptron iEQ45 Mount
Scopes: C8, C5, SV110 ED, EON-72 ED, ST 80, ATRC6, Megrez 90