new roof drive

I have stiffened the gable and the mounting for the new roll-off roof drive at Sandlot and gained a lot of reliability & performance in the drive system. Now the roof rolls off in less than 45 seconds (about 13′ of movement); and also closing in 45 seconds.

Apply this same rate to Farpoints 33′ of movement needed to fully open or close the roof, the roof movement should take about 2 & 1/2 times as long (just under 2 minutes each way). The unit is still not as smooth as I would have hoped but I now know how to accomplish that. The shape of the hub prongs need to be spherical instead of just 1 dimensionally round. I’m encouraged my 1/6th HP motor seems to work OK but maybe just a bit underpowered. If and when we switch over Farpoint’s cable system to this hub style drive I’m estimating a 1/2 HP motor will be needed.

But maybe at the next board meeting we should discuss proceeding with Farpoint’s roof drive conversion. Alternatively, with an in pouring of copious of amounts grant money (somewhere around 25 to 30K dollars) we can convert to a dome which, I believe, would nearly double the amount of time the Tombaugh is usable for imaging via increased wind protection. A dome would also provide greater security especially if we would operate the system via the web.

The dome can be slaved to the telescope operation so that where ever the telescope is pointed the dome drive will move the slit to accommodate.

I really don’t want to go through work and expense of changing the roof drive we currently have and then latter remove it in favor of a dome..

cheers,
Gary

motor and gear reducer

Farpoint Mantainence

I went to Farpoint yesterday morning (3-30-11) and replaced one of the pulleys for the roof cable.  Actually the other pulley will need to be replaced too.  I’ll try and remember to do that but for now it’s working OK.

I also made and installed a holder for the end of the shaft on the cable reel.   This will limit the radial movement and should help stabilize the roof roll-out system.