New Crossbow EQT-200 Equatorial Platform Arrived.
Posted 17 March 2013 - 08:21 PM
Today I fine tuned my new rocker box to work with this platform. Stock the LB uses a lazy Susan bearing. This mod involved adding an Ebony Star bearing and increasing the teflon pad size to accommodate my heavier telescope. The width of the bearing is 1.5 inches. That means there will be 9 square inches of surface area for the teflon pads. This is more in line with a 15 lbs per square inch of telescope weight recommended. It works great now.
Posted 17 March 2013 - 08:23 PM
Posted 18 March 2013 - 11:16 AM
After 15 minutes I went back out and checked Polaris. It had moved ever so slightly from the cross hairs. I almost nailed alignment by eyeballing it. Pretty cool. I have to say the long axis of the north/south part of the platform gave me a nice long part to eyeball while setting it up. Nice. I bent down and nudged the south end of the platform to make the correct drift alignment. I was glad there was the part that sticks out on the south end. It gave me a great point to push and lever the platform while it was set up like this. Polaris was re-checked for center then I went back inside.
After 10 more minutes I went back out and checked Polaris. No appreciable shift. I was excited now. The platform had gone through almost half of it's radius by now so I reset it. The Great Orion Nebula/M42 was hanging above just asking to be looked at. I spun the telescope around, put in a 13mm Nagler T6 and focused on the target. The nebulosity just hung there in the center, not drifting, not moving, just being. I watched for a few minutes marveling and getting my head around the new experience. My big dob was tracking effortlessly.
Ultimately I wanted to see how close it tracked so I put the Orion illuminated cross hair ep back in and moved down centering Rigel. Again, I just let it drift. After 5 minutes it still was dead on. I figured this was a good time to take the dog for a walk and earn brownie points with the wife. Coming back 30 minutes later Rigel had no appreciable shift. I was so happy.
I spent the night hopping here and there for another hour or so. I was able to go back to M42 and put a 2x Barlow on the 13mm T6. It was so sweet to not have to nudge and track the target with it zoomed in. At one point I tried to use a 3.5mm T6 but seeing conditions prohibited clarity. I can say that while switching between the 13mm to the 3.5mm eps I could tell the target remained centered albeit unclear for good viewing.
Stability was outstanding. The Crossbow eq platform is more stable than the stock ground board and lazy Susan set up. The radius of the telflon pads on the new eq platform is wider than the radius of the lazy Susan bearing. This has the effect of giving more stability and less rebound time after moving the telescope. The actual platform is rock solid. It takes a significant amount of pushing the telescope in ways it isn't designed to wiggle it at all. In normal viewing the platform doesn't wobble a bit. The platform also tracked through over 60 minutes before needing to be reset. There were no problems at all through all ranges of the tracking radius. It never slipped, stalled, or otherwise stopped tracking accurately the whole night.
Before breaking down I marked the position of the three feet on the ground to speed up set up next time. By not having to drift align I can be viewing much faster now.
I would give the Crossbow EQT-200 a solid "A" grade.
Posted 18 March 2013 - 12:21 PM
Posted 18 March 2013 - 12:47 PM
Posted 18 March 2013 - 06:17 PM
Posted 30 April 2013 - 04:19 AM
I have a question. How do you transport the scope? My 18 inch Obsession is heavy and requires wheelbarrow handles and wheels to move.
Posted 30 April 2013 - 12:48 PM
Normally, I put the platform where I want it. Then grab the rocker box, place it on the platform, next grab the mirror box (in your case, you may need two people to carry it from your vehicle) and place it on the rocker box. Assemble trusses, etc.
Note: The round ground board is removed from the rocker box as the platform replaces it.
Posted 05 June 2013 - 10:37 PM