stephenmcnelley
08-01-2007, 09:00 PM
Hi folks, recently there has been a few positive comments about an ep/laptop rack that I devised for a Dobsonian base, some suggested a short how-to article might be worthwhile, so here ‘tis.
Originally I built the rack with a notebook computer in mind, but there was just one problem…. I didn’t have one. So with the rack built, screwed solidly to the base and doing nothing I surmised that the small flat computer table would be a useful holder for eyepieces if I took to it with a hole saw. After matching the 1.25 and 2” barrels to the right hole saws and some careful spacing measurements on the plywood board I set to work, 30 minutes later and a bit of a clean up with sand paper there was an eyepiece rack that could fit 16 ep’s, and it could be used to fasten other useful goodies to also.
This version was built from waste timber- plywood and Tassie oak using wood glue and some suitable loose screws from the loose screw department, but any materials could be used for construction. I won’t go into the construction in any depth because the photo’s explain most of the details, it’s just a matter of measuring the few angle’s involved, the height you want the rack to be when sitting viewing and some common sense. You only need a protractor maybe, a tape measure, a tennon saw, wood glue, a vice and a some appropriate screws loose.
I found the most important consideration was how you fasten the main rack struts to the inside (outside might work to) of the Dob base frame walls. You need as thin a timber as possible because there is not usually much clearance between the OTA and the Dob base walls and you don’t want the rack’s mounting struts to rub on the tube when it swings through altitude, yet these two supporting strut members need to be strong- Tassie Oak does the job and is light. Countersunk screws are the best choice for the whole thing from a functional/aesthetic perspective as they sit flush in the timber. Also, being careful not to drill your small pilot holes for the screws all the way through the Dob upright frames and matching the length of the fasteners to the timber/frame widths pays big dividends.
With this rack, once the thing was trial attached to the mount, and I sat down and got over my amazement, I removed it and sprayed the whole thing with a cheap flat black enamel. Viola, very chuffed.
Now that I have just begun to image with the 25cm scope the rack is fulfilling its intended role very nicely, cost nothing too and the two extra alloy ep holders I made and screwed onto the left side of the base accommodate the ep division with ease if required when it is laptop time.
Included is an image of the wide wheelbase Dob transporter trolley, which doubles as a height adjustable viewing seat. I built it as a trial experiment a year and a bit ago. Low and behold if I am still using it as is, and are always vowing to one day ‘make a better looking one’.
Thanks for reading,:)
Steve.
Originally I built the rack with a notebook computer in mind, but there was just one problem…. I didn’t have one. So with the rack built, screwed solidly to the base and doing nothing I surmised that the small flat computer table would be a useful holder for eyepieces if I took to it with a hole saw. After matching the 1.25 and 2” barrels to the right hole saws and some careful spacing measurements on the plywood board I set to work, 30 minutes later and a bit of a clean up with sand paper there was an eyepiece rack that could fit 16 ep’s, and it could be used to fasten other useful goodies to also.
This version was built from waste timber- plywood and Tassie oak using wood glue and some suitable loose screws from the loose screw department, but any materials could be used for construction. I won’t go into the construction in any depth because the photo’s explain most of the details, it’s just a matter of measuring the few angle’s involved, the height you want the rack to be when sitting viewing and some common sense. You only need a protractor maybe, a tape measure, a tennon saw, wood glue, a vice and a some appropriate screws loose.
I found the most important consideration was how you fasten the main rack struts to the inside (outside might work to) of the Dob base frame walls. You need as thin a timber as possible because there is not usually much clearance between the OTA and the Dob base walls and you don’t want the rack’s mounting struts to rub on the tube when it swings through altitude, yet these two supporting strut members need to be strong- Tassie Oak does the job and is light. Countersunk screws are the best choice for the whole thing from a functional/aesthetic perspective as they sit flush in the timber. Also, being careful not to drill your small pilot holes for the screws all the way through the Dob upright frames and matching the length of the fasteners to the timber/frame widths pays big dividends.
With this rack, once the thing was trial attached to the mount, and I sat down and got over my amazement, I removed it and sprayed the whole thing with a cheap flat black enamel. Viola, very chuffed.
Now that I have just begun to image with the 25cm scope the rack is fulfilling its intended role very nicely, cost nothing too and the two extra alloy ep holders I made and screwed onto the left side of the base accommodate the ep division with ease if required when it is laptop time.
Included is an image of the wide wheelbase Dob transporter trolley, which doubles as a height adjustable viewing seat. I built it as a trial experiment a year and a bit ago. Low and behold if I am still using it as is, and are always vowing to one day ‘make a better looking one’.
Thanks for reading,:)
Steve.