Posts Made By: glenn littledale

hi all. thanks to those who offered advice on my previous post. i decided to sell my fs-78 and mount to finance parts to build up a 10" f/6 conical. bob royce had the mirror to the coater within days of my order. just received a kineoptics helical focuser and it seems like a very nice unit. secondary is in the mail now from antares. parts total should be around $1200 which somehow seems reasonable to me
now i'm choosing a secondary support. i like the protostar systems,and i'm thinking of their curved support. on their website that say the total diffraction from the curved support is about the same as the total from their 3 vane, but the curved support concentrates the diffraction around the object. their website simulations show this as well. i wonder if this would translate into a perceivable loss of contrast of an object - saturn for instance when compared to a three vane spider. i probably should not be sweating this decision. probably the bigger question is if diffraction spikes bug me or not, but i thought i would toss this out there in the hope that someone has some direct experience with this.
thanks,
glenn

does anyone have experience getting an ultima 8 to autoguide from an sbig st-7e?
thanks,
glenn

hi all,
i use an older C8 for imaging. i'd like to find a way to limit mirror movement. the mirror moves relative to the tube when scope is moved significantly. i solved a similar problem on an older meade sct using the mirror lock screw hole provided for shipment. the C8 doesn't have such a provision and i'm wondering if anyone out there has found a good solution. i could take the scope apart and see if i could make the same holes the meade has, but wonder if there is a better idea out there.
thanks,
glenn

hi folks,
i'm looking for a planetary eyepiece in the 6mm range that is fairly close to parfocal with my tv plossls, but i do have another 2/10's of an inch in travel if necessary. don't have enough in travel to make it with my short focal length u.o. orthos. i could modify my primary cell, but would prefer not to. can't really go over $100. another possibility is if anyone makes a 2" to 1.25" recessed adapter, but i have not heard of one.
thanks,
glenn

hi all,
just finished this scope. (well, ok, i do have a couple of items left on the punch list). primary is a 10" f/6 conic cross section from bob royce. cool down is very fast. contrast is terrific. i really like the protostar curved vane secondary support. still waiting for a few moments of good seeing (a bit rare here in vt)to really see what it can do, but so far it has been spectacular on deep sky. don't think i'll ever paint a scope again, but i wanted this one gloss white. scope weighs 50 lbs fully dressed.
glenn

hi all,
i just finished a 10" f/6 sono tube dob and have started work on a 15" f/4.5 truss. i was thinking about connecting the uta and have alway liked the idea of a connecting ring between the truss poles and the uta. i know that this is typically done on much larger scopes, but i thought of another possible use this morning. putting that ring in there allows the possibility of drilling several sets of mounting holes in different orientations. while certainly not as nice as a rotating cage, it would allow for mounting the focuser in line with the alt bearing axis when working high up, but on nights when most time might be spent working around sagittarius (which doesn't get very high up in my neighborhood), the option of tilting some comfortable amount relative to the alt bearing axis might be nice. of course i would expect to tweak collimation. so, nice feature? bells and whistles? what do you think? the down side is increasing weight far from the fulcrum and just having more parts to the scope.

more questions: berry and kreige call for a 22" bearing for this scope with width at 1.125". my mirror box will be 20"x20"so i thought it would be nice to keep the bearing the same width as the box. will i loose much? don't want to mess with a sucessful recipe but... also, i'm thinking of making a fairly tall mirror box. if the alt bearing is attached to the mirror box on much of it's side, do i need to go with such a thick bearing or can i get away with 3/4"?
thanks,
glenn

so i'm wondering why so many 6" tec maks seem to have hit the market. don't know how many were made, but it seems like a lot of ads for what i assume was a fairly limited production and very desirable scope. wish i had some extra cash!

as long as there is room, is there a disadvantage to orienting the spider so that a vane will be along the line of the focuser? i'm about to drill a 16" aluminum uta and was thinking this way would make offsetting the secondary a little easier.

been thinking about using black corduroy. has anyone tried it? seems like it would make a nice mini baffles too.
glenn

hi folks,
does anyone out there know of a nice plossl less that 8mm focal length that is parfocal with tv to compliment my other tv plossls? i'm thinking 5 or 6 mm.
thanks,
glenn