Binocular finder alignment rings

[JamesF]

My 50mm binocular finder has progressed thus far:

The focal length of the objective lens would appear to be about 200mm and I have a 25mm eyepiece in it which should hopefully give me somewhere around 8x magnification, though it's a standard 1.25" diagonal so I can swap eyepieces to alter the magnification if required.

I'm now trying to think of ways to make it adjustable when fitted to the scope. I have a finder base, so I can use that to mount it, but I'm coming up short of ideas for actually aligning it.

Anyone have any suggestions?

James

[Stargazing_Cliff]

I have broken pair of 50mm binoculars interesting could make somet similar

hmm

[Xession]

It wouldn't be the most accurate way but if you are looking for something quick and dirty, you could make a small dual fork mount and then drill a straight hole through each. Run some decently thick bailing wire through the holes (2 wires each). Then separate the wires and put the finder in and fold over the excess wire on the sides to hold it in place. The wire should be soft enough t position decently and stiff enough to stay put.

-- Sent from my Palm Pre using Forums

[Mr TamiyaCowboy]

old RDF body work.

this would give you up/down - left/right alignment options.

using the rdf base with the cowl removed allows the finder to be mounted to the current framework (superglue). RDF usually has a cheapish dovetail clamp, you could run a couple grooves in the mount body so the dove clamp would slot in and grip finder mount shoe

then all you do is mount the unit in usual way and then use the ALt screw and lft/right wheel on the rdf unit to align the scope.

maybe those cheap RDF's could have a secondary use at last

picture of mine, remove the red marked bits and glue finder to the adjustment bed

[AndyH]

Most interesting possibility Mr TC.

BUT, the body length of the finder is very short. How about using the finder base, take off the rdf unit. Get a bigger piece of pipe tube, to go round the finder's tube/body. Attach, somehow(glue, screws?) to the base. If the bigger tube is thick enough, it should be able to take a thread. Fit 6 alignment thumbscrews. Bosh, job done?

[JamesF]

I was wondering if exactly that solution might work, Andy. I have a scrap length of 75mm drain pipe that might do the job if it is rigid enough. If I could find something closer to the 41.5mm OD of the body I'd be tempted to fix the front with an O-ring and just have adjusters at the back (or vice-versa). I have some of the retaining screws from the DB-9 connector of the USB<->serial interface that I took apart to do my SPC900 LX mod that might make good adjustment screws.

My other idea at the moment is to make up a U-shaped metal bracket with a hole in each side of the U. One side would be fixed between the body and the objective housing and the other between the body and diagonal. The base of the bracket could then be fixed to (say) an RDF mount to allow for adjustment.

James

[Mr TamiyaCowboy]

try a fishing tackle shop, they sell things called float tubes. long tubes with caps on both ends, may want to take a tape to get right id.

my float tube i has an ID of 42mm with a 1mm thick wall, how long a piece do you require ( i got about 10-12cm in length)

oh its red in color so may need a quick dip in paint/ or flocked.

[Mr TamiyaCowboy]

Most interesting possibility Mr TC.

another idea :

gut the led from the body, rehouse a maplin laser pointer head in its place, and wire up to the 3v small watch cell.

makes those RDF's more useful , am not sure on peoples stance of laser pointers. me i like the old style finderscope. i find the rdf a quick an easy modding platform lol. i thought the laser mod a handy idea for setting the economy motor drives for eq1/2 mounts

good old superglue and duct tape style modding, may look ugly but works ( 'ish )

[JamesF]

Thanks for the offer. I think what I really need though is something closer to 50mm ID so there's room for the internal tube to move around for alignment. I'll have a look in a tackle shop to see if they have anything bigger though.

The best I've found at the moment is some 68mm OD drain pipe. It has 3mm walls, so should at least be fairly rigid. I might give it a try anyhow as I at least then have a reference point if I need to look for something smaller.

James