meade rcx 400 10" measurements

[p1taylor]

Hi all

I am looking for dimensions for fixing holes in base of rcx 400 10", as I wont to build a wedge, also all dimensions will be handy, when wedge is fitted if my lat is 52 degrees do I set wedge to 38 degrees from horizontal,

peter

[Psychobilly]

Do you have the tripod? If so then you can get the dims off that ... thats what i did for my CPC800

Yes the latitude is the top corner angle of the triangle that's the "wedge" so in your case its 38 degrees from the horizontal.

I have Made a few wedge designs starting in plywood , Aluminium and Fianlky a Steel Moster Wedge and Pier for the Obs...

Ideally you will need some form of adjustment built into the system for Alt and Az....What are you hoping on achieving ? -long exposure unguided astro photography will need precise alignment...

Billy...

[Paxo]

Peter,

The meade website has a couple of drawings on it, one of which I'm sure is a 10" RCX scope, might be worth a look.

Steve..

[centroid]

Peter, you might struggle to get accurate polar alignment with a wedge, with a 'sole plate that's fixed at the calculated angle for your latitude, unless you are very accurate with the measurements, and install the base absolutely to the true horizontal.

Some degree of adjustment, would be a far more practical solution.

Dave

[barkis]

Peter, you might struggle to get accurate polar alignment with a wedge, with a 'sole plate that's fixed at the calculated angle for your latitude, unless you are very accurate with the measurements, and install the base absolutely to the true horizontal.

Some degree of adjustment, would be a far more practical solution.

Dave

You're so right Dave. I surmounted my Pier with a large diameter 38mm thick Aluminium Disc, which I attached to the pier with adjustable L brackets bolted to the side of the Pier. I used four brackets with M16 Adjustment bolts. I precisely levelled the disc, verified with a bubble level, and a horizontal level placed in every direction on the table. Once I had the wedge in place, and the LX90 Installed, I Checked the table level again. Spot on. However, I know for a fact the wedge is not level, so I need to build some levelling adjustment into the wedge itself.

It is annoying, because the table is perfectly levelled, and the wedge base sits perfectly on the table. The problem has to be in the tilting table on the wedge, that adjusts the latitude angle.I don't think these things were made with absolute accuracy as the criteria. :nono:

Ron.

[p1taylor]

HI dave

I will mack my wedge so it will be level and adjustable, pier top is adjustable on three 20mm rodes set in pier top plate is 40mm steal and is level

peter

[Ant]

Yes the latitude is the top corner angle of the triangle that's the "wedge" so in your case its 38 degrees from the horizontal.

Polaris should be 52 degrees from horizontal - 38 degrees from verticle.

The height of polaris is equal to your latitude in degrees (ignoring the fact that polaris isn't quite on the pole).

Ant

Ant

[Psychobilly]

All I know is all my wedges and pier work perfectly with the OTA aligned to the forks the tube points at the NCP ..... actually it 5 arc mins out in azm and 1 arc min out in alt but I cant be bothered to adjust it as the guidsed images are fine..

Seems Mike Covington agrees as well.... take a look at his wooden wedge design here...

http://www.covingtoninnovations.com/astro/woodenwedge/

(click to enlarge)

(click to enlarge)

Billy...

[Ant]

That can't be right surely?

If you at the equator, your latitude is 0 degrees, polaris is on the horizon.

For every degree north you go the angle increases by one degree.

My mount and every other mount has always been set to (roughly 52 degrees) and then fine tuned...

Ant

[barkis]

The sum of the angles in a triangle always add up to 180 degrees.

Ron.

[Psychobilly]

I think your hung up with GEMS.... its different with fork Mounted SCT's ....

With a fork mounted scope like an SCT the tube is set parallel to the mounts arms to align on the NCP which is at 90 degrees to the base... theres a pic on the net somewhere of Authur C Clarkes SCT where the fork arms are almost horizontal

Thank you google...

SRI LANKA Colombo 6° 54' N 79° 52' E

Ohhhh just look at that lovely wedge mounted SCT the base of the scope is clearly almost horixontal. :)

on no sorry its almost vertical so he must have got it setup wrongly... :scratch: :scratch:

.....whos the geezer in the shirt and skirt...

If you were at the North pole you wouldn't need a wedge as the NCP would be directly overhead...

Ron you are correct but as the text says its not a traingle If you look very carefully you will see that the "hypotenuse" isn't a straight line... thats the method I use to give and adjustable angle on the front mounting face of the wedge using a screws and jack screws working against each other...

P1Taylor... go with whichever you think is right...... or move to a latitude of 45 degrees in which case there won't be an issue...

Oh look heres a link to a very expensive low latitude wedge....

http://www.milburnwedge.com/equatorial-latitude.php

Billy....

[Reggie]

Billy is spot on, I've used his given description of the angles on my wedge that I took from a design he gave me for an aluminium wedge which helped greatly with my simplified wooden design. It really did work for me, it had to be accurate as mine was a fixed angle for the plate, I used my north facing tripod leg to adjust the angle.