Dovetail Bars

[sharpiel]

Hi guys.

I have Parallax rings on the TOA130. The rings are mounted top and bottom on Sky-Watcher 13" V style dovetail bars from Bintel. The bars are actually around 334mm long on my tape measure (approx 13.1"). Importantly the hole spacing between each end where the Parallax Rings attach are 310mm apart. These are center drilled for single screw mounting.

I want to replace the bottom bar only with a wider D style bar. Because I want to keep the narrow V style on the top I'd like the bottom D style bar to have the same hole spacing as the V style. I'd prefer to use the dual mounting holes underneath the Rings which are 3.5" apart than just the center hole only.

Have had a look online but can't find exact dimensions for the Orion and Losmandy Universal D style bars. Thought someone out there may have already addressed this issue. There may be other bars I haven't thought of that others have used..?

Looking to buy one that fits if anyone has one to sell :)

[LewisM]

http://www.williamoptics.com/accessories/vixenDovetailLong_features.php

Maybe? Used them before - pretty good! And MUCH cheaper to buy direct from W.O than any Aust. retailer.

[Mamba]

On Bintal's website there is quite a reasonable drawing of the plate with dimensions.
Mamba

[sharpiel]

There is. I've had a look at that already. If I'm not wrong you can't add up all the long side dimensions between all the holes to calculate the total distance between the end holes because there's no dimension stated between any of the holes closest to the 7" midline.

Have a go :D

As there are no dimensions at all for the Orion D Style either online from what I've found I was hoping someone (or more people) each who own the Orion and/or Losmandy bars would do a measurement for me.

http://www.bintel.com.au/ckfinder/userfiles/files/DUP.pdf

[sharpiel]

Thanks Lewis. Just had a look at them. Very nice! On this occasion though I'm hoping to pick up something suitable locally or second hand through the IIS Classifieds if I can find a match.

[casstony]

The Losmandy Universal D bar doesn't have 3.5" spaced holes that are 310mm apart.
I bought a cheap drill press and a set of DeWalt pilot point drill bits just for such occasions. The drill press was about $80 off ebay and the pilot point bits allow me to drill square bottomed holes where I need them. I only use it about twice a year but it's a very handy piece of gear.

[sharpiel]

Lovely. Thx Tony.

Does anyone out there have the wide Orion Universal Dovetail bar and can give me its total length?

[JoelyE95]

Les,

I have the Losmandy D Universal Dovetail Plate (the one with all the holes). If you can identify what measurement exactly you are after on the linked (http://www.bintel.com.au/ckfinder/userfiles/files/DUP.pdf) drawing, I can measure it for you. At the 7" midline, I measured 1" (25.4mm) if that helps you out in any way.

Joel

[sharpiel]

Thanks Joel. That measurement helps me a lot. Now I can work out the hole spacing and as Tony stated there are no mounting holes I can use that are 310mm apart.

[JoelyE95]

Les,

If you use the 1/4"mm hole on the left (along the centre), 310mm would end up all the way to the right oval before the last 1/4"mm hole. Granted it would mean possible blowing out the thread on the left if you need to resize the hole, but it is Food for thought.

Joel

[sharpiel]

Good thought.

In the end though I sorted out the dimensions for the Orion Wide Dovetail and I think it may suit me better. 2/3 the weight of the Losmandy as well.

Anybody got one out there they want to sell?