Need Losmandy help!

[masjstovel]

Hi, I am unfamiliar with the Losmandy dove tail bars, but i want one. 
I have a SW 150PDS with the standard tuberings. I want a Losmandy between 30cm-40cm and I see there are hundreds around. 

They all fit to the standard Sky Watcher tube-rings or is there something i need to be aware of regarding this?
If thats the case - which fits?

 

[masjstovel]

No one got something on this?

[Louis D]

Pretty much any dovetail bar can be attached to any tube or tube ring if you have the proper hex head cap screw (HHCS) to fit the threads on the tube mounting block or tube rings.  They're generally 1/4-20 sized.

Dovetail bars vary in style from extruded aluminum to CNC machined aluminum stock.  Lengths and hole patterns vary widely.  Some smooth holes and slots are for attaching the bar to the tube while others are threaded so accessories can be attached to the bar itself.

The question is, does your dovetail clamp fit a Losmandy or D-style dovetail bar?  It's much wider than the more common Vixen or V-style bar.  There are some clamps that will accept both.

[Dinglem]

You will need an imperial one not metric as I needed one recently and @FLO recomended this https://www.firstlightoptics.com/adm-losmandy-type-d-series/adm-losmandy-style-universal-dovetail-bars.html

it's not cheap but it fitted my Skywatcher tube rings perfectly. already had an altair astro bar and the holes didn't line up.

[masjstovel]

25 minutes ago, Dinglem said:

You will need an imperial one not metric as I needed one recently and @FLO recomended this https://www.firstlightoptics.com/adm-losmandy-type-d-series/adm-losmandy-style-universal-dovetail-bars.html

it's not cheap but it fitted my Skywatcher tube rings perfectly. already had an altair astro bar and the holes didn't line up.

Thank you! Thats very useful information!
I have the SW medium vixen dovetail https://www.teleskop-express.de/shop/product_info.php/language/en/info/p9965_SkyWatcher-Vixen-style-Dovetail-Bar---length-21-cm.html

If i keep the tube rings in the same distance as before, and mount the vixen on top - will it still fit the Losmandy holes on the bottom? 
I think the 15" (38,1cm) is the one i would go for.

[Dinglem]

I'm not sure about how they will fit together, you may be adding flexure, but how critical that is is debatable, I've used a vixen to vixen female clamp before with no issues to mount a guidescope on top of a scope.

[Carbon Brush]

You have no doubt noticed the 'Vixen type' dovetail bars have profile differences - but you can usually cope.

'Losmandy type' bars have a similar situation.
When I made my first attempts to use Losmandy fittings, around 2007/8, I found certain parts did not fit together very well.
But which part to hacksaw or file?

After making enquiries of different bar manufacurers, and retailers, I got somewhere.
First of all, there does not appear to be an agreed standard dimension or dovetail angle  for the profile.
Second most retailers and manufacturers gave vague responses about the dimensions of their offerings.

The exceptions to this were ADM as a manufacturer and FLO as a retailer.
Thanks to these helpful companies, I ended up with a copy of an ADM manufacturing drawing. Attached.
I now use the ADM supplied drawing as the standard for width and profile if I need to trim other bars on used kit.
Any new parts are ADM (via FLO).

By the way. Going to Losmandy fitting is big step up on bar/clamp weight.
You will be fine with your NEQ6. But don't try it with an EQ3 or there won't be any weight capacity left for a scope😞
Quality will be remembered every time out. Long after price is forgotten.😁

David.

 

DUP7.pdf

[whipdry]

On 24/01/2020 at 00:56, masjstovel said:

Hi, I am unfamiliar with the Losmandy dove tail bars, but i want one. 
I have a SW 150PDS with the standard tuberings. I want a Losmandy between 30cm-40cm and I see there are hundreds around. 

They all fit to the standard Sky Watcher tube-rings or is there something i need to be aware of regarding this?
If thats the case - which fits?

 

This one offers plenty of fixing options... 

https://www.teleskop-express.de/shop/product_info.php/info/p8517_TS-Optics-Losmandy-level-dovetail-barl-w--flat-surfaces--356-mm-long.html

Peter

[masjstovel]

Thanx @Carbon Brush! 

On 25/01/2020 at 17:10, whipdry said:

This one offers plenty of fixing options... 

https://www.teleskop-express.de/shop/product_info.php/info/p8517_TS-Optics-Losmandy-level-dovetail-barl-w--flat-surfaces--356-mm-long.html

Peter

Peter, alot of holes yes! i imagine i need to have an exact fit, but its normal to use 2 screws - 1 in center each way? That way those "long" holes are nice.  I mean, if not it has to fit the holes on the opposite vixen perfectly (?)