Tal 150k dovetail

[musherrob]

Hi all,Recently got hold of a Tal150k and looking for a suitable dovetail to attach to an eg6 head.....so......looking at the pics there is a dovetail attached to the base of the ota which is the same shape as the dovetail of the mount so from my limited knowledge i need a double dovetail that would slide into the dovetail on the ota and then the mount !! hope you get my drift so to speak !!Looking into the tube the dovetail fixings appear to be rounded studs/bolts ! So is there such a dovetail out in the market place ?? TA All.

[nightfisher]

correct me if im wrong but i think the dove tail shown in the picture is for the finder scope

[AndyH]

Ahhhhha. So you got!

Congrats. I wish to see so many pictures of it.

Regarding the saddle/dovetail.

You've got the 'attached to the scope' saddle, but are missing the heafty/huge steel dovetail. That's a bummer. Normally you'd attach a std vixen/skywatcher dovetail to the underside of the Tal dovetail, letting the scope mount on most std mounts.

It's dimensions are similar to a Losmondy(sp?) dovetail, but not quite.

I've got a drawing of the dimensions somewhere. I'll have a hunt.

Should probably be able to get one from the Tal factory, unless you know someone who could mill you a piece on the cheap.

Andy.

[Cornelius Varley]

The Tal 150 is usually supplied with a special vixen adapter plate. The top half is profiled to suit the saddle on the tube and the bottom half suits the Vixen style saddle on the mount.

[AndyH]

Some pics of the dovetail.

If anyone reading this and is wondering about the strange mount attachment system, it is because all Klevtsov dovetails screws directly onto the Tal Stepper mounts(MT-3S) plate. It's an exact length and width for it.

Anyhoo here's a link to some pics, which may help explain. The last 2 pics are the dovetail on the stepper mount.

Andy.

[AndyH]

Pants Can't find the tech drawing. It's somewhere.

Basic measurements are.....

Length = 200mm

Width(widest part of dovetail) = 80mm

Width(shortest part of dovetail) =

Thickness = 11mm

Angle of dovetail = 60°

You could get a piece of aluminium flatbar milled to suit. Someone on SGL may know someone with a mill?

80mm x 15mm aluminium is available(I got some online, for the 2M/MT-2C conversion).

Just need to dovetail the 2 sides. The 15mm thickness/depth is fine. No need to mill out the top as in the stock Tal piece. Drill & countersink 2 holes to suit the holes on your dovetail of choice. Buy 2 countersunk setscrews that suit the dovetail thread. Screw together. Job done.

Might be quicker than getting one sent from Novosibirsk?

Andy.

[SpookyKatt]

Congrats on the 150K musherrob, here's a thread with some plans

for a dovetail for a 200K, but it should be a match for the

150K.

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/2403909/Main/2373314

Kathleen

[AndyH]

Nice link Kathleen !

[SpookyKatt]

Cheers Andy, yeah I found that link a few years ago

after I got my 200k as it didn't have a dovetail

either.

I was going to get one machined but didn't need

to in the end as I managed to get one.

Kathleen

[AndyH]

Hi Sloz !

Jeez, I got caught up in the dovetail and forgot to ask

Is it a straight veined or curved veined variety?

Any idea of the age? Normally there's a small sticker inside the front of the tube?

Cheers,

Andy.

[AndyH]

And another Q

The focuser backplate. Solid blank piece or with holes for access to the primary setscrews/bolts ?

Don't know if you'll need it but I'll add the file for the r&p focuser stripdown/rebuild.

Cheers,

Andy.

TalScopes Tal focuser rebuild.pdf

[AndyH]

Jeez.

Whilst I think getting a dovetail, made up would be best, I can't believe I didn't mention trying to source tube rings. Maybe you won't get the bang on size, but they could be packed with thick leather. Have you or someone got a thick leather belt? Stick it to the rings, add felt etc and that should work really well.

edit: I could be wrong, but the tube diameter may(stress, may) be 183mm. Skywatcher do a pair in 182mm size. Might fit. I find their sizes to be under estimated.

Andy.

[AndyH]

Some lovely pics in this Russian forum review of a 2005 model 150K. Run it through your webbrowser translation to get the details. The translation is not the worst I've read.

http://astro-talks.ru/forum/viewtopic.php?f=7&t=697

Andy.

[AndyH]

Jeez.

Whilst I think getting a dovetail, made up would be best, I can't believe I didn't mention trying to source tube rings. Maybe you won't get the bang on size, but they could be packed with thick leather. Have you or someone got a thick leather belt? Stick it to the rings, add felt etc and that should work really well.

edit: I could be wrong, but the tube diameter may(stress, may) be 183mm. Skywatcher do a pair in 182mm size. Might fit. I find their sizes to be under estimated(ie: size slightly larger than quoted. At least the 2 pairs I have are)

Andy.

[musherrob]

Ok All, Many thanks,especially to Andy H for suggs and finally got one milled(pics) for 15 quid.So a nice snug fit on the dovetail...so...just awaiting this cloudy spell to blow away.Out of interest the label in side the tube reads No 0150 03 and it is the 3 vane type .Ta Rob

[nightfisher]

A great outcome, all sorted and ready for action

[AndyH]

Excellent !

Hope you get some clear nights soon.

Andy

ps: 03 suggests it's a 2003 scope. Nice to see it's the trad curved veins.

[rawhead]

Very pretty

I want a 150!!!