Tak clamshell & Vixen dovetail?

[MortonH]

As a prospective Tak owner I'm having a hard time nailing down a standard Vixen-style dovetail that will attach to a Tak clamshell without modification.

Is it really that hard or am I missing something obvious?

[ariefm71]

I used the Losmandy VUP4 dovetail. Bintel have it or I can loan you mine.

[ariefm71]

Only if your clamshell uses M6 bolts...

[MortonH]

Ah, I actually have one of those or something very similar to it. I just wasn't sure if the M8 bolts for the Tak would fit through the slots.

[MortonH]

Oops, posted at same time.

Do some clamshells use M6 bolts? I thought Tak used M8?

[LewisM]

What tube diameter? If it is a 114mm Tak tube, I have 2 pair of Vixen 115mm rings which fit beautifully on the Tak 114 tubes (since you can tighten them up).

If it's a 95mm tube, the best is K-Astec in Japan, but expensive. WELL worth it.

Otherwise, yes, use the Tak clamshell, and modify a Vixen dovetail bar. Not difficult.

[MortonH]

It would be a 95mm tube.

Actually, I found something that said Vixen's own standard dovetail plate has central holes 35mm apart that match the Tak clamshell. Someone said that in the old version the holes are 6mm in diameter but in the newer "white" version they are wider and would take 8mm bolts.

The picture about halfway down this thread on CN seems to show this setup.

http://www.cloudynights.com/topic/517214-fc-100df-vs-tsa-102/

[anj026]

I use a standard vixen dovetail plate on my TSA which I use on a Vixen GPD2 mount. I can't remember if I had to drill out the holes from 6mm to 8mm. In fact one of the pictures in the thread you linked to is my scope (my post). On the FC 76 I use a home made plate that goes on a Vixen Porta mount.

[MortonH]

Looks like MyAstroShop now offers a solution - a 7" dovetail with four 8 mm holes.

http://myastroshop.com.au/products/details.asp?id=MAS-096I3

The weird thing is it seems that the pairs of holes on either side are 35mm apart but not the two nearest the centre, so to mount this on a Tak clamshell you'd be lopsided. I've asked Steve Massey to confirm.

[Kunama]

Fs102 tube is actually 114mm Morton.
I have seen a dovetail that is drilled for the 2 M8 bolts, I'll try to locate one.

[issdaol]

AEC were selling Vixen Dovetails pre-drilled and with a countersunk circular section for the Tak TSA clamshell to sit in.

Actually very well made and done in Australia

[Allan]

Does it have to be a Vixen style plate. What about this one, which is made for the Tak clamshell

http://www.farpointastro.com/dovetails/FDTCS.php

[MortonH]

Interesting. I'll need to ask Claude about this.

Thanks.

[MortonH]

Yes, has to be Vixen.

[issdaol]

Thats a Losmandy style plate you need a Vixen style which is a thinner width but thicker depth.

The one that was available through AEC was an extremely solid bar with the countersunk section similarly placed so the clamshell slotted nicely into the body of the bar to reduce any potential movement.

[issdaol]

Im using the slightly smaller version on my TSA120 which is using that AEC supplied bar and a Vixen SWX mount and Tak TSA120 Clamshell.

Works great :-)

Will see if I can get a chance to take a pic for you. It would actually be very easy to get one made at a aluminium machine shop from a solid piece of aluminium.

[Peter Ward]

Losmandy have a new Takahashi ring spacer for use with his universal plate

Picture attached.

[anj026]

I am home again now after being away for a few weeks. My Vixen dovetail is a standard $19.95 one from MAS. I had to drill and tap the 6mm holes to M8. It is quite solid and I have no issues with it for visual use on a Vixen mount. :)

[Peter Ward]

Some more pictures to illustrate how Losmandy's new Taka ring adapter can be configured for D or V series plates.

It's an effective and cheap accessory...about $US 20 or so.

[MortonH]

What I've discovered is that the dovetail clamps on my mount won't accept an actual Vixen dovetail. The typical black Synta dovetails have angled edges and my clamps are designed to match. It seems an actual Vixen dovetail is different.

I found this out when I got my Tak as it came with a specially made ring adapter that is designed to fit a Vixen mount. However, only one side was angled to match my mount's clamps while the other was almost flat. So if I pulled slightly on the scope once mounted the dovetail would slip out on one side.

[MortonH]

I'm not sure how this helps since you still need 8mm holes in the dovetail bar. Wouldn't that setup still work without the ring?

[Kunama]

https://www.optcorp.com/telescope-accessories/mount-accessories/mounting-hardware/dovetail-saddle-plates/ls-150ps-6inch-dovetail-bar-150mm.html

[anj026]

That is frustrating when the "Vixen standard" is not standard between manufacturers. Here is a link to the Astro-Physics standard which also shows the Vixen dimensions for comparison.

http://www.astro-physics.com/products/accessories/mounting_plates/DvsVBars.pdf

[Peter Ward]

While it is true all Losmandy Universal Plates (both D and Vixen sizes) have threaded holes with Taka spacing, the adapter ring gives you a much wider and stable base which allows the raised inner section of the Taka rings to sit flush.

[MortonH]

Claude confirmed they still sell these for $95 posted. Not sure how long they are. I've asked for a picture.

Luckily my Tak also came with rings AND clamshell so I've been using the rings so far. Not sure I want to spend another $95 just to use the clamshell.

[issdaol]

This bar is not as good as the one AEC can supply..... plus as Peter mentions the countersunk ring helps the clamshell sit flush and more stable than other bars on the market :-)

Sorry have not gotten around to taking pics of mine....been distracted by some recent goodies arrived from Italy :-)

[MortonH]

Hi Phil,

A pic of yours would be good as Claude says he doesn't have a photo he can give me.

[johngwheeler]

I got one of these from A.E.C. with my Tak, and it's very solid and well made. The actual dovetail was "free" when included with the Tak clamshell - just as well - just about everything else on a Tak that you need in order to use it is "an optional extra" :(

[MortonH]

Ah, so that's the big shiny thing in the pic you posted on CN.