Would a Skywatcher Duluxe Table Top Tripod Take the Weight of a 130p Dobsonian?

[Craig79]

Hi,

After buying myself a lovely Skywatcher Heritage 130p last year I'm loving it but would like to take it camping with me and enjoy the dark skies I get there.  To this end I was thinking of reducing the size of the scope by removing the Dobsonian mount and attaching the tube to a table top tripod - that way I can stash both units in the wardrobe when we are camping and keep the kids sticky fingers off them!

Would the table top tripod take the weight of the tube?  From what I have read about fitting 130p's to a tripod I know I would have to drill / tap a second hole in the dovetail but apart from that would it work?

Thanks,

Craig.

[Guest Tuomo]

Try it with cable ties and report to us!  Well, to be honest I dont know. One of those thing one has to try out.

[Geoff Lister]

Craig,

My Heritage 130P OTA with 25mm eyepiece weighs 3.3kg. This is a bit heavy for an average table-top tripod, but may be OK if the tripod is sturdy.

The balance point of my extended OTA is about 20cm from the rear end of the dovetail plate, so the tripod mounting face will need to be a similar height, or greater, above the tripod's extended feet, if you want to see anything towards the zenith. The gap between tripod legs may also limit available altitude.

The dovetail plate has a 1/4" tapped hole at the front end, but this is nowhere near the balance point; so, as you mention, you will need to drill and tap a new hole at the balance point.

One alternative, for viewing at moderate altitudes, would be to use a table-top tripod in the front hole on the dovetail plate, and a "gorilla" style mini tripod, with bendy legs, supporting the rear, to give variable altitude. I have just tried this, and my rear tripod kept collapsing. With the dovetail plate at the bottom, the red-dot finder is a bit low for easy use.

My gut feeling is that, with a mounting hole at the balance point, the OTA would be better mounted on a proper photographic tripod. This would also give you the option of using the OTA for bird watching if you use an erecting eyepiece.

Geoff

[Craig79]

Thanks Geoff, thats food for thought.  It wasn't until after posting I thought there could be a issue with enough clearance to get to the zenith. 

[happy-kat]

Do you have a photo tripod?

Only one member attached just the telescope to a photo tripod using an attachment and a normal photo ball joint. If interested I'll dig out a link to that post.

[happy-kat]

link to Heritage 130p telescope on photo tripod

[Craig79]

That's great, thanks. I've googled it a lot and never come across that post. Looks like its exactly what I am after. 

[Geoff Lister]

Craig,

happy-kat's suggestion is a good one, but this clamp retails for about £40. It should be possible to get a compatible dovetail clamp for under a tenner.

Geoff

[Craig79]

Thanks Geoff, I'll keep an eye out for one. Until this thread I didn't know they existed. 

[JOC]

It's difficult in the other thread to see how that attachment to the photo tripod was achieved.  However, I just considered the fittings on my new grab and go baby Vixen and how I've used that with my camera tripod so I can get it higher than a table if I want to and wondered if the following observation was of use.

My Stitz Hi-Low angle camera tripod has a removable square plate that screws to the camera in the standard tripod thread and then the thumb lever on the tripod quickly allows the attachment/removal of the camera with the attached plate to the tripod (see photos - imagine if the plate was in the camera screw thread).  I was quite lucky the baby Vixen telescope attaches to its own table top tripod via the same thread.  The burgundy square plate attaches to the Vixen in exactly the same way as it does to my Canon and thus it is a work of moments to mount my Vixen to the camera tripod.  The attachment is quite secure and though I don't know how heavy the 150P is it might be possible to obtain a tripod (you can get something similar on ebay) with a similarly removable plate and find a way of attaching it to the telescope, possibly a spacer might be needed, but maybe not.  In any event the pictures might spark a similar idea.  My tripod has one-touch L-R, Up-down movement and carries my baby Vixen telescope well.  NB.  Apologies if this is how all tripods work (I've only ever had mine), but it wasn't clear in the other thread how the attachment worked hence I thought some photos of mine might be helpful.

[LukeSkywatcher]

Ive seen the Heritage 130p mounted on a motorized AZ3 (or maybe an AZ4). AZ3 im pretty sure. Great scope. Really punches above its size. I have a Horizon 8115 photographic tripod which i use for my little 70mm refrac scope and solar wedge. I also use it for my 20x90 bins and also for my DSLR using pretty much the same attachment as in the pics above. 1 came with the tripod but i bought a second one so i dont have to keep removing it.

[happy-kat]

The heritage 130p telescope mounts straight onto the Star Discovery mount as it does my Virtuoso mount so I expect it might mount on the Az4 as the heritage 130p telescope has a telescope dove bar mount. It does not mount straight onto the Az3 as that expects a telescope with tube rings or with the optional camera attachment plate a telescope with a camera thread.

[LukeSkywatcher]

Must have been the AZ4 i saw it mounted on then.

[Geoff Lister]

A couple of days ago, the postman delivered 2 small packages from China. One contained a pair of 1/4" - 20 UNC taps (about £1.50 each), and the other a tripod to dovetail clamp adaptor (just under £5 including P&P).

Be aware, there are photographic dovetail clamps that look similar to those compatible with Skywatcher/Celestron/Vixen telescope dovetails, but are slightly too small. The clamp that I ordered came in that category. The jaw opening was about 3mm too small and the inward slope on the jaws was about 45 degrees, instead of the 'scope's 15 degrees. After a bit of work with saw, file, wire coat-hanger offcuts and epoxy glue, I now have a clamp that fits on a tripod and grips my 130p's dovetail bar, and the other OTAs similarly fitted.

The 130p's dovetail bar now also sports an additional pair of 1/4" threaded tripod mount holes. With the OTA fully extended, and a typical eyepiece fitted, I found the balance point, using a length of 40mm white plastic dishwasher drain pipe as a fulcrum; and marked the point with Tipp-ex (other correction fluids are available) on the side of the dovetail. This point is also useful when attaching the OTA to the mount, as, if aligned with the centre of the  dovetail clamp, the OTA will only require light application of the altitude clamp whilst observing. If you are likely to use a binoviewer, DSLR, or heavier eyepiece + Barlow, it is worth fitting these and marking the additional balance points. The dovetail plate comes off by removing 3 bolts. These bolts go directly into tapped holes in the main tube, so there are no nuts to drop.

I used a centre punch to mark the dovetail's base centre rail at my various balance points. If close together, make the mark at a compromise position between the 2 points. I drilled the plate, from the base, to give clean holes on the tripod mount side. I used 3mm, 4mm then 5mm drills, and they go through the soft alloy quite easily. The 5mm is slightly smaller than the "official" size for the core of a 1/4" - 20 UNC thread. The tripod's male thread is usually quite short as it has to go into the blind recess of a camera, so it is important that the tapped thread is at its best on the tripod side of the dovetail plate. To achieve this, I used a 5.5mm drill, and opened up the holes, from the tube side, for about a quarter of the hole's depth. The tap was then able to engage easily in the hole, tapping from the tube side towards the tripod side, so that the tap was fully engaged in the thread as it exited on the tripod side.

 

The OTA fits on my tripod, and by placing it between the legs, gets up to the zenith.

Geoff