Acuter "Merlin" electric mount. (first thoughts)

[iancandler]

As most know the Merlin mount is a small alt az driven mount that allows tracking.

It is not goto or as far as I know convertable to goto.

The mount is a single arm design with a standard dovetail clamp, similar in some ways to the celestrons etc we all know, though the arm is upright and not canted backwards.

A rigid L bracket is supplied that fits into the dovetail clamp and has the faciility to allow the mounting of camera's or small scopes up to around 7LBs.

Also supplied is a rather dinky, yet nifty hand controller, a reasonable quality alloy tripod, with locking brace and geared centre column two cables for camera control, manual and with the model I bought a table top mount plate similar to the astro engineering ones.

On opening the box I got a suprise as there where several other boxes inside and not just some foam balls and the items thrown in.

The first of these contained the tripod, which also comes in its own carry case.. a nice touch there..

Next another large box, this time with just two cables in a plastic bag (packaging overkill)

The next was suppossed to contain the table top platform but the box was completely empty.

Finally the box with the head, hand controller and manual, very well packed in fitted foam.

Feeling like a kid at christmas I hastily removed all the items and set about fitting them together.

Now this is where the manufacturers have made a monumental [removed word] up.

They have omitted something from the design of the tripod so essential that it beggars belief.

The aluminium plate on the top of the tripod that the head screws down onto via a single central 3/8" screw is just bare metal.

No cork or neoprene cushion has been fitted.

Consiquently once the head is fitted it cant be tightened down properly, with a small nudge being all thats needed for the drive head to rotate slightly anti clock wise.

Something else is that its not pointed out in the manual is to grip the drive head below the drive gear to screw it on, anyone who didnt think a bit first would grab the head higher, meaning that once tightened as far as it could go you would be putting pressure on the drive gears, and its not a good idea to move driven mounts by hand unless you can dissengage the gears first, which on this head you cant.

Obviously I noticed the head wasnt tightening fully and removed it only to find a fair bit of paint had been scrapped from the base of the mount and the alloy head plate on the tripod was covered in swarf that had fallen out of the threaded hole in the mount.

I cleaned it up, then cut the neoprene from an old mouse mat to size, re-fitted and it was problem solved.

The point here is that something so basic shouldnt have been overlooked in the design stages let alone made it through production and into the shops.

If I was OVL I would be having a word with the suppliers about rectifying it on future models.

Obviously the weather here at present isn't conducive to actually getting out and using it but having played with it today indoors so there are a few observations I can make.

Aside from the above, its good quality and solidly made.

I dont think the tripod will give anyone any issues unless they plan on using it standing up, in which case if your my height (6ft) and/or planning on using a small refractor on it I recommend getting a decent quality large tripod so you dont have to extend the centre column.( I have yet to find one that isnt wobbly to some degree)

The mount itself handles my antares 80mm ZS80 clone with ease, but its fairly balance critical. ie if you mount the scope to far forward it will pull on the alt gearing and the nose will drop slightly.

The same will apply if you mount a camera on the rear of the scope, except it will drop tail first. so make sure your kit has its balance point sorted out.

Angle wise 60 deg plus of alt was easy to achieve, even with a 2" quality diagonal fitted. the only issue was when using the L bracket to mount the scope there was very little clearance between the side arm and the micro focuser knob at times.

With the scope mounted to the dovetial clamp directly the best you can do is 52 deg before the base of the focuser comes to close the the main body of the mount.

Another little idea that myself and a couple of guys have been throwing around is using this mount on an equatorial wedge, something that seems feesable.

As long as the scope is mounted so its centre of gravity is directly above the L bracket it shouldnt be an issue.

Initial tests with the tracking shows that if you set your latitude as 0 deg it will track perfectly flat when conventionally mounted which should mean it will track equatorially on a wedge or angled tripod.

Currently several methods of mounting are bieng expored:

One is to mount directly onto a suitable geared tripod head such as the manfrotto 405 or 410 via thier 3/8" screw on the top plate.

mounting onto "arthurs mounts" old wedge via a 3/8" bolt and locking washers, or getting the counter balance bar for it turned down and threaded to the right size.

Fitting onto a meade or nexstar tripod as both have the adjustable eq platform on them, again it would require a central hole and 3/8" bolt.

As a little grab -and - go mount this certianly fits the bill, its light enough for me to pick up one handed, packs into a neat little package that would stow in the footwell of a car let alone a boot.

In fact if you obtained a large aluminium tool case you could probably fit the whole lot in it.

Coupled to a light OTA such as the little ZS66 this would make an excellent package to take on holiday and running on either 12 volt or AA batteries means running out of power wouldn't be an issue.

And thats about it for now, but once I get out and do some observing/take some short exposures I will update this.

*update 1*

Well I've got out to use it now and found out a few things.. the first and most important is to impress upon you that this mount is very balance critical, time needs to be spent indoors trying out various mounting methods and postitions to get it right.. get it wrong and the scope will drift up or down depending on the balance point.

From that point of view it pretty well precludes using the L bracket for anything other than a very light weight OTA with 1.25 eyepieces or camera and lens.. stick a 2" diagonal on the back of a ZS 66 mounted via the L bracket and you'll find out what I mean.

Mounting direct to the dovetail is a far better solution.

For the WO ZS 66 I used the WO dovetail bar I have length ways and spent an hour fine tunning so that the image in the centre of the viewfinder didnt move at all, even when left for some time.

Needless to say this was done with the camera and right-angle finder in place.

With the C5 I had to reverse the dovetail bar on the base of the scope to move the main OTA further forward, I then connected the DSLR via an sct-t thread connector and balanced that as above.

The only limitation I have found is that due to the camera being on the rear there just isnt sufficient clearance to incline the scope past 55 deg, so your limited on objects altitude wise.

I still havent gotten around to trying this on a wedge, and to be honest want to get some method of counter balancing sorted before I do, so nothing has an argument with the unforgiving concrete.

As a platform for short exposure camera use its fine.. no issues there at all..

Finally no reply from OVL at all about the email I sent them.

[blinky]

Great report, might be interested in one of these for my ZS66.

[Whippy]

Sounds good Ian, I'll be interested in the updates permitting.

Tony..