+Graham Posted October 8, 2017 Share Posted October 8, 2017 That's looking great. Link to comment Share on other sites More sharing options...
Doc Posted October 8, 2017 Author Share Posted October 8, 2017 2 hours ago, Graham said: That's looking great. Link to comment Share on other sites More sharing options...
+Bino-viewer Posted October 8, 2017 Share Posted October 8, 2017 Great work Mick. Really impressive bit of engineering there. Whats the height of the riser ? The discmount version is 8 inch, and i have to use it all the time with a long refractor. Its very rigid though. Are you still looking at a Planet tripod ? Link to comment Share on other sites More sharing options...
Tweedledee Posted October 8, 2017 Share Posted October 8, 2017 That's looking rather special Mick. Link to comment Share on other sites More sharing options...
Doc Posted October 9, 2017 Author Share Posted October 9, 2017 (edited) Cheers guys. The riser is nearly 10" Rob and it's really sturdy, no flex in it at all. If it works which I think it will, I'll sell the Losmandy and get the Planet. Edited October 9, 2017 by Doc Link to comment Share on other sites More sharing options...
Doc Posted October 9, 2017 Author Share Posted October 9, 2017 I've used one of my old Losmandy dovetail saddles today and drilled 4 mounting holes to make it extra secure. Clamped it onto the altitude disc and drilled through so I knew it was straight and centered. Then I mounted the scope and.... Well I'm bloody impressed, it's smooth and rock solid. I can adjust it so the scope doesn't droop while I'm using heavy and light eyepieces, the scope stays put in the same position while changing eyepieces. The azimuth axis is very smooth and so easy to move. I'm still not happy the shafts being made out of aluminium so I'm going to change them to stainless steel and I need a handle to move it around but I'm well pleased so far. Here's a few photo's. Tweedledee and philjay 2 Link to comment Share on other sites More sharing options...
Brantuk Posted October 9, 2017 Share Posted October 9, 2017 Functional perfection in a subtle blend of art deco and brutalist style..... But who cares in the dark lol! Very nice result Mick! Link to comment Share on other sites More sharing options...
BAZ Posted October 9, 2017 Share Posted October 9, 2017 Looks good Mick, how does it feel when you move it, is it dead smooth? Link to comment Share on other sites More sharing options...
Doc Posted October 9, 2017 Author Share Posted October 9, 2017 Pretty much Martyn. The azimiuth is very smooth. There's a small tight spot on the altitude but then that's just inside the beginning of the 90° travel range. I'm going to look into that and try ti improve it. Link to comment Share on other sites More sharing options...
BAZ Posted October 9, 2017 Share Posted October 9, 2017 Nice one. I look forward to seeing this in operation. Link to comment Share on other sites More sharing options...
+Bino-viewer Posted October 9, 2017 Share Posted October 9, 2017 It looks great Mick A job well done. Do you have any plans to install encoders in the short term ? Link to comment Share on other sites More sharing options...
Doc Posted October 9, 2017 Author Share Posted October 9, 2017 I would like to but don't want to pay the price of a proper set up, you are talking £400. The best one I have seen is the new Nexus set up but it's expensive. I've always used the wixey type of encoder that gives you the azimuth and altitude readings and you combine your Sky Safari or similar on your phone to look up the co-ordinates and just move your scope until you are at those points. I was thinking off two of these, one on each axis and make up an enclosure for the display boxes to sit in. https://www.machine-dro.co.uk/rotary-angle-encoder-and-remote-display-with-a-6mm-diameter-shaft.html . I have used these before on a dobsonian and only had little success but the engineering is better this time. Inside the enclosure i will include red lights so I can see the display better. What do you think? Link to comment Share on other sites More sharing options...
+Bino-viewer Posted October 9, 2017 Share Posted October 9, 2017 They look great, assuming they will both fit ? I've never seen these Wixey setups in detail before. They look very good value for money don't they ? Link to comment Share on other sites More sharing options...
Doc Posted October 9, 2017 Author Share Posted October 9, 2017 They do look good and I've been using wixeys for years and they are very reliable. Ok you don't get the bells and whistles of a proper set up but they are accurate if set up correctly. Link to comment Share on other sites More sharing options...
BAZ Posted October 10, 2017 Share Posted October 10, 2017 I blame you Mick!!! I have just ordered that rotary encoder. I used to have a different version of this on my Dob some years ago, but could never get it to work right. I found it used to get very small errors that built up by moving it backwards and forwards, after a while these compounded and became huge and absolutely way out. I am hoping this will be as good as my Wixey for altitude, which is bob on. When they work they are usually very accurate and it is easy to get an object in an eyepiece. In fact do you remember that EMS at Anderby, You, Daz and Myself all got Uranus within seconds as we all had them set up bang on that night. I should have that for the Weekend, I might see about getting a longer cable to be able to mount it on the scope at the top end. Link to comment Share on other sites More sharing options...
Doc Posted October 10, 2017 Author Share Posted October 10, 2017 I do remember Martyn it was a great night. The wixey uses a standard ethernet cable there are loads of different lengths on e-bay. I used to use the older version as well and like you it wasn't always accurate fingers crossed this one is better. Link to comment Share on other sites More sharing options...
Doc Posted October 10, 2017 Author Share Posted October 10, 2017 Well these encoders don't fit by a long shot, tried all different positions and the gap is too small. Rob can you measure the physical size of your encoders for me including the length of the shaft. Thanks. Link to comment Share on other sites More sharing options...
+Bino-viewer Posted October 10, 2017 Share Posted October 10, 2017 (edited) Hi Mick My encoders are 55mm wide, and stand 42mm above each axis (from the base below the adjustment bolt) They come close to each other : about a 5mm gap between them. The encoders are by US Digital and have '4000 steps' each. https://www.usdigital.com/products/s2 I don't think the encoders themselves are particularly pricey ; its the interfacing computer that costs a bit, but there are various options there from other manufacturers. I've only recently upgraded from a 'Skysensor' to a Nexus DSC. Edited October 10, 2017 by Bino-viewer Link to comment Share on other sites More sharing options...
Rusty Strings Posted October 10, 2017 Share Posted October 10, 2017 I'm a bit late to the party with the compliments but, that is a mighty fine job you're making of that Mick. Link to comment Share on other sites More sharing options...
Doc Posted October 10, 2017 Author Share Posted October 10, 2017 Thanks John glad you like it. Even those won't fit Rob. What I'm going to do is have one of wixey on the azimuth, and place the altitude on the dovetail bar like I have always done. +Bino-viewer 1 Link to comment Share on other sites More sharing options...
Doc Posted October 13, 2017 Author Share Posted October 13, 2017 I was thinking about encoders and it turns out there is not enough room for two of the machine DRO encoders inside the mount. So I decided to have one on the azimuth and a normal wixey on the altitude. The next problem is securing the 6mm shaft of the encoder into the azimuth axis. I came up with this idea, a plastic "D" shaft insert into the end of the azimuth shaft. Well you try to find one, what I did was buy a potentiometer and was going to glue that into then of the shaft. I ordered the following: http://www.ebay.co.uk/itm/4pc-D-Shaft-6mm-Stereo-Audio-Rotary-Switch-Potentiometer-Aluminum-Knob-13mmx10mm/290692264897?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 It turned out the outside diameter was 11.9mm, my thread on the azimuth shaft was M12 so not enough spare meat after I drilled 11.9mm. So armed with a hacksaw I removed the plastic insert. Now I needed to drill 8.7mm and superglue the insert in. Perfect fit and hopefully the encoder shaft will be exactly on axis with the azimuth shaft. BAZ and +Graham 2 Link to comment Share on other sites More sharing options...
+Graham Posted October 13, 2017 Share Posted October 13, 2017 I just love the ingenuity and lateral thinking behind this solution. So what stops the encoder body moving is it fixed to the side wall of the mount head. Link to comment Share on other sites More sharing options...
Doc Posted October 13, 2017 Author Share Posted October 13, 2017 Yes Graham fixed by 4 bolts to the side wall of the mount. Link to comment Share on other sites More sharing options...
BAZ Posted October 13, 2017 Share Posted October 13, 2017 Duct tape! Link to comment Share on other sites More sharing options...
Doc Posted October 15, 2017 Author Share Posted October 15, 2017 Just weighed it and it is 13.9 Kg or 2.2 stone Tweedledee 1 Link to comment Share on other sites More sharing options...
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