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Posts posted by Daz69

  1. I use a 4 stage computer charger for my 110ah caravan leisure battery, and my smaller 9Ah 12v deep cycle batteries that I use for my fishing trips. My caravan battery stays connected to this charger EVERY day, and the computer board inside the charger, cycles the battery to keep it at absolute peak. These chargers have dropped considerably in price, so should be considered above the normal type heavy duty chargers that are still out there. My charger has LED's that indicates it's state, and when I take a battery off charge, I let it rest a while, and it normally reads around 13.6v. 

    This is the one I use http://www.ebay.co.uk/itm/Sakura-Car-Van-4x4-Bike-12v-6v-5-3A-Automatic-Intelligent-Smart-Battery-Charger-/301663140633?hash=item463c863b19:g:askAAOSwmtJXa-11 

  2. 1 minute ago, faulksy said:

    no daz, not at all. look nice and it will match your tube :grin:

    :D  Haha, I was sat here thinking, "Why does it need to be black? What am I missing?" :D  If I had some then yes it would've been black, but I've got a half 2.5L tin of exterior white gloss which won't be used as we have no need for it. i suppose it could've gone to the dump a long time ago, but I'm a hoarder of "Oh that'll be useful one day" bits n' pieces. 

    What I plan to do, is use the round base board as an azimuth circle and have a fixed illuminated pointer on the box section, so I'll be engraving 360 marks around the edge (I must be mad!) to aid alignment, and will use black enamel model paint in the marks so they don't rub off and will be more visible in red light. I thought about laminating an azimuth template on top of the base board using Doculam. This is quite thin but very strong as I've used it to cover a balsa RC plane, and I've got around 50 metres of it, but I cannot get my computer to enlarge and tile such a template. I might try another laptop to see if that one will do it, otherwise I could try and find a print company perhaps. I suppose it would save me a few hours using an arm protractor. 

    • Like 1
  3. I absolutely love fishing and cycling (not at the same time :D) but when I can't do either, I play the guitar or do some more on my next RC plane. Keeping and breeding budgies is a hobby AND a chore due to the regular cleaning, feeding and checking. Yes I know I've got too many hobbies but it keeps me from sitting on my 'aris. 

    • Like 4
  4. 10 minutes ago, faulksy said:

    looks great mate, are you painting it black

    Hi Mike. I'm painting it white because that's what I have got in the workshop and it can be used for exterior wood. Any specific reason why it should be black? 

  5. Check the output in amps for your charger. If it's around 5 amps, and then use the same sockets to power your device, then those devices are fused at the same rate. You will be way over protected, and your device can theoretically pull up to 5 amps if something goes wrong. If you have a short, the dew strap could get excessively hot and cause damage to whatever it is warming. If you know how many amps (or milliamps) the dew straps pull when both used, (if they are shop bought it will be shown, but if home made then you should have used Ohm's law to work out what the draw is), then use a fuse that is slightly higher. So if they both pull 1.2  amp together, fit a 1.5 amp fuse and separate charge and load sockets.

  6. 3 hours ago, John said:

    The 200mm F/5's are good optical tubes. Excellent performance per £ spent when you can get them for £120 !.

    Years ago I picked up one with the older "Helios" branding and made a dob mount for it. Not as nice a job as yours though :rolleyes2:


    Thanks for your kind words. 

    There was no way I was going to let that go at that price, so I jumped on it. 

    I've got to sand down the filler which I put over the joints (not that they were bad joints as it was all cut on my tablesaw) to cover the tear-outs as the ply wasn't the best, and my blade needs sharpening. I also put filler over the end cuts that are visible. I got my T nuts today so I'm all ready to go once it's painted. I'll get some photos once it's all done.

    • Like 4
  7. 1 hour ago, John said:

    Just catching up with this build - it's looking good ! :icon_biggrin:

    Shane built me a dob base to fit my 12" optical tube but that was an F/5.3 so it's definitely a standing scope. I like standing when observing and Shane managed to design the base so the eyepiece was at a good height for me :icon_biggrin:

    It's a robust piece of work as well - still going strong and more or less unmarked after 2 years of ownership and quite a few star party trips:



    That's a good looking tube. I actually found your set up when searching on Google for images of a dob base, didn't realise it was yours, and seeing how tall yours was, decided to add the extra 5". Mine is f/5 and meant to be on a tripod, but I bought it S/H without a tripod (£120). I'd like an HEQ5 but funds do not permit, and with a load of 3/4" ply in the workshop, and a workshop full of woodwork machines, thought I'd build a dob base so at least I can use it until I get a tripod or a pier. 

    • Like 2
  8. You can use the same one set of positive and negative sockets to charge when not using, and to power your dew heater when you want to, so long as the charging amps don't exceed your fuse for the dew heater. If your charging amps are around 4amp as most chargers are , put 2 sets on, and have different rated fuses on each pair, say 5amp for the charge circuit, and 2 amp for the dew heater. 

    Use suitably rated banana plugs for the charger to battery sockets, and RCA's for the dew heater. Try not to have any sockets that are trailing from either box, so get surface mount types. Forget the Tamiya plugs as they become loose and fail. The XT90's are good, but again this would mean that you have trailing sockets. 

    2m RCA leads are about £2 a pair, so that does 2 dew bands as each lead has an inner core and an outer shield that will happily take a few amps. Banana plugs can be bought in sets so you get both male and female in red and black, again they're about £4 for 5 of each set. I get all mine just from ebay. 

    As for teminals, you would be best soldering it all, rather than ring terminals, although you will need some for your actual battery connection, if that's what you meant?

    • Like 1
  9. A bit more done today. I took the boards out of the clamps and sanded the joints on all three boards. Cut the box base board and stuck it all together. I put the whole thing together on the base board using a large washer (just for this set up) between the box and the base. Stuck the scope on to see what the difference is going to be.


    I then got the stool and gave it a try for size.


    I'm now much happier :)  I have planned all along to put my battery box and power distribution box inside the dob base so I don't have any wiring outside of the base that can get snagged or tripped over, so that will add a bit of ballast. I then too it all down, removed the alt wheels and routed out the beautification holes (hand holes :)) and rounded over those. I then set to with the filler and went over all of the joints and end grain, as the ply had a few voids. I haven't put any filler one the outside of the alt wheels as I want the adhesive for the formica to stick to wood, but everything else has been done.



    I'll let the filler dry overnight, and rub it all down tomorrow and start painting the primer on. I popped down to the local charity shop and bought a Shirley Bassey album (it was that or Cliff Richard) and opposite is our local hardware store. I got my centre bolt and had a look at their T nuts. For some stupid reason, they stock metric nuts and bolts, but imperial T nuts! Even the shop worker couldn't figure. Luckily, there's another little shop on my home from work, so I'll pop in there as I pass through. 

    So far, it is all going fairly smoothly. Unfortunately with the way my head is and the brain fog I suffer due to my meds, everything takes so much longer for me to do, however, do it slowly do it right! I'm going to paint this white, as that's what I have got in abundance, rather than go and buy even more paint for the remnants just to sit on my workshop for another 5 years!

    • Like 2
  10. 15 hours ago, Uplooker said:

    Sorry, forgot to say well done. That is a mighty fine looking dob. Just need to increase the aperture to gain access to the Dob Mob ?

    So, even though I have built a dob, I still can't be a "Dob'ster"? Fine, that's it, I'm going home! :(  :(  

    So, after taking Shane's advice, I got my workshop stool which is one of those gas adjustable types with castors (I use it for drawing and making my RC planes on the model bench) and tried it with the tube at 51 degs. and it still left me hunch backed, even more so when the tube is lower, so I've added only 5" to the bottom of the sides and front. That allows my chair to lowered right down and still be comfortable. By using the stool I don't have to get up, I can just scoot along on the wheels. 

    Mrs Daz had said the other day that I can build an area of decking for observing, which will be at the end of the garden, so I won't be able to use the stool on the grass for the time being, but will be able to use it on the patio. The reason for not wanting to use the patio is that it is right next to the house and I don't want to keep getting disturbed by the kitchen lights coming on. Well I guess once the dob is finished I'll be making a decked area :) 

    Jobs for today, finish the round over routing, sand the panels, go to the charity shop to buy an LP, hardware store for a centre bolt because the one I had planned to use may be about 5mm too short, glue and screw the lot together. Painting will be another day I think.

    Thank you for the advice Shane and Ian. 

    • Like 1
  11. 10 minutes ago, Moonshane said:

    Great job!

    This might give an idea re the eyepiece height ;)


    Thank you. So you're sat in a chair when you use yours? Aren't you forever having to move the chair all the time to follow an object? I prefer standing, so think I will have to add the height I need, keeping in mind the top heavy likeliness that will be as a result. I'll have a look through and see if there is a thread for "show us your dob" and see what heights others have done. 

    Thank you. 

  12. Hi guys.

    I put it all together, still got to do lots of finishing to do, so it is in the rough at the mo.


    In this next photo, you can see that it is way too low, even though I followed the measurements given to me by the excel spread sheet. 


    With the scope set in the position you see (51 degrees) it is 2 feet too low if you put the centre of the draw tube at my eye line, give or take an inch. I know I can rotate the tube a bit, so I may be able to just add 20-22" on the bottom of the box. The actual platform has the adjustable feet wound right in, and I reckon I've got about 3" of allowance on the feet. 

    I've never had a dob before, so tell me if I'm going wrong here, but I cannot see myself bending over for a few hours, as my back will not be able to do that. 


    Edit: Forgot to mention, the tube is in the rings with the balance point centred between the rings, and that was checked with the finder scope and my heaviest EP in.

    • Like 3
  13. Quick question, If you have made such a base, where do people keep their dob bases and scopes that have these large alt wheels still attached, or do you remove the wheels (and tube rings) and bring your OTA's indoors? 

  14. A bit more done today. Box panels are all cut to size and square, Sides have had the alt bearing cups cut out and the large holes routed out, just need to round over the holes for aesthetics. I've screwed the box together dry (no glue) but I still think it's too low. I'll get everything ready (only got the "dovetail" spacer bars to make which will be 3/4" ply) and build it all up and then see just how high up the eye piece is. Once I'm happy, it'll all be broken down and every panel sanded, then the box can be glued and screwed ready for the finish. Still no photos while they are all single bits of boring wood :) but once I get it all together tomorrow with the scope on and while it is still the dimensions given, I'll take some photos  just in case I do glue on another few inches to the box sides and front. 

    • Like 4
  15. Just now, Uplooker said:

    Sounds like you are enjoying yourself, I look forward to seeing the completed build?

    I hear on the grapevine that estwing is going for larger scope ?

    He'll have to apply for planning permission surely, and stick a flashing red light on the top for passing aircraft :D:D  I can't wait to see it! 

    I do enjoy making things, keeps my mind occupied and off my head issue, but it just takes me longer as I am always treble checking everything before committing. 

    • Like 1
  16. 43 minutes ago, jaygpoo said:

    Battery not hot but just puzzled as to why its run down so quick when it shou;d last ages. Got an electrician looking at it tomorrow and will report back.

    Was the battery fully charged before you used it? You're right, it should last a long time. My 9ah deep cycle batteriy box lasts several days when I use them for when i go away fishing for a couple days, running an LED strip light when needed, and charging my phone and my tablet. I can also connect another battery box in parallel to give me 18ah if needed. This would be plenty for my astronomy needs at the mo, and save lugging my caravan battery out every time. 

    If you haven't got a multimeter get one because they are a real godsend for things like this. If you've got plenty of cash get a FLUKE one, or just a simple digital one from ebay. They start around £3.99 and last a few years. 

    I'll sit down over the weekend and draw a simple diagram with a parts list for you, no probs. My box only cost around £25 but I did have a few bits already including the box, but they are only around £5 each, again on ebay, but much cheaper than Maplins boxes for that size. Don't forget though, they are no longer weather proof when you start adding sockets etc. It took me a couple of days to build but I work slow due to being on some heavy meds. 

    Good luck with the electrician. 

    • Like 1
  17. Have I read this correctly? You're trying to give a constant 14v from a 12v battery Fully charged and rested off charger will only give around 13.6v. You might be lucky and get your battery back up to accepting a charge if it hasn't been damaged by running it that low. Leisure batteries are deep cycle batteries, and in my experience as a caravanner, they charge best on a computer controlled "stage charger". Are you using a step up boost converter? Where did you buy it (post a link if you can) or did you build the board yourself? Have you set the output voltage correctly?

    In regards to the battery rising back up, it will do when it is at rest and off load. It sounds as if you are just pulling far too much from the battery rather than having a short somewhere, but to pull 50 amps every hour, 100/2, that is going some! Personally, I'd de-solder each circuit and test them separately, concentrating on your step up converter and leaving it powered for another couple of hours just to see if it is that that is causing the issues.

    1. Are all of your circuits, that's every USB port and other sockets independently fused? That would show if any circuit has a short as it would blow that fuse, rather than just using one master fuse for the whole box (if you have one).

    2. If you have a circuit tester, check every possible circuit for current drain when it has power but nothing is plugged in, including any switches, sockets or shop bought electronic circuit boards to try and find a drain. An LED voltage meter will only take a few milliamps if it is on constantly, but I doubt very much that is your problem, as they are very fragile and will just give up if there was any short on the board.

    3. Can you post a link to the USB charging device?

    4. Personally I would not have every socket wired in parallel, i.e. just simply jumping live and negative from each one to the next, because if you have an issue with anything plugged into one of the sockets, it could damage anything else that's plugged into the other sockets. Look up "Wago" connectors here http://global.wago.com/en/products/product-catalog/terminal-blocks-connectors/installation-connectors/compact-splicing-connectors-all-conductor-types-222-series/index.jsp I have used the 5 port ones, and have the master fused supply live wire from the battery input go into one hole, and then you use the remaining 4 like a CANBUS to power other circuits via their own independent fuses suitably rated. Same with the negative wires for each circuit. 

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