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jacksdad

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About jacksdad

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    Salisbury, UK

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  1. Ok, so, an almost useless example... Image taken with a Pentax K100D (with a very dirty sensor), fired with an IR remote unit (so no shakes induced by touch), though a double glazed window with only the small cap removed from the 'scope (see, I said useless) In all honesty I only took the picture to see if it was possible to achieve focus with a directly mounted dslr (I've seen many references to this not being possible on this 'scope without moving mirrors and such) so I did nothing at all with respect to setting up - that hedge is a good 1/2 mile+ away so I think I achieved the actual aim of the pic.
  2. I can't do much of a before/after I'm afraid, having not done much before... The only form of before evidence I have is an image I took through a double glazed window in the daytime, which showed two things: As the shutter was fired by remote, the inertia of the mirror flipping on the dslr was enough to blur the image slightly, and The sensor on my camera is in dire need of cleaning I'll upload it in a bit - I don't have it stored on my phone...
  3. Yeah, maybe I ranted a bit about it I just see a lot of instances where people suggest trying something and are told it's not worthwhile, better to buy something - sometimes it's better, often it's just easier and quicker instead.
  4. I had no idea it had a name It's a good idea though, and one that deserves investigation and an experiment I think.
  5. Please read the following in the spirit it's intended, I'm in no way saying any one way is right or wrong, they're just different. In most hobbies, broadly speaking, the majority of people tend toward one of two camps. There are those who buy solutions, and there are those that make their own solutions. Obviously it's rare that anyone is completely one way or the other, but the tendency is there nonetheless. Take me (and my son) for instance - he (we) bought the 'scope - we could've gone down the beach, collected sand, smelted some glass, ground a mirror blank, coated it, rolled a tube (you get the idea) but instead a complete solution was purchased. When it comes to making improvements, yes we could go shopping, but making the solutions not only saves money for other things it also helps develop his skills - there are times that something needs fixing and you simply can't call on someone else. Now: I actually agree (except for the spending £ part - if you don't have them it's not an option anyway). If you're a "buy solution" person then buying this particular solution will leave you wanting. As standard, calling the mount and tripod borderline for the tube might actually be a bit generous. Thing is, if you have the money and desire to buy solutions and simply want to sit at the ep then more power to you - but the one thing I wholeheartedly disagree with is telling someone they're wrong to want to go a different route. I know I'm perfectly capable of making parts - casting aluminium, machining the blanks to tighter tolerances than mass production allows, that sort of thing - so the advice to "buy something else" kinda gets my goat a bit.
  6. Seems a bit 'financial' for my liking Steel legs are a future option though, I have a variety of interesting lumps of metal sat about so you never know
  7. So, those areas... Firstly, the spreader is attached with these tiny self tapping screws (well, they were, I replaced them with small machine screws) But that's still not good. I'm intending to put through bolts in instead so they definitely can't pull out and make the 'pod do the splits. The other part is where the legs join the top. These rely on the fit of the pivot bolt for location - if you tug on the counterweight bar lightly there is discernable play here - overtightening the bolts won't do any good... I may well ream those holes and sleeve them to remove the play. A more remote possibility is using one of the plastic lugs as a pattern to cast some aluminium ones which will remove some more flex - I'll probably see if that's warranted after sleeving...
  8. Wooden one looks nice. My concern would be stability with my son's ota mounted - I'd want something like an eyebolt up at the top so I could tie it to the ground and make falling over an impossibility. With a lighter (and shorter) tube the natural damping ability of wood would help a lot though. With 'mine', what I've done so far has reduced the shakes (looking through the ep, knocking the tube etc.) from almost 10 seconds to about 1 1/2, but it has highlighted other areas that need a coat of looking at.
  9. Let's go over all this again! Hopefully, one or two things might be a little different though The mount itself, I just followed the usual steps of stripping the whole thing down, cleaning, new grease and carefully adjusting to get everything as smooth and stable as possible. There are a couple of very small details that might be worth mentioning later, but I'll leave that as an 'on request' for the moment. By far the weakest area is the tripod. It's too lightly built, it's too flexible and with a 150PL mounted it just feels wrong. From my camera days I'm bringing the thought that lack of weight and stiffness = lack of stability. I always used to tighten all joints on my photo tripods and hang stuff off the middle to make it stable, so that's the route to begin with. Filling the legs with sand is quite common, so I got some play sand out of the shed and made sure it was nicely dry... A toughspot between the window sill and dining room table seemed the ideal location to me as it was over a radiator - I shan't write what the wife thought though... So, strip the 'pod and apply sealant to the leg caps Then fill with sand. But not just that, I put a length of 1/2" galv steel pipe inside too These central leg sections weighed 600g as stock, now they're a bit more portly I did pretty much the same with the outer sections too, which seems less common. The lower ends don't have caps though so the last inch or so needs flooding with sealant to hold the sand in, as do all the screw holes on every leg. In total, this added almost 6kg to the overall weight of the 'pod and whereas I could deform the legs with my fingers before, now I can't. More soon...
  10. So that random plastic cap type thing, that needs holes in... Using the original scale dial as a template is accurate enough for a handwheel, and then using that dial as a washer was the route of least resistance. That takes care of the 1:1 part (almost, I need to trim that flange off and put a grip on, and possibly flood it with epoxy or something maybe) and putting the original knob off the drive gives the 8.5:1 reduction. While holding the drive housing, turning the large cap (fast/coarse focus) moves the spindle 1:1 - with a little extra resistance due to having to spin the planets and sun, but it's still easier and smoother than the bare focuser was to begin with - while turning the little one a single turn (slow/fine focus) moves the spindle approximately 0.12 revolutions. As it stands, that's as far as I've got. I want a bigger 'fine' knob that's easier to grab, and there's the teensy job of affixing the whole caboodle to the focuser housing. Hopefully I'll get to at least some of that later today...
  11. To continue: The reduction drive needs modifying as it's limited in rotation to something near 280° (to match the limits of an average potentiometer or variable capacitor) - the method to achieve this varies, but on this one it was simply a lug on the planetary cage which I snipped off - now it carries on turning. I didn't take a pic of this, but it's not very interesting anyway. Inside should look something like: Now, turning the sun gives the reduced drive, but sticking something knob like onto the planet cage means it's possible to retain the 1:1 'fast' focus too. Another dig about found this random piece of plastic (maybe it was a lens cap at some time, dunno) Still, that's getting ahead of myself. So, the original knob needs to come off the shaft. It was a bit reluctant and needed heat, hitting and turning to break the threadlock compound, but eventually it unscrews. Careful here if you want to do this, the spindle is chromed brass (knobs are aluminium) so it would be really easy to shear on the thin portion near the middle if you just grab both knobs. This reveals a threaded portion of approximately 5mm, which obviously doesn't fit nicely in the 1/4" hole of the drive. Precision shim stock to the rescue: A few turns worth gives a nice tight interface (actually aimed for needing to screw the spindle home, which I got) and a nip on the lockscrew holds well. To be continued...
  12. But to get the same ratio of control it'd have to be 8.5 times the diameter, and that would mean the tube (and the viewer's head) would get in the way
  13. First published project here, so bear with me... This is being done on the stock Skywatcher focuser fitted to the Explorer 150PL, but it'd work the same on anything. Since my son got his 'scope we've managed two short sessions with it, and that's been plenty to discover how awkward the single speed arrangement is to use. Following the first go I stripped it down and cleaned out all the swarf and glue they seemed to use in lieu of lubricant before applying actual grease and adjusting the preload - which improved things massively but it could be better. So... A dig around in the useful stuff box produced this: That's an 8.5:1 ratio slow motion knob. Now just to drop out the shaft from the focuser. Will they fit together?
  14. Thanks guys. Seeing as sunny Wiltshire isn't so sunny today (and I don't see this cloud shifting any time soon) I've got the eq3 and tripod in bits to see if I can reduce the wibbly shakes a bit... I've got some improvement ideas that I've not found elsewhere yet - I can't say if they're unique (or any good tbf) but I'll see if I can find an appropriate section to stick a thread up about it.
  15. Thought it'd be polite to say hi - so hi! I'm normally pretty good at finding information myself, but I'm new to this and sometimes a question is more efficient than searching for something when you don't know what it is So my son has been on about wanting a telescope for a while, and for his 8th birthday last week he asked family for money towards one instead of random presents. We looked around and had almost settled on getting something like a skywatcher heritage 76 as a starter - that was until we went to a family member's house to try their 'scopes (skymax 127 and a random 76mm reflector)... Another look around and we got followed home by a used (well, pretty much unused) sw explorer 150PL with an eq3-2. It's my son's 'scope, but y'know, I've got to know how it works! For a start, I've got some tweaks planned on the mount and tripod to get some extra stability and we both want to try some imaging fairly soon (I've got a bit of background with photography and quite a bit of kit, just have to translate that knowledge... "just"...) Well, that's enough waffling for now.