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IBob

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IBob last won the day on January 26

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About IBob

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    Well-Known Member
  • Birthday 04/22/1948

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  • Location
    Wairarapa
  • Country
    New_Zealand

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  1. IBob

    Why I don't fly now

    That's hard, Ian. I've come to my flying later in life than many. I hope the years allow me a few hundred hours, for all that. All the best.........)
  2. IBob

    Flying Club Sign

    Indeed, and nowhere..........NOWHERE.......does it warn against the risk of placing fingers over the holes while viewing!!!
  3. IBob

    Rotax 912 Coolant

    Downunder, I had seen that, but only in passing. I find I have tended to focus mainly on what comes next, rather than All Of It with the build: less than ideal in some ways, but All Of It has sometimes felt overwhelming. But what comes next will be the first runup in a couple of weeks. So time for me to focus on that, and thanks for the reminder.
  4. IBob

    Rotax 912 Coolant

    First new engine run not tooooooo far off now. Time to be sourcing various vital liquids. And this site continues to give a wealth of practical information. Thanks to all.
  5. IBob

    Bolly

    For sure the maths needs to be a bit fancier than 1 in 60 if trying to set an exact known angle using stick and floor measurements. But it should be fine for 'a bit more/less' type adjustments, and for checking that all blades are pitched the same.
  6. IBob

    Bolly

    PS Fallowdeer here suggested using a laser pointer mounted to the blade, intead of a stick. Assuming the mounting was a neat fit on the blade, it sounds like a good idea to me..........
  7. IBob

    Bolly

    I'm about to pitch a prop for the first time. The Bolly manual details several methods. They describe the stick and measure method in some detail, with the comment 'this method is so simple, no-one thinks it is good enough'. On the Sav, the floor measure per degree will be in excess of 20mm. So if I can set the blades to get the stick within 1mm on the floor, they will be within 0.05 degree of each other. I just spent some time online trying to locate the specs on smartphone inclinometers. I was looking for resolution of plus and minus x degrees; drift due to temperature and other factors; and repeatability, which is with what accuracy the instrument will keep giving the same result when returned to the same angle. I had no success at all: these numbers are certainly not advertised up front. What they do seem to do is fudge round the question by stating the phone/instrument reads to within 0.1 degree. This is essentially meaningless: an instrument with a readout to one decimal place will always give a readout to one decimel place regardless of how accurate it actually is.
  8. IBob

    Bolly

    Yep, that...and gravity...are wonderfully reliable things.....)
  9. IBob

    Bolly

    I would check the phone inclinometer carefully before doing that: I had a microwave dish installed a while ago, the tech waved his phone at the little hokeystick mast, then when it came out ridiculously out of plumb, I passed him up a spirit level................
  10. IBob

    Another NEW Savannah S on it's way in NZ

    Blueadventures, and Kyle Comms, thank you for your input. This is my first and only build, so I have nothing to compare it with. What happens with those corrugated pipes is that they can be formed into surprisingly tight bends where necessary, and they just stay there. So they lend themselves to the manufacture of quite precise shapes, though I lost a fair bit of knuckle skin here and there, as some of those shapes have to be formed in situ if they can't be threaded in after forming, and you have to get quite physical with the larger stuff. We were initially nervous about it here too, Mark: it first appears in the build for the fuel lines in the wings. But it seems to be surprisingly strong and durable, and we assumed that if it was failing we would have heard about it: my kit left the factory Dec 2014 and they are still supplying it. My other thought was that there must be considerable pipe losses due to the corrugations, but I guess they factored that in, and most runs are either short or low velocity. The result, when combined with my unusually high exhaust pipes, has been very compact, and the cowlings went on easily with clearance all round. Rubber replacement, when it comes, will probably see a few more barked knuckles, and will probably be most easily done by dismantling the whole lot (and there's actually not much of it) rather than hoping to reach in and do this pipe then that pipe. I guess I'm going to find out! Thanks for the heads up on the cable ties, Mark. I assume you are referring to the ties on the larger pipes on the RH side? I will look for something more durable there. I went through bulk ties as I routed then rerouted, fastened then refastened stuff, working out how to fit it together mostly neatly. But it will be simple enough now to replace ties in vulnerable areas, as you suggest. Blueadventures, yes the fittings on the oil cooler are surprisingly large. Fortunately the Sav has a prop extension up there, so there is more than enough room. I like very much the look of those alloy pipes. I guess you could say the corrugated pipes ICP supply are a DIY version of that; as noted above, I'm hoping they prove as durable!
  11. IBob

    Another NEW Savannah S on it's way in NZ

    Hi Dan and thank you for your kind words. I'm pretty happy with the way the Sav is coming together, for a first try. (And I'm sure anyone who ever built one, or any aircraft, come to that, would do a few things differently second time around...not that I'm planning one!) And thank you for the pics: it surely all helps add to the general picture. Since my previous posts, above, I have made progress. In the case of the exhaust, I have turned the No1 cylinder coolant pipe out well to the right, and shifted the pipes as far to the left as they would go with available play. The result is a small gap between coolant pipe and exhaust, but enough to avoid contact and fretting, I hope: I will need to keep a close eye on this, certainly during initial running. (I will also be watching carefully for coolant leaks, as I have had to move two engine pipes and 3 pump pipes, and two in particular were moved several times.) That part was completed by purchasing and fitting an extra length of coolant hose from pump to No 1, as the original hose was now far too short. Should I have further issues, I will set about modifying the No 1 exhaust pipe. With that done, I have been able to complete the remaining plumbing and wiring. And with the exhausts tucked so high, fitting the cowling was a breeze, with clearance all round. I am presently fitting the prop (so many things I have never done before, so much still to learn). I am waiting on delivery of the oil pressure gauge, the panel is all built and wired but still on the bench. Once I have that in, (and no doubt a number of other bits and pieces) I'll be ready for engine runs etc, then some time later I take the various pieces to the airfield and bolt them all together. I'm deliberately not setting any deadlines, but I just the other day reserved the registration, and it's looking like i'll see air under the wheels for autumn.....) In other local news, Perry is putting hours on his new S, Peter has begun the build of his (but only when the weather grounds his VG) and Hank has also made a start. Good to hear from you and hopefully you're getting some sky time. Go well. IBob
  12. IBob

    Rotax 912uls oil level

    Because some of the oil is then remaining in the engine....until you burp it.
  13. IBob

    Rotax 912uls oil level

    Hi DGL, there may be some misunderstanding here: The Rotax is a dry-sump engine , with the bulk of the oil held in the oil tank. However, after running, residual oil in the engine will drain down to the sump of the engine. With oil still in the engine, you cannot accurately check how much oil is in the entire system. Futhermore, if large amounts of oil pond in the bottom of the engine for whatever reason, the engine may be damaged on startup. For this reason, the standard drill is to manually turn over the prop until a gurgle is heard from the oil tank: this indicates that the engine sump is now empty of oil. (the gurgle or burp is the oil pump passing air because all the oil is gone from the engione. With all the oil back in the oil tank, level can now be checked. And the engine can be started without risk of damage from excessive oil. So. When burping the engine cold, the oil level in the tank will go up. If, on burping, the level is too high, then there is too much oil in the engine.
  14. IBob

    My Savannah S model rebuild Blog

    Big job, Mark...very I found the sheets so much easier to store and handle when rolled...though also gave myself a nasty gash when one of them partly unrolled during handling. I used rivnuts instead of rivets when closing off under the fuel tanks, as I know you did. When it comes to rubber replacement, I'm thinking I will cut in the inspection hatches that are part of the newer kits, rather than unscrewing the whole lot. I see you using a diamond(?) wheel there. Is that a better option than a nibbler?
  15. IBob

    Updraught cooling

    I just revisited that: Aluminium has somewhere between 4 and 6 times the thermal conductivity of steel (depending on steel type). (And pure silver has twice the thermal conductivity of aluminium, so if born with silver spoon in mouth, be sure you didn't stir your tea with it first!)
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