Jump to content

Andy Blackburn

  • Posts

  • Joined

  • Last visited

Recent Profile Visitors

The recent visitors block is disabled and is not being shown to other users.

Andy Blackburn's Achievements



  1. It's done. My conscience (such as it is) is once more as clear as can reasonably be expected. A.
  2. > not sure what you mean by ‘slight pull towards the canopy’ - I would say a successful CG dive test is one which has a gradual unassisted pull out Yes, same thing - been round power models too long... What I do for balancing is to get hold of a couple of used matchsticks and (for a low-winger) tape them to the top of the wing, aligned spanwise, at the required c.g. position. Then I turn it over and balance it on fingertips - it's not going to be more than a millimetre out either way. What I'll do (later in the week) is to move the c.g. on the plan to the 78 mm position with a note to say that it should probably be optimised using the dive test.   Edited By Andy Blackburn on 21/07/2020 08:51:45
  3. OK then, that all sounds very reasonable; I have my hands full for the first part of this week but will try and get some updated files to Phil before next weekend. I take it that we are all certain that 7 mm (85 mm - 78 mm) is the correct amount to move the c.g. forward? If you do a dive test (useful as a general reference even if you don't really believe in it) then there should be a slight pull towards the canopy... A. P.S. - hoping to get up to the Orme before the end of the year, Covid and accomodation permitting...
  4. > I will check the decalage before the next flight and add some more weight to the nose. Hi Jez - all that would be really helpful; I did move the c.g. forward from the original plan (partly because I have my c.g. on the smaller one fairly far back anyway), but obviously not enough. A.
  5. Well, this is - frankly - shocking. One just can't get the staff. My apologies to Jez for the unnecessary excitement. I'll make the appropriate changes to the CAD files and re-issue the plan to Phil. It'll take me a week or so because I have my hands full at the moment... A. P.S. Pete - you built the first JP, did yours need the c.g. moving forwards as well?...
  6. I hadn't noticed that (or the glass) - well spotted. I might try that technique... A.
  7. Top planking tips, particularly liked the one about "Nobody likes planking. Well that is nobody who has done it before likes it! Regardless of what people may say it's not therapeutic! It's tedious, time consuming and will draw blood!". I've never had the blood but everything else is right. . Helps if you put the radio on and kind of get into the zone. Speaking persoanlly, I use medium CA (new bottle) to glue the planks to the formers and Titebond for the plank-plank joints, so I don't have to bother with pins much. I think I tend to slightly over-sand the chamfer on the plank (by feel, with a permagrit block) so I don't get any gaps. In the past I've tapered the planks so that they're narrower at each end, which means that you can use wider planks but that's another 2-minute process added to installing each plank. Might use the parallel-plank method on this one. I've never had a twisted fuselage but then I've always planked when the fuselage halves are already joined, adding each plank on alternate sides - by the time the top half is done, it's more-or-less completely rigid. (Can't start my F-86 yet, just doing a Peanut. Shouldn't take long, though...) Edited By Andy Blackburn on 12/11/2019 08:22:08
  8. Posted by Peter Garsden on 27/10/2019 19:00:19: Posted by Andy Blackburn on 25/10/2019 19:50:35: Posted by Peter Garsden on 23/10/2019 20:13:47: Sorry Andy - have now covered the wing. I can weigh everything though if you wish? OK, no problem - if you could maybe weigh the covered parts without the radio, that would be great. I can make allowances for the covering (Oracover, I assume?) Just weighed it at 65.8oz or 4ilbs 9 oz. Here is a picture so you can tell how much solarlilm there is. There are 2 servos in the wings but no servo or battery in the fuselage. Will now look up the surface area of the wing to work out the wing loading - it is 3.8 square feet which is 17.8oz per square foot - bit more to take account of the rest of the solarfilm and the battery. Edited By Peter Garsden on 27/10/2019 19:08:39 That's looking pretty good - it's only just over 4lb so let's call the final weight about 4.5 lb, maybe 4.75 lb with a bit of nose weight, so even though it's about 60" span I'd say you're probably looking at 19-20 oz/sq ft. Perfect! A.
  9. > Things have moved on a bit since then and I am wondering what model would be best for very light wind (12mph or less) slope soaring. Well... 12 mph isn't really what I'd call "very light", and it depends whether you want to build something in the traditional manner or assemble some glassfibre parts. If the former, I'd drop a line to Phoenix Model Products to see what they recommend. However, if you want to assemble something glass then I'd try a Mini Ellipse - they're really good on normal slopes, will fly in a few (single digit) mph and are ballistic if ballasted. If neither of those floats your boat, almost any DLG will be fine (but might be expensive if you buy new) but unless they can take quite a bit of ballast they are unlikely to offer the same overall performance as a Mini Ellipse. Just my two penn'orth...
  10. Posted by Peter Garsden on 23/10/2019 20:13:47: Sorry Andy - have now covered the wing. I can weigh everything though if you wish? OK, no problem - if you could maybe weigh the covered parts without the radio, that would be great. I can make allowances for the covering (Oracover, I assume?)
  11. Looking good, impressed with the dashboard. Any chance you could weigh all the structural bits before you start covering, please...? A.
  12. Where Eagles Dare (because it's a rip-roaring yarn) Kelly's Heroes ("Mulligan!!"..."Did you lose my aerial photographs?"...) Saving Private Ryan (no explanation necessary)
  13. I don't suppose you've weighed it yet, have you?...
  • Create New...