Jump to content
Please be aware of scammers when using the Sale/Wanted forum areas

John Roberts 9

Members
 View Profile  See their activity

  • Posts

    372

  • Joined

  • Last visited

 Content Type 

Everything posted by John Roberts 9

  1. John Roberts 9

    CNC Wood Pack

    John Roberts 9 posted a gallery image in Member Albums

    CNC Wood Pack
  2. John Roberts 9

    CNC Wood Pack

    John Roberts 9 posted a gallery image in Member Albums

    CNC Wood Pack
  3. John Roberts 9

    Extra Wood Pack

    John Roberts 9 posted a gallery image in Member Albums

    Extra Wood Pack
  4. John Roberts 9

    Extra Wood Pack

    John Roberts 9 posted a gallery image in Member Albums

    Extra Wood Pack
  5. John Roberts 9

    Extra Wood Pack

    John Roberts 9 posted a gallery image in Member Albums

    Extra Wood Pack
  6. John Roberts 9
    Thanks for the reply Ian. My plans arrived today and I can visualise exactly what you did from your description. Although I haven't taken any measurements yet it looks as though it will be necessary to construct a mounting box on the front face of F1 in order to get the electric motor into the same position as the IC motor. This should assist with the CG issues. It might also be possible to cut a rectangular hole into F1 to allow the LIPO to be positioned further forward (into the motor box) if necessary. My compliments to HMS on the extremely prompt delivery of the plans & balsa. I don't feel that the "Complete Set" offers especially good value for money. The extra wood pack in particular is, frankly, pretty sparse. Having said that, buying the complete set is a convenient way to get building quickly for those who don't already have a stock of balsa. Photos of what is included to follow tomorrow. Cheers, John
  7. John Roberts 9
    Thanks Ian for confirming the battery location issue. I agree that a removable canopy would be vastly superior. Having to take the wings off before and after every flight gets 'old' very quickly. Do you happen to have any photos of the mod on your extended nose version? As soon as my plan arrives I will try and work out a suitable mod and post my thoughts here. I also agree that the all inclusive plan & wood pack *seems* expensive but I will reserve my final judgement until the packages arrive and I can assess the quantity & quality of what I receive. Again, I will post my thoughts & photos here to help inform others who might be thinking of buying the package. David. What a coincidence. I too have an Evolution Fusion to build and I will shortly have to make a decision about which one to tackle first. As a kitchen table builder I can only have one build on the go..............trying to do 2 simultaneously wouldn't be wise! Cheers, John
  8. John Roberts 9
    Thanks Ian and Ian for the additional information. I have decided to go with the HK G15 motor and (hopefully) fine tune the CG by battery positioning. I have just managed to place my order for plans and wood after wrestling with the MyHobbyStore web site for 45 minutes (/sigh). Hopefully I can start the project in a few days time. A couple of questions for those who have already built an electric version please. First, I assume that battery insertion & removal requires the wing to be removed? And second has anyone done a fuselage or canopy modification to enable the battery to be top-loaded to avoid the wing removal chore? Thanks, John
  9. John Roberts 9
    Hi Steve, Very sorry to hear your bad news. I guess that it could be down to the carbon tube flexing wildly. My Whiz Kid ended up with a boom which is just over 20 inches long. The carbon tube I used was also 6mm (external) but the wall thickness was 1mm giving an internal diameter of 4mm whereas your wall thickness is only 0.5mm. Oddly enough I flew mine yesterday (very sprightly it was too with its larger prop - see my earlier posts for more details) and, whilst I have always had slight concerns about the length and flexibility of the extra-long carbon boom, it flys nicely. Do you intend to rebuild yours? Earlier posts in this thread suggest that a 7mm x 5mm boom might be a better choice although this was recommended to assist with CG issues rather than flexing. Good luck. Cheers John
  10. John Roberts 9
    Posted by Ian Jones on 18/10/2013 18:23:54: Mine was originally built by someone else for IC and I rather uncharacteristically converted it to electric. As you can see it needed a lot of weight on the front. Some years ago now and can't remember what the problems were except that it seemed rather unpredictable. It showed the same weak spot a Kevins did in a hard landing though the damage was less serious on mine. I passed it on to someone into electric flight but haven't seen it since. So I too would recommend beefing up the fus above the wing and it may also be worth planning ahead re weight distribution. Ian Hello Ian Thanks for the photo and comments. It does look like it is carrying lots of lead ballast at the front. Do you have any recollection of the motor/ESC/battery combo you used? On the face of it the heavier motor suggested by Sparks LINK might be the preferred choice for my build. Cheers, John
  11. John Roberts 9
    Hi Sparks Your thoughts on motors are interesting, especially the weight comparisons with the IC equivalents. Like you I don't want to end up adding weight to the nose in order to get the CG right. The HK motor that I was leaning towards is about 50g lighter than your suggestions so it would be helpful to know from others who have already built a Mini Jazz how the CG turned out. Particularly whether additional balancing weight was needed on the nose or the tail. The other issue to factor into this consideration is the weight of the LIPO battery & ESC. I intend to use 3S 2200s in mine because I already have lots of them. My expectation is that the combined weight of a 2200 (180g) and an ESC (around 50g) will probably weigh more than a tank of glow fuel and this ought to compensate for the relative lightness of the electric motor. Thought and observations from others gratefully received. Thanks, John
  12. John Roberts 9
    That cowl looks spot on Roy . I am pleased that you got it sorted out. Cheers, John
  13. John Roberts 9
    Hi Robin, Ideas about the Mini Jazz, including my own thoughts on possible power trains are being posted here . Cheers, John
  14. John Roberts 9
    I am just starting to think about my build, especially with regard to a suitable power train. I have a 300 Watt BRC motor lying around already LINK which might be suitable. Oddly, despite the motor reference number (2814), this has a diameter of 35mm rather than the implied 28mm. Another option, which I am probably more attracted to, is a 12 quid HK offering LINK. This is the same size (35mm) and weight (102g) as the BRC motor but, if the quoted spec is accurate, should produce around 400 Watts on a decent 3S LIPO. With an anticipated all up flying weight of around 2 pounds this should be pretty lively Speed controller will be LINK if I use the BRC motor (just because I have one in my spares box) or LINK if I go for the more powerful HK motor. Servos will probably be some TowerPro MG90s LINK because, again, I happen to have a few in my box. More than happy to reconsider any or all of this in the light of more informed opinions! Cheers, John
  15. John Roberts 9
    Roy, If your cowl doesn't turn out right do you really need to go to the lengths of rebuilding the fuselage? I would be inclined to remove the cowl, cutting it off flush with the front face of F1. You can then dispense with the X mount and re-drill F1 allowing you to attach the motor directly to it as Chris & I have done. Then its just a matter of constructing a balsa box around the motor using scraps of balsa and some triangular fillet pieces. Sand to shape and the job is done . Of course without seeing a picture of your build/installation I can't be 100% sure that my suggestion will work but I would give it some serious thought before ripping the fuselage apart and starting again. Good luck! Cheers, John
  16. John Roberts 9
    Hello A couple of detailed close-ups that might assist. Cheers, John
  17. John Roberts 9

    John Roberts 9 posted a gallery image in Member Albums

  18. John Roberts 9

    John Roberts 9 posted a gallery image in Member Albums

  19. John Roberts 9

    John Roberts 9 posted a gallery image in Member Albums

  20. John Roberts 9
    Hi Roy, The cowl was a bit fiddly to make. The plan suggests using a shaped motor surround carved and sanded from a soft balsa block. I decided against this method. Instead I extended the length of the fuselage sides so that they formed "cheeks" either side of the motor. The gap between the inside faces of the cheeks is 30mm which leaves 1mm clearance on each side of the motor which is only 28mm in diameter. I then used soft balsa blocks above & below the motor (glued between the extended fuselage sides) with 4 small pieces of triangular balsa glued in the corners. Viewed head on this produced an octagonal shaped cavity with a diameter of approximately 30mm and the motor sits comfortably inside. Being fussy I also used a bit of broom handle wrapped with sandpaper to make the cavity more circular and also to give just a tad more clearance around the motor. The exterior shape of motor surround was then achieved with a small plane and sandpaper. At a guess the minimum wall thickness in a couple of places is a bit less than 1/8th but generally it is quite a bit more and once covered it seems to be very sturdy. Incidentally I didn't use the 'X' shaped aluminium motor mount (it was too big to fit easily) preferring instead to locate the motor directly onto F1 with 4 short cap head bolts passing through the rear of F1 & which can be easily accessed from inside fuselage cavity. All of this is far more difficult to describe than it was to execute in practice. I will try and take a couple of photos and post them here later which might help with clarity. Cheers, John
  21. John Roberts 9
    Mini Jazz for me.
  22. John Roberts 9
    I wouldn't stick rigidly to the top 6 going through to the next stage. If there are, say, 3 contenders that each got a decent percentage of the vote and the rest have comparatively few votes then we should go forward with just the top 3. As BEB points out, the figure of 6 was chosen arbitrarily. For the next round of voting I am inclined to go for a 'first past the post' wins but I would be very happy to compromise and have 2 choices if we ended up with 2 models being closely matched in terms of final votes cast. I think this approach may well encourage a greater number of people to participate. Speaking personally, if an "oldie" (TM kevin b ) model won I would be less inclined to participate but if I had an option to do an "aerobat" instead then I almost certainly will have a go and I am sure that vice versa applies to quite a few other potential participants. Cheers, John
  23. John Roberts 9
    Hi Steve Congrats on your model, it looks great Hope the maiden goes well...................I found mine to be very gentle and easy to fly. Let us know how you get on. Cheers, John
  24. John Roberts 9
    Yes please, I'm in Thanks John
  25. John Roberts 9
    Hello   Well the test results with different sized props were very revealing.   I used a 3S 800mah 30C GensAce battery and got the following results:   7 x 4 = 10A / 116W 8 x 4 = 13.2A / 149W 8 x 6 = 19.6A / 212W   The motor is a Hobby King 2826-10 1400kv LINK. Good value at under seven quid.   It looks like the 8 x 4 could represent the best all round compromise in terms of power and flight duration but the 8 x 6 appeals to my inner-hooligan .   As soon as we get a dry & calm day I will try out both set ups and report back again.   Cheers, John Edited By John Roberts 9 on 02/10/2013 16:02:58
×
×
  • Create New...