Dave Cooper 3

Hi E.D. That price sounds more than reasonable if it's a good unit. Just been on Jet Hangar's site (jethangar.com) and they advise 80-100% of Fan Swept Area (FSA) for inlets and 70-80% for outlet. They do warn about cheap Chinese clones of their product, a number of which have failed in service....You pays your money....etc. There's a formula for calculating FSA under the "EDF Rules" heading. It does look like it's a compromise between take-off power and top speed. As I'll have 2 inlets and one outlet I'll have to get the calculator out ! Hope to get bench testing soon...one or two other projects to finish first. Dave

Good to hear the thrust should be OK. The "Banggood" 12 blader looks good - couldn't see a price on the ad' though. As my model is EPP I was just wondering if this would have some sound absorbing qualities. Presumably, I'll have to conjure up some form of thrust pipe as well ? Rolled ply /balsa sheet ? I'll have a look at the Youtube videos on balancing as well... Dave

Yes, thanks for that John - quite a few of our sites are noise-sensitive. I will test the unit and see if the neighbours complain first ! A '12-blader' may be more appropriate anyway - more efficient ? extra thrust perhaps ? A real learning curve for me... Dave

Thanks for the reply E.D. A trip to the workshop has now revealed : Fan: 6 Blades - 75mm diameter Motor - 3500KV (QF 2827) Fuselage width - 70mm and depth 100mm. (measured at approx. C of G). Width could be made wider with air intakes to accommodate the fan unit Weight : approx. 2lbs (without LiPo and without fan unit). I would imagine a 6s may be needed to give reasonable flight times ? The model was designed as a PSS glider, so, an EDF version would need some mods ! I will bench test the fan soon to see how it sounds /performs... Dave

Hi, I have recently acquired a brushless EDF fan unit and a PSS Aermachi model at an auction. I think the fan unit is an '8-blader' and the jet model is about 51" span. I was intending to fly it PSS to start with and, later, convert it to EDF. What data would we need to decide whether it was suitable for conversion or not ? I have in mind : Model weight, KV rating of the motor, fan diameter, fuselage width /depth at the CG for starters.....anything else ? Thanks for any assistance (only previous 'jet' experience is with "Jetex" models as a young lad !) Dave

Castor Oil - the word superceded should be spelt "superseded" (from the word supersession)...I got 'picked-up' on this whilst at Airbus, by the Quality Assurance Team, writing the requirements spec' for the A350's wing ! Compliments of the season everyone... Dave

All very mysterious....status, profiles, public, friends, clicking etc etc. Tutorial anyone ? (I'm not volunteering by the way !). Thanks to all the contributors so far... Dave (for testing purposes 'status' = "Improver Mark 1" sadly, no 'friends' as yet)

I don't think I've ever seen a member "On Line" notification on this forum, but, will pay more attention in future ! We live and learn it seems.... Dave

OK thanks eflightray - I'll try something....

If there's a Moderator around, the posts are now repeating whilst the 'post counter' does not seem to be incrementing Even more confused of Wiltshire.....(sorry to be a pain everyone !)

Ron - such as what exactly ? Do I just make something up, or, are there 'standard' status's (stati ?). Where else does it appear on the forum once set ? Confused of Wiltshire...!

Just found the blank "Edit" box....but, really, none the wiser ! Allowable settings ??? Dave

Under "My Friends" on the Forum home page it tells me to 'set a status'... How does one actually do this ? I can't find any relevant help anywhere on the forum or am I becoming myopic ? Dave

Hi All - a quick update : Having just finished working with the builders to level my garage floor and applied the (very expensive floor paint !), I can now get my modelling projects back on track... (Andy mentioned an interest in motorsport in an earlier post - so, the level floor is for my 10% wind tunnel. This to give me key lift /drag data for a Le-Mans style sportscar that I'm building. Also, it now gives me reliable 'datums' to take chassis measurements from). So, finally dug out the plan for the JP and it's a Roger Howells' design for a 40-size power model. About 47" span, and, prettymuch-true-to-scale. If I can keep the wing loading to a reasonable level, it might just work as a PSS job. Wing section looks OK(ish), but, yet to verify the actual section. Will probably need some tip washout to make it nicer nearer the stall plus some lead up front in lieu of motor /fuel etc. Anybody tackled anything similar ??? Dave

I think the worst-case scenario is late cut-off of the BEC. This happened to myself and a friend when we built the HobbyKing Phoenix 1600 electric glider (this is our club's chosen one-make competition machine). The motor is a modern brushless with a programmable ESC and a 2s LiPo. His model crashed (fortunately without too much damage) when he ran out of radio contact and he immediately phoned me to check mine. The motor and ESC are supplied with the kit. I tested mine on the bench and had a max.of two or three control movements just as the motor was running down. None of the other kits had this problem and came from an earlier shipping 'batch'. After some more bench testing, HobbyKing supplied a replacement ESC...the first job was to 'calibrate' the ESC to the motor, the second was to set the prop brake (using their instructions). Next, I took a LiPo that was down to about 50% capacity and timed a 'dummy' last flight until I was satisfied that I had enough range and control movement to safely land the glider. The moral of the story, IMHO, is to know the limitations of each model /installation and use planned flight duration times if there is any doubt...Happy flying everyone ! Dave