David perry 1

Quick question before I fall foul of Ye Olde English over-engineering bug... I'm prepping the retracts for the Ju but as the original build wasn't made for them I have had to cut out some skin and rib and so am left with what you see. My intention is to add a ply plate between the motor bearers which stretches back to the aft extent of said bearers. This will be well glued in even possibly glassed around the bearers. On the other side, upper surface, I am not yet sure: I can add further lite ply ribs or struts or just pour in some poly foam and watch it expand! My question really is this: as the retracts came from a foam spit (big one, 70inch and 6s) and were only bonded to the foam and yet worked, is my plan here sufficient, overkill, or right (or just wrong). Size wize, the wheels are 3.5in and the legs are 5mm piano wire. I know it will work...but at what cost! I'm after experience - giants shoulders on which to stand if you like. Remember that this is a resurrection build...it was started 20 odd years ago and it is what it is. Ta D

Call me sceptical but I would like to see that prop flown because I cant see why it should self destruct. Ive used a lot of 3d stuff we have made here and when you TRY to break it its flipping tough. D

Other answers notwithstanding, it depends on your model. I have an eglider with a large folding prop and the roll against torque is a very leisurely affair but the roll with torque is most snappy! So it depends how fast you want to turn. I suspect that there is no "safer" way to turn unless youre perilously close to the stall. To which Id ask "why are you?"

Forgive me if thisnis a dupe byt Ive just heard that Eric Clutton has passed away. RIP old boy and thanks. David

Getting interesting. Im using the retracts from another, sadly now gone, model which will do the job but as I try to fit them I find the previous owner (and builder) hasnt really factored retracts in. A lot of work to be done to fit them, all do-able of course. It's making the modelling very interesting indeed as Im having to assess what can be removed, what must be removed and what needs to be left or replaced to support the retracts. Nothing to actually show yet but in a few days there should be. Digits crossed!

Ju 88

Nick, yes understood. I really meant apart from diff thrust....in this case specifcially. I cant see one hence my natural assumption that I'd use a Y lead. I think one Y lead, one missing red wire connected to a red wire of the joined retracts. i.e. each retract unit red wire pulled and joined together, then joined to an esc red wire. The the rx gets one red from an esc, and each retract gets 5v from the same, spare, esc +ve wire. Phew

John, dunno...just made sense to use one channel. A slave is also a possibility. Is there a benefit to using two throttle channels? D

Thanks D

I like the idea of separating out the retracts. Do you use a second rx for that?

Yes of course...an even better tip. Though, removing and reinserting a pin could lead.to future unreliability maybe? Good tip tho, thanks. Edit...ok, two for the same. Ill do that.

Ah clever tip about the y lead! Thanks

Can i just clarify please... To run two motors / two ESCs /two batteries on one throttle channel- BOTH signal leads and BOTH negatives go to the rx, ONE +ve lead goes to the rx. Crucially the +ve leads are not connected together. Only one of them feeds the receiver and servos the other is cut and insulated. Is that correct? David

Eric What esc did you use with those motors?

Started the process of filling in roughly cut pushrod slots and installing new servo boxes for flaps and ailerons. 9g metal geared servos will be fitted. They work.on my b24, should work here.

Eric cheers. I won dered about batteries in nacelles. Good for c of g. Needs a hatch then... Any photos of yours? D

Andy thanks. I was going to bin the pushrods but closed loop hadnt crossed my mind. Thanks for that. Okay on the rudder. I will check that against the plan. Trying to straighten the (thanfully unskinned) wing right now D

Just checked the wing and it might be that onenis badly warped. Its difficult to see and im tryingto fix it. Is the warbirds kit still in production should i need a new wing? Foam seems easier than built up! Call me lazy...

Prop clearance...a bridge yet to cross. Three blades. .four...therell be a way. Washout...i havent checked yet but my guess is yes. Somenof the glue has come away so im doing remedial work as i go. Just about to buy four 9g metal gear servos for flaps and ailerons.

Thanks!

Current weight. Just under 4lb.

I'll start a new thread... I have taken over a very old build, maybe 20 years or more, of the 1976 Roy Scott Ju88 bombermaschinen. Most of the construction is done, some sheeting left to do and the installation. As it stands - I will add photos - the flying surfaces are done. No retracts with it, a very interesting frame for the canopy and he nose glazing are all here. Whilst it is designed for 2x 30 glows I shall be electrifying it which is why I was dismayed to learn the target weight is 9 1/2 lb...I thought maybe 7lb, so 800 - 1000 watts would do. At nearly ten pounds even that kilowatt might be light... I hope to shave weight where I can now. I havent yet weighed it, so its hard to make an acurate stab. Thats this afternoons job. A few ideas...the pushrod and bellcrank system for aileron control is probably heavier than two mini servos. The full length push rods for elevator and rudder ditto. The tail wheel is more like naval plumbing and simply has to be taken out. I will probably replace with a plstic castoring t/w. Undercarriage is designed for the then standard electric retracts but todays will be lighter so I might go that route. Alternative is fixed or dolly. At this stage I am thinking lightweight electrics though. Any and all ideas and thoughts most welcome. Photos to follow (assuming anyone is remotely interested) David

Thanks Chris. 9 1/2 lb...wowee. I havent yet read the article but I had guessed at 7lb ish...an extra 2.5 is some fat! Ok on the new thread...will do that to avoid messing up the WB one. In fact I'll do it now... D ps. Not sure who the boys are or the right rev'd sweep...i"ll pull my mitre down hard and hope to get away with it.

Crickey...it is fast.

Late to the party but i have just picked up a second hand part built Scott ju88...it has been started for ic motors but i shall be changing to electric. What are those retracts usednin the mains? I had considered fixed gear because the ic build is probably heavier than an eflight version, but havent weighed it yet. Built up wing, no foam...and engineered like a ship. I will save a lot by stripping out the push rods and bellcranks i think...I shall use local servos instead. Im looking forward to this one. David