Lots of Advice Needed Please !

[mike newall]

Gents,

My Bro and I have just acquired G-AVKI from Mick Greenway.

95% done, 50% needed to complete !

Seriously, it is nearly a bolt together and fly project, however there are one or two things we need to discuss.

1. Oil Cooler - we have a Sauer 1800 engine out of a Falke. No inverted, Ellison throttle, no filter. Do we need a cooler, if so, do we need outlets in the cowling (std Barry Smith) or does the airflow take the cooling air out at the back, rather than the bottom?

2. Baffles - does anyone have any plans/templates/suggestions ? We have some bits made by Mick but don't have a clue as to where they go. We are also building a Vans RV7 and have just done the baffles on our IO-360. That was 2 weeks work !!!

3. Mags - we have a Bendix, boat anchor, dual mag that hangs through the firewall into the cabin. It has a stainless box that surrounds it to preserve the integrity of the firewall. Is this a problem ? How do you you cool the mags ?

4. Canopy - how do you seal below it ? P seal ?/ foam rubber ?/sorbo ?

5. Under wing panels - are you using plain perspex with cut outs for the throttle ? - we have 2 curved, molded thingys but they don't seem to fit anywhere !

6. Ballast - why do some Nippers need lead in the tail ?

7. Radios - where are you all putting the aerial ? We intend using an Icom via an aircraft mounted aerial. Where are you putting the groundplane ?

8. Behind the seat - we have no structure or cloth screen - what are you guys attaching the fabric to, to form a closure behind the seat ?

Thanks in anticipation - I am likely to be the main contact in our partnership, however I am not sure I will do much flying - I can't fit into the friggin thing ! I am 6'1" but with long thighs - I have tried but my knees jam against the corners under the spar and I can't get full pedal movement without severe contortions. No, we haven't done the seat mod...... No we haven't done the rudder pedal mod - all too late as we got the project almost ready to fly.

Oh, well, at least I can fit in the RV7 !

Regards
Mike

A330 for a living, RV7 as therapy, Citabria for pleasure

[G-BYLO]

I'll post my thoughts on a few of these!
3. the bendix mags on my engine sound similar and have no cooling
4. I've used P seal with a poorly fitting frame- the current nipper just has a close fit frame with a bonded canopy
5.yes, and the faring is stuck on the outside- have a look at a few nipper pictures- many owners have dispensed with this as they come loose- the throttle position can also be changed.
6. Depends on the w&b- c of g has moved forward for this type and I suspect it wont be required
7. either on the tailplane faring- if aluminium or on the turtledeck with a foil groundplane inside. you can also mount the aerial on a plate inside the rear fuselage- attach plate with p clips to fus tubes
8. either superseam the fabric to the first hoop, leave it open or make a fabric bag/curtain that attaches with tie wraps or similar to the first hoop/stringers- I suggest the latter 2 otherwise access for inspection is difficult

[G-ARBG]

Mike,
In reply to your various queries:

1. I have only ever come across one other Nipper with a Sauer engine (SE-XPF) which I believe had an oil cooler (but no starter). Are you retaining any of the self start features from the Falke (pull or electric) ?
Nipper MK III’s fitted with the standard Ardem had no oil cooler fitted and indeed the oil temp gauge was deleted as “no longer required” in 1967. I am advised that larger engines do in fact run hotter than the original 1600cc Ardem and consequently an oil cooler may be desirable. However an oil cooler is not fitted in my aircraft which uses an 1834 cc modified Ardem and the oil temp does not exceed 80C. So as long as I fly in UK then I do not intend to fit one.
2. I can send you photos of the baffles I have made for my aircraft based on the original Slingsby pattern (see my photo on this site) and may still have the old ones which I could loan you but I suspect you have already learned from the RV that they can become very personalised even if you follow previous patterns.
3. Having fitted a bendix D-200 mag to a Nipper (G-ASXI) myself in much the same way as you describe I found it unnecessary to provide further cooling (see photo attached).
4. Slingsby canopies were ‘sealed’ using a simple rubber section but there are obviously ways to get a better seal and finish (and save weight?) using same techniques used when fitting glider canopies (se G-BYLO for example).
5. Under wing panels are necessary closures for the wings and are normally simple flat Perspex panels cut out to clear throttle, pressure gauge bracket and aileron pulley brackets. They are supported by the two little ‘tabs’ welded to the longerons, screwed to the wing and slid into joggled metal fitting at the rear edge. They need to be of a thickness to match the wing recess.
The curved mouldings fit over the throttle linkage port side and are usually added to the stbd side to ‘even things up’.
6. Ballast – All Nipper MK III’s carried three shaped lead ballast weights in the tail of approx 3lbs each. These ballast weights are not always present because CG positions have changed with modifications to the aircraft. The Ardem weighed 158lbs, what does your engine weigh? If your aircraft is already covered then it is not possible to fit ballast iaw the plans without having to remove fabric to expose the sternpost.
7. Radios – I carry an Icom attached to the spar with a rubber duck aerial. It works! Alternatively you can follow previous advice or fit it under the belly on a ground plane of kitchen foil. Either a metal or the rubber aerial work OK here although a metal aerial is more likely to get damaged. I have tried using the metal tailcone without the same success.
8. Having bought my Nipper without the fabric closure behind the seat I was going to do as Mike has on G-BYLO but decided instead to trim and attach the bag to the frame using Velcro. The bag now accommodates my original Pooley’s flight case and hence all my loose gear whilst doing aerobatics.

Regards,

David G-ARBG[attachment=0]Nipper - mags1.jpg[/attachment]

[G-ARBG]

Herewith another attempt at photo of my D2000 magneto installation on G-ASXI when it had VW engine,

R.

David G-ARBG