Winter build project: Wolfgang Matt’s ATLAS

The Biplane is his Citrin probably from around 2010 or 11, still flying competitively now so more modern than the Miss Wind

I think the first f3a biplane was around early 90's

I'll rightly be accused getting off the subject but this topic has illustrated an encouraging resurgence of interest in woodwork and I couldn't resist sticking in this illustration of fine craftsmanship in wood and dedication to a challenging subject so there is a little synergy here:



There must be an easier way to loose your marbles!

There is not much more I can say other than... Wow.

Blimey, just to come up with the idea and then to work out how all the timings and interactions are going to work is just wonderful. Thanks for finding it and posting David, I remember being mesmerised by my dad's ball bearing clock when I was a kid, this is on a whole new level.

There's not been anything new on this thread for a while, so I thought I'd see any anyone can see any flaws in my thinking with regards the correct axle positioning of the main wheels

I'd originally established my ground level and mocked up the retract on the plan to get my measurements:



But this morning it occurred to me that the wing has dihedral and is tapered from root to tip, so any measurement at the root of the wing as I have been doing on the plan is inaccurate.

When Mike kindly sorted out the foam cores for the wings, he built in both the wing taper and the dihedral, so I've measured the bottom half of the foam core waste at the retract position and at the root.


The difference being 11mm (94mm & 105mm) and plan to add that to my original measurement I took at the root down to my ground level (minus half the wheel diameter)

Does this all sound about right?

That all sounds fine...the bottom of the wing does have a lot of dihedral in order to accommodate the 8mm on the top. However, I did not take this into account and ended up ok.

You wanted a positive angle of attach anyway, you might have just got a little more than you planed for. Does the Blue Angel have 0º angle of attack or negative, I'm assuming it was the sticking to the ground nature of the Blue Angel that made you purposely build in a positive angle of attack for the Atlas. All the similar MK plans seem to indicate the undercarriage is set to give 0º wing incidence to ground level.

TBH, the Atlas appears to sit a little more nose down than the Blue Angel. I don't have incidence meters so cannot tell you how they sit in degrees. The nose-down attitude of the Atlas is possible an advantage for landing...it tends to bounce less...but both are very similar and it's early days yet.

With reference to the Curare and other trike gear generally, Jon told me that the comp boys used to have nose down attitude to help stick it down and avoid bounces on landing.

Don't worry Chris!! They will soon be out of shape after a few heavy landings

Very true Pete, and I'm probably doing my best to over think things, but this being the first plane I've built I've not yet got the experience to say 'that will be fine'.

That's interesting to know, thanks Phil.