Jump to content

Traditional Wot 4 Mk3 Build - Suggestions Please


Scruffmeister
 Share

Recommended Posts

Thanks Richard good to hear . I thought the air brakes may "add interest " although we don't need them as our grass strip is long. I might have fitted them on my Acrowot though as that does run on a bit in still conditions . It's really whether they do much. I'm not a great fan of torque rods in wings , so will certainly be using separate aileron servos. If I don't put the air brakes on I might put in a tow hook so it can pull up a small glider?

Link to comment
Share on other sites

Advert


That's a much more powerful engine than actually required so make sure you read the extra instructions about reinforcing the tailplane for use with larger engines ( presumably it's still in an extra sheet of instructions )

Link to comment
Share on other sites

Thanks KC . Yes I will use a 6in spruce rod like my Acrowot with its OS80 FS and it's going to be glass epoxy covered too. No worries on strength😉 I build em strong. I will prob use my own Birch ply for firewall too. I like powerful engines . What I'm really wondering though is if the air brakes are worth bothering with.

Link to comment
Share on other sites

Hi had a wot 4 powered with an OS 60 2s . I had a set of Classic  wings and a set of Mk111 wings . The plane flew very well with unlimited vertical power . The downside to the bigger engine was the extra weight made it land fast. The tapered Mk111 wing was IMO more fun to fly with less drag . Never found the need for air brakes etc. A low slow circuit for landing suficed . IMO still the best all round fun model.

Link to comment
Share on other sites

Great to hear engine Doc. Just what I wanted to hear. I went for the Mk 3 as the classic wings look to draggy for what we want. We wanted the high wing as it will be better in the winter on our wet field. Now I am veering towards keepingit simple. It will save a fair bit of time leaving the air brakes out especially as I'm planning to glass it. It's going to have a simple black and white paint job like my Acrowot. I must admit I'm a useless and impatient painter! The piped 55 should allow some nice big loops and good vertical. 😊

Link to comment
Share on other sites

  • 2 months later...

Here is the fuselage i joined this weekend with help from the handy SLEC jig. Rotten weather! I have decided its going to have a big lump in it! Ooh Er matron! Yes Im actually putting a laser 80 in! I am going to put air brakes on it with 1 servo for each brake on the wing. The air brakes are to add interest and my son especially wanted them anyway will keep all updated. I build strong so it will easily take it. Like my acro wot it might be a bit lardy img_0724.jpg

Edited By Timothy Harris 1 on 10/12/2016 19:31:40

Link to comment
Share on other sites

Couple of personal observations regarding the design and use of the wottie, bearing in mind I've always built and flown the classic.

Chris Foss is a superb designer and also a pretty damn good pilot; I think this is where reality comes apart. If we could all fly as well as CF then I think the plane, as designed, would be pretty indestructible. If we all flew like me then I think he could have designed it like a royal tiger panzer and I'd still get the better of it. The one point I wouldn't argue with is the firewall, originally it was two laminations of iirc aircraft quality 1/16" ply, subsequently this was replaced with a single piece of 1/8" 3 ply which I think doesn't have the same resilience. Is it adequate? Yes it is but it isn't me proof.

I've flown the plane with very many different engines from an irvine 36 through to an irvine 72 with laser 70s and saito 82s in between with the 82 powered one with a 14x6 apc far and away the best performer. The nicest one to fly had a thunder tiger 42 GP with a graupner grey 12x5 prop.

I totally disagree with the suggestion that the artf is lighter than the kit built version, the one I assembled was about 1/2 a pound heavier than the kit built one which weighed just a smidgeon over 4 3/4 lbs.

Regarding the U?C apart from my earlier comments, if you use the wire u/c, it is far more resilient in all directions than the fibre glass version and seems to impose far less load on the mounting structure.

Link to comment
Share on other sites

On the old foam winged SLEC/Precedent Funfly the instructions were to insert a big block of soft balsa at the wing join where the wing retaining dowel fitted. That meant it was easy to drill and fit the dowel into the balsa and there was a big glueing area to the foam. Trying to drill accurately at the join where there is epoxy adhesive is just about impossible. I think I may have used the technique on my own Wot4 Mk3 but it was a long time ago. Mine has an ASP 52 two stroke which flew it well. Not had it out for a few years, though.

I'm seriously thinking of using the same method on the Skyways Percival Mew Gull part kit I'm currently building. I'm also using Precedent's wing joining method with 3mm birch ply dihedral braces slotted into the foam rather than a glass fibre/epoxy bandage.

Geoff

Link to comment
Share on other sites

Agree Mr Braddock. I certainly have to reinforce my planes to make them "me proof" plus its nice if ever i have to land it in the ploughed section of our field that there probably won't be any damage.

What worked very well for me on my kit Acrowot and takes a lot of the " crash strain "off the dowels is a flat section I moulded and stuck on the front centre section of the wing. I used cling film in the gap between wing and fuselage and blue tack on each side and poured in epoxy resin with finely chopped fibreglass. Thats my DIY fibreglass filler. It is darn strong. We used to use it for sticking boat engine mounts into hulls. Anyway the super strong bumper on the front centre of the wing stops the wing twisting in the horizontal plane during a crash so can protect the dowels. I will probably do the same on this. I think Chris suggests something similar in the plans with Cataloy filler. I will use exoxy/glass.

Edited By Timothy Harris 1 on 11/12/2016 00:12:46

Edited By Timothy Harris 1 on 11/12/2016 00:14:00

Edited By Timothy Harris 1 on 11/12/2016 00:14:30

Link to comment
Share on other sites

  • 2 weeks later...

Hi Ian I use the bumper on the Acrowot wing. It is made of standard epoxy with chopped glass fibre matting in it that makes it very rigid. I moulded it by putting cling film between wing and fuselage with blue tack on each end to sop it running out. Here are some photos. Sorry the Acrowot is muddy it was a muddy on the runway on Sunday! The plane has knocked its wings off from ground interfaces quite a few times without any damage img_0742.jpg

Edited By Timothy Harris 1 on 21/12/2016 19:42:00

Link to comment
Share on other sites

Bottom photo shows underside of wing . The same type of mould could work on the Wot 4 either attached to the fuselage or Wing. Chris Foss suggests making a similar mold attached to the fuselage. Given Wot 4 is a high wing,  attaching to the body like Chris says should be better. He suggests using Cataloy filler , but i will use epoxy. Will post photos when i do but thats a bit later on..

 

Edited By Timothy Harris 1 on 21/12/2016 19:47:22

Link to comment
Share on other sites

  • 2 months later...

The Wot 4 is now built . i didn't use the same "bumper idea" on it but I built a fibreglass reinforced canopy lip on it. The shape was initially made using P28 car filler . Its easy to do. Just put the wing in the plane with cling film and fill the gap with filler. Take it out when dry and sand. I then added a few layers of fibreglass and epoxy to make it vey strong. The first glass layer was wing joining tape then finer matting wot4_front_top.jpgand i used more filler to make it smooth.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...