Topic: Busa 1/3 Fokker D VII

Hi all just started building the BUSA Fokker d VII , has anybody got any advice about building this kit.

Hi all just started building the BUSA Fokker d VII , has anybody got any advice about building this kit.

Sure provostguard will be along in a moment....

has anybody got any advice about building this kit.

Yes post us lotsa pickies please    other than that 

It's a great kit and a dream to fly.  If you haven't decided on an engine yet I recommend a G62 with the MR belt reduction drive.  You'll swing a 30x12 prop at about 4200 rpm's.

My only complaint with the kit is the the sub wing and landing gear it is the same size wire as BUSA uses for all their 1/4 scale kits.  It is a little weak for a 40lb + airframe.  I have over 200 flights on mine  and have had to do alot of maintenance on the gear.  I plan on replacing it with a 1/3 scale GTM  sub wing landing gear assembly this next winter.

Best of luck with the build.

John

Look forward to this build. Post lots and lots of pictures please.

Simon

Hi thanks for the replies ill try to post some pics today a bit busy working nights a the moment , for power I'm going to be using a G62 and was thinking of using a Mick Reeves reduction drive.

hi can anyone tell me how you up load pics, do you use the attachment part?

hi can anyone tell me how you up load pics, do you use the attachment part?

"Link inline image", use the drop down box and goto "inline full size attachment" then at the bottom of the page "additional options" then "Browse" for the file you want to upload.  If you picture is to big use "windows Image Resizer" which is a free download, "power toys for XP from HERE  it's simple to use, just right click on the image you want to resize and choose the size you want, it will save a smaller copy leaving the original untouched.

Hello Buzz2,

I built the DVII for Provostgaurd and I kept what I suppose is called a "build thread" in the form of several e mails. I did a complete write up for each stage of the build and took a total of 80 odd photo's. If you pm me your details, I'll send it all to you on a disc through the post. There's too much info to try and send it over the web, and I'm not much cop on computers.

Regards.

Jonesey

Hello Buzz2,

I've had a second thought, I could send you copies of the e mails, one at a time, over the web, it's up to you. Provostgaurd is out of the loop at the moment as he is in the process of changing broadband providers.

Regards.

Jonesey

Welcome Dave

Could you post some pics one here mate? I'd love to see some, I'm sure AlanC would post 'em with pleasure now he knows how!! Apart from the fact he goes away very soon that is.

Did you deviate from the plans at all?

I'd love to see a build thread Buzz2

Cheers, Ian.

Dave, please see my PM

Steve

Hello Ian,

I've sent a copy of my "build thread" to rcfanuk and he's going to sort through it and put it on the forum. Re mods to the kit, at Ken's request I replaced the balsa longerons with Cyparis and made the tail plane/fin assembly a detachable unit. Off my own back I replaced all the American nuts and bolts with metric as they are easier to replace if you lose any. Also, some of the fuse formers are two piece and butt jointed, I covered the joins with 1/64" ply to give them more strength. Again, the curved outlines for the rudder and elevators were made up from butt jointed die cut laminations, I replaced these with overlapping laminations for more strength and rigidity. Ken replaced the wheels supplied with the kit as they were a bit naff,(plus, they came with black tyres.........enough said!!)

Regards

Jonesey   

Hi all still trying to sort out the pics.Thanks for the tips Norfolkngood , also if the build info could be sorted that would be great Jonesy I'm very interested how you made the tail removable , this would be great for transport . Also did you register the DVII with the LMA over 20kg scheme as the is a big heavy bird and is very close to the 20kg weight.

i can answer this one for you,   jonesy is a mate of mine, and we all chewed the fat over this plane all through its birth,    it wasnt registered,  and came out under,    not much, but it was under,  it was covered in Glen Torrance lozenge, and doped,  plus all the scale detail,    be carefull with the glue,  and i cant see any problems,      keep the back end light as possible,  even with the Z62, and the reduction gear, a swage of church roof was needed (i know, i provided it!!)      of on hols now,     so i wont be able to see you reply,    hope jonesay gets the build on here,     its impressive

hope jonesay gets the build on here,     its impressive

Al, it's already on here, see THIS thread

Steve 

Hi Buzz2,

Re the removeable tailplain, I built it as per the plan and added a balsa infil to the centre section. I then infilled the top of the fuse at the tailplane seat with liteply. Set up the tail plane as normal but, instead of gluing it, drill four holes through to take M4 cap head bolts and fit four captive nuts under the liteply fuse infil. You can countersink the top sheeting a little to allow the bolt heads to sit flush. I think Ken later re drilled the holes in the tail plane and added brass tube bushes to stop the balsa from crushing. Thinking well ahead, use cap head bolts where you can, especially for all your rigging, get some metric balldrivers and it makes life a lot easier for you at the field. Hope this helps.

Jonesey

hi all, happy crimbo can anyone help me, I'm trying to replicate the full size pull pull system for the elevators has anyone got any tips on the best way to do it thanks

Not til you show us some pics 

I'd fit a belcrank in the fuselage to take the front end of the closed loop system. Connect the servos to it using short pushrods. Make the cable holes in the horns slightly behind the hinge pivot so there is no extra tensioning as the control surface travels to its limit.

Still would love to see some pics though

Ian.

Thanks Ian how about a direct drive pull pull cable straight from servos to elevators what do you think, ill try to post some photos later thanks Neil

the fuz

the completed fuz me my brother and dad

photo of cockpit detail

pic of full-size pull-pull system . Got more if you need them.
Bob

hi bob thanks for the offer, what it is Ive never done this before and Ive installed pull pull cables direct from the servo, and the cable that makes the control surface go down is tight in the neutral position and then goes very slack when the surface goes down, its only this cables that do it can you help (Ive experimented with bigger and smaller servo horns i think my horn on the surface might be too big)

hi bob thanks for the offer, what it is Ive never done this before and Ive installed pull pull cables direct from the servo, and the cable that makes the control surface go down is tight in the neutral position and then goes very slack when the surface goes down, its only this cables that do it can you help (Ive experimented with bigger and smaller servo horns i think my horn on the surface might be too big)

Ah! You need to have the servo horn the same width (from cable to cable) as the horns on the elevator, rudder, etc. As this usually means large servo arms, it is sometimes better to make up a bellcrank in the fuz connected to the servo by a rod. Complicated to describe, but simple in practice. It is the difference in width of the horns/servo arm which makes the cable go slack. Also, with such a large arm, you would need a powerful servo. Using the seperate bellcrank idea is better.

Ive try ed a servo horn the same size as the surface on (made out of g10 fiberglass) still the same, is it better to cross the cables like you do on the rudder of have a straight run at it (I'm using hitec metal geared 645 i think cant remember of the top of my head)

Servo is what I have. No problem there. Dont cross the wires, its better to pull straight. Plus, unless you use plastic covered, you will get metal to metal noise causing interference. Cant understand this, if your servo arm and horn are exactly the same size, you should have tight wires all the time. Also dont forget you need some form of adjustment, as the wires will slacken off after a while.

it has been puzziling me for days when you remove the clevis of the bottom control horn, and you just hold it over the position on the horn and move the surface after about 15 degress or so the cable stops moving, i have guided the pull pull cable in the fuz with sullivan pllastic bowden cable about every 6"s

it has been puzziling me for days when you remove the clevis of the bottom control horn, and you just hold it over the position on the horn and move the surface after about 15 degress or so the cable stops moving, i have guided the pull pull cable in the fuz with sullivan pllastic bowden cable about every 6"s

There is no need to guide the cable unless you have corners to go around. Could it be something binding in one? Do you have any sharp bends? Try the closed loop directly without the guides, the cables should be exactly the same length, and if the horns and servo arm are the same, they have to move the same, with no slackening.

If the control linkages are not exactly in line with the hinge you can get this happening. However you don't need to worry about it. In flight  the control surface will be blown back towards neutral and the pull line will always be tight. The other line will slacken off but as it is not doing any work it doesn't matter. As long as the lines are tight at neutral you will be OK. Many people deliberately set up their closed loop linkages like this. There is really no need to have the servo horn and the control horn the same length, having different lengths can help in getting the right control surface movement.

Jim

If the control linkages are not exactly in line with the hinge you can get this happening. However you don't need to worry about it. In flight  the control surface will be blown back towards neutral and the pull line will always be tight. The other line will slacken off but as it is not doing any work it doesn't matter. As long as the lines are tight at neutral you will be OK. Many people deliberately set up their closed loop linkages like this. There is really no need to have the servo horn and the control horn the same length, having different lengths can help in getting the right control surface movement.

Jim

quite correct Jim, it just doesnt seem right to me, so I always set it up geometrically right! However, I feel that buzz2 has another problem which needs to be investigated.

I think the easiest way to diagnose this potential problem is either a vid or some clear piccys, any problem should be easy to spot this way, What you say Buzz2? Is that possible?

have a look at index, they have a lot of info on this. also pic below.

      control horn on top                                                                            control horn                                                                                          control horn bottom                                                                                                             neutral position                                                                                                                    up postion                                                                              down position

servo

hope these photos are ok, its only the bottom cable that sags

In the piccy of the bottom sagging cable, have you simply pushed the ele down by hand, or is the servo doing the work?

servo is doing the work