Douglas DC-7
#27
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RE: Douglas DC-7
Gentlemen.......I have a "Z" B-25 and the Robart mains of the 118" come very close to what we are looking for.......it would be necessary to reverse sides as the B-25 gear retracts aft and DC-4/6/7 gear retract forward.........might need a stronger cylinder to pull up 2 tires on each main ...but worth looking into......nose gear is also in the ballpark.........atleast somewhere to start........I'll be watching for updated posts.....Happy Holidays.....Bill.......
#28
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RE: Douglas DC-7
Hi Fly-guys,
I just came acroos this thread and it looks as if it went dead......is there still interest in the DC6-7 ?? I really want to build a Big-Six and need some help. Did you ever get the plans finished Proflooney? if you have I would love a set to start with.
I just came acroos this thread and it looks as if it went dead......is there still interest in the DC6-7 ?? I really want to build a Big-Six and need some help. Did you ever get the plans finished Proflooney? if you have I would love a set to start with.
#29
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RE: Douglas DC-7
I started my airline career as a Flight Engineer on the DC-6. All of our training flights were in DC-7s. I have a rather beat up full size picture of the DC-6 front instrument panel in my shop.
#32
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RE: Douglas DC-7
Several years ago I designed and built a 1/10 scale DC7 about 139 span with 4 OS 91 and Ziroli style construction. It flew great except unstable in uncontrolled pitch up when nose raised up over about 20 degrees the nose rose higher and higher and only increasing power and full down elevator would lower nose then it would fly great. moving Cg forward did not help finally lost it close to ground.
I am presently building a 1/10 scale DC4 which has shorter nose to see if the lifting was caused by the long DC7 nose or some other reason. ANY IDEAS John
I am presently building a 1/10 scale DC4 which has shorter nose to see if the lifting was caused by the long DC7 nose or some other reason. ANY IDEAS John
#34
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RE: Douglas DC-7
Joe Huntley was doing plans for the Douglas (hows the progress Joe)
Also others here are working on plans for the Douglas DC-4/7 I would appreciate the opprotunity to get a set and would contribute financially.
I'm interested in the C-54 as my late Father flew the Berlin Airlift.
Keep up the good work Tailskid,
Also others here are working on plans for the Douglas DC-4/7 I would appreciate the opprotunity to get a set and would contribute financially.
I'm interested in the C-54 as my late Father flew the Berlin Airlift.
Keep up the good work Tailskid,
#35
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RE: Douglas DC-7
ORIGINAL: John La Belle
Several years ago I designed and built a 1/10 scale DC7 about 139 span with 4 OS 91 and Ziroli style construction. It flew great except unstable in uncontrolled pitch up when nose raised up over about 20 degrees the nose rose higher and higher and only increasing power and full down elevator would lower nose then it would fly great. moving Cg forward did not help finally lost it close to ground.
I am presently building a 1/10 scale DC4 which has shorter nose to see if the lifting was caused by the long DC7 nose or some other reason. ANY IDEAS John
Several years ago I designed and built a 1/10 scale DC7 about 139 span with 4 OS 91 and Ziroli style construction. It flew great except unstable in uncontrolled pitch up when nose raised up over about 20 degrees the nose rose higher and higher and only increasing power and full down elevator would lower nose then it would fly great. moving Cg forward did not help finally lost it close to ground.
I am presently building a 1/10 scale DC4 which has shorter nose to see if the lifting was caused by the long DC7 nose or some other reason. ANY IDEAS John
Was quite surprised to see your posting;I would VERY MUCH appreciate a set of plans as stated in my previous post I would be quite willing to help with any financial costs with regard to your plans. Please let me know at your convenience
----->All you 4 engine Douglas lovers (the pictures) and postings are interesting indeed lets keep this one going!!
Whens the last time we saw a Douglas DC-4/7 in model magazine?
#36
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RE: Douglas DC-7
Hi Guys; am glad for the response I do have the plans on autocad but until I solve the pitch stability problem the plane is too dangerous. I hope the shorter nose length of the DC4 will solve the problem. I understand the scale jet airliners in europe are having this problem they seem to offer no solutions for this, Do you guys have any ideas. I am convinced the CG is not the problem as I moved it to less than 20% for flights 3-5 . I am using scale tail surfaces which look large enough and are about 4' wide I do not want to enlarge out of scale ( might as well build an extra if we can't have scale) Have some earlier construction photos ( how do you attach to posts) have the fuse mostly done tail surfaces finished and fiberglassed am presently building stronger landing gears as the robarts I used on the DC7 were not strong enough ( robart said they would not work in reverse and they were right) IDEAS ON PITCH PLEASE John
#37
RE: Douglas DC-7
John,
A few years ago I built and flew a 1/16 scale DC-6 which flew fine. The airfoil was copied from the Royal DC-3 scaled up a bit and the tail section was symmetrical. Wing incidence was +3 degrees and tail was set at 0 degrees. Engine nacelles were all at 0 degrees. CG was 25% and seemed about right. I didn't have any problems with pitch and I'm wondering what could be causing your problem.
Hope you get it all sorted as I would like to build a larger DC-6 or -7 perhaps at your 1/10 scale. Please post some photos!
Paul
A few years ago I built and flew a 1/16 scale DC-6 which flew fine. The airfoil was copied from the Royal DC-3 scaled up a bit and the tail section was symmetrical. Wing incidence was +3 degrees and tail was set at 0 degrees. Engine nacelles were all at 0 degrees. CG was 25% and seemed about right. I didn't have any problems with pitch and I'm wondering what could be causing your problem.
Hope you get it all sorted as I would like to build a larger DC-6 or -7 perhaps at your 1/10 scale. Please post some photos!
Paul
#39
RE: Douglas DC-7
tailskid,
You obvioulsy have great taste in airplanes!
I'm hoping we see more of these in model form with all the progress in electrics these days.
Now if we can keep the airlines from suing us because we used their logos...........
Paul
You obvioulsy have great taste in airplanes!
I'm hoping we see more of these in model form with all the progress in electrics these days.
Now if we can keep the airlines from suing us because we used their logos...........
Paul
#42
My Feedback: (34)
RE: Douglas DC-7
Sorry to disagree, but GP wanted to make a P-38 and call it a Lightening and approached Lockeed. Lockeed had long been sold to another company and they wanted something like hundreds of dollars for each model sold! GP finally released the profile P-38 but notice it has NO ties to Lockeed.....I got this information from Don Anderson himself. That legal hoop they tried to jump cost GP a lot of time - the kit was ready to go but they had to dodge the legal ties to Lockeed. I was not aware of DJ Aerotech's situation.
Jerry
Jerry
#43
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RE: Douglas DC-7
Hi PS2727 I went back and checked the cad file for the DC7 the airfoil was 2013 a standard transport airfoil the tail at ) wing at 2.562 degree and balance first flight at 25% moved forward to 20% after 2nd flight the engines 2% downthrust and 2% outboard thrust the same criteria I am using on the DC4 now under construction does anyone see a galring error in this setup will try too attach a picture of DC4 construction if I can figure out how John
#45
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RE: Douglas DC-7
Hi Jerry; this is an earlier picture of DC4 construction. the fuselage is now covered with 1/8 balsa the tail surfaces are covered with 3/32 and are installed and covered with 3/4 oz cloth and Z poxy. I am presently working on building the landing gear.( as the Robarts mounted in reverse did not work well on my DC7- not their fault) will try to take updated pictures and post this weekend. I would like to hear how the 1/10 DC7 's mentioned earlier in this forum flew and if they had pitch problems. I had no pitch problems on the first flight as I apparently did not pull the nose up steep enough on the first flight. The second thru 5th were scarry John
#47
RE: Douglas DC-7
John,
What was the flying weight of your 1/10 DC-4? And what engines will you use in the new version?
When I built the DC-6 I wanted to make a custom set of gear and made mockups. In the end I used plain retracts but a custom set is really what we need. Here is a photo of the mockup along with another gear for the Convair project. They were never finished but something along these lines would work as they are fairly straightforward gear. I think the nose unit would need to be custom too because of the angles involved. The only complication is that you need to move the fuel tanks out of the inboard nacelles to make room for the retracted gear.
Have you started the wing construction?
Paul
What was the flying weight of your 1/10 DC-4? And what engines will you use in the new version?
When I built the DC-6 I wanted to make a custom set of gear and made mockups. In the end I used plain retracts but a custom set is really what we need. Here is a photo of the mockup along with another gear for the Convair project. They were never finished but something along these lines would work as they are fairly straightforward gear. I think the nose unit would need to be custom too because of the angles involved. The only complication is that you need to move the fuel tanks out of the inboard nacelles to make room for the retracted gear.
Have you started the wing construction?
Paul
#48
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RE: Douglas DC-7
Hi Paul; The weight of the DC7 was 42 lbs and used OS 91 4 stroke which was ok on power will use same on DC4. I am presently designing and building retracts for the DC4. I designed and made a set of electric retracts for the plane but with batteries etc they weighed over 10 lbs so started over and designed an air retract system have them designed and partially built wwill be much lighter and stronger. On the DC7 I installed the inboard tanks in the cowl itself which worked ok Wing is designed but not started. You may be on the right track with servo overload I had futaba 9303 mg in the DC7 around 110 torque will go with the largest I can easily get when ready thanks for the suggestion can't hurt. what is shown in this picture weighs 8 1/2 lbs. I best shut up for now John
#49
RE: Douglas DC-7
John, it's looking good. Do you plan on using a fiberglass windshield section like the Ziroli DC-3 or will it be all wood? And will the nacelles be wood or fiberglass?
Keep sending those pictures!!
Paul
Keep sending those pictures!!
Paul
#50
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RE: Douglas DC-7
Paul- will probably make nose and cabin out of fiberglass. because if in the long shot the plane flys good, others may want them . In the long term if the DC 4 flies I plan to build the DC6 and another DC7 in 1/10 scale and fiberglass items like these may work there too. The nacells are designed of wood with fiberglass cowls. John