Dash7ATP

Since I have almost 10,000 hours in the DHC-7, I have a keen interest in building one. The only plans I have heard of are by Dan Palmer, and they are somewhat expensive. I have heard several comments about his plans. Some good, some bad.... Well detailed but parts don't seem to fit properly, unrealistic target weigthts, and probably no prototype model ever built from his plans.

Has anyone see this plan, and if so did you build the model?

There used to be a six foot span foam E-power model of the Dash-7, but I have been unable to locate one.

I also saw a photo of a European model and it was very large, I'm guessing a span of around 14 feet! Does anyone have any info on that model? (Photo below)

Thanks in advance.

Joe

SunShyne

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Joe

I have a Robbe Dash 7 still in the box. Maybe we can talk about it

Wish I could help on the plans but I kow this bird is hard to locate decent plans for. I flew on a Dash as a kid on alot of short hops and I used to love it! Are you still flying?

Dash7ATP

I would love to talk about it! I have heard about it, but know nothing about it other than it was supposed to come with the motors, etc. I don't think it even had any wheels, did it?

Is there any chance you could send me some photos of the kit and give me an idea what you would sell it for. As much as I want the kit, I'm going to the DC area tomorrow to buy an F-15 ducted fan kit from a guy. My wife would have a fit if I tell her I'm thiniking of buying another kit! And on toip of that, we are trying to sell our house to move into a condo! Way too much going on! At least I'll get the two car garage to set up as a shop!

I retired from my airline job six years ago in May. I guess you could say I hung up my headset. I haven't flown myself as pilot since.

Joe

skyhawknut

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I've got the Dan Palmer plan. Havn't built it yet as I need a bigger workshop and I'm getting the kit cut and trying to get all the other pieces together (canopy, radome, nacelles, etc...)

Dash7ATP

Hi Skyhawknut,

You are the first person I've heard of who may have seen those plans. What do you think about them? What about the construction, scale details, etc. I'm particularly interested in what landing gear he came up with , as the real gear is pretty complicated.

P{lease let me know what you think.

Thanks,

Joe

skyhawknut

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I think I'm the only one with these plans as well!

It is very scale - he used the original factory blueprints to make his plans. Everything from the wing airfoils right down to leaving provisions and some discription for a fully detailed cabin. The only thing he comprimised on was a single flap - rather than the double fowler. The real one was pretty complex and probably very difficult to do in model form.

Mine will be electric - I'm not going to mess with trying to keep 4 .25's running properly and engine outs will not be a problem.

I've attached a pic of the custom gear made by Century jet specificly for the plane. While expensive and not all that scale - I'll probably use them as this bird will need some serious gear.

I've read all the stuff about Dan's plans as well - but the more I read about building from ANY of the big names plans - they all have the same problems with parts not fitting and plans not being clear. In the end - Dan's plans are a master piece. There is a lot of info on them and I've had to study some parts a few times to figure out what's going on. As far as I can tell the parts seem to fit better than his other plans - but I'm sure that some will be out, and the only way I will truely find out is when I put the laser cut parts together and build it. It's true that his designs probably haven't been flown - however I don't think I've read a build on any of his planes that didn't fly VERY well. (except 1 where he used too small an engine) One thing with these is the target weights are unrealistic. If you build one - build it and then when almost done - pick the powerplant based on your weight. The guy I spoke of above bought his engine with everything else and then built the plane, of course he was overweight and didn't have enough power.

Try this link :http://www.rcscalebuilder.com/

There is a section in the forums for Dan Palmer plan builds. Lots of good info.

Dash7ATP

HI again,

I have heard all that you mentioned about the Palmer plans. In any case, it will be much better than starting from scratch.
You mentioned having lazer cut parts. Is this a CAD drawing? If not, was it very expensive to have it converted so it could be lazer cut?

The gear is no where near scale. On the real one, there is a yoke at the top that goes about half way down to the wheel. The strut extends upward above that, and the whole thing folds during retraction to save space in the gear well. I wish I had a drawing of it. It would be very neat to duplicate it.

As for the flaps, they were four seperate pieces on each side. You could say it was complicated. All four pieces move together down to 25 degrees. The next step was 45 degrees, and that was the three trailing edge pieces moving together. The front section which was one very long piece was extended by three (or four-been a long time) jack screws. The trailing edge sections were hydrulic. Did he make provisions for the flaps to extend as the went down (fowler flaps). That extra area had a lot to do with the STOL preformance that I really loved to show off. WE could land and be stopped within 1000 feet from the approach end of the runway. Every time!

It was a fun plane to fly, and I really do miss it.

Joe

Dash7ATP

Here are a few photos of "my Dash7". Enjoy.

Dash7ATP

I do have another question regarding the plans. The ailerons on the -7 are very small. Most of the roll control was done with two spoilers on each wing. The outboard spoilers were disabled at about 130 kt's. Does he show the ailerons at the scale size, enlarged, or does he also use spoilers for roll?

Reason for asking: If they are the proper size and spoilers are not used, the roll control will be very weak. With ailerons alone, in a hydrolic failure mode, the plane was very sluggish.

Joe

loukos

My Feedback: (2)

Regarding the large model above in the photo, if my memory serves me right belongs to Jerremy Shaw in the UK, built in the early nineties. I think you may be able to reach him through the Large Model Association in the UK (google "LMA").

Good luck on your quest.

Regards
Loukis

skyhawknut

My Feedback: (3)

About the laser cut kit. No it's not a CAD plan but their are at least two companies that have scanned and made laser files for it. The one I'm going to get is from Precision cut kits.

As for the gear - it's better than stright gear. It would be insanely expensive and very difficult to get a near perfect scale gear. I'll probably dress up these ones with a fake drag strut and maybey some yokes that I would shape an then JB weld to the side of the strut. That would be much more ecinomical and yet have an easy install, reliable, and fully functional strut and gear.

Yes - the flaps are fowler, but as I said only a single flap due to the complextity of trying to get a double flap to work on such a small scale and without hydralics as mentioned.

There are no spoilers on this model - but it wouldn't be hard to install some from Robbe (I think) One of the hobby stores was importing some units from Europe. They are really nice. Made for sailplanes - just cut a hole and drop them in. They are fully self contained and have almost no depth. Actuated by 1 servo pulling on the rod at the end of the unit. Even without these and a scale looking sized aileron I'm still not worried about how it will fly. As I said earlier - all Dan's planes seem to fly like *****cats.

I'll try and take some small section pics of the plans and post them.

Voyager airways in Canada operates 7 Dash 7's. One of them is based in Vancouver in the same hanger as my company. So I see it all the time and I hang out with the mechanics. They let me poke around and ask questions so I'm pretty familliar with the 7 and it's systems. And I have the real one to help with my build!

Dash7ATP

Hi again,

It's good that you have a real one to look at. You should be able to make a super looking model. Keep us posted. I would like to see some of the details of the plans.

JL

skyhawknut

My Feedback: (3)

Joe,
I have included some shots of the plans just to show the level of detail. There are 4 sheets at 36" x 72". Fwd fuse, tail, outboard wings + nacelles, and inboard wings.

The wings bolt to the fuse and they also break down between the inboard and outboard nacelles. The fuse also splits between the vertical and the wing trailing edge - so the model is fairly transportable in even a small car.

The spoilers I talked about earlier are PN GR93. and you can see them here:
http://www.hobby-lobby.com/spoilers.htm

Dash7ATP

WOW! There is no question that he goes into a lot of detail! That's going to be a big project, to say the least! I am curious what you are having to pay the get the parts cut out. I assume the fuselage rings are light ply, aren't they. I can't believe he even has the seat locations and details.

Do you think you are the first to ever tackle this model from these plans? I would also like to see the plans for the big one show in the photo above.

Thanks for your time.

Joe

skyhawknut

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Yea! I think I'm the first not only to build it but to also purchase these plans!

Which one do you want to see?

The only part I'm worried about is the Horizontal stab. If you look at the plans pic the stab is a flat bottom airfoil and is shown on the plan mounted inverted. I don't know if this is a mistake or not as some aircraft were built with inverted airfoils on the tails. Do you know if the full size one was like this?

I think the kit is in the $550 range - which isn't too bad concidering it's 1:12 scale........93" wing and 80.5" long. Judging by the detail in the plans - - - - THAT"S A LOT OF WOOD!!!![X(] It includes all the parts plus all the sheeting. The fiberglass nacelle halves and cockpit section are about $85 and the gear is $510.

Oh well - what are you going to do? It would be just as bad trying to scratch build something of this caliber, and anyway - this is a hobby it's supposed to be fun.

Dash7ATP

[quote]ORIGINAL: skyhawknut


The only part I'm worried about is the Horizontal stab. If you look at the plans pic the stab is a flat bottom airfoil and is shown on the plan mounted inverted. I don't know if this is a mistake or not as some aircraft were built with inverted airfoils on the tails. Do you know if the full size one was like this?

I think the kit is in the $550 range - which isn't too bad concidering it's 1:12 scale........93" wing and 80.5" long. Judging by the detail in the plans - - - - THAT"S A LOT OF WOOD!!!![X(] It includes all the parts plus all the sheeting. The fiberglass nacelle halves and cockpit section are about $85 and the gear is $510.


Since i don't remember ever being in a position to see the top of the stab, I can't tell you for sure if it was relatively flat on top. Having said that, it being inverted doesn't surprise me, since all stabs are exerting a down force on the tail to maintain stability. I have an F-4 Phantom with an all flying stab. The top of the leading edge is somewhat cupped as if it were an undercambered airfoil inverted. Being an inverted airfoil actually reduces drag slightly, since it doesn't have to as much incidence to produce the force needed for stability.

So, as for the parts, who makes the fiberglass nacelles and cockpit section? Did Palmer have someone do that just for this model?

Joe

Dash7ATP

The only part I'm worried about is the Horizontal stab. If you look at the plans pic the stab is a flat bottom airfoil and is shown on the plan mounted inverted. I don't know if this is a mistake or not as some aircraft were built with inverted airfoils on the tails. Do you know if the full size one was like this?


While I was writing the previous reply, I remembered some drawings I copied from a tech manual the mechanics had where I worked. It was some views of the wing plan, Stab plan, and some details of the nacelles, and fuselage stations. It was mostly, the locations of the various "stations" used to locate various parts. The side view of the rudder shows the Stab center rib profile but not much detail. It appears that the Stab airfoil is semi-symectrical with the deepest side on the bottom, to produce lift in a downward direction.

Joe

skyhawknut

My Feedback: (3)

Thanks for the info on the stab - It makes me feel a lot better!

The fiberglass parts were being done by Stan's Fibertech, but they were bought out by Aero Fibertech. Parts are still available, the cockpit section was lost for a while, then they found an unknown one and he sent me a pic - it was the Dash 7's. So I'm going to order the parts next week. They just offer the canopy section and the 4 1/2 cowls - not full nacelles. The half cowl is basicly just what would be the engine intake section on the real one.

http://www.aerofibertech.com/products.html

Palmer also includes a short history on the real aircraft and some basic "instructions" for building the plane.

Dash7ATP

Skyhawknut,

It's been awhile since a post was made on this thread, you're Dash-7 build from the Dan Palmer plans. How's it going? Have you started construction yet? Any photos?

Joe

Scale Freak

Hello there, I too would be very interested to see how your doing with the Dash-7.
I am in the extreamly slow process of creating Dash-8 plans myself.
I did work for deHavilland in the early 80s and actually worked on the last -7
produced.
As the -8 is still in production I cannot get a lot of detailed info (such as airfoil, propriatary info they say),
but I do have some things.
Keep us posted!
Dan

Dash7ATP

Hi Dan,

I also flew the Dash - 8 before I was forced to retire. Nice airplane, but I still liked the Dash-7 better. It's a much more fun plane to fly.

As for the airfoil, I think I'd forget the scale airfoil and look into one that flies better at the Reynolds Number your model will be flying at. There is a lot of stuff available for model builders out here to choose from that work much better than many of the full scale sections. Google[i] Michael Selig low speed tunnel results[/i]. If you aren't familiar with him, he did his PhD work on slow speed airfoils. HIs work is the bible when it comes to airfoils for gliders.
Joe

Props4ever

I am getting interested in doing Dash 7 myself also, i had Palmer's larger 165" B24 and didn't really liked the way those plans were and ended up selling them with basic structure of the fuselage. I was really leary the way he mounted the wings to the fuselage, didn't look to promising to me and then i had others who also didn't like short coming as parts wouldn't fit right and you literally have to work in forward thinking as 2 steps ahead on that bomber.

From the above posted pictures it seems as its not that bad but yet again Palmer never built any of his own designs as prototype to see his set back issues and that is one area where one really don't know what will happen to the model when it takes off.

What is the update on this build, are you doing the build or model is still sitting a side?, i would really interested in your build also, let us know what happening with it now days..

Sammy

Props4ever

Anyone know where i can find large scale plans for DASH - 7?

jamie_duff

Hi folks.

A while after seeing this thread and the plans previews I've bought a set for myself. I'm very pleased with them I too have found memories of the Dash-7, as does my father who worked on them for many years. They were the ones owned by Brymon Airwarys and were flying under British Airways colours between Aberdeen airport and the 2001ft long runway on Unst, Shetland Isles when I first had any involvement with them.

I think I've come up with a simple (as simple as the simplified system anyway) method of achieving the double slotted flaps.

I also enquired with Sierra about an undercarriage with drag braces, but as they've never been asked before and don't expect to ever be asked again for a Dash-7 undercarriage it would mean a very expensive pair of retracts. I'll probably go with CJM which has the correct geometries at least, and I'll add my own drag braces. I do infact have the diagrams Dash7ATP was wishing for above

As well as the flaps, I reckon I can include the articulated rudder with minimal weight gain and thanks to a bit of foresight in Palmer's drafting, the scale spoilers would hinge from the rear spar. I believe it will need roll spoilers because I am not optimistic about the Dash-7's roll control on the tiny ailerons it has.

Mine too will be electric using low KV outrunners and 11" props - hopefully four bladers but if not, it'll get scale static props instead.

Ben_E

Building progress anyone?

The Dash-7 has been a favourite aircraft to built for some time, but the lack off plans has kept me off such a project - yet. I have known about the Palmer plan for some time, and occationally I do a search on the web and this thread came up. Very interesting indeed

So let's see some balsa in the pictures

Ben_E