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May 14, 2019, 12:19 PM
Foamy and Glider fanatic
Blacky's Boy's Avatar
Lockey,
It looks GREAT! I'm sort of surprised you didn't 3D print a Spinner to give that extra "touch"
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May 14, 2019, 04:25 PM
Registered User
rajazo's Avatar
Great foam work Lockey as allways... definitely, you are a master.

Just I have a little shame because you left the 3d fusselagge, but thank you for your hard work because proved that 3d print isnīt the easy way to go , at least for the moment.

At this point, please make a summary of the results because the difference in weight that I found in the thread is not clear:
In post #31 AUW of the plastic albatros is 1122grs
In post #58 it is pointed out that the weight of the foam albatros is 878grs without battery, then + battery (200grs for a 2200mah 3s) it should be 1078grs. I think the difference between both version should be more.

Just a general comment, is clear that the one perimeter 3d fuss is too fragile because the FDM skin is too isotropic compared to the homogeneous foam, and the lack of strenght in the cutting effort is the worst part. Any fuselaje in this technic needs some reinforce in the longitudinal direction that takes the efforts of traction of the fuselaje because it works as a beam when it lands, but with new weight penalty.
Another aspect I saw in the albatros corpse , is the typical Sharp corner failure (vertex in front of pilot- battery box). Sharp corners concentrate stress and produce diagonal fissure from the vertex. Because that is really important make fillet in all Sharp corners to disipate stress .

Anyway , because you are working in the foam version, you can replace all plywood parts with 3d printed pieces, because laminar surface as ribs, support plates and screw plates works great and the weight is equivalent or less than the plywood, and precision is impossible to achieve with saw, drill and ply.

Just check this sheet that I made at home with the weight of different materials
Last edited by rajazo; May 15, 2019 at 02:37 PM.
May 14, 2019, 09:08 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Thank for your comments rajazo, as always .. very welcome .. not sure I totally understood ALL so I will mark the ones so you can maybe clarify


Just I have a little shame because you left the 3d fusselagge, but thank you for your hard work because proved that 3d print isnīt the easy way to go , at least for the moment. I definitely haven't given up on the 3D printed fuselages, just maybe a little rethink

At this point, please make a summary of the results because the difference in weight that I found in the thread is not clear:
In post #31 AUW of the plastic albatros is 1122grs
In post #58 it is pointed out that the weight of the foam albatros is 878grs without battery, then + battery (200grs for a 2200mah 3s) it should be 1078grs. I think the difference between both version should be more.
OK .. to try and clarify the weights and compare apples to apples .. see pics .. I am not quite sure why there isn't a lot bigger difference, maybe I have weighed the plastic one without the battery and thought it had the battery in ??????

Plastic fuselage with larger motor = 1154 grams ... Foam fuselage with large motor and with 2200/3s battery 1047 grams = only 107 grams .. somethiing seems wrong .. I would have thought there would have been a lot bigger difference between the two ???

Just a general comment, is clear that the one perimeter 3d fuss is too fragile because the FDM skin is too isotropic compared to the homogeneous foam, and the lack of strenght in the cutting effort es the worst part. not sure what is meant here ?

Any fuselaje in this technic needs some reinforce in the longitudinal direction that takes the efforts of traction of the fuselaje because it works as a beam when it lands, but with new weight penalty. I have been thinking of maybe a few CF stingers running lengthwise along the fuselage, problem being to make the slot for these and STILL able to print in "spiral" mode (which in my opinion is much better/stronger than single wall printing)
Another aspect I saw in the albatros corpse , is the typical Sharp corner failure (vertex in front of pilot- battery box). Is this the battery box/hatch area you are taling about ?
Sharp corners concentrate stress and produce diagonal fissure from the vertex. Because that is really important make fillet in all Sharp corners to disipate stress . I will certainly bear this in mind when designing

Anyway , because you are working in the foam version, you can replace all plywood parts with 3d printed pieces, because laminar surface as ribs, support plates and screw plates works great and the weight is equivalent or less than the plywood, and precision is impossible to achieve with saw, drill and ply. this is where the 3D printed parts come into their own

Just check this sheet that I made at home with the weight of different materials Great comparison sheet
May 15, 2019, 02:44 PM
Registered User
rajazo's Avatar
sorry, some technical terms are incorrect, I was referring to SHEAR STRESS.
about the weight, I thing the plastic model was taked without the battery, that makes more sense.

I hope you test the foam version soon to get more coments about the diference in handling and performance.
May 15, 2019, 08:22 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Quote:
Originally Posted by rajazo
I thing the plastic model was taked without the battery, that makes more sense..
It may not have been rajazo ... the same plastic parts that make up the fuselage weighed 28+33+45+80=186 minus the foam fuselage 186 - 116 = 70 grams (only 70 grams lighter) thats amazing really

I didn't use the nose cone which weighed 49 grams .. I used the same cabanes, wheels, undercarriage and hatch (with motor) same wings and tail plane, same servos, push-rods, reciver, ESC etc .. so no changes there

70 grams for the fuselage plus 49 grams for the nose cone 70+49=119 grams which is pretty close to the difference in weight of the 2 airplanes (and it might have been a different 2200/3 battery I used to weight each one .. as I have a few different ones)

I REALLY WOULD HAVE THOUGHT THERE WOULD HAVE BEEN A LOT BIGGER DIFFERENCE IN THE WEIGHT OF THE PLASTIC AND THE FOAM FUSELAGES
Last edited by Lockey; May 15, 2019 at 08:33 PM.
May 16, 2019, 08:51 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Thought I would have a look at putting a couple of CF spars through the fuselage to see how much it strengthens it .. here is the first part I have printed .. weight is 50 grams ... equivalent part is the black one in the earlier post weighing 45 grams

Carbon fiber spars are Hobby King 5mm

Lockey
Last edited by Lockey; May 16, 2019 at 08:56 AM.
May 18, 2019, 03:33 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Maiden of the all foam Albatros (second flight really) I flew it once and then used a lighter battery, moved it as far back as I could and took off the hatch to see if it would fly OK with the CG back further

Lockey

Maiden of all foam Albatros (4 min 34 sec)
May 18, 2019, 05:04 AM
gpw
gpw
“There’s no place like Foam”
gpw's Avatar
Quite NICE !!!
Latest blog entry: Lost plans
May 18, 2019, 08:07 PM
skumgummi dave
Well done Lockey!
May 18, 2019, 08:07 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
This is the actual maiden

Lockey

Albatross Maiden Foam Fuselage (8 min 32 sec)
May 19, 2019, 02:49 PM
Retired CAD guy
birdofplay's Avatar
Nice flyin' mate.

Is that the field just South of the field that I flew at ?
Looked like it , at least to me, on GoogleEarth.
Coolamon Oval Pavilion

Changed my mind looks more like
Ellenbrook Baptist Church grounds

I just got home from a 5 hr drive from Michigan.
I'll watch both new vids after I get unpacked.

Couple of suggestions:
Widen out those downwind turns.
Use a little rudder to coordinate those turns.
Bipes I've had, tend to drag tail around turns so Coordinate with a touch of similar Rudder.
Left turn -> Left rudder and vice versa.

Just don't want you to stall during turn a turn. :>}
Last edited by birdofplay; May 19, 2019 at 03:45 PM.
May 19, 2019, 08:51 PM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Hey Bob, good to hear from yo mate, hope you and Mary had a good trip

They have put huge fences and gates around the one we went to and until we can maybe get permission to fly there again we are on the hunt AGAIN .. the one in the video was Ellenbrook Christian College

Thanks for the suggestions Bob .. welcome as alway .. I was flying fairly tight as not knowing the park I wanted to stay close

Not sure how long we will be before someone complains and we get chucked off hope we can arrange something to get a key to back to the old place

Lockey
May 20, 2019, 08:26 AM
Retired CAD guy
birdofplay's Avatar
Thats the one I found !

Looking at houses, Buildings and Tree lined road
I knew it had to be.

New surroundings Do tend to throw off situational awareness
and make one a bit uncomfortable.

I saw a White SUV watching you take off in one of the vids , then pull into
their driveway. My guess is that the problem will come from there.
Aug 18, 2019, 09:48 AM
Tony Audsley Retired Locksmith
Lockey's Avatar
Thread OP
Crashed 2 planes .. the Taube with the latest 3D printed fuselage (see 28seconds in and again at 39 seconds and at the end of the video) and the Albatros with the foam fuselage .. Now .. I have been blaming the weight of the plastic fuselages for all the crashing I have been doing lately BUT it seems, after repairing the Albatros AGAIN I flew it with my other radio and it flew fine

After a succession of crashes over the past few weeks, the new Orange radio is heading for the bin .. got myself a new Spektrum DX6

Lockey

Albatros crash (0 min 44 sec)


Taube Crash AGAIN (5 min 55 sec)
Aug 27, 2019, 07:19 PM
Registered User
PC Pilot's Avatar
I was looking at the map and wondered if you have checked the farmland west of the college? If it isn't to rough, the end of the dirt road looks like a good candidate. The shade trees, on the south side, would be a nice bonus.


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