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brahman104

HK B-17...C!!!!!!!! 4/9 drifting to the right

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Very impressive Craig! If I’m remembering rightly, I believe you once told me you CAD skills could use some improvements, I’d say they have. Well done and looking forward to more! I actually started looking at this printer since you posted these.

 

Perhaps with all your free time you can also do a new thread on using the Photon? :whistle: :D

 

Will be following along, can’t wait to see more!

R/S -David

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Just a tidbit of information , I don't know about then , but more

recently Boeing calls your pedestal an aisle stand.

 

There , I've made my contribution  :rolleyes:

 

BTW , I think you might possibly be insane  :mental:

 

;)

 

 

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19 hours ago, TKB said:

 

chilly ---- same goes for your fan shroud! Was that pic "as printed" or "post cleaned-up?"

Since this was a resin print I did need to wash it in 91% IPA, then do a follow up cure in a UV chamber for a few minutes.  But there was no sanding or other manipulation.

19 hours ago, TKB said:

 

 

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15 hours ago, Geddyme said:

Very impressive Craig! If I’m remembering rightly, I believe you once told me you CAD skills could use some improvements, I’d say they have. Well done and looking forward to more! I actually started looking at this printer since you posted these.

 

Perhaps with all your free time you can also do a new thread on using the Photon? :whistle: :D

 

Will be following along, can’t wait to see more!

R/S -David

 

Hahaha, thanks David! But did you read the bit where I had to email them half way around the world for Tim to fix up my mistakes? :) Yeah mate, I am massively impressed by the photon, but it still isn't a miracle worker. Even if I print for copies of exactly the same part, at the same time, they all come out a little different. There's still about a 20% chance that it won't print anything at all (really disappointing when you come back 2 hours later really excited!) and they are quite messy to clean up. Ummm, I could, but there's some pretty good youtube videos out there already, and more than likely I'm doing it the hard way, because that's just what I do!

 

5 hours ago, MikeMaben said:

Just a tidbit of information , I don't know about then , but more

recently Boeing calls your pedestal an aisle stand.

 

There , I've made my contribution  :rolleyes:

 

BTW , I think you might possibly be insane  :mental:

 

;)

 

 

 

Thanks Mike! The title of this post will be named accordingly!

 

4 hours ago, chilly said:

Since this was a resin print I did need to wash it in 91% IPA, then do a follow up cure in a UV chamber for a few minutes.  But there was no sanding or other manipulation.

 

 

Agreed. I actually wash the piece in 3 different jars of methylated spirit first, then a squirt off with IPA , then into the UV lightbox for curing. I'm getting better at it but the post processing is still a bit messy!

 

2 hours ago, LSP_Ray said:

Nice work, Craig! Haven't checked your thread for awhile and you have been going great guns!

:goodjob:

 

Thanks for looking in Ray! it's always slow progress but it IS progress nonetheless :)

 

Okay! So I've used the "scale" command in Rhino for the first time!

 

As you know from the last post, the "aisle stand" (thanks Mike!) looked like a giant over-sized novelty loch-ness monster when I test fitted it into the cockpit. Working back with the dimensions I actually had, the stand could be no more than 17mm high overall. In the side view in Rhino, I resized by scale 2-D to the appropriate dimensions. It then looked excessively wide (even though it is the same width as the HK part) :hmmm:. Comparing to period photos, I decided to reduce it to 9mm wide..... after the initial print of four here's my working example next to its original big brother.....

 

rbHhc5t.jpg

 

Bit of a difference right? 

 

Well have a look when it sits in position.....

 

iqhSz0c.jpg

tEBsqM2.jpg

 

As opposed to.....

 

jjD2Mt3.jpg

 

Much better I do believe!

 

I still have to clean it up and add the rear console to it, which may look oversize now, but we shall see. In any case, I think I've got a winner!

 

Oh and for those of you wondering, this is how the others turned out just so you can see.....

 

L0SzJHT.jpg

 

And THAT's why I do a few of them! :)
 

Just need to get back to the actual bench now and do some REAL modelling!!!!

 

Cheers,

 

Craig

 

 

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That looks much better!

I have never worked with the 3D CAD program you are using, but I have done (2D) CAD to make decals, I always drew everything full size, then printed them out at whatever scale I wanted them. That way I never got confused in what scale my decals were printing out at, and it made it easier to draw from references as I was using the original full size dimensions. 

Not always possible when trying to get stuff to fit in a model that might not be perfectly in scale, but was always a good start.

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Craig, just a tip for building, try tipping your stl files up at a crazy angle. I have found with the FormLabs, and to be fair all the sla printers I have used in the past, you get surprisingly much better build quality if you avoid placing things vertically and/or flat, or nearly so.  Counter-intuitive I know, but try it! Tip that console up so it is literally standing on one corner, so no edges are parallel with the build bed. It works because every layer is then only slightly bigger or smaller than the one underneath, rather than some no different and some drastically different, and the effect is a much more even finish.  I avoid having parallel surfaces to the platform like the Plague!!!

 

Crack on though, excellent project!

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Hi Craig,

 

If it helps, I would join aircorps library - they have every drawing of every component for many aircraft including the B17

 

What I do is find the drawing, copy it into coreldraw

then find a measurement given on the drawing- say it''s 4 inches ( even if i find a part within a part drawing to get that from)

convert this to mm @ 101. 6mm

divide by 32 = 3.175mm

then draw a box on your drawing in corel that goes between the two measured points

look at the dimensions, say it's 14.933mm

tell corel you want that box to be 3.175mm

corel than says you have scaled it by 21.2%

then finally scale the entire drawing by 21.2% and you end up with a scale version of your part

 

I do this all the time so I can print out something as reference, or find a dimension I need - I did it with your pedestal below - drawing number 65-5690..

 

b17_zpsee9hzkcy.jpg

 

If you followed that it's quite a useful process - there are no dimensions on this drawing so I used a control wheel to scale from - hope its accurate :)

 

All the best

Peter

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1 hour ago, wunwinglow said:

Craig, just a tip for building, try tipping your stl files up at a crazy angle. I have found with the FormLabs, and to be fair all the sla printers I have used in the past, you get surprisingly much better build quality if you avoid placing things vertically and/or flat, or nearly so.  Counter-intuitive I know, but try it! Tip that console up so it is literally standing on one corner, so no edges are parallel with the build bed. It works because every layer is then only slightly bigger or smaller than the one underneath, rather than some no different and some drastically different, and the effect is a much more even finish.  I avoid having parallel surfaces to the platform like the Plague!!!

 

Crack on though, excellent project!

 

Hi Tim! That's really food for thought there.... excellent tip! I'll be sure to do that very next print. Thank you! :)

 

47 minutes ago, airscale said:

Hi Craig,

 

If it helps, I would join aircorps library - they have every drawing of every component for many aircraft including the B17

 

What I do is find the drawing, copy it into coreldraw

then find a measurement given on the drawing- say it''s 4 inches ( even if i find a part within a part drawing to get that from)

convert this to mm @ 101. 6mm

divide by 32 = 3.175mm

then draw a box on your drawing in corel that goes between the two measured points

look at the dimensions, say it's 14.933mm

tell corel you want that box to be 3.175mm

corel than says you have scaled it by 21.2%

then finally scale the entire drawing by 21.2% and you end up with a scale version of your part

 

I do this all the time so I can print out something as reference, or find a dimension I need - I did it with your pedestal below - drawing number 65-5690..

 

b17_zpsee9hzkcy.jpg

 

If you followed that it's quite a useful process - there are no dimensions on this drawing so I used a control wheel to scale from - hope its accurate :)

 

All the best

Peter

 

Hi Peter!

 

Wow what a spin out.... that's exactly the drawing I used! I actually did join aircorps library a while ago, but they must've added the B-17 stuff since then, as I didn't see any of this. I'll have to go back on there, as I have the 10,000 odd un-arranged scans, which is a nightmare to look through! I did draw it straight over this drawing, so I must've stuffed up something in my original calculations for the scale, as I normally do the same thing, but scale in Rhino as a background bitmap. Interestingly enough though, the height you came up with there is nearly the same as what I ended up getting on the second go, so I guess that means my good old mk1 eyeball is still going pretty good for calibration!

 

Thanks for the tip though! I'm going back to aircorps library now to go hunting for drawings :)

 

Cheers!

 

Craig

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Oh, by the way, you can import and scale drawings straight into Rhino, either as a background image, or a free floating planar object which you can then scale, cut up, mirror, orientate in your 3d workspace. I've even brought in perspective images, lined them up at an angle, and 'back-perspectived' them (is that a phrase?)  to get some idea of the proportions of things. It isn't perfect, you really need to know the angle of view of the lens to be closer,  but for getting things like panel lines and fasteners in a good place, it is very useful, sometimes.

 

Other times, Mk 1 Eyeball is perfectly good at the job! Never knock it....

 

Tim

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On 9/23/2018 at 10:35 PM, wunwinglow said:

Oh, by the way, you can import and scale drawings straight into Rhino, either as a background image, or a free floating planar object which you can then scale, cut up, mirror, orientate in your 3d workspace. I've even brought in perspective images, lined them up at an angle, and 'back-perspectived' them (is that a phrase?)  to get some idea of the proportions of things. It isn't perfect, you really need to know the angle of view of the lens to be closer,  but for getting things like panel lines and fasteners in a good place, it is very useful, sometimes.

 

Other times, Mk 1 Eyeball is perfectly good at the job! Never knock it....

 

Tim

 

 

Thanks Tim! I'll have to the free floating planar object a go.... sounds fun! :)

 

Sooo, last post was September hey? Geez, where does the time go?

 

So along with a myriad of other (non-modelling projects) I've been working on, I finally found some long awaited time to do a little on the big girl. In the background, I've spent a long time re-doing the tail (again). 3rd time lucky I guess! Anyway, here it is.... (thanks for your help again Tim!)

 

Xpp9Yz3.jpg

 

Yes it's tail 3.0 in all her glory!!! This time I feel I've finally nailed the shape, which was bugging me a lot (just like the nose saga!) Compare it when overlayed on tail 2.0....

 

igKDxQj.jpg

 

As you can see, the real issue was the chord of the fin. It doesn't seem like much, but once you see it, you can't unsee it! :)

 

I also built in a male and female edge to allow the fin and rudder to actually sit together.....

PUzHTEf.jpg

 

Couldn't resist a little mock up with the nosecone and bathtub too ;)

BotMbwp.jpg

 

Moving on, the driftmeter is pretty much done. Some litho plate wrapped around the bottom and a decal for the compass card to be added, but she's pretty pretty much ready for duty!

 

jN5e7wT.jpg?2

 

HNlulbx.jpg?2

 

I made some progress with the "aisle stand" too! I combined HK's rear panel (with the master battery switch) and my printed version, as well as the correct amount of levers for mixture and prop control :) Gets busy!

 

p9haqh3.jpg

 

And with a basic coat of paint to tie it all together.... I gave it a coat of clear too, as these seem to look a little glossy in most photos.....

 

mvmPdAY.jpg?2

 

I think it'll do the trick!

 

Now, back to some basics...... I'm keen to work for a while on getting the cockpit roof underway. I have a fair amount of scrap 6mm acrylic so I roughed out the shape. This will then get progressively filed until I can obtain just the right "look" for the "face." The clear acrylic should work well as it files nicely, and I see through it for the most part about where I need to address. I'll also use this piece to work out where to put the observer's done.... Once this piece is shaped I'm going to make a silicone mould of the exterior shape, then come up with an interior profile so I can cast the overhead console into it in one go. 

 

GQtfMuO.jpg

 

Ambitious yes, scared maybe! :)

 

Cheers,

 

Craig

 

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