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HK B-17...C 11/2 progress resumes!


brahman104

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Cool !

 

A question though. I thought one of the issues with the HK kit was that the nose section just ahead of the windscreen was not flat enough. Yours looks very rounded when mated to the kit, but one of the photos of the part on the platform may lead to think it has the flattened curvature.

 

Hubert.

 

Hi Hubert,

 

You are indeed correct about the flattening of the nose. When the printed nose halves are standing on their own, they do have a more rounded appearance to them due to the elasticity of the ABS, but I have devised a "proper" (to me anyway) shaped bulkhead that they will mate to around where the instrument panel sits. This bulkhead conforms to the curve that the lower fuselage of the kit has, then flattens out just below where the windscreen sides come up (if that makes sense). The difference is only about 2 or 3 mm from the HK part, but it is enough to make a big difference to the shape, so I will end up having longer/deeper windscreen panels which should correct that "offness" the HK kit has about it when you look at it from the front.

 

I hope that when I post some pics of the I.P bulkhead you will be able to see the difference more clearly. Believe me, I've spent a long time trying to work out that very part!

 

Thanks very much for your question Hubert, I hope my reply makes sense!

 

Craig

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Are you going to commercialize this as an AM add-on?

 

Hi Bill,

 

I did think about it for a little bit, but probably not. The main reason is that most of this has been done by eye and what I think is correct; I don't have any really reliable plans to work from. The other is that while it could be done for those who might be interested, I'm not really sure how far you would go with it. Even with the printing there is still a massive amount of "old school" modelling that needs to be done, like the whole interior for a start! 

 

My intent is to make the rear fuselage in the same way, as well as the tail plane. This will save me a lot of extra work and time, and I will keep the files so they can be reprinted. I would certainly be happy to share those with anyone that was interested in doing this conversion, but I don't think I could ever make a "complete" conversion per se, I'm just not that clever!

 

Cheers, Craig

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Hi Hubert,

 

You are indeed correct about the flattening of the nose. When the printed nose halves are standing on their own, they do have a more rounded appearance to them due to the elasticity of the ABS, but I have devised a "proper" (to me anyway) shaped bulkhead that they will mate to around where the instrument panel sits. This bulkhead conforms to the curve that the lower fuselage of the kit has, then flattens out just below where the windscreen sides come up (if that makes sense). The difference is only about 2 or 3 mm from the HK part, but it is enough to make a big difference to the shape, so I will end up having longer/deeper windscreen panels which should correct that "offness" the HK kit has about it when you look at it from the front.

 

I hope that when I post some pics of the I.P bulkhead you will be able to see the difference more clearly. Believe me, I've spent a long time trying to work out that very part!

 

Thanks very much for your question Hubert, I hope my reply makes sense!

 

Craig

Very clear. Many thanks for taking the time to answer.

 

Hubert

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Hey guys,

 

Just a quick update for some not-so-quick progress. Well that's probably relative. Over the weekend I've managed to design and print the forward half of the rear fuselage and have just about finished the rear 3 parts, which I have yet to separate to fit them in the printer. Here's a screen shot of what I've been working on all day. It's not quick, but it is very enjoyable. I just wish I had another weekend now to do some work on the cockpit and bomb bay! 

 

I'll post up pics tomorrow of the other printed parts.....

 

Screen%20Shot%202015-03-08%20at%2010.01.

 

Not quite sure how to add the fillets along the horizontal and vertical stabs but I'm sure in due time Tim will be able to point me in the right direction....

 

Cheers, 

 

Craig

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Guest Peterpools

Craig

I'm in total amazement at what you are doing. It's nearly a new world for me, trying to follow all the CAD work

Keep 'em coming

Peter

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Thanks Peter! This whole CAD thing has literally leapt onto the WIP forums in the last few months and it's opening up a lot of doors for many people. It's very addictive, I only started using Rhino about three weeks ago, and struggled to draw even a straight line, but once you get the basic concepts and conventions down, you find that you are no longer satisfied with basic shapes and the drive to go further means the learning of new techniques happens by default!

 

It is a whole new world in that you could quite easily spend your time just making models on the computer, even if you never did them for real. That's probably a real bonus for me as I go away a lot, usually for extended periods of time. But no matter what, I still miss good old fashioned modelling and I don't think any model is complete without it :)

 

Craig

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Update time!

 

So all my modelling time has been devoted to drafting up the rear fuselage and tail fin, in preparation for printing. I've been leaning heavily on Tim's assistance to get me out of a few jams when it came to using Rhino and thanks to his advice, everything has been overcome to the point where I can print the parts I need that will serve as a good base point for extra work to be done at a later date. Despite how quick it is to draw basic shapes on the program, you can still quite easily sink many many hours into parts, so they are "completely watertight" in order to print them as solids. 

 

Tim reinforces the point to constantly take the time to ensure your work is clean and all the lines are joined. Yes, Rhino is clever enough to make the best guess to what you are doing to help you out, but when it comes to the printing process, the machine will struggle if you haven't done a good job and the results will be plainly obvious for you to see.

 

The other thing I've learnt is that during printing, the orientation of the parts is critical to the overall finish. Below are two prints of the "bathtub" turret under the rear fuselage. 

 

IMG_1037_zpsg4ccriva.jpg

 

As you can see, this was printed horizontally on the bed. The printer also struggles with big open spaces like windows, as it is trying to print onto thin air, or at the very most a fairly flimsy raft. Due to earlier experiences, I had a feeling it would do this, so I split the part in two on Rhino, then stood both the parts vertical and tried again.....

 

IMG_1038_zpssi8p1vlu.jpg

 

MUCH BETTER!!!!! 

 

So most of the aft fuselage is done. Knowing what I do know now about the program, I could have probably gone back and made recesses where I wanted the entry door and blister windows to go to ensure they were exactly the same, but I don't feel it will be too much of an issue to sort them. 

 

IMG_1034_zps6lbmoicc.jpg

 

I printed the fin as a solid piece, vertically, and it came out pretty well. It will just need some clean up around the edges and then I will separate the fin and rudder. I'm thinking I'll probably rebuild the rudder using brass and then see if I can use something to replicate fabric over the ribs for a better look but that will be much, much later :)

 

Also, if you haven't been following the Rhino user tutorial that Tim is doing in the General discussion forum, here's my drawing of the rear fuselage tail assembly, with sections 4 and 5 together. All I had to do then was mirror it and press print! Mind you, do draw that up took me pretty much the entire weekend........

 

Screen%20Shot%202015-03-08%20at%2010.01.

 

Lastly, here's the whole lot together. The fuselage is so big I have to put it on the floor and stand over it to photograph it!

 

IMG_4401_zpsqp5kg72r.jpg

 

IMG_4402_zpsv0pagdnu.jpg

 

IMG_4403_zpsqpqhidjf.jpg

 

Now to cut some windows and get back to the cockpit and bombay!

 

Thanks for looking, Craig

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Excellent progress Craig, you are clearly having a ball pushing back the frontiers! This will make a great model when done, and I'm so pleased to have been able to help you a bit. What is it they say about teaching someone to fish? Looks like you will be eating for life...

 

 

Onwards!

 

Tim

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This is very cool, though I confess I still cringe a bit at the thought of hacking up a $300+ kit to do it!! Ouch....you have more stones than I do.

 

I hear you! I really wanted to wait and see if someone was going to start one, get sick of it then sell it off second hand. Unfortunately no-one seemed to be doing that and I wasn't sure if these were going to become hard to get in the future. I also run with the "it seemed like a good idea at the time" theme and I find the build part much more fun than the sitting on the shelf collecting dust part; maybe it's not about having stones as much as being hopefully optimistic of a successful outcome? :)

 

Cheers, Craig

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