Jump to content

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


brahman104

Recommended Posts

G'day all,

 

just a quick update on some more R&D I've done in the quest for rivets :)

 

As I said last post, I felt the curio had potential to produce entire panels worth of rivets, thereby saving me time and taking out some of the human error factor in the riveting process. Not a problem if you're guys like Peter, Rainer or 109, but it's pretty much a given that I'm going to put one rivet in the wrong place and stuff a whole panel or line up.

 

Anyway, I felt that the machine needed a few weeks to get what I wanted out of it. The work area support boards were flimsy, and allowed a lot of slop. This slop combined to absorb the impact of the stipple tool and reduce the imprint on the metal, at times to the point where you couldn't see any distortion in the surface at all. Then there was the issue of the sticky surface not being adequate to hold onto the material which will deform during the stippling process. So here's what I've done......

 

IMG_4618_zpsiyazpsdf.jpg

 

With the laser cutter, I made a "riser" platform in 3.5mm MDF. This would produce a nice rigid surface which unlike the styrene/foam combination the machine comes with, will also stand up to the impact forces of the tool. The next layer I initially had as a sheet of 1mm styrene, but I ended up using the #1 platform to provide just a little "give" under the metal. I'll show you a comparison soon...

 

The top layer sits over the metal and the whole lot is taped down with masking tape. I made it clear so I could see exactly where I was placing the metal. The top layer prevents warpage through the deformation and stops the metal being able to pull away during the embossing process.

 

IMG_4620_zps0zyohhaa.jpg

 

Here it is all assembled. The only thing missing is the tape to hold it all down, but as you may be able to see, the two round lugs on the base do a pretty good job as it is, all I did was make sure all my plates lined up. The material in the picture has already been through the process, I just forgot to take a pic beforehand!

 

For the skeptics, here's the proof.....

 

IMG_4621_zpsvfkp17xa.jpg

 

As you can see, the top one was done with the 1mm styrene layer and the bottom with the #1 platform, both on top of my MDF riser. As you can see, the "give" that the #1 platform allows almost doubles the depth of the imprint and is clearly the winner. I still feel that I'll go along the reverse side and deepen the rivets even further, but that's just me and in all honesty straight off the press is probably pretty close to scale effect I'd say :)

 

I also made a new tool in the 3D printer, using a spare #00 beading tool just to see if it would make any difference than the curio stippling tool. Probably not, but the stippling tool is slightly sharper, so I feel mine is an improvement as it will give a slightly bigger impression in the metal.....

 

IMG_4622_zpsjxo1l4ri.jpg

 

So there you have it. I think I've got a winner here; perhaps it's a little extreme for most to go to these sorts of lengths, but given the external surface area of the fort I shamelessly going to grab any advantage I can. ;)

 

Cheers,

 

Craig 

Link to comment
Share on other sites

Craig,

 

Your modeling skills aside, you are quite the "tinkerer" --- if something is good, then it can be made to be even better!

 

The results of the mods you came up with for your stippler looks like 100% improvement! Seems like you should be able to simulate different type rivets, depending on the backing material used.

Lots of rivets on a Fort --- you'll really be putting this to use.

You have to be naming the stippling machine "Rosie the Riiveter", as she's going to be plenty busy!

 

I don't own a cell phone and am totally reliant on my son to keep my computer functioning properly. The most I can do is hand it to him and say "Uggg --- you make work again!" Seeing what you are doing on the "D", I have to admit I wish I was twenty years younger and had a better capacity to understand and use all the new technology.

 

Oh well, at least I can live vicareously through your (and others) work ---- and once in awhile throw my two cents in.

 

You wish you lived near Dayton; the way your going Dayton will be asking for your input on the restoriation of Ole Betsy/Swoose!

 

 

Terry

Link to comment
Share on other sites

Way to go, Craig, and taking  notes. I can see this B-17 kitbash in a 307 moving one step closer to starting, now that there is a way of dealing with the miriad of rivets visible on the polished alu fuselage;)

 

Hubert

Link to comment
Share on other sites

  • 3 weeks later...

Craig,

 

Your modeling skills aside, you are quite the "tinkerer" --- if something is good, then it can be made to be even better!

 

The results of the mods you came up with for your stippler looks like 100% improvement! Seems like you should be able to simulate different type rivets, depending on the backing material used.

Lots of rivets on a Fort --- you'll really be putting this to use.

You have to be naming the stippling machine "Rosie the Riiveter", as she's going to be plenty busy!

 

I don't own a cell phone and am totally reliant on my son to keep my computer functioning properly. The most I can do is hand it to him and say "Uggg --- you make work again!" Seeing what you are doing on the "D", I have to admit I wish I was twenty years younger and had a better capacity to understand and use all the new technology.

 

Oh well, at least I can live vicareously through your (and others) work ---- and once in awhile throw my two cents in.

 

You wish you lived near Dayton; the way your going Dayton will be asking for your input on the restoriation of Ole Betsy/Swoose!

 

 

Terry

 

Absolutely Terry, I do love tinkering around. The tools I have just add to the methods I can use to build things. The learning curves on each have been substantial, but definitely worth it. Especially when it comes time to do the exterior I think!

 

Amazing work, Craig. You're like the MacGyver of modelling!

 

Kev

 

Hahaha, thanks Kev! Strangely enough, you aren't the first person to call me MacGyver (which incidentally I own the box set B) )

 

Way to go, Craig, and taking  notes. I can see this B-17 kitbash in a 307 moving one step closer to starting, now that there is a way of dealing with the miriad of rivets visible on the polished alu fuselage;)

 

Hubert

 

Yep, the 307 can definitely be a thing Hubert. I've just got to get better at learning how to draw the panels in the software and I'll be away. Can't wait for you to make a start on that one!

 

this is pioneering on so many levels - I love the approach you have to optimising processes and being on the (b)leading edge of technology :)

 

Peter

 

Hahaha, thanks Peter! It really comes down to it that I'm lazy and don't have your patience to do each rivet by hand. No matter machine or not, it still won't look as good as yours though! :)

 

Neat!  This is really envelope pushing stuff 

 

Thanks Brian! 

 

Gosh!

 

Nuff said...

 

Torben

 

Cheers Torben :)

 

It's been a very hectic last couple of weeks at work, with precious little time to play at the bench. I did some laser cutting for a presentation for work and have been learning about the intricacies of vector drawings with inkscape (hopefully for some time saving laser cutting later) but today I finally got back to the bench and stayed most of the day.......

 

First task was to build up the shape of the rudder. I had ordered some solartex to cover it like Peter did with his Spitfire, but I think scale-wise it may be more appropriate with tissue paper. Before I could do any covering though I had a lot of work to get the structure ready.....

 

IMG_4653_zps6o72i0zq.jpg

 

Jumping between the rudder, fin, stab and elevators, I continued building these up. I used a combination of balsa and body filler, as well as high density foam to bulk out the structures.

 

IMG_4654_zps5focv5zp.jpg

 

The only photo I could find of the control surface structure was of the model 299. Even though it changed a little by the time the D model came around it was better than nothing. At this was going to be covered and painted, I also thought it was time I tried my hand at some litho skinning. Of course I started on the "easy" compound curve on the top of the rudder. Did I ever mention I like to do things the hard way?

 

IMG_4689_zpscefsa3sg.jpg

 

After a lot of work, I think I managed the overall effect fairly well. Not perfect, but acceptable for something that was going to be painted. Got to start somewhere right? :)

 

IMG_4690_zpsftxyqqk7.jpg

 

IMG_4691_zpsnyqsdsav.jpg

 

IMG_4692_zps4ezloely.jpg

 

Now, I  turned my attention to the fin, bulking it out slightly to mate up with the rudder. I also installed two pins that run through the acrylic spar and line everything up. These look a bit agricultural at the moment, but I'll clean them up later.

 

IMG_4694_zps6oj0sxp5.jpg

 

And a quick Boeing beauty shot while I wait for glue to dry overnight.....

 

IMG_4695_zpshn7n8b6o.jpg

 

Hopefully by the next update I'll have the structure covered and maybe some more metal on the fin..... 

 

Stay tuned :)

 

Craig

Link to comment
Share on other sites

  • 2 weeks later...

Well not really mine, the B-17's...... :)

 

Picking up where I left off, I had my first real attempt at adding external aluminium panels with rivet detail to the build. I figured the fin was a good place to start, for the most part the panels would be flat and technically easy to make.

 

Having said that, I got so focussed on the lower one on each side and getting them to sit properly, I completely forgot about adding the rivet details, which of course, as "domed" rivets, have to be added from the back side of the panel. Idiot.  :doh:

 

None of my reference photos show a good close up of the rivet patterns on the fin, so this was my best guess. I also overlapped each panel for what I hoped would be a good effect, seeing as that's how I plan doing the rest of the fuselage. After a few hours, I got to this point.....

 

 

 

IMG_4713-L.jpg

Luckily, my two lower, unriveted panels were easy enough to remove, so I carefully flattened them out again and made new ones that slipped in under the panels above....

 

IMG_4712-L.jpg

 

 

IMG_4714-L.jpg

 

I also added something to cover the clear acrylic spar to give the impression of lightning holes.

 

IMG_4719-L.jpg

 

 

The nose cap on the leading edge of the fin was a bit temperamental. It took 3 goes to get this more or less right, as it tapers in thickness towards the top. It also could't handle the radius forming without getting close to cracking, so I had to anneal the piece. Lining it up was also fun, as I really only had one shot at it with the contact cement. For quite a while I considered using some sort of rubber glued on to both hide my average handiwork and simulate the de-icer boot, but I got there in the end and it came out looking acceptable :)

 

IMG_4720-L.jpg

 

IMG_4721-L.jpg

 

The next challenge was covering the rudder. I had seen Peter's efforts in using Solartex and had some ordered, but while it looked good on his 1/18 Spitfire, I thought the "grain" may look a little heavy in 1/32, so I found some tissue paper (for balsa free flight models) that I had obtained a while ago. 

 

I have no doubt everyone on this forum would have built a guillows kit at some point and remembered the delightful odour of the dope, used to attach the covering. As I began searching the net for some, it did occur to me that maybe in this risk-averse age we live in, I might not even be able to get it any more, or by searching on-line for "dope," I might find something a little different to what I was looking for, probably followed by a knock on the door from Mr Plod.

 

What I did find was that the free-flight fraternity these days has moved to using the humble Uhu glue stick to adhere the coatings onto their models. As mine was essentially the same structure, I figured it should work for me. I put it off for a long time as I could only picture this turning into a fiasco involving extended clean up and much swearing, however.........

 

IMG_4726-L.jpg

 

IT WORKED!

 

In the end it was actually really easy, and the material behaved beautifully. Once the glue had taken a decent hold (about 20 minutes), I sprayed the surface with isopropyl and it tensioned up just lovely. 

 

 

IMG_4725-L.jpg

 

Now that I've done both sides I'll probably see if I can add some sticking detail using maybe some fine stretched sprue and covering that over with more tissue. 

 

Overall, pretty darn happy! :)

 

Got to run (literally),

 

Craig

Edited by brahman104
Link to comment
Share on other sites

Really Kev? You can't see them? They look okay to me

 

Bugger.

I can now see the ones in your last post, but not in any of the posts before that. Did you change anything with the image links in your previous post to make them work?

 

Kev

Link to comment
Share on other sites

Yep. I've just been getting up to date with the issues everyone's been having with PB. I joined the trial on Smugmug as a few have done and reposted the pics. 

 

I'm glad you can see them now. As for the previous ones, I can still see them, but maybe if I log on as a guest I wouldn't be able to. In any case, I think PB is dead to me now......

 

Thanks for confirming the new pics Kev!

 

Craig :)

Link to comment
Share on other sites

Thanks Hubert! All good practice for the main event to come :)

 

You got me curious to see if I could find a definitive answer on the panels, and it turns out that on page 15 of the Peter Bowers book, Fortress In The Sky, is probably the best picture I can find featuring some construction pics of the original 299.

 

My interpretation of that picture is that while it does seem to show overlapping panels from the top down as I have, I got the rivet pattern completely wrong! The spar structure appears to be several lots of ribs angled back slightly from the vertical, and hence the rivet lines following..... Oh well you win some, you lose some! :)

 

The Big tail birds seem to show the lower forward part of the fin to have a few panels like that too, and then on the main vertical section they overlap from top to bottom and forward to aft, although there's only a precious few photos that show it in good light. I could try and scan (they are in a book) a couple and send them to you if you like.

 

Might be of interest for your 307 :) When are you going to start that by the way..... nudge, nudge..... ;)

 

Once again, only my interpretation of photos.... the closest B-17 to me is Swamp Ghost, so hopefully I can check her out at the end of August.

 

 

Cheers for the feedback on the pics too....

 

Craig

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...