1/18 Scale Blue Box F4U-1A Corsair Modification

[RLWP]

2 hours ago, JayW said:

My anger and frustration are already subsiding; getting replaced with determination.  Stay tuned!     

 

You know, I learned a lot from my Father in law while working on projects in his garage. Probably the most valuable thing I learned from him was persistence. There's always a way to do something, if you keep at it

 

If I can pass some of that on, that's worth it

 

Richard

[Citadelgrad]

Yep, Jay.  Just keep moving forward on this.   Come at it a different way.  Ponder it, i know youre already doing it.  I am just throwing factory parts together, and i spend way more time thinking about how to do the next step than almost any other aspect of building.  
 

you got this!
 

This and your other builds are both an inspiration and a master class in...its not even detailing, its miniaturizing a real plane. 

[JayW]

Well I debated even posting this news; I'll be brief.

 

I was nearing the finish line with my first outer rim, after several disappointing failures, and this happened:

 

  

 

I intentionally selected extra large picture for you to show just how good this part was going to be.  Anyway, I had flipped it over to machine off the prodigious amount of material from the back side, got pretty far along with no issues, tried to part off a portion of it to save some time, and got a jam.  The kiss of death.  The part was ejected off the chuck jaws bending and marring the rim up as you can see.  A tragic operator error.  

 

I'm going to sleep some on this state of affairs.  Take a break.  It is getting soul destroying to invest so much time and effort (and worry that I might ruin a part at any point), only to have it self destruct in an instant.  I believe I have solved all the problems - it's just getting through the process without a screw-up.  

 

I am very aware that this is a detail that can be 3D printed and maybe be better than the machined part......you'll hear from me before long.   

Edited March 30, 2021 by JayW

[Landrotten Highlander]

As the Klingons say:

 

Qi'yaH...

[RLWP]

How about changing your machining sequence? Holding the thin rim to take the milling forces isn't working, so rough turn the wheel, cut the spokes, then machine the rim

 

Richard

[JayW]

5 hours ago, RLWP said:

How about changing your machining sequence? Holding the thin rim to take the milling forces isn't working, so rough turn the wheel, cut the spokes, then machine the rim

 

Yes, I have been thinking along those lines.  If one were to rough machine this thing, the raw stock would preferably be larger in diameter than the finished part, which unfortunately is not the case here.  I am using 1.00 inch diameter brass rod (the largest stock I have), and the OD of the finished rim needs to 1.00 inch!!  So I have to carefully shim the rough cut to the chuck to minimize the wobble, and then turn the OD to .99 inch max, and live with it.  I have been able to do that so far, but it doesn't give me the luxury of working with an oversized OD as a clamping feature.  BTW, I have larger OD acrylic.  The rough machining idea might solve the problem.  Wow - could that be it......

 

I wish I did not need to flip the part around in order to finish the back side.  That's the problem here.  But I think I don't have a choice given the machine I have and the limited skills I have.  Instead I have committed to flipping the part around to complete it.  The concentricity concerns we discussed a little while back have largely disappeared, now that I have a 4-jaw chuck and a dial gage.  So I am not afraid to remove and replace a partially machined detail, although it is a bit painstaking to restore the rotational centerline and it's never perfect (just good enough).   

 

Even if I rough machine, I still have to have something to clamp on in order to do the final machining of the front side of the part.  Given that I have to flip it around to finish the back side, that means there is going to be some fairly heavy shape (that I used as the clamp surface) that must be turned away. 

 

There is a way that I can redesign the part such that the rim is more robust (less thin).  If I try this over again that is what I will do.  I'd still have to clamp to it to machine the far side, but it will be a more robust feature for clamping forces and I would be a bit more confident.  Even then, few parts regardless of the machining sequence and regardless of robust features are going to be OK after a jam like what occurred to that part you see there.   I must be more vigilant to make sure no jams!  Unfortunately with this part, a whole helluva lot of material must be machined away with a whole helluva lot of passes.  And a helluva lot of opportunity to screw one up and all it takes is one.

 

In parallel with this machining effort, I am looking into a 3D print part.  It may not happen, but if it does, I can incorporate some more realism (like the beads around the spoke holes) that I currently cannot do.

 

What a tough project this is.  Let's see how it turns out.      

[JayW]

I have taken a break from machining of wheels and tires.  In the mean time, I am exploring the possibility of creating them from 3D print, something I have not done yet.  It has the potential for adding more detail and more exactness than I can provide with machined parts.  We shall see.  It also has the potential of saving me from more failure and heartbreak!

 

And, I went back to work on the cockpit.  Recall the LH side is as done as it can be for now.  So now it's the RH side.  The RH side cockpit is as busy as the LH side, and is dominated by the big electrical console, and the radio units.  Other stuff for sure, but those are the biggies.  Similar to the LH side, I decided to use the aux (side) instrument panel as the anchor, and go aft from there.  This laser etched part was provided to me along with the main instrument panel by none other than Peter (Airscale), special order.  Here it is painted, with decals, and ready to go:

 

 

A few comments.  Decals are from Peter's Lope's Hope 1/18 Mustang effort.  This is a laminate of sorts - a metal back plate, where the decals are applied, a metal front plate with holes, and a clear plastic plate between.  You see a blank large hole - it was supposed to receive a rounds counter, and I had no idea what it looked like.  So I left it out!  It would hide in the shadows anyway, so this aircraft will have no rounds counter.

 

Installed on its larger aux panel, it looks like this:

 

 

The white part with the paint scraped off is for the front end of the big electrical console.  You see the yellow O2 bottle that I worked on a couple months ago - still with no inspection tag!  No worries; it will get one Wolf.  Note there is some stuff in front of the aux panel, and some new bracketry below and aft of it.  See the next picture, labelled:

 

  

 

That cluster of heating system valves is going to be orphaned - it gets a bunch of hydraulic lines that will never be seen, MOF the valves will never be seen.  A waste of time.  

 

The fuel pressure regulator cannister is also largely unseen, except its red knobbed turn handle which can fairly easily be seen, and if one looks through the unfilled hole in the aux instrument panel (where the rounds counter would ordinarily be), one can see the top of the cannister!   So there it is.  It didn't get a max effort...

 

The hydraulic valve assembly will also be a bit hard to see, but 10 (ten!) hydraulic lines emanate from it, 8 or 9 of which I will try to represent because they are more visible.    

 

There are a couple more little brackets I will fab and install, then it is on to the big electrical panel, its wire bundles, and the battery.  That will get a max effort!  And you will see at least some of that next post.

 

Take care, hope you are having a nice spring.  I am.

Edited April 13, 2021 by JayW

[RLWP]

He's back!

 

 

Richard

[brahman104]

Do you do contract work for internal fitouts? There's a B-17 I know of that could use some of your talent.........

 

Craig

[JayW]

19 hours ago, brahman104 said:

Do you do contract work for internal fitouts? There's a B-17 I know of that could use some of your talent.........

 

You kidding???   Craig you are an all out pro at this kind of thing!

[JayW]

Well I am sort of derailed here.  I am making slow progress on the cockpit which I'll show next post.  But also I am trying to learn a CAD program (Rhino 7), on a 3-month free trial subscription.  Because why?  Because I think I want to get some parts 3D printed - namely the wheels and tires.  Here is my progress so far on the tire:

 

 

That one is hot off the presses, and I am excepting critiques.  Comments?  As you might expect, the diamond tread pattern was far and away the most complicated part of the modeling.   It's also going to get a bulged flat (I hope).  I must first learn how to do something like that - it will involve several 2D curves, used for a lofted surface.....

 

Peter is kind of holding my hand here.  We'll see how it goes!

 

Stay tuned for adventures to follow.

Edited April 27, 2021 by JayW

[brahman104]

Great start Jay! 

 

I've been using Rhino for about 6 years now and looks like you already have a better handle on it than me! I did manage a bulge on my tailwheel for the B-17 and you can loft the cross sectional curves, but you can also use control points on the surface to "pull" the bulge out to where and how you want it. Have a look at some tutorials about manipulating control points.... pretty useful stuff for more natural surfaces!

 

Craig

[Warbird Kid]

11 hours ago, JayW said:

Well I am sort of derailed here.  I am making slow progress on the cockpit which I'll show next post.  But also I am trying to learn a CAD program (Rhino 7), on a 3-month free trial subscription.  Because why?  Because I think I want to get some parts 3D printed - namely the wheels and tires. 

 

Not sure if you've seen this already:

https://www.shapeways.com/product/CMJWNZ6FU/1-18th-corsair-landing-gear-wheel-kit?optionId=41072772&li=marketplace

[JayW]

What???   It's a rear day where I find 1/18 scale aftermarket stuff!  And Corsair wheels to boot!  Do you think these are 3D print?  He got the iside wheel halves wrong, but the outer halves look pretty good.  And the tires look great!

[Citadelgrad]

7 hours ago, JayW said:

What???   It's a rear day where I find 1/18 scale aftermarket stuff!  And Corsair wheels to boot!  Do you think these are 3D print?  He got the iside wheel halves wrong, but the outer halves look pretty good.  And the tires look great!

Hi Jay. I think shapeways is a 3d printing clearinghouse.  Ive never bought from there, but my understanding is it puts buys in touch with printers.

 

Bill

Edited April 28, 2021 by Citadelgrad