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SEPECAT Jaguar GR3A


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Timmy!

This is amazing! I do CNC milling for a leaving and would love to know some details:

What -CAM

-CAD

-milling machine

-interface for uploading the program to the machine

-cutters

-and is that 6065 t-6 aluminium or aircraft grade?

It all sounds expensive. :jaw-dropping:/>

Anthony

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Timmy!

This is amazing! I do CNC milling for a leaving and would love to know some details:

What -CAM

-CAD

-milling machine

-interface for uploading the program to the machine

-cutters

-and is that 6065 t-6 aluminium or aircraft grade?

It all sounds expensive. :jaw-dropping:/>/>

Anthony

Anthony,

Here's the workflow

Design in Rhino (CAD) models exported as STL files to Mesh CAM

From Mesh CAM I get the tool paths. Mesh CAM has the post processor for LinuxCNC g-code which drives my Sherline 5400 Mill.

Cutters are End and Ball mills ranging from 3/8" to 0.005". Small ones are standard and long reach end and ball, 0.040", 0.020", 0.010" and one 0.005" (for fun) all carbide 2 flute. The bigger standard sizes are 3/8 to 1/16 end mill are HSS 4 flute (not great for aluminum I gather but I bought them before I knew anything) ball mills are two flute carbide.

Finally, I'm using 6061 stock though I'm sure to play with aircraft grade 7075 down the road.

Hope that answers most of the questions,

Timmy!

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7075 will machine much better but at a serious cost!

Thanks for the info, I just looked up .005 thou ball mills, you need a scope to see if there is a cutting edge :wacko:/>

and some fast RPMs

Wish you were closer so I could come and see first hand.

What a blast.

Anthony

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  • 2 weeks later...
  • 2 weeks later...
  • 5 weeks later...

Progress to share at last. First few parts are done and I'm stoked that I have a solid proof of concept represented in these parts.

I was somewhat reluctant to share at this stage as the parts are still a little rough and photos don't really do the parts any favors. But here they are none the less.

acrj.jpg

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pf44.jpg

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qhua.jpg

This is a reject part that I have partially finished. A little work with a file and buffing wheel and these parts are really good. I'm was always intending to to some hand work to these parts anyway.

neai.jpg

e3wp.jpg

Some behind the scenes work are things like this custom clamp. It's shaped to fit the part and allow the part to be held in a vice after the part has been partially milled.

mvl1.jpg

g16k.jpg

Thanks for looking in.

Timmy!

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  • 11 months later...

It lives...though just barely.

This project has been very experimental to say the least.

Let me recap the project...no there is too much...let me sum up.

So far the I have gone from a hand built master with cast parts so I could make multiple models. I wasn't happy with the accuracy so I scrapped it. Thinking CNC one off models was the way to go I tried cutting solid hunks of aluminum. Successful, accurate, looks dynamite but the process is way too slow and very hard on my machine. So guess what I have done? Yep scrapped it.

So now I am on the third if not fourth iteration of this jet. Here is what I have done.

I finally found a relatively cheap supplier of machinable foam and wax and I have started over. I'm still using CNC to cut the shapes of the airplane in a similar fashion to what I have done in aluminum, but I'm not machining so much detail this time. Now I am machining foam parts that will be sheeted in aluminum, like I did on the first hand built master. I will then cast parts to make copies of the model.

There should be several advantages. One, the new material cuts MUCH faster and is easier on the machine and tools. Two, the parts can be more easily fine tuned and mistakes fixed. Three, I should regain some of the "hand built" look which should capture some of the minor surface variation seen on the real jet.

So here is where I am as of today.

I have completely rebuilt my CNC mill and have increased its accuracy and its machinable area so I can mill larger pieces.

SO NOW THE JAG WILL BE BROUGHT TO YOU IN 1/12th SCALE!!!

Here are some of the foam parts:

The nose section forward of the cockpit

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Vacuum form master for the next section forward, that houses the LRMTS. This area will start as a vacuum form shell detailed out and should fit a milled lip on the foam parts from the previous photos.

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The change is strategy also required some rework of the CAD model so here some teasers of the cockpit area:

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The multi-colors in this shot are coded to the different material I plan to make the individual parts from.

16244204888_276f36ebc4_b.jpg

More later,

Timmy!

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Given your industrial-like set up, you could have gone the route of creating injection molds instead, and have had the model made in injection molded polystyrene - as a regular kit. :-)

I guess a similar but different approach to the one you've chosen would be to print the parts in a 3D printer instead of milling foam. If they are to be skinned with aluminium, a relatively cheap 3d printer could be used. I think they are cheaper than the cheaper CNC milling machines. Just thinking out loud here from the viewpoint of someone not owning a CNC milling machine. :-)

Too bad you can´t reuse any of that fantastic detail already created, but I am sure you will be able to do it all over again. Good luck!

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As always i am amazed and humbled...

Wow...

What foam are you using for milling?

William G

Thanks to you and everyone else for the encouragement.

The stuff I'm currently milling is a closed cell urethane foam, 48 lbs. Precision Board Plus is the brand name.

Timmy!

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  • 4 weeks later...

How's about an update?!

Here is the progress after a few uninterrupted days in the shop. Several more foam parts have been cut and have done a few more in acrylic. Also the 3d printer has pumped out few parts while I was at it.

Here are the representative parts hastily placed together to give the idea of the construction.

16513500837_2cdc6e162b_b.jpg

The acrylic bulkhead that incorporates some detail for the nose gear well. The acrylic is hard and stable but quite brittle. Sometimes a miss calculation of the feed of the bit and I get a little bit of chipping of the detail. Although I will be able to repair this without too much effort.

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Here's the rear cockpit bulkhead set into milled recesses of the foam fuselage side.

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Again the fuselage side with a 3d printed gun shroud.

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The gun shroud in place..nice fit better than expected and this is before any post mill/print finishing whatsoever.

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Last one these are two of the three vacuum form molds that will shape the nose section of the Jag; that house the LRMTS.

The process is light coat of primer is applied followed by careful file and sandpaper work to remove the primer. As the low spots mark the true shape of the part once the paint is gone the part should be closer to it's nominal size.

16513594427_d471c73030_b.jpg

That's it for now more later.

Timmy!

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This build is completely crazy- and completely entertaining as we watch you push the envelope of scratch-built modeling at an extreme skill level. Thanks for all the pics and updates, because I know they can be a real pain to do!

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  • 4 weeks later...

Quick little update.

I finished post processing the milled vacuum form molds and pulled some plastic.

16348844454_2e43b6e432_h.jpg[/url]

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Also I got the 3d printer working here are the cabin pressure valve and safety relief valve.

16763857687_7b51fde755_h.jpg[/url]

Better photos coming soon. I have more parts from the printer and the vac parts have been trimmed up.

Timmy!

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The promised update to the last update:

Parts, parts, parts all in various stages of finishing. I'll just let the photo's do the talking. Nothing new here just basic finishing and detailing work.

Printer parts.

16798793517_a875b294be_b.jpg

Vacuum formed parts.

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Detailing the acrylic cockpit rear bulkhead.

16818447528_92b29cf61b_b.jpg

Thanks for watching!

Timmy!

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  • 1 month later...

The latest progress. A few more parts cut and printed.

Here's the windscreen frame. The part will hold three separate acrylic clear parts, just like the real thing including a thicker center section.

The part in the printer.

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The part with supports attached. I'm really happy with the print. I managed to get the channel for the canopy seal to print perfectly.

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The parts so far. No clean up and just set together. Getting close to having enough parts to start some assembly and surface detailing.

17681578953_9ca00a1616_h.jpg

That's all for this one. Thanks for checking in.

Timmy!

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  • 1 month later...

Finally some satisfying progress. Glad to get some detail work accomplished...while the production of parts has had it own satisfaction. This is sweeter work.

You are looking at the parts that will make up the cockpit tub. Mostly CNC acrylic parts with metal, styrene and printed part detail. This is the first coat of color to spot flaws. I'll take a set of loupes and fine sand paper and files and do some final clean up and then assemble the parts. I have enough parts cut to assemble the fuselage forward of the intakes.

On to the photos...

Cockpit side walls

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Side consoles and floors

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Pressure and safety valves with a little paint so the detail can be seen.

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Parts set together

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That's it for now...

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