New Patrol Scratch-Builder in Maryland

[SpruceForest]

Plan set P471 arrived last week from Bob, and acquiring knowledge base, materials and tools/tooling for a scratch-built Patrol. Job 1 was QC on plans changes and a couple warmup projects - a little tin-bending/forming and catching up on my neglected CAD skills with a virtual Fusion 360 wing task to allow a better understanding of which bits go where.

Background: Aero engineer with 1975-2005 active/reserve career as a military pilot, with a few years in there flying commercially offshore and corporate. Currently flying occasional in-flight data collection and avionics test projects for a research and engineering think-tank near DC, but looking for a T-cart, 140, or similar to dust off the long-neglected conventional gear skills and fly on a more frequent basis than corporate projects allow.

Still in sponge mode, but will likely be back with a lot of questions once I get sorted on the basic stuff.

Glad to be here - love the tone and the obvious interest in one another's projects. Looking forward to getting to know y'all.

WR,

Todd

[sjt]

alaska bearhawk

https://www.youtube.com/watch?v=6TqgxL8kn3k&t=453s

a.jpg

Check local cabinet supply houses for high density MDF in 4x8 sheets. I myself liked the 1 inch stuff that can be gotten at cabinet supply houses.
If you can not find 1 inch then lowes MDF seems to be slightly higher quality then HomeDepot but only available in 3/4

Get a can of spray glue to that is used to attach mylar to 032 aluminum.
two.jpg

Dust mask
dust.jpg


Get a jig saw.
one.jpg Routers are useful for trimming. You need to make MDF blanks that are nearly to the line. You can not use router to cut more then the radius of the bit or it will get away from you.
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1
bit.jpg






three.jpg



b-spot

n3uw

https://www.youtube.com/watch?v=iY6Gbf_rOkY

desert bearhawk

https://www.youtube.com/watch?v=aKEBGDSN1YM

kit planes ken scott

https://www.kitplanes.com/building-the-bearhawk-lsa-2/

for eaa members there is a free build log

https://eaabuilderslog.org/

my log is https://eaabuilderslog.org/?blproject&proj=7XFn3SHmH
there are 56 builders using site:

https://eaabuilderslog.org/?blhome&advsearch&zip=&cal=

There is a commercial site for logs:
http://www.mykitlog.com/search.php?s...tate=&country=

Eric Newton has 3 manuals that are for sale.



----------------------------------------------------

Glenn Patterson has some good stuff on forum bh-4 727
https://bearhawkforums.com/forum/bea...anks#post35840



https://bearhawkforums.com/forum/bea...5416#post45416




https://bearhawkforums.com/forum/bea...?p=790#post790
Glenn Patterson capstrip1.pdf


https://bearhawkforums.com/forum/too...s-dies#post233
Glenn Patterson ROUTER METHODS FOR BEARHAWK.pdf


https://bearhawkforums.com/forum/bea...-edge#post1615
Glenn Patterson Vert Riveting Spar.pdf

https://bearhawkforums.com/forum/too...g-assembly-jig Glenn Patterson Wing Jig Frames.pdf

[SpruceForest]

Thanks for the warm welcome!

Great links and suggestions, Stan. I've been laminating 1/2" MDF with West 105/205 when I need 1" or thicker patterns for my non-airplane work (build/repair acoustic/electric guitars/basses/mandos, etc. in addition to the engineering gig), but more labor... good suggestion to see if one of the local DC or Baltimore cabinet places has 1" in stock. Already headed up to Baltimore to see if I can find a brake for spar work (used to walk by a left-behind 12'+ brake and equally large shear in one of the old Fairchild hangers every time I was up in Hagerstown, MD at the Army flight activity there during the 1980's... could have had them for the cost of removal...hope they made it out to one of the colleges or homebuilders in the area).

One of the reasons for the Patrol from scratch was that I've worked in wood and composites since my early teens, but never got a chance to do all that much sheet metal or tubing work outside of the stuff necessary to hang composite parts on a metal structure, so the links to that content is much appreciated! Was wondering whether Adels were the best route for hanging the wing wiring chase... that alternate approach is pretty interesting!

Again, thanks!

Todd

[sjt]

Building from scratch requires a change of mind set. When first starting you see drawing dimensions like 1.021 rivet spacing. You might think that you are suppose to do something with accuracy to a thousandth.
That is not the case what Bob is saying in a compact form is that the ribs are spaced out 12 1/4 inches. He also wants 12 rivets in that spacing. 12.25/12=1.021

The plane is made with a plastic mallet from harbor freight. It is very likely that one of the EAA chapters in your area has a 10 foot brake. That is where I got access to one. Everyone thinks they would want a 10 foot brake but, you only need it for the flap spar. The rest of time it takes up a huge amount of space. It is not even useful for setting down your coffee.

I must warn you, builders suffer from a disease. You see a nice tool a fellow builder has. You know that it is not necessary to do the job. Within an hour you have convinced yourself that you need one.

You may see tools in the the background - I have claimed that they are not needed. Every tool you see you think you need.


There is nothing that can be done to cure this malady. I can tell you not to do what I did, but you will.


snips.jpg
This is the most useful tool. Hard to find. Do not Do not Do not get an electric shear from Harbor Freight. Probably estate sales or ebay

The beginning of the project is all about mdf. Make about a hundred form blocks.
This is only some of my forms.
mdf.jpg

I used a router mounted upside down. I made a plastic shield to keep mdf and aluminum from being ingested. A router is very useful early in project.
The sliver tape you can see but there is also clear packing tape around periphery.
(THIS IS MY REPLACEMENT ROUTER AFTER NOT DOING THIS THE FIRST TIME)
router.jpg
image_11057.jpg The bit I recommend is a down spiral 1/2 bit. Even so burning hot chips fly everywhere. Because it is a down bit the chips are suppose to go toward router. That is why you need a plastic shield and a vacuum.



In making the mdf forms I recommend a table saw, jig saw, and a circular hole cutter in addition to router and drill press.
circlecutter.jpg
The circle cutter is the most dangerous tool. More dangerous then the router.
You get chips everywhere. Because the drill is set to slow speed you think you can reach in and brush away chips.
You can not - blood everywhere on your new mdf form.

Buy lathe bits for circle cutter and grind whatever profile is useful.

jigsaw.jpg jig saw indispensable.

tablesaw3.jpg table saw absolutely indispensable. - You can get 10 inch aluminum cutting blades.
In this picture I am cutting down a 3/4 6061 angle down the spine. Sometimes you need
material in a size it is not commercially available. The 3/4 angle is turned into the 1/2 inch 6061 strips I need.
tenuru10.jpgthinkerf.jpgtablesaw.jpg
Make all sorts of things with table saw. Also can be use to support coffee cup. The thin 7 1/4 thin kerf blade made a wood jig to allow me to clean up the edges of aluminum strip.

Things that are useful and can be gotten from Harbor Freight if you have a coupon:
hammer.jpgimage_11054.jpghammerhandle.jpgclamps.jpgsander.jpg
plastic hammer
Almost every clamp you can find will eventually be used. In one of the pictures I have epoxied plastic Delron that suited my purposes.

You can cut off the head of one of the their hammers and make a tool for squaring up aluminum ribs.

I do like their cheap sander. You need to get it on sale.

Things from estate sales:

papercutter.jpg More clamps from Harbor Freight.
Converts a paper cutter to a tool for making 2024 aluminum angles.

When you finish mdf forms you need to buy or make a tool to help forming the flange edge:
image_11052.jpg
Even when you think you are done
making mdf forms - you will find that you need hold down mdf forms.


Keep your eyes open for cheap stuff that can be repurposed.
I myself have been keeping my eye on the fire hydrant across the street. I am sure I can use it to bend something.

[N3UW]

Plan set P471 arrived last week from Bob, and acquiring knowledge base, materials and tools/tooling for a scratch-built Patrol. Job 1 was QC on plans changes and a couple warmup projects - a little tin-bending/forming and catching up on my neglected CAD skills with a virtual Fusion 360 wing task to allow a better understanding of which bits go where.

Background: Aero engineer with 1975-2005 active/reserve career as a military pilot, with a few years in there flying commercially offshore and corporate. Currently flying occasional in-flight data collection and avionics test projects for a research and engineering think-tank near DC, but looking for a T-cart, 140, or similar to dust off the long-neglected conventional gear skills and fly on a more frequent basis than corporate projects allow.

Still in sponge mode, but will likely be back with a lot of questions once I get sorted on the basic stuff.

Glad to be here - love the tone and the obvious interest in one another's projects. Looking forward to getting to know y'all.

WR,

Todd

Welcome to the group. There have been very good suggestions posted here. I am a bit of a hybrid builder. I scratch built the wings but bought the quickbuild fuselage kit. I scratch built the wings because I enjoy working with aluminum and wanted to make sure I really wanted to do the build. I am also a woodworker and have restored several certified aircraft so I had the tools I needed with minimal investment. I got loved the scratch build process on the wings so I knew I was on the right path. Steel work is not quite the same area of expertise....that explains buying the fuselage.

[SpruceForest]

Stan...wealth of knowledge... trying to spend 2-3 hours a day on the deep dive! Thank for the sage advice, and appreciate your time.

John...thanks so much for the welcome...I've watched some of your vids on YouTube and envy your stage presence! The rib flow-forming vid was informative, and I'm tooling up for a combination of 20 ton press (in hand) and flow forming gun. Again, thanks for the time spent on your response as well as the vids on YouTube...super helpful!

[sjt]

Todd,

I did mention the malady of monkey see monkey do.
John showed the use of a 20 ton press so I had to have a 20 ton press.
John connected a switch to automatically lower the press - so I had to use the same switch setup.

I was not a complete copy cat. I felt the need to actually make the entire 20 ton press.

John found a source for a flow forming set in a rivet gun - so I had to have a flow forming gun.

I was not a complete copy cat. I did a write up in the recent beartracks on how to make your own flow forming set. https://bearhawk.tips/beartracks-pricing
set.jpg
As an aside. There are rivet guns and there are air hammers. Flow forming is the only thing that can be done with an air hammer. Always use a real rivet gun for rivets.

I used the press like John to make the flanges but I went a step further.
4130.jpg
press1.jpgpress2.jpgpress3.jpg



There are certified airplanes.
There are pre-punched kit airplanes.
There are kit airplanes where you can buy sub-assemblies - John is an example of buying the fuselage portion of a kit. - You can also buy just the spars or just the ribs from Mark Goldberg.

And there are individuals who make tools to make an airplane. These people usually come from a software background.
(Software engineers are famous for rewriting all the code of the previous engineer.)

p.s.
These days the pneumatic over hydraulic press is used to make chicken filet sandwiches. My filet sandwiches are thinner than anyone else makes them.

[SpruceForest]

Monkey-see, monkey-do...sounds like how Ray Sovia (first military flight instructor...4 tours in Vietnam...but actually earned his hazard pay for flying with me) would have described me on a good day going through Primary. Yeah - def will look for jobs that the press can pay for itself... all those brackets and standoffs look like something with exploring.

[Chewie]

Welcome Todd. Glad to see another scratch builder. Together we'll get there.

[SpruceForest]

Absolutely... every build ends up to be a team build, and as someone I have never met once said, there is no 'I' in 'team.' Sadly, there is also no 'I' in 'beer' but I hope we get to hoist a few together a few years from now to celebrate completion of our projects!