Merry Christmas to all!

Taking a break from building to enjoy the holidays with my family. Merry Christmas to all and to all happy CX4 building!  Hope Santa brings your goodies. And a Happy New Year!

Greg.

Spar Ends - Three more hours

Finished shaping and smoothing spar end pieces today.  The 1/4" pieces for the wing spars are primed and drying.  Here is a picture of the first one I finished.

1/4" Spar end finished with self etching primer

After cutting the pieces out, I hand filed them, then a couple of minutes on the bench grinder wire brush and finally hand sanded with 220 grit to a smooth finish.  Cleaned with mineral spirits and then painted one coat of self etching primer.  The final piece looks pretty impressive.  Looks like a machined piece. Eight more to go for the 1/8" spar ends that go on the center spar.  That will be tomorrow's task.  Although I'll probably be back in the garage/workshop this evening.  I wanted to keep dust down while the primer sets on the pieces I sprayed today.

Thanks for checking in!

Spar End Fabrication - 4Hrs

Cutting, grinding, filing, and wire wheel polished half of the spar end pieces today.  Wow, that 4130 chrome alloy steel is H A R D! stuff.  Went through four jigsaw blades cutting the 1/8" material.  Following the plans I needed to cut off 1/4" of material from the end to 2" from the other end to allow for the spar ends in the spar angles.  I set up the parts to show the way it will fit together:

So here is what 4hours of work looks like:

Very satisfied with progress today.  It was quite rewarding to take the raw metal from bar to finished shaped part.  So these are officially the first real aircraft parts that I have made!  

I will cut the spar webs tomorrow hopefully.  Need to get some help unrolling the .040 Sheet to do that.  Also will need to clear off the work bench to do that.  Sheet is 12' long.  And I need to cut two lengths of 93 1/2" and one 35" by 7" pieces for those parts.

Stay tuned!

Post Turkey Update

Hope everyone had a safe Thanksgiving.  Back to the shop tonight.  Bought a bench grinder from The Home Depot.  This will help with the parts fabrication.  The hand filing is S L O W.  Now if I can just keep my fingers away from those spinning wheels... :)

Here's what I purchased:

Ryobi 8" Bench Grinder

I will start shaping the 4130 Steel parts for the spar tomorrow.

2hrs spent assembling and testing/aligning new grinder.

** Update ** Parts missing for the left side guard and work rest assembly.  Contacted the manufacturer since that's what is says to do in the documentation (do not return to place of purchase if parts are missing)

So a quick email to Ryobi.  They responded telling me parts were on their way.  Need to wait for those parts to use the grinder.  So no spar ends work tonight.  Will turn to other tasks.

Spar End Fabrication - Slow and steady hand filing - 4hrs

Started spar end fabrication today.  About 4hrs work and I still have five more blanks to cut/shape.  It's slow going without a bench grinder.  I'll need to invest in one.  Been hand filing all the ends and still have to shape and smooth them.  Tomorrow I will finish the five remaining 1/8" pieces and then start milling the end shapes and finishing.  Here's what I have so far:

Three of the eight 1/4" pieces

I have been getting consistent with my cuts.  Using a hand orbital jig saw with a metal blade to do the cuts.  I rig up a guide for each cut to help me keep it square.  Less filing that way :)

Makeshift guide to keep things square when cutting

Progress at last!  I am starting to understand that this is going to be a long process.  But a little at a time. That's how I'll take it.  I'm sure the work today would have gone faster with a bench grinder to do the finishing and shaping.  However with a hand file it is likely I won't over shape or remove too much material during the shaping.  Heck, the Wright brothers didn't have electric grinders did they?  Well, maybe they had some steam or foot powered tools in their shop.  

6061-T6 .040 and .020 Unwrapping - Not yet

I received a sheet of .020 and a sheet of .040 6061-T6.  I was going to unroll it and start tracing out my spar webs and ribs.  But I think I'll wait until I have a second set of hands to help me given this warning on the roll:

I was able to get a 2'x3' 26 gauge galvanized steel from The Home Depot for the firewall - so think I'll trace the form onto that stock and cut out the firewall tonight.  Pictures to follow.

"A journey of a thousand miles begins with a single step" - 3hrs

 Lao-tzu
(The Way of Lao-tzu)
Chinese philosopher (604 BC - 531 BC)

After a couple of months planning, reading, and studying - started on construction of the spars today.  Wanted to get more done but time passed so quickly this weekend.  

What I did get done - I built the jig that will be used to align and clamp the main and center spar pieces together for assembly.  Spent about 2 hours on this piece.  I think the second one should take half the time.  A lot of time was spent measuring, checking, measuring, clamping, checking, and re-measuring.

Here's what I ended up with after two hours:

Will make a second jig tomorrow evening and then start putting the spar parts together.

A long journey ahead indeed.

Stay tuned.

Thanks ---  Greg.

**UPDATE**
Yes, I was right.  Made the second jig in about 30 mins.  And yes - I made the jig wider than the plans. 

CX4 Step One - Build a work table

I think that is what is says in the construction manual.  First - build a table ...

Well that's what we did today.  My son and I built the work table for my CX4 project.  Greg (my oldest) is great with wood and he pretty much free-handed it.  Told him what I needed, we got the wood, and two hours later we had the table.

The table is a little over three feet high and this one is eight foot long.  We're going to make another one to extend the total length to 12' or 13' depending on how much work-around room that leaves me in the garage/workshop/CX4 Factory :)

The table is stable, strong, and quite level - which is important.  I should have my aluminum (sheet and angle) and other materials required for the main spar and center spar sections soon.  So construction will  commence shortly.  Meanwhile I'm going to continue making bulkhead and other forms from the leftover plywood like I did for the ribs:

Here are a few more pictures of the work table construction:

Stay tuned!  More to follow -

BTW - Thanks Greg for your help!!

Sandy, the fireworks are hailing over little Eden tonight...

"Sandy, the fireworks are hailing over little Eden tonight, forcing a light into all them stoned out faces left stranded on this 4th of July" (Bruce Springsteen, 1974)

Well, it's not the 4th of July - but Sandy will be hailing over us during the next few days.  

Batten down and hold tight east coast.  There's a storm coming.  Sandy is no lady.  She's gonna bring havoc on us from NC up to NY.  Hold on all.  No CX4 work this weekend.  Getting ready for the storm.  

Hope we all ride it out safely.  Good luck to all.  Keep safe, stay smart, and be ready to help your neighbor.

Greg.

Rib Forms - Ready for the bending - 5hrs

I sanded and fine-tuned the rib forms today.  Used my hand held Black & Decker "Mouse" sander. It was a little faster than just hand sanding.  I think the little sander did a good job.  Laid the forms back on the original plans to check accuracy of my cutting/finishing of the forms.  The forms match the plans so I think we're good to go.

Also received another bag of nuts & bolts from AircraftSpruce.  Checked these parts into my inventory.  I now have all the hardware necessary for the main and center spars.  Just waiting for my aluminum stock order to arrive.  I found a place locally that can supply .040 6061-T6 sheet and angle stock.  The guy told me he could not supply any sheet stock thinner than the .040 so I am still searching for a local distributer.  The shipping of aluminum sheets is very expensive and I'm trying to control costs.  So I'll try to find the .020 and .032 locally before committing to ordering it from Wicks or ACS.

Rib Forms

Cut out main and nose rib forms.  Started using my 10" Band Saw but found it difficult to control the work that I was cutting.  Reverted to a hand held orbital jig saw.  Worked okay.  I have some fine tuning to do with sandpaper.  But I matched the cut out forms to the plans and they match up rather well.  My woodworking skills are getting better.  I found by the third cut that I was able to control the jig saw quite well.

Following the lines that I traced to the wood using tracing paper and graphite paper

The main and nose rib forms

Spent about three hours to finish the cut outs for the ribs above and the wing tip ribs.  Drilled each for the bolt/wingnut/washer that holds them together.  A bit more sanding and they are ready.

Still waiting on material order for spar stock.  And also still trying to find a local 6061 supplier.

Thanks for looking.

Home Economics is what they called it -

When I was in high school - the boys took shop and the girls had home economics.  That's just the way it was done.  Guys learned how to build small wood or sheet metal projects and the girls made brownies and learned how to sew.

Today the two worlds have clashed.  I transferred my wing rib and nose rib tracings to wood form stock successfully using a method my wife learned in home economics.

I got some graphite transfer paper from the craft store along with a sewing pattern transfer wheel.  Total cost about $5.00.  And by gosh it worked.

Here are some pictures of the process:

Graphite Paper and the Sewing Transfer Wheel

Put the graphite paper between the tracing paper image and the plywood form stock and trace the shape

Peel it back and view the results.  Some touch up needed but hey - it worked!

Next step - the jig saw to cut out the shapes.  I did the main and nose rib forms on this piece of plywood.  Will be cutting it out using my 10" band saw and then fine tune the shapes with sand paper.  I will post those results too.

Stay tuned!

Zero Progress

The title of this post says it all.  Zero progress on my CX4 project this weekend.  The weather was just too nice to be in the shop.  Enjoyed a wonderful weekend including a trip to the Flying Circus in Bealton,  Va.  They have a weekly airshow there featuring a collection of beautiful airplanes.  Mostly Stearmans with a Waco or two.  You can get a Stearman ride for $70 including an aerobatic ride for $110.  Truly worth it.  Especially if you have never experienced an open cockpit biplane.  The first time I took a ride was when I realized if I had the fiscal capability that open cockpit biplane flying is my calling in life.  The Flying Circus puts on an airshow each Sunday during May - October.  

Perhaps the title of this post is a bit of a lie.  I did do some "work" on the CX4 project.  I stopped at a Hobby Lobby store and picked up some transfer paper.  I mentioned this concept in an earlier post.  I'm going to try transferring my tracing paper rib and other parts shapes to wood for forms utilizing a method that my wife recommended.  It's the same process she has used for tracing a dress pattern to fabric.  Should work.  Only cost a couple of bucks for the materials.  And we can see if it works.

Hardware Order

Ordered a bunch of hardware from Aircraft Spruce today. Just the nuts, bolts, and rivets for the spar and center section.  Sure does add up fast. Also ordered the rivet package from Great Plains folks. A lot cheaper than anyone else.

Hope to get my workshop table completed this weekend so I can start on the spars! 

Stay tuned!  :)

More Plans Tracing

Continued tracing wing and center section parts from plans.  Finished tracing the shapes for wing ribs (front and rear), wing tip ribs, center seat ribs, and associated parts.  Will be doing the transfer of traced patterns to wood tomorrow after I get the transfer paper to try that out (see previous post)

Two more hours spent on this task.  Very time consuming.  A lot to do but we have started the journey.

Pictures and results of transfer paper attempts tomorrow.

Rib Form - Tracing Patterns - Transferring to wood

Started tracing front and rear rib patterns for the wood form blocks tonight.  Spent about 2 hours tracing the nose rib, main rib, F6, and wing tip rib patterns.  Using tracing paper on the plans I will be transferring that directly to the wood for forming blocks.  I have been reading about how others have done this.  Trace the plan, cut out with poster board then glue to wood for cutting.  My wife had an idea when she saw me tracing the plans to tracing paper.  She said it looked somewhat like a dress pattern.  And she told me how she use to transfer the pattern to fabric using transfer paper and a wheel marking tool.  I'm going to try that method.  Use the tracing paper image of the ribs and some sewing transfer paper to mark the wood directly.  I'll post some pictures tomorrow with the process and we can see how it worked.  Transfer paper is only a couple of bucks at AC Moore (craft store) so I'll get some tomorrow and we will try it out.

Will let y'all know how it goes.  Stay tuned!

Clecos and Drill Bits from Aircraft Tool Supply

Clecos, cleco pliers, and drill bits arrived today.

Addendum: Brief Comment

Would like to know if others undertaking a plans built experimental aircraft - Did you spend as much time planning, studying, tool gathering as I am documenting here?  Does this time all go to the total "build time" for the airplane?  --just wondering.

Word to the wise: Rivet Puller (Don't go cheap)

I purchased a swivel-head blind rivet tool from Harbor Freight (HF).  Also bought some aluminium stock pieces from The Home Depot.  Intended to practice drilling and shaping the material and then start to develop my blind rivet skills.  The rivet puller (manual) I got at HF was on sale for $4.99 (regular price $9.99).  And it comes with four heads for different sized rivets and a collection of aluminum rivets.

Don't buy one of these.  I pulled two aluminum rivets with it and it failed.  With the volume of pulled rivets in this project - this is not the tool to use.  I will probably buy one from AircraftSpruce or Wicks and pay a bit more for better quality.  I will also invest in a pneumatic rivet puller.  As I noted in an earlier post - 5,000+ blind rivets to pull.  The tool from HF won't cut it.  Good news - I bought the rivet tool from the HarborFreight online store and was able to return it to the store in Gaithersburg without any problems. 

Guess the lesson here is - you get what you pay for.  A $4.99 rivet puller won't measure up for my CX4 project... 

More Shop Preparation

Fact is I need to set up my workshop before I can build my CX4.  I have spent a bunch of time reading and studying the plans and construction manual.  I have done a lot of planning and materials purchase research and pricing.  Have laid out my first build task which is the main and center spars.  Ordered some material, ordered some tools.  I'm going to need a band saw for this project.  Several years ago I got a band saw from my Dad's workshop after he passed.  The saw has been sitting in my garage for a few years and so yesterday I pulled it out, dusted it off and cleaned it.  Found that the power switch was not working.  Pulled the power panel off of it and found it to be a simple SPST toggle type switch.  Went to Home Depot.  Got a switch and put it in.  Voila!  The band saw works!  Okay, that's a couple of hundred bucks I don't have to spend on another tool for the shop.   Here's a picture of the cleaned up band saw.

Old Sears Bandsaw from my Dad's shop

Thanks  Dad.  I know you would appreciate this being used for my airplane build.

Another tool that's going to be well used is a drill press.  So I went to Harbor Freight Tools in Gaithersburg, MD.  Found a nice drill press for a reasonable price.  I know it's a China special.  Everything at Harbor Freight is made in China.  But I hope this is sufficient for my needs.  

Drill Press - $69.00 at Harbor Freight

Also went to a craft store and picked up some tracing paper for transferring plans drawings to poster board and then on to either wood for parts fabrication or directly onto aluminum as needed.  

I'm going to do some plans tracing now.  Think I will trace the rib forms from the plans to some 3/4" plywood to make the ribs.  If anyone reading this doesn't know - the wing ribs and other sheet aluminum parts are formed by sandwiching aluminum between two "form blocks" and then banging them into shape with a hammer.  The EAA has a good series that shows this method here.  I'll post some pictures and progress on this next time.

Stay tuned!

More on Rivets - There sure are a lot of them in an airplane!

Stainless Steel Pop Rivets

(Thatcher CX4 Construction Manual)

4500 CCP-42

500 CCP-44

100 CCP-46

That's what Dave Thatcher says you will need for the CX4 build.  Think I will invest in a pneumatic rivet pulling tool (about $70) or risk having a forearm the size of Popeye's at the end of this all.   

Oh, and there are a few pounds of AN470 rivets to pound into the spar build as mentioned in the last post.  More tools, more parts, more money.   

Rivet Methods and Project Table

Still doing a lot of research, reading, studying, and making material lists.  I wonder if other builders count the time spent studying plans and shopping for material in the build time for their projects?

I have discovered that the CX4 Community Yahoo group is VERY helpful.   The photos provided by other builders in the group are a great help.  Also, the time I spend studying the plans is starting to be realized - I am getting better at interpreting the plans and visualizing the spar build task.   Seems the more I study the plans - the more detail I can visualize.  Think that is a good thing.

I am going to do more shop organizing and setup.  Get the materials and build the table I will need.  Dave Thatcher says to build a 13x3' table for the project.  There are some good references from EAA regarding the design and construction of work tables.  I found that EAA Chapter 10000 has  a good write up on their website.

So far progress on the actual CX4 is limited to planning, analysis, reading, and studying.  I feel that this time is not wasted.  I hope my attention to detail and planning will limit the expected goofs and errors that are part of the building/learning process.

One of the things I have been looking into is how to rivet the spars.  The spar construction task is  just about the only parts build that require traditional bucked rivets.  You can use a rivet gun/bucking bar method, rivet press, or arbor press methods for rivets.  Any way you do it I understand it takes practice to develop this skill.  To that end I have decided to do some test rivets using aluminum "test" stock that I can get a TheHomeDepot or Lowes.  They both stock aluminum angles and sheets in smaller (non-aviation grade) pieces.  I think practicing drilling, shaping, and riveting these test pieces will be a better way to develop the skills required without wasting valuable and more expensive 6061-T6 stock.

I plan to try the arbor press method that is documented in the EAA website here.  You can get an Arbor Press (picture above) from Harbor Freight Tools for less than $50.  I will let you know how it works.

Stay tuned..  :)

I have been reviewing the plans and have started detailing the steps for the first task.  The wing spars and center spars are assembled first for the CX4 per Dave Thatcher's instructions.  The spars are assembled using .040 6061-T6 aluminum sheet or "Spar Webs" which are sandwiched between extruded 6061-T6 angle riveted to the top and bottom and steel end spar caps.  I will be posting pictures during the construction phase to document the process further.

Most of my time this evening was spent identifying the materials required.  Aluminum sheet, angles, bar stock and rivets, bolts, nuts and other material.  The price is just around $800.00 for the spars/center spar fabrication and build.  I could purchase pre-made (and professionally built) spars and center spar for $1995.00 + shipping.  That's about $1100.00 more than the raw materials.  Figuring labor at an approximate shop rate of $56/hr (sounds fair, yes?) that means it would take about 20hrs of (professional) labor to produce the spars.  I seriously doubt I will only spend 20hrs to get the same results as the pros.  And this IS probably the most critical part of the CX4 airframe.  The rest of the fuselage is built from the center spar.  And a MAJOR part of the spar/center spar task is getting the dihedral to be exactly 7degrees for each wing spar/center spar mating point.  BUT I am on a limited budget.  So I will try the build it yourself route.

This is getting interesting.

Oh, and here is the way I study the plans and make notes.  Note the nice glass of cabronet sauvignon on the table.  :)

Plans Arrive

Got my plans today. Started to study the construction manual and planning for the first task. Building the main spar and center spar. Need to make a shopping list of materials for these parts.
Here we go!  The journey begins!

This is my CX4 Builder's Blog.

I am starting to build a Thatcher CX4 aircraft.

This is a photo of what I hope to have at the end of this task.  The Thatcher CX4 is a single place experimental/amateur built aircraft.  It was designed by David Thatcher.  The aircraft is powered by a VW based conversion engine of 60-80HP.  I plan to use a 60HP engine from Hummel Engines.