New Memeber

[mfcummings]

Hello All, I am reaching out to the group who have scratch build experience with the Bearhawks. I am new to the forum and am thinking of scratch building a 4 or 5 or a portion thereof. I've started doing some research on the process. Definitely a long term commitment. One of my concerns move forward is the availability or option to purchase aircraft assemblies and parts that were previously available under Mark's ownership. I've noticed that the store on the new website is still not up and operational. I'm hopeful that the store will be up and running soon with the same part(s) availability as before. But....In the event that that is not the case, what challenges could this pose for a scratch builder or should I say maybe someone not wanting to be a 100% scratch builder?

I am planning to attending the Lincoln welding class in a couple of weeks at Oshkosh and hope to see some of you out there and your planes.
I built and am flying an rv10 and yes love it. I'm kinda thinking i need another project and a plane with a bit more off pavement or floats option sounds like fun.

Thanks for any input you can provide,

Mike

[geraldmorrissey]

I would buy the rib and spar web kit if it becomes available, and build as much as you want of the rest. My guess is there are few 100% scratch built Bearhawks, most are hybrids. If nothing else, you have to buy the wing struts. My Patrol will be a hybrid with a lot of scratch built in it. Good luck.

[Djokovic0]

Welcome to the forum

[Battson]

Welcome to the forum!

Disclosure - I am not a scatch-builder, but having spent over 15 years in the BH community, some patterns emerge

I have it on good advice that forming wing ribs etc from scratch is not that educational (or even enjoyable depending on your personal preferences) once you've done the first dozen or so. There are a lot of lightening holes to form... The BH wings are a relatively involved build all of their own. But....

I guess that depends on your motivation for scatch-building, usually it's hard to offer good advice in recreational aviation circles until you know what someone wants i.e. do you like the building process just for the enjoyment of building, or do you want a finished aircraft at an affordable price point, or are you mostly interested in going flying at the end of the build?

[SpruceForest]

Good to have you here!

The reason to buy the spars and ribs done is a) avoiding the hunt for tooling, and b) spending hours and hours bathing in MDF dust doing form blocks. I hope the company will continue to offer parts and assemblies for those interested in hiring certain jobs done, and I admit to being sorely tempted early on to do just that.

That said, if you are a process person that loves figuring stuff out, the rib and spar processes are pretty cool. There are a number of vids out on press-forming the ribs, as well as hammer-forming, and a quick search here will give you a bunch of links and pdfs which document process. Yeah - looking at my flaps and ailerons at the 'Hellraiser Pinhead' stage (IMO, clecos are some of the coolest things on the planet... top-notch and almost up there with girls, bourbon, and airworthy aircraft) as well as spars and ribs coming together and knowing I did all that from sheet is pretty cool, but the trade is 150-200 hours of time spent producing what is in retrospect limited production tooling. Glad I did it, and my build buddy Carlo benefited from the durability and engineering put into that tooling, but it was a time suck. Would I do it again? Yup.

A few lessons learned:

- Being able to fab nearly any part of the airplane from sheet, bar or tube was a project goal for me, but that makes little sense for others with different priorities (like a flying airplane in minimum time...although that begs the question as to why the heck scratch build???)

- Any good commercial sheet metal place will have a 10' or 12' press brake that can make all the long bends (which for a Patrol is a bigger issue than for the BH4 or 5). I would suggest getting the spars bent prior to fabricating all the ribs, as it is far easier to adjust the rib tooling to produce a good fit with the spar (to include building in joggles) needing only minor tweaks latter than to have major fit issues which require significant rib rework. Most of these shops will have an 8' leaf or box and pan brake as well, so make friends and find out when you can come by and not interrupt things. Also - they will likely be curious enough to offer to do it for free - don't take them up on it. As a minimum, figure the shop is losing money and plan on paying whomever helps what amounts to their hourly in CASH. Keep the foreman or floor boss happy with whatever he wants and - if over lunch - feed the troops (everyone delivers... make it so). You'll want to have material reserved for fabricating an 032 shoe on that press brake if it's not already set up with a 0.100" radius.

- The main, aft, aileron, and flap spar flange angles will need to be tweaked to final angles if you go with a commercial press brake, but I found that surprisingly easy to do with a shop-made set of 1/4" MDF templates and 3" offset hand seamer (the one from Cleaveland tools is better than the usual big box stuff... Amazon sells it for about the same price as the MT14030 Fairmont Tongs Offset with Cushion Grips, so get it from Cleaveland). The first spar will be a bit lumpy as you get the technique down, so bend an extra short section (3-4') of flap spar to get the feel for the process. Mark off in 3" increments and advance from one end to the other in 1.5" increments... trust me - this is smoother than trying to tweak larger segments with a wider seamer.

- The router/rubber press method of rib fabrication produces 'better than Cessna' ribs with basic woodworking tools, a 20 ton harbor Freight press, and an air over hydraulic bottle jack, but you can go tin-snips, hammer, and Bob Stick if willing to put the time in and get airworthy results. Some familiarity with woodworking and basic tooling (table saw, band saw, router table, and drill press) is nice to have and shallows out the learning curve.

- 24/7/365 access to a good 4' box and pan brake makes life a lot easier during the construction of the flaps, aileron, and wings, and avoids wearing out your welcome at the commercial sheet metal shop or your friendly airframe repair-focused A&P. There are a bunch of bends that run up to 48" in 16g or lighter material, and the project moves along a lot faster when it's a trip to the garage or shop to fab a leading edge cover versus 20 miles out and back to a buddy's shop or the airport. Use the need for a bending brake stand to justify an early welding project... in fact, use any excuse to practice your welding if not already competent.

Finally, if you have not scratch-built before or at least worked from a basic kit, here's a quiz on suitability to plans-build:

Q. Your spouse/life partner/crazy roommate announces that they will be absent over the next four day weekend. What is your first thought?

A.

a) fantastic... turning off the phone so I can bliss out with 96 hours of uninterrupted shop time!
b) sounds like road trip time with my buds... already have my clubs loaded and cooler filled!
c) cool - 96 hours of Netflix marathons without any need to shower or even get dressed... a nag-free couch potato weekend!

If answer is b or c, rethink the scratchbuilt thing.

[fairchild1934]

making the wing ribs is not hard (once the MDF tooling is made) - but it is time consuming I guess.
i think the spars will soak up the most time ---- partly because ( I would say) you cant afford any mistakes there. So you have to go slow and get it right the first time. (thats my expectation--)

[mfcummings]

Spruceforest, thanks for the detailed reply, lots of great info and the answer is A. Also thanks Gerald, Fairchild, Battson and Djok.

I am still looking into this and if I make the move I’m sure I’ll have more questions, thanks again!

Mike C.

[Redneckmech]

Welcome! I look forward to watching your build!