ROUTERING METHODS FOR BEARHAWK JIGS & DIES

[Glenn Patterson]

There has been some back & forth as to about dies and parts to flange rib lightening holes etc. I decide that I would share what we did & used as it worked great for us. The first 14 pages illustrate how to accurately make all your jigs & dies with a Lee Valley precision circle cutter base for a router and a couple of good bits. The flanging dies are the easiest part to make. This write up includes extracts from our 727 documentation plus some illustrations that I quickly assembled. The last half of the write up shows a lot more that we did with the router that I am not advocating for or against. Once you get started it will come together really quick and your imaginations may take this to another level. Hopefully this will make some lives easier when confronted with making the tool & die without any specialty equipment. I would recommend buying quality router bits if you elect to go this route as I still have all the bits that I purchased from Lee Valley tools years ago.

Glenn Patterson BH727

[John Rheney]

Excellent writeup Glenn. I will point out to new scratch builders that the usefulness of the router doesn't end when finished with the ribs. I used the router to fabricate all of the inspection cover plates and support rings and to route the inspection holes in the wing panels. You just can't beat the repeatability and speed of routing with patterns.

John

[Glenn Patterson]

Thank you.
We did the inspection cover frames & covers as well. It worked slick . We used the router for just about everything. We made wood tips to reinforce the nose ribs so we could get the skins tight with out buckling the the unreinf. ends. etc. If the builder starts with the template master this tooling fits and locates itself perfectly. The repeatability is key & pressing the ribs this way they all looked like they came of a production line.
Glenn

[Gavin Chester]

Good job Glenn. As well as what you and John have used a router for, I used it to finish trim my spar cap strips and cut the spar web holes.
I also used it to finish trim all my spar webs and wing skins.

[DRLPatrol]

Very nice write up, thanks.

[eh009us]

Great write up, guys.

[mikeno]

Great information Glenn! My experience with routers was almost nil until I started this project and through trial, error and a little blood I've come to realize what a great tool I've been missing. I just wish I'd had your info 8 months ago. Thanks Mike NAULT BH #1250 KLXT

[Glenn Patterson]

Thanks Mike. Sorry for the timing. I intended to do a write up years ago so I decided to put my head down yesterday & get it done.

I had a router & was a fan of Lee Valley tools. I was trying to see how to make a plug then it came to me to use the Lee Valley router base. Cutting all the circles are easy.

We live in the middle of nowhere & needed a low tech solution as it is hard to get any machining done here. Everyone has access to a router so this may help others to make tooling with a router no matter where they live. Builders can see the process then make it work for what they have available to for cutters.. The router base and router bits are affordable.

Going forward, the PDF may help someone struggling to get their tooling done at home with this system.

Glenn

[wingnut13]

Thanks for the writeup Glenn. It will be cold soon and this is the next project!

[fabricman]

Glenn - Excellent write up and good photo detail. Really appreciate the effort as I know how much time it takes as I make my living writing reports.

[Glenn Patterson]

Thank you for your comments. It was done in a bit of a rush & I tried to make it as clear as possible without a lot of writing. I though once people start reading it they would catch on pretty quick. I used all photos in the last half to try to pass on a lot of information without writing. It was good fun & comes with its complimentary errors.
All the best,
Glenn

[X'N]

Nice job on the write-up. If I may I'd suggest people use a dove tail bit to taper the sides of their rib jigs. I used this to do some of my rib jigs and the parts bent on them came out almost at 90* after the springback.

[onebadjudge70]

Excellent write up! Thank You! This will be a huge help when I get started.

[Bcone1381]

What is your favored Router and Bit to perform this process?

I am tooling up to start this procedure for a scratch built Patrol. I have limited experience routing. Is it worth the effort to get a new router with a 1/2 drive, or will my 1/4 drive Bosch serve me well for the future of the build? Also, which router bit is best? Do you agree the Lee Valley Template Bit is the choice rather than the flush trimming bits they offer?

[Glenn Patterson]

Hi, Sorry I have been off the forum for a while. I bought a Hitachi 3-1/4 hp router at the start of the project for about $250 which was about 10 yrs ago. I had a Craftsman 1/4" that has worked hard for me & may have done okay. The Hitachi has been a beast & I think safer to use. It has a bit of weight to it and will cut with absolute confidence which I think makes it safer. I had a router table that I built for my craftsman that I used also for my Hitachi. Working with the router firm in a table cuts square every time. You can use either flush cut or template. I bought a template bit but I always used the flush cut. I like the 1/2" diameter cutters and the Lee Valley bits stay sharp. The other thing I did with my router table was put good sized magic marker arrows to show feed direction. If you feed in the right direction it cuts perfect. If you feed the wrong way it "climb mills" and can shoot the piece. The other thing with a table is if something goes sideways then hands instantly in the air and step away. I have launched a couple pieces but at least I am not holding a router that went wild. The arrows help as it conditioned me to look before I fed it into the bit. The arrows on each side of the table so no matter where I stand I get it right. I know 3 people that have lost a finger to a router so that is in the back of my head and I treat it with respect but not fear.

I also have a strong router to do woodwork as well. I made a set of basement stairs for my son and it plowed out the slots for the treads with ease. I personally love the Hitachi. There are lots of other makes but at the time it did everything I needed, easy to set up and it was on sale. I am using a Hitachi M12V that is a variable speed which is a great feature as well. I think the new version is a Hitachi M12VE which still seems reasonably priced.

I think that if you buy quality bits the brand name can be different. Lee Valley is quality all the way and a person cannot go wrong.

Glenn

[Bcone1381]

Glenn,

Thanks for your reply. I performed my first routing a few days ago using my 1.75 hp Porter Cable. I had to go slow to keep it from bogging down as it went thru 1.5 inches of MDF. I had it mounted onto a table, and understand what you mean by "climb mills".

I discovered that could use a larger table to support the large heavy full size wing jigs. So that will be my next 'tool' to fabricate.

Thanks for validating the Lee Valley Tools. I got three bits from them last week for pattern making.

For now I am on the fence about getting a higher power router. I just ordered a plunge base for the Porter Cable, and wonder if it will be just fine by going slow, or if I threw money away at an insufficient tool. How did the Varible Speed make a difference? Are you slowing down the rpm when cutting Aluminum? When you slow down the rpm, do you get more torque, or just less hp output of the router motor?