Zenith 601 XL  Bending the gear.....

I have place photos on the Matronics photo and file share site showing the bending fixture for the nose gear fork and main gear on the 601 XL.  Dimensions that I used are as follows:

Rollers are 2 inch diameter thick wall pipe.  Wall thickness of the pipe is about 3/8 inch.  Don't know where to get it.  It was in a scrap pile when I picked it up.  The end bushings are steel about 3/4 inch long and turned to fit inside the pipe.   The centerlines of the rollers on my fixture are 207 mm apart.(about 8 1/8 inches The rest of the frame is 1/2 inch steel.  The piece of billet is 6 inches in diameter and is what I used to form the inside radius of the bent parts.  The bolts are grade 8's.

When building the bending fixture, square and parallel are very important if you want accurate bends.  I match-drilled the two sides on my mill.  When you weld the frame together, make sure the rollers are at right angles to the sides. I assembled the rollers and sides before welding to the base plate. 

When bending, make sure you align the piece to be bent so it's at right angles to the rollers. (My fixture is accurate, so I line up the edge of the part to be bent with the side of my bending fixture---that makes it 90 degrees to the rollers)  I mark a bend line on the part to be bent and line it up with the line on my billet.  If your alignment isn't accurate, you end up with a "twisted" bend.  Note that I have also placed a line on the billet.  The billet must also be lined up parallel to the rollers.  (Again, twisted bends if you're not aligned properly)  It isn't all that hard to line things up, so don't worry that much about it.  Just be careful and you'll end up with accurate bends.

The above dimensions (207 mm between rollers) also happens to be good for the nose gear fork.  I made the inside block out of walnut and bolted the nose hear fork material to it and simply pushed it down between the rollers.  I also had the 3/16 steel plate that welds onto the bottom of the nose gear bolted up as part of this bending arrangement, but don't know if it would be necessary.  The bend isn't quite complete, so you need to squeeze the sides together some more.(I did mine in a vise)  I found that overbending the nose gear fork slightly and then opening it back up gave good results.  I opened it back up with a large screwdriver pried against the walnut block. The unbending is really very easy to do, and I suspect the mains will have to be overbent slightly and then unbent a little---we'll see. The nose gear fork in the picture is a scrap part.  I ruined it during the "overbending and opening it back up" phase of the first part I made.  I probably shouldn't have even shown it since most of you are probably plenty capable of making scrap parts. 

Again, as with the bending fixture, accuracy is important.  The walnut block was squared up on my vertical mill.  The radiuses we done by hand on my belt sander.  Done by hand very slowly with lots of checking with squares for accuracy.  Just go slow.  You can do it. 

Please be aware that I have only done test bends on the 3/4 inch thick material.  The piece of bent 3/4 inch material you see in the pics is the piece I cut off one of the main gears.  I have not actually bent up a main gear yet.  I have bent up two perfect nose gear forks.  E-mail me at tigermiller1595@msn.com if you have additional questions about anything.  

Dave Miller