Skybolt Landing Gear

Page Index
-Axles
-Axle Support Jig
-Brakes
-Gear Cross Tube
-Gear Diagonal Tube
-Gear Truss
-Gear Legs
-Rear Gear Bracket
-Reinforcing Straps
-Tailwheel Mount

This page was updated on 03/04/2010
*New stuff!* 11/22/06- Fabricated the tailwheel mount. New pictures. Click on the images to enlarge them. Supersize the image by clicking on the sizing icon that appears when you hold the mouse in the lower right corner of the picture.
Landing Gear Truss
8/26/05- I've been working on the landing gear truss for the past week. Each tube took me 2 hours to notch using my bench grinder since my tubing notcher won't handle 1-1/8" tubing. Grinding a little and trial fitting, I was able to get real close joints. Don't forget to drill the oil holes at each joint before tack welding. I built the jig on a smaller piece of MDF rather than the table so that I could do the next step. See the next picture.
8/26/05- Once the truss was tack welded, I used the 1-1/8" hole saw to drill out the holes for the crosspieces exactly where I drew them on the jig. Then, with the truss in the jig, I flipped everything over and put it on my drill press and sawed the holes for the crosspieces through the truss. The board was a perfect guide for the hole saw and it was easy to do. Thanks to Brad Roberson for this idea.
8/26/05- This is the crosspiece notch that I just made. You can see the hole through the MDF jig that guided the hole saw perfectly from the backside.
8/26/05- A perfect fit. You can't get a tighter joint than that. By the way, the Bahco hole saws from the U.K. are the best. They run true, cut a perfect size hole, they're cheap, and the teeth don't chip for a looong time. Go to top.
8/26/05- Another view of the crosspiece fit in the truss and going through the MDF. You can see that 1 notch is cut and one isn't. Just flip the jig over with the truss in it and saw the second notch on the drill press. Works like a charm.
8/26/05- To tack weld the crosspiece, just run it halfway through the same MDF jig, hold it in place at right angles with a welding magnet, and put the torch to it.
8/31/05- Don't forget to notch the ends of the truss for the lower longerons using the same method as the notches for the bungee crosspieces.
8/31/05- The completed landing gear truss. I made mine out of .063 tubing as suggested in the construction booklet, rather than the .049 tubing.
Landing Gear Legs
9/15/05- I decided to layout and tack my landing gear on the table according to the plans instead of building them on the fuselage. It just seemed like I would have better control and be more accurate. I'm going to jig these assemblies on the fuselage to weld on the axles. I hope I made the right decision. 10/24/06- It's a year later and time for a word to the wise. After finishing the gear, I wouldn't build the gear legs on the table again. For accuracy, take the advice from the Skybolt manual and build the gear on the fuselage. If you insist on building the gear like I did, follow along. Go to Top.
9/15/05- I purchased some 3/8" smooth rod from Lowes and cut some angle iron for the jig brackets to hold the bushing in the correct position. Notice that I drilled out the landing gear legs for the bushings before trimming the tops off. I also tried some 3/8" threaded rod, but the bushing fit was way too sloppy.
9/15/05- I found that 1/4" copper pipe couplings from Lowes make perfect inserts for the 9/16 x .065 front bushings. If you enlarge this thumbnail, you can read the label on the package to get the part #.
1/29/06- Sorry for the long layoff, but I had a lot of work to do with Hurricane Wilma repairs. The legs are notched at the top for the bushings and at the bottom where they join.
1/29/06- The leading leg is notched (drilled actually) for the front bushing. I still have to heat and taper the tubing down to the bushing.
1/29/06- The trailing leg is notched for the bushing, cut, and trimmed. Next I have to make the patterns for the steel plate that boxes this joint together. Go to Top.
1/29/06- I used my bench grinder to get the lower leg notch close and then finished it with my die grinder. That way you get a perfect fit for TIG welding.
1/31/06- I tack welded the lower joint of the landing gear with my trusty Lincoln 185 TIG.
1/31/06- Before I started forming the top of the legs to meet the bushings, I tacked the bushings on the front and rear sides of the leg.
1/31/06- Then, I heated up the tubing and carefully formed it to the bushing with my ballpein hammer. Take your time and you can shape it nicely.
1/31/06- The rear leg gets the same heat and hammer treatment although it takes a lot less force. Take your time to curve the tubing down to the bushing. Go to Top.
2/1/06- Today, I spent the morning making patterns for the 3 pieces of .065 steel that will box in the bushing at the top of the rear landing gear leg. I use file folders for my patterns.
2/9/06- Cut, trimmed and filed the 2 .065 steel plates that form the rear leg attachment for the bushing. Even after the patterns, it took a lot of filing and fitting to get it right. You can see here that the tip of the 1.25" tubing just catches the back half of the bushing. The drawing in the plans does not look like this which caused me some confusion.
2/9/06- You have to be careful that you get the inside and outside plates on square and parallel. I left the outside plate flat on the bottom to help keep it aligned with the line on the table.
2/9/06- You can see the .065 X 11/8" plate under the leg to help keep the plates aligned. The next step is to heat and wrap the third 11/8" plate around the front and back sides and box the joint in.
2/10/06- I tacked the .065 wraparound plate to the inside of the side plates. Go to Top.
2/10/06- Be sure to get the plate flat and square to the lines on the table so that when it is wrapped around the bushing, it will fit perfectly between the side plates and not cocked off to one side.
2/10/06- We're finally ready to box in the rear bushing joint. The trick here is to get the .065 steel strap lined up accurately so when it is bent all the way around, it lines up properly on the other side. I tacked it in place in 2 spots perpendicular to the sides so that the plate wouldn't bend at a funny angle.
2/10/06- When you put the torch to the .065 plate, it bends like butter, so be careful. A little heat goes a long way. Here, the plate is bent all the way around and all I have to do now is tack it on this side and then heat and bend the tail ends down to the 1.25" tubing.
2/10/06- From this angle, you can see that the the seams all the way around the bushing are nice and tight for welding. I still have to grind the side plates down flush with the wrap around plate before I finish the weld.
2/10/06- The tail ends are bent down to the tubing and the front and rear plates are ground down to be flush with the long plate. Go to Top.
2/10/06- Now we are ready to finish weld the assembly.
2/10/06- This is a top view (with the gear laying on the bench). All the seams are TIG welded. Be sure to take the 3/8" alignment rod out of the bushing before final welding, or you might never get it out.
2/10/06- This view plainly shows how the drawing on the plans is inaccurate. The drawing shows the 1.25" tubing coming up right underneath the bushing on the inboard side when it is more than an inch away. Just lay out the gear on your table using the true dimensions and everything will work out right.
2/10/06- This is the rear angle of the rear landing gear bushing mount.
2/12/06- I bought the 2 landing gear ribs from Steen Aerolab and welded them in today. I just used my tin snips to notch them. Go to Top.
2/12/06- This is the rib joint at the front leg of the gear. I burned the heck out of the table when I heated the tubing to form it down to the bushing. After I burned 2 spots on the table, it dawned on me that I could put a piece of steel underneath and avoid the scorches.
2/12/06- The rib is located 2 1/8" on center, down from the hinge line. I set my Lincoln 185 TIG to just 35 amps to weld this light steel rib to the heavy landing gear. While the gear is still in the jig, be sure to draw the centerline at the top of each leg to help in trimming the bushings and alignment of the gear brackets later.
Axle Support Jig
7/18/06- Before I could install the landing gear, I needed to build a jig for supporting the pipe that will hold the axles straight.
7/18/06- After pricing 4'x4' sheets of plywood at Home Depot, I figured that it would be cheaper to build a set of axle jigs similar to those on Brad Roberson's website. This picture is of the adjustable top of the jig.
7/18/06- Using materials at hand: 3/4x.035, 1x.049, and 1.5x.058, the jigs turned out to be an easy little project. The top of the jigs are adjustable to get the axles set at the correct 27" height. Go to top.
7/18/06- The completed jigs rest on the bottom longerons with the fuselage upside down.
7/18/06- The jigs are fastened to the longerons and the axle tube with automotive hose clamps. Tomorrow, I'm going to the steel shop to get a pipe that is 1 1/4x.063x8'. Hopefully it is cheaper than 4130 tubing.
7/18/06- This is a .pdf copy of the axle jig plan. Click on it to open the file. This file requires the Adobe Acrobat Viewer. If you don't have it, you can download it for free at Adobe.com.
7/20/06- Spray the jigs with some red Rustoleum and they look great! Go to top.
Rear Landing Gear Bracket
7/25/06- Rather than building my landing gear on the fuselage, I jigged them up flat on the table to make sure they were exactly the same. Now, to jig the landing gear and mounts on the fuselage, I first made 2 jig boards to center the mounts over the bottom longeron using a 36" steel dowel.
7/26/06- I decided to start with the rear brackets since they double as the lower wing spar attachment and mounting the wing at the proper station is critical. This picture shows how I lined up the 1-3/4" spacer board with the station 34 mark on the floor. Of course the fuselage is lined up with the centerline on the floor and level.
7/26/06- On my tablesaw, I ripped a vertical board is exactly 1-3/4" wide to keep the brackets properly spaced, parallel and square which is critical since this is also the front spar attachment.
7/26/06- Make sure that the spacer is plumb so that the brackets are vertical. Go to top.
7/26/06- Here, you can see that the alignment rods keep the landing gear holes centered over the longeron and the bracket spacer board keeps the bracket square and plumb.
7/26/06- If you look closely, you can see where I bent the brackets to mate with the cross support tube at station 34.
7/25/06- One rear bracket fit and tacked, just 3 more to go.
7/27/06- I left the 1-3/4" spacer board in place and then fit and tack welded the 2nd half of the bracket in place. The next step is to tack weld the front gear bracket at station 13.
Fitting the Axles
10/24/06- I chose to weld the landing gear flat on my table according to the dimensions on the plans. I wouldn't do it this way a second time. The Skybolt manual advises you to build the gear on the fuselage. This is a better method and more accurate. Go to Top.
10/24/06- I put a piece of masking tape on the floor and then drew the axle line on it. I then used 3 plumb bobs to line up the axles as I notched the gear.
10/24/06- Here, you can see the red axle jigs holding the 1.25 tubing for axle alignment.
10/24/06- You can see the 3/8" threaded rod that I made into a gear support jig.
10/24/06- I flattened one end of the 3/8" rod and welded a small tab to a short piece of tubing that is clamped to the gear leg.
10/24/06- This is the turnbuckle end of the gear support jig. It is connected to the bungee crossbar with bailing wire. Go to Top.
10/24/06- The rear gear / front spar bracket is tacked on. Notice that the end tabs are bent under to mate with the cross tube. Be sure to get this bracket mounted plumb and square with the fuse to avoid problems mounting the spar.
10/24/06- The axles are placed in relation to the fuselage centerline. The plumb bogs ensure that everything is in line.
10/24/06- I rough cut the notch in the gear legs with my pneumatic cutoff tool.
10/24/06- After rough cutting the notch, I finished it with my 4" electric grinder.
10/24/06- Finally, it's time to tack the axles to the gear. Go to Top.
10/24/06- Next, I welded the 1x1x5" square tubing for the bump stop.
10/24/06- The bungee bump stop tacked in place.
Fitting the Landing Gear Cross Tube
10/25/06- I taped a piece of 1/4" plywood to the bump stop and then started fitting the cross tube. I will cut it in half when the streamline tubes are welded in place.
10/25/06- Lots of trips to the bench grinder taking a little off at a time. I had to do a little bit of touch up with my pneumatic die grinder.
10/25/06- The cross tube is notched and tacked in place after checking that it is level. Once the streamline tubing is tacked, I will cut the cross tube in half, finish weld everything, and then form and weld the reinforcing plates over all the joints. Go to Top.
Fitting the Landing Gear Diagonals
10/26/06- This is the first time that I have notched and fitted expensive streamline tubing and was a little nervous. But it turned out to be just like notching any other tubing- 100 trips to the bench grinder.
10/26/06- The sharp eye will notice that I departed from the plans by spacing the diagonal about an inch further away from the gear leg. Steen Aerolab suggested that I do this to make it easier to use a floor jack under the gear when servicing the wheels and brakes. I'm all for easier service.
10/26/06- I used duct tape to hold the diagonal in place while I tacked it.
10/26/06- Since this is 2" streamline joined to 1.25" tubing, I'll have to figure out the best way to cover up the overhang. I'll deal with that when I cut the gear apart and weld on the flat plate.
10/26/06- I notched the streamline so that all the overhang would be at the trailing edge at both ends. It should be easier to cover and look better that way. Go to Top.
10/28/06- Both landing gear are finally all tacked together and the jigs are removed.
10/28/06- This pic shows all the basic tubes that make up the landing gear.
10/28/06- When the landing gear were both tacked, I cut them apart in the center of the bungee tube.
10/28/06- The axle end of the gear. All I have to do now is cut off the excess axle, finish weld it and weld on the reinforcing plates.
Fitting the Reinforcing Straps
10/28/06- Using my cutoff tool, I started cutting off the axle. Then I will follow it up with my grinder to shape flush with the streamline tube before finish welding it. Go to Top.
10/28/06- The top end of the gear needs to be cut off, shaped and welded too. Using the cut off tool is way easier than a hacksaw.
10/30/06- After rough cutting the axle ends and cross tube with the cutoff wheel, it's time to start grinding everything flush.
10/30/06- The axle ends are ground flush with the streamline tube.
10/30/06- I tried to match the center of the bungee tubes without getting too anal.
10/30/06- These are my cutting and grinding tools. They are indispensable. Go to Top.
10/30/06- The axle is beveled in a straight line with the streamline.
10/30/06- This pic shows how I beveled the trailing edge of the streamline to fair it into the axle.
10/30/06- I will cover the opening in the streamline with some .063 plate.
10/30/06- After the ends are all trimmed and ground, I finish welded all the joints. The next step is to form and fit the straps.
11/1/06- After fitting and finish welding the fillers over the open trailing edges of the streamline, it was time to tack and bend the straps in place. Go to Top.
11/1/06- This is a fun project since it is so easy to do. First, tack one end to hold the strap in place. Second, heat and bend the strap around the end of the tubes. Third, tack the 2nd end down. Fourth, heat and lightly hammer the plate to the shape of the tubes and the corners. This pic shows the plate covering the axle and streamline tube.
11/1/06- This is the plate covering the end of the bungee cross tube and streamline tube. Notice how nicely the plate lies down in the corners at the end of the tube.
11/1/06- Notice the fill piece covering the bevel on the streamline tube.
11/2/06- The reinforcing strap takes a little more work to form it tight to the bushing. All it takes is some kind of rounded edge tool to pound it into the corner and form the edges down as much as you can. Go to Top.
Mounting the Brakes
11/14/06- The first step in mounting the brakes is fabricating the brake mounting plates out of 1/8" plate. After drawing a template and transferring the hole centers to the plate, I rough cut the plate on my bandsaw and then ground to the outside line with my bench grinder. Using a jig like this clamped to a 12" disc sander, I spun the steel plate and got a perfect circle. The center hole is 1/4".
11/14/06- The Cleveland brake kit model 199-104 requires 3/8" bolt holes as opposed to the 1/4" holes called out in the plans. Because of the bigger holes, increase the outside diameter of the plate from 2 7/8" to 3". The other dimensions on the plan remain the same.
11/14/06- Drill the center hole with a 1.5" holesaw. Take it slow and use WD-40 or some other coolant while cutting the hole to preserve the holesaw. File and polish the outside edge.
11/14/06- The mounting plates are located 6" from the end of the axle. I used a 1.5"ID x 5" pipe nipple to help keep the plate square when I made the top tack.
11/14/06- After the first tack, I squared up the plate again with light taps with a hammer and made the next tack on the bottom. I tapped again with the hammer before I made the 3rd and 4th tacks. Go to Top.
11/14/06- It doesn't mention it in the plans, but I need a 1 5/8" x .058 x 1.62" spacer for this model brake. I also used the round style axle nut. Notice that the outside brake pad is removed to facilitate mounting the wheel.
11/14/06- The complete wheel is mounted. I mounted the calipers facing forward like the Yellowbird. If you want to mount yours vertically, you need more axle sticking out from the gear legs so that the caliper won't hit on the legs.
Tailwheel Mounting
11/22/06- This is the tailwheel rear mount bracket. The top piece came from Steen Aerolab when I bought the tailwheel assembly. The rest is easily fabricated.
11/22/06- To make the bottom (actually the top, since the fuse is upside down) half of the bracket, I cut and bent a piece of .063 steel and then notched it to fit the tailpost. Notice the piece of split tubing under the tailspring. Go to Top.
11/22/06- Then, I drilled both brackets together with an 1/8" drill bit. I then enlarged the holes in the clamp bracket to 1/4" and the holes in the top bracket to 3/8" for the 1/4" bolt bushings. Then I welded the bushings in place while the brackets were bolted together. Finally, with the bracket in place on the tailpost and the tailwheel assembly aligned, I tacked the split tubing to the bracket.
11/22/06- After the bushings and split tube are finish welded, the bracket assembly is located on the tailpost and tacked and finish welded in place.