Fresh Breeze Frame
I have a 2006 Fresh Breeze 122 simo that I really
like in a lot of ways but one. I like the way the cage breaks down and
all of it fits in the trunk of my VW. I like the way it feels (comfort
wise) while flying and even when I have it on my back while ground
handling. What I don't like is the frame. It it made out of 5024
aluminum that is light weight and strong until it gets bent, when you
try to bend it back it gets brittle and breaks. I have welded one spot
4 times now. I had to cut the frame apart and take out the flimsy
reinforcement tube FB puts in at the factory and replace it with a
thicker stronger piece of 6061 aluminum tube (on the inside) and
re-weld the frame back together. Since then it has not broken yet. But
it still feels flimsy and weak.
A lot of the times I go flying I take my suburban to the field in which I have a hitch and I also have a cargo carrier. It would be nice like a lot of guys do is just throw their completed paramotor onto the cargo carrier and drive to the field not having to put anything together and then break it down to go home. My issues is the frame feels so weak that I think the weight of the motor would actually bend the frame during transit to and or from the local LZ. Since I was building the Skybolt frame and decided not to use it for now, I came up with another idea, what if I made a chromoly frame? The nice thing is it would be 2x greater in strength but yet only a couple of pounds heavier than the current frame and I could still use all the original cage pieces since it is just the main frame that is the issue. I had almost all the tools and I could weld it much better. I would need to make a tool that would bend the tubes to get the same radius bend that the Fresh Breeze uses.
So I measured the stock frame to figure out how much tubing I needed and I ordered the metal from Aircraft Spruce. I went with 3/4 OD .049 wall tubing for the main frame tubing and 1/2 inch .035 wall for the stiffener tubing.
Building the Tube Bender/Tools Pictures Link
Frame Pictures Link
Tools needed:
Safety is a big deal. Please use proper eye and ear protection and any other proper safety gear when drilling, cutting and even just handling tubes. Wear gloves until edges are smooth etc. Having metal in your eye is not fun (been there before) so please at a minimum wear safety glasses. I put them on as soon as I walk in the garage so I don't forget. This has saved my eyes more than once.
After looking over the frame it did not look like it would be too hard to copy. But getting the tight bends that FB uses I would have to make my own bender. The regular conduit benders for 3/4 inch have a 6 inch bend radius and even the 1/2 inch bender have a 5 inch bend radius and I need a 4 inch. Buying dies and a machine to bend to a 4 inch would have cost a lot more than I was willing to spend so I started looking into different ways to bend the 3/4 tubing. Once way was automotive pulleys (found on the internet) but I was not real keen on that idea. Another was a pipe bender which again I did not want to spend $120 just for a few bends. The most common was home made tubing benders that uses a bottle jack, but again I would have to buy parts to make it and it still would have been expensive. Well my other option since I already had a metal lathe was to make my own out of some solid stock aluminum. I had some 5 inch solid 6061 aluminum rod and 3/8inch aluminum plate from my rocketry days so off to the lathe it was. I know I could also use a hickey to bend the tube but I want nice clean bends without kinks in the tube.
3/15/10 - Welded tube to frame
I visited my local welding supply High Plains Welding to get some argon gas today. After talking with them for a minute or two I upgraded my 20 cubic foot bottle for a 65 cubic foot bottle plus gas for only $45, woohoo. I love this place, they have always treated me right. Any other place would have charged me over $100 just for the bottle and no gas. Anyway I was back in business to get back to welding my frame.
So I removed the motor from my old FB frame so I could do some alignment testing with the tacked tubes first just to make sure I was on the mark. I was off a little so I cut the top tube welds and repositioned the top tube in the correct place and retacked the tube. Now it was time to weld. I finished welding all the tubes and it took a while. The tubes are thin and a small diameter and with the angles they are at they change as you go around with them so it take four or five times to weld then since you have to reposition each time to get into the tight spaces. So after a couple of hours I was finished so I checked the motor mount alignment by placing the motor on top motor mount tubes, perfect fit. I forgot to put on a long sleeve shirt so now I have a nice little UV sunburn on both my arms. It is not bad since actual welding time was not that long it is still a reminder for Safety First.
The rest of the time I have in the garage was spent working on my starter upgrade since I had the motor off the frame.
3/13/10 - Frame weld and tacking tubes (starting to look like a real frame)
I was able to go flying today but I needed to get back so the wife should use the Suburban. I also did a little work on my car with my son but then is was my time in the garage with the frame. Today I was going to finish up the tube notching and start doing some welding on the frame. I decided to start with welding the main legs to the top tube. I just laid the front side of the top top down with the legs pointing up in the air. Then I got my carpenters square out and made sure the legs where straight up at a 90 degree angle. Once I knew everything was straight I tack welded both tubes. Then I rechecked to make sure everything was straight and lined up...it was so I finished the welds. I purposely burned through the wall of the outer tube to make sure I tacked the insert tubes to the outer tubes in a couple of spots on both sides for a little more stability and to keep them from sliding down the tube over time if they loosened up.
So the last tube I needed to cut down and notch was the tank tube. After a couple of measurements...ok I eyeballed it, I cut the tube and then notched the ends. I then prepped both ends of the tube with a dremel drum sander as I did will all the other tube ends. I then test fit all the tubes again t make sure they fit and they did, some with a couple of slight vise adjustments.
I started with the tank tube at the top. I measured several time to make sure it was going into the correct position. Then I tack welded the two outer tabs. Next was the top motor tube, again several measurements before I tack welded the ends. Then is was time for the bottom tube, again several measurements be fore I tack welded it into place. With the tack welds I and still able to do a slight bend up or down to make sure everything lines up but it is real close already. Maybe just a tweak here and there. I was not able to finish the welds since I was out of argon gas. and the welding shop I get it from closes at 1:00pm on Saturday's. I looked up at the clock to see it was past 1:00. Oh well at least the basic frame is built. The next item will be the slight bend tube at the bottom and trimming the bottom of the legs or feet I guess you would call them.
3/10/10 - Tube cutting and notching
I got a little time in the garage tonight so I worked on getting the tube cut to the proper length. I started with the frame tube since they where about 1/4 inch too long. After measuring several times and comparing to the actual frame I made the cuts and refit the two side tubes back to the top tube with the little insert tubes I had made. Next I turned to the tank tube and top and bottom motor mount tubes. Again after several measurements I cut the tubes.
Next I set up the 3/4 hole saw in my drill press to notch the tank and motor mount tubes so they would mate up to the frame. They needed to be cut at a 90 degree angle so it was pretty easy to setup. Using a 4 inch drill press vise and some 1/4 thick wood pieces I positioned the vise to cut the notch's right in between the wood boards with a tube pinched in between them. The wood is in there to protect the vise jaws from the hole saw. I also needed to put another tube on the other side just out of reach of the saw to keep the vise jaws from canting. With this setup I have the drill on the lowest speed. It is also a safety issue. The if there is not another piece of tubing to help the jaws stay square, there is a chance the saw can catch the wood and shoot it out sideways out of the vise. Please note the saw will cut very slightly into the wood and this is ok. The key is to have the tubing right in the middle so the saw does not cut one side of the tube more than the other. It took a couple of very small adjustments to get it in the correct position.
Once I had the vise setup it was time to test the notcher. I started with a couple of scrap pieces first to make sure everything was lined up. They turned out pretty good. I cleaned them up in with the bench grinder and wire wheel and then did a test fit.... perfect. So now I chucked up the top motor mount tube in the vise and made sure the drill press platform was level and I rigged up some items to hold the non drilled side of the tube level to the platform to make sure I was getting perfect 90 degree cuts to the tube and to the frame position. Ok here we go, I turned on the drill and took my time. First side done and looks like it came out ok. So I turned the tube over to do the second cut on the other side. Interesting thing happened. Right as I finished the second cut which came out good, the 1/2 inch drill chuck came of the head of the drill...hole saw and all. The head looks like a morse tapper system but I never had seen a setup like that before on a drill press. Needless to say dinner was ready and I did not have time to fix that so I quickly cleaned up the top tube with the grinder and did a test fit on the frame. Woohoo, looks great and fit perfect.
03/09/10 - Welder testing and tube inserts
Tonight after doing some welder testing I started work on the actual frame. First was to measure and cut the two side legs and top tube. I went ahead and measured a bit long for the first past. I don't want to have to buy any more tubing as I am out if I make a mistake. Once I measured and compared to the original frame I cut the top tube and I only needed to trim one of the side legs. Then I put them together to see how it looked. While I was looking at it on the floor taking pictures I got an idea. Why not take some sort scrap pieces of tubing cut a notch along the length of the tube squeeze it and fit it inside both the top tube and leg tube. This would serve several purposes with the first being it would hold the tubes in proper alignment for welding, second it would help stiffen the joint and last...well heck it it just a great idea. So I did a little experimenting and cutting and I was able to make two inserts about an inch long to place them in both sets of tube joints. So now it holds the frame together so I can take a look at it before I weld it permanently.
While I was cutting the inserts I went ahead and cut the last tube which is the slightly bent tube that the cage pieces plug into at the bottom of the frame. I got out the conduit bender and did slight small bends to make the same FB shape and it came out great.
Once I was done with the bottom cage tube, I put the pieces together with the inserts and set it next to the FB frame. A couple of things I noticed is the frame is a little tall which makes sense since I left the tubes a bit long. I can fix that next time. Also I noticed that my frame sits back a little further, That is also an easy fix for next time.
03/04/10 - Making more tools
Next I needed a jig to hold the tubes together straight while I was welding them. I did a little research on the internet and found a great simple tube butt joint jig using 1/2 angle iron. I had a couple of feet in the garage so it was perfect. I did need to get a couple of tools from harbor freight like a small set of welding magnets and some cheap 3 inch clamps for the jig. I got out the 4 inch grinder and put a cut off wheel to cut the channel, one 6 inch piece and two 1.5 to 2 inch pieces. Using the magnet to hold the the short pieces at both ends of the longer 6 inch piece good enough to tack weld the short pieces. Once that was done I welded the the pieces on so from the end view they looked like an X. I used a short piece of straight pipe to verify everything lined up and it was slightly off.
I tried a new trick. I cut two pieces at 7 inches each Then I lined them up with the magnets and welded just an inch and a half from each end inward. Then I just took the 4.5 inch angle grinder with a cut off wheel and just cut the part out that I did not weld. This way I knew it was lined up perfectly. So I did a quick check and it was lined up. Next was the c-clamps, I lined up the C-clamp to see where I needed to place it to be in the middle of the channel and I only had to cut a small section off the clamp to do it. Then I ground down the tip of the clamp into a V shape to fit into the V shape of the upper and lower channel. Then I used a small piece of tube to help guide the clamp into place while I held it in place and tack welded both clamps. Then I checked the alignment with two tubes using the clamps, perfect. See tube jig pictures.
03/02/10 - Bending tubing
More work on the frame as tonight it was time to bend some tubing. I had already ruined a couple of pieces of tubing testing out the harbor freight pipe bender so I used those pieces to do some practice bends to see how my bender worked. I was able to salvage a couple of the shorted pieces from the original tubes I purchased for the cross member parts. I did buy 4 more 4 foot pieces to help save on shipping since I found out anything over 4 feet cost extra because it is oversize for Fedex or UPS to ship. I really only needed 3 pieces but I messed up on the top tube of the frame by making the top tube too short between the bends so I am glad I had a fourth piece. So after a couple of test bends and learning that the roller system pulls the tube from the "V" channel I knew where to mark the lines and where the bends would end up. Like I said I messed up the first top tube bend as I did not think about which way it was going to get pulled so the second bend ended up too close. Then after that little mishap I took my time thinking about where the bend would come from and everything else turned out almost spot on.
I got all the tubes bent that I needed which was the top, both sides, the tank cross member and the two lower motor mount cross members. Using a cheater pipe and having the tube marked and loaded into the bender the bends only to less that 20 seconds each. The process was the quick file and burrs at the end of the tubes from being cut. Then I took two pieces of duct tape about 4 inches long and got them ready to put on the end of the tube. Them I took brake cleaner and a rag to clean the end of the tube of the light coating of oil usually on them so the duct tape would stick. Then put one piece of duct tape on and flip the tube over and using a small funnel I would pour sand into the tube. I little trick I found is the sand doesn't always settle so you have to tap the entire length of the tube with a hammer to get the sand to settle in tight then add more sand and do it again until you get to the top. Then take the second piece of tape and place it over the end. Now the tube is ready to be bent. I did have remove the smaller pulley bolt each time to load and remove the tubes since the tape was just thick enough that it would not go through, but it was designed that way so the tube had no room to squeeze out of and kink. I started off using a couple of layers of tape but I found that only one small piece worked just fine. See pictures (tape 1-5) to view how I taped the ends of the tubes. Next I will have to cut the tubes to the correct lengths and prepare them for welding. This also includes the 1/2 inch stiffener tubing as well.
02/24/10 Making bender tool
I was able to finish up my tubing bender last night. I cut the square tubing and notched the channel then I welded it together. I then put the whole thing together and checked the alignment and everything was ok. Now for the big test. I grabbed a piece of 4130 3/4" x .049 wall chromoly tube and loaded it up to try and bend it. It was hard to pull around but I did get it started which is the hard part. I got to about 40 degrees and I noticed it starting to flatten out...crap. I took out the tube and saw it was going to buckle (see picture). So I still had some tube already filled with sand so I loaded it up in the bender. Again it took a bit to get it started but I used a cheater pipe at the end of the handle so it was easier. I slowly pulled it around and kept checking, looking good. I got to about 45 degrees, no sign of buckling so I kept going. I pulled it all the way around to just past 90 degrees which is what I need to make the frame. I took the tube out and WOOHOO, it was a perfect round Nice bent tube with no kinks or elongation's (see picture). So I am just waiting for the rest of my tube to show up hopefully tomorrow and I can start work on the frame.
Pictures of bend tube with different benders and the results:
Tube 1 - The tube was filled with sand and the Harbor Freight 12-ton pipe bender was used. Result big kink in the middle.
Tube 2 - The tube was filled with sand and the Harbor Freight 12-ton pipe bender along with the 3/4 inch conduit bender was used. Results the tube had a better bend, but it still had a ripple and bend was much wider than I wanted.
Tube 3 - The tube was not filled with sand and I used my tubing bender. Result the tube started to kink at about 40 degrees.
Tube 4 - The tube was filled with sand and I used my tubing bender. Result perfect 3 inch radius bend with no kinks and bent just past 90 degrees.
Tube 5 - The tube show next to the aluminum tube of the Fresh Breeze frame. Result the tube is a perfect match to the bend in the Fresh Breeze frame. I will now be able to copy the FB frame using chromoly tubing.
02/23/10
I know it has been a while since my last update. It has been very cold here in Colorado and snowing lots and I have been real busy with various other things going on in my life. However I was able to sneak away into the garage the past couple of night and get some work done on the bender.
Before I continue I will say that I did try to buy one of the Harbor Freight 12-ton pipe benders just for kicks and giggles. They were on sale for $90 so I thought what the heck, try it and if I don't like it I can take it back for a refund. Just to be as safe as possible I even filled the tubes with fine sand and packed it tight before I attempted to bend the tubes. Well the first try was not good, It was ok and I also used the conduit bender to help but the radius of the 3/4 HF pipe bender form tool was just too tight and so the tube started to kink. I tried a couple more times alternating back and forth with the conduit bender which works great but just not tight enough bends to the pipe bender which I still ending up kinking the tube. So I took it back.
Ok so I stopped off at Home Depot to pick up 2 sticks of 1/4" x 1-1/4" x 3' foot cold rolled steel for the swing arm of the puller and some 3/8 inch bolt, nuts and washers. I also cut and drilled the two aluminum plates and angle iron for the bottom half of the bender. I did have to trim about 1/16 of an inch off both sides of the angle iron so it would not touch the main tubing die. I want to have it sitting just over the top of the main die to hold the tube in place while it is being bent. I also have some square tubing that I am going to use to shoulder the two plates (keep them separated) the same distance as the main die. I will then notch the back side of the angle iron just wide enough and weld the angle iron to the square tubing. I added more pictures and more coming soon.
02/07/10
Today I got the smaller pulley done and it only took me about an hour to make, It was a lot less material I had to take off, plus I already had the just of how to do it faster. I drilled the center hole to be 3/8 of an inch so I could use 3/8 inch bolts. I spent the rest of the day making up another set of dies for 7/8 tubing which is used on the skybolt.
02/06/10
Ok so I started on the pulley or tubing bender die for the tube bender today. The first main big die is just under a 4 inch radius bend. It took about 5.5 hours to make on my lathe and it is a very close fit. Man I wish I had a cnc milling machine but I had to do it the old fashion way which takes longer but it still gets the job done. Work on the smaller die to start tomorrow.
A lot of the times I go flying I take my suburban to the field in which I have a hitch and I also have a cargo carrier. It would be nice like a lot of guys do is just throw their completed paramotor onto the cargo carrier and drive to the field not having to put anything together and then break it down to go home. My issues is the frame feels so weak that I think the weight of the motor would actually bend the frame during transit to and or from the local LZ. Since I was building the Skybolt frame and decided not to use it for now, I came up with another idea, what if I made a chromoly frame? The nice thing is it would be 2x greater in strength but yet only a couple of pounds heavier than the current frame and I could still use all the original cage pieces since it is just the main frame that is the issue. I had almost all the tools and I could weld it much better. I would need to make a tool that would bend the tubes to get the same radius bend that the Fresh Breeze uses.
So I measured the stock frame to figure out how much tubing I needed and I ordered the metal from Aircraft Spruce. I went with 3/4 OD .049 wall tubing for the main frame tubing and 1/2 inch .035 wall for the stiffener tubing.
Building the Tube Bender/Tools Pictures Link
Frame Pictures Link
Tools needed:
- Metal chop saw or hacksaw
- Set of files
- Tubing bender with a 4 inch radius (I made my own)
- Tube butt jig (I made my own)
- TIG welder
- Bench grinder
- Drill with drill bits
- 3/4 inch metal hole saw
- Pliers
- Painting gear (optional)
- Two 6 foot 4130 1/2inch od x ,035 wall tubing
- Three 6 foot 4130 3/4 inch od x .049 wall tubing
- One 1 foot 4130 1/2 x 1/2 inch od.035 wall square tubing
- Paint
Safety is a big deal. Please use proper eye and ear protection and any other proper safety gear when drilling, cutting and even just handling tubes. Wear gloves until edges are smooth etc. Having metal in your eye is not fun (been there before) so please at a minimum wear safety glasses. I put them on as soon as I walk in the garage so I don't forget. This has saved my eyes more than once.
After looking over the frame it did not look like it would be too hard to copy. But getting the tight bends that FB uses I would have to make my own bender. The regular conduit benders for 3/4 inch have a 6 inch bend radius and even the 1/2 inch bender have a 5 inch bend radius and I need a 4 inch. Buying dies and a machine to bend to a 4 inch would have cost a lot more than I was willing to spend so I started looking into different ways to bend the 3/4 tubing. Once way was automotive pulleys (found on the internet) but I was not real keen on that idea. Another was a pipe bender which again I did not want to spend $120 just for a few bends. The most common was home made tubing benders that uses a bottle jack, but again I would have to buy parts to make it and it still would have been expensive. Well my other option since I already had a metal lathe was to make my own out of some solid stock aluminum. I had some 5 inch solid 6061 aluminum rod and 3/8inch aluminum plate from my rocketry days so off to the lathe it was. I know I could also use a hickey to bend the tube but I want nice clean bends without kinks in the tube.
3/15/10 - Welded tube to frame
I visited my local welding supply High Plains Welding to get some argon gas today. After talking with them for a minute or two I upgraded my 20 cubic foot bottle for a 65 cubic foot bottle plus gas for only $45, woohoo. I love this place, they have always treated me right. Any other place would have charged me over $100 just for the bottle and no gas. Anyway I was back in business to get back to welding my frame.
So I removed the motor from my old FB frame so I could do some alignment testing with the tacked tubes first just to make sure I was on the mark. I was off a little so I cut the top tube welds and repositioned the top tube in the correct place and retacked the tube. Now it was time to weld. I finished welding all the tubes and it took a while. The tubes are thin and a small diameter and with the angles they are at they change as you go around with them so it take four or five times to weld then since you have to reposition each time to get into the tight spaces. So after a couple of hours I was finished so I checked the motor mount alignment by placing the motor on top motor mount tubes, perfect fit. I forgot to put on a long sleeve shirt so now I have a nice little UV sunburn on both my arms. It is not bad since actual welding time was not that long it is still a reminder for Safety First.
The rest of the time I have in the garage was spent working on my starter upgrade since I had the motor off the frame.
3/13/10 - Frame weld and tacking tubes (starting to look like a real frame)
I was able to go flying today but I needed to get back so the wife should use the Suburban. I also did a little work on my car with my son but then is was my time in the garage with the frame. Today I was going to finish up the tube notching and start doing some welding on the frame. I decided to start with welding the main legs to the top tube. I just laid the front side of the top top down with the legs pointing up in the air. Then I got my carpenters square out and made sure the legs where straight up at a 90 degree angle. Once I knew everything was straight I tack welded both tubes. Then I rechecked to make sure everything was straight and lined up...it was so I finished the welds. I purposely burned through the wall of the outer tube to make sure I tacked the insert tubes to the outer tubes in a couple of spots on both sides for a little more stability and to keep them from sliding down the tube over time if they loosened up.
So the last tube I needed to cut down and notch was the tank tube. After a couple of measurements...ok I eyeballed it, I cut the tube and then notched the ends. I then prepped both ends of the tube with a dremel drum sander as I did will all the other tube ends. I then test fit all the tubes again t make sure they fit and they did, some with a couple of slight vise adjustments.
I started with the tank tube at the top. I measured several time to make sure it was going into the correct position. Then I tack welded the two outer tabs. Next was the top motor tube, again several measurements before I tack welded the ends. Then is was time for the bottom tube, again several measurements be fore I tack welded it into place. With the tack welds I and still able to do a slight bend up or down to make sure everything lines up but it is real close already. Maybe just a tweak here and there. I was not able to finish the welds since I was out of argon gas. and the welding shop I get it from closes at 1:00pm on Saturday's. I looked up at the clock to see it was past 1:00. Oh well at least the basic frame is built. The next item will be the slight bend tube at the bottom and trimming the bottom of the legs or feet I guess you would call them.
3/10/10 - Tube cutting and notching
I got a little time in the garage tonight so I worked on getting the tube cut to the proper length. I started with the frame tube since they where about 1/4 inch too long. After measuring several times and comparing to the actual frame I made the cuts and refit the two side tubes back to the top tube with the little insert tubes I had made. Next I turned to the tank tube and top and bottom motor mount tubes. Again after several measurements I cut the tubes.
Next I set up the 3/4 hole saw in my drill press to notch the tank and motor mount tubes so they would mate up to the frame. They needed to be cut at a 90 degree angle so it was pretty easy to setup. Using a 4 inch drill press vise and some 1/4 thick wood pieces I positioned the vise to cut the notch's right in between the wood boards with a tube pinched in between them. The wood is in there to protect the vise jaws from the hole saw. I also needed to put another tube on the other side just out of reach of the saw to keep the vise jaws from canting. With this setup I have the drill on the lowest speed. It is also a safety issue. The if there is not another piece of tubing to help the jaws stay square, there is a chance the saw can catch the wood and shoot it out sideways out of the vise. Please note the saw will cut very slightly into the wood and this is ok. The key is to have the tubing right in the middle so the saw does not cut one side of the tube more than the other. It took a couple of very small adjustments to get it in the correct position.
Once I had the vise setup it was time to test the notcher. I started with a couple of scrap pieces first to make sure everything was lined up. They turned out pretty good. I cleaned them up in with the bench grinder and wire wheel and then did a test fit.... perfect. So now I chucked up the top motor mount tube in the vise and made sure the drill press platform was level and I rigged up some items to hold the non drilled side of the tube level to the platform to make sure I was getting perfect 90 degree cuts to the tube and to the frame position. Ok here we go, I turned on the drill and took my time. First side done and looks like it came out ok. So I turned the tube over to do the second cut on the other side. Interesting thing happened. Right as I finished the second cut which came out good, the 1/2 inch drill chuck came of the head of the drill...hole saw and all. The head looks like a morse tapper system but I never had seen a setup like that before on a drill press. Needless to say dinner was ready and I did not have time to fix that so I quickly cleaned up the top tube with the grinder and did a test fit on the frame. Woohoo, looks great and fit perfect.
03/09/10 - Welder testing and tube inserts
Tonight after doing some welder testing I started work on the actual frame. First was to measure and cut the two side legs and top tube. I went ahead and measured a bit long for the first past. I don't want to have to buy any more tubing as I am out if I make a mistake. Once I measured and compared to the original frame I cut the top tube and I only needed to trim one of the side legs. Then I put them together to see how it looked. While I was looking at it on the floor taking pictures I got an idea. Why not take some sort scrap pieces of tubing cut a notch along the length of the tube squeeze it and fit it inside both the top tube and leg tube. This would serve several purposes with the first being it would hold the tubes in proper alignment for welding, second it would help stiffen the joint and last...well heck it it just a great idea. So I did a little experimenting and cutting and I was able to make two inserts about an inch long to place them in both sets of tube joints. So now it holds the frame together so I can take a look at it before I weld it permanently.
While I was cutting the inserts I went ahead and cut the last tube which is the slightly bent tube that the cage pieces plug into at the bottom of the frame. I got out the conduit bender and did slight small bends to make the same FB shape and it came out great.
Once I was done with the bottom cage tube, I put the pieces together with the inserts and set it next to the FB frame. A couple of things I noticed is the frame is a little tall which makes sense since I left the tubes a bit long. I can fix that next time. Also I noticed that my frame sits back a little further, That is also an easy fix for next time.
03/04/10 - Making more tools
Next I needed a jig to hold the tubes together straight while I was welding them. I did a little research on the internet and found a great simple tube butt joint jig using 1/2 angle iron. I had a couple of feet in the garage so it was perfect. I did need to get a couple of tools from harbor freight like a small set of welding magnets and some cheap 3 inch clamps for the jig. I got out the 4 inch grinder and put a cut off wheel to cut the channel, one 6 inch piece and two 1.5 to 2 inch pieces. Using the magnet to hold the the short pieces at both ends of the longer 6 inch piece good enough to tack weld the short pieces. Once that was done I welded the the pieces on so from the end view they looked like an X. I used a short piece of straight pipe to verify everything lined up and it was slightly off.
I tried a new trick. I cut two pieces at 7 inches each Then I lined them up with the magnets and welded just an inch and a half from each end inward. Then I just took the 4.5 inch angle grinder with a cut off wheel and just cut the part out that I did not weld. This way I knew it was lined up perfectly. So I did a quick check and it was lined up. Next was the c-clamps, I lined up the C-clamp to see where I needed to place it to be in the middle of the channel and I only had to cut a small section off the clamp to do it. Then I ground down the tip of the clamp into a V shape to fit into the V shape of the upper and lower channel. Then I used a small piece of tube to help guide the clamp into place while I held it in place and tack welded both clamps. Then I checked the alignment with two tubes using the clamps, perfect. See tube jig pictures.
03/02/10 - Bending tubing
More work on the frame as tonight it was time to bend some tubing. I had already ruined a couple of pieces of tubing testing out the harbor freight pipe bender so I used those pieces to do some practice bends to see how my bender worked. I was able to salvage a couple of the shorted pieces from the original tubes I purchased for the cross member parts. I did buy 4 more 4 foot pieces to help save on shipping since I found out anything over 4 feet cost extra because it is oversize for Fedex or UPS to ship. I really only needed 3 pieces but I messed up on the top tube of the frame by making the top tube too short between the bends so I am glad I had a fourth piece. So after a couple of test bends and learning that the roller system pulls the tube from the "V" channel I knew where to mark the lines and where the bends would end up. Like I said I messed up the first top tube bend as I did not think about which way it was going to get pulled so the second bend ended up too close. Then after that little mishap I took my time thinking about where the bend would come from and everything else turned out almost spot on.
I got all the tubes bent that I needed which was the top, both sides, the tank cross member and the two lower motor mount cross members. Using a cheater pipe and having the tube marked and loaded into the bender the bends only to less that 20 seconds each. The process was the quick file and burrs at the end of the tubes from being cut. Then I took two pieces of duct tape about 4 inches long and got them ready to put on the end of the tube. Them I took brake cleaner and a rag to clean the end of the tube of the light coating of oil usually on them so the duct tape would stick. Then put one piece of duct tape on and flip the tube over and using a small funnel I would pour sand into the tube. I little trick I found is the sand doesn't always settle so you have to tap the entire length of the tube with a hammer to get the sand to settle in tight then add more sand and do it again until you get to the top. Then take the second piece of tape and place it over the end. Now the tube is ready to be bent. I did have remove the smaller pulley bolt each time to load and remove the tubes since the tape was just thick enough that it would not go through, but it was designed that way so the tube had no room to squeeze out of and kink. I started off using a couple of layers of tape but I found that only one small piece worked just fine. See pictures (tape 1-5) to view how I taped the ends of the tubes. Next I will have to cut the tubes to the correct lengths and prepare them for welding. This also includes the 1/2 inch stiffener tubing as well.
02/24/10 Making bender tool
I was able to finish up my tubing bender last night. I cut the square tubing and notched the channel then I welded it together. I then put the whole thing together and checked the alignment and everything was ok. Now for the big test. I grabbed a piece of 4130 3/4" x .049 wall chromoly tube and loaded it up to try and bend it. It was hard to pull around but I did get it started which is the hard part. I got to about 40 degrees and I noticed it starting to flatten out...crap. I took out the tube and saw it was going to buckle (see picture). So I still had some tube already filled with sand so I loaded it up in the bender. Again it took a bit to get it started but I used a cheater pipe at the end of the handle so it was easier. I slowly pulled it around and kept checking, looking good. I got to about 45 degrees, no sign of buckling so I kept going. I pulled it all the way around to just past 90 degrees which is what I need to make the frame. I took the tube out and WOOHOO, it was a perfect round Nice bent tube with no kinks or elongation's (see picture). So I am just waiting for the rest of my tube to show up hopefully tomorrow and I can start work on the frame.
Pictures of bend tube with different benders and the results:
Tube 1 - The tube was filled with sand and the Harbor Freight 12-ton pipe bender was used. Result big kink in the middle.
Tube 2 - The tube was filled with sand and the Harbor Freight 12-ton pipe bender along with the 3/4 inch conduit bender was used. Results the tube had a better bend, but it still had a ripple and bend was much wider than I wanted.
Tube 3 - The tube was not filled with sand and I used my tubing bender. Result the tube started to kink at about 40 degrees.
Tube 4 - The tube was filled with sand and I used my tubing bender. Result perfect 3 inch radius bend with no kinks and bent just past 90 degrees.
Tube 5 - The tube show next to the aluminum tube of the Fresh Breeze frame. Result the tube is a perfect match to the bend in the Fresh Breeze frame. I will now be able to copy the FB frame using chromoly tubing.
02/23/10
I know it has been a while since my last update. It has been very cold here in Colorado and snowing lots and I have been real busy with various other things going on in my life. However I was able to sneak away into the garage the past couple of night and get some work done on the bender.
Before I continue I will say that I did try to buy one of the Harbor Freight 12-ton pipe benders just for kicks and giggles. They were on sale for $90 so I thought what the heck, try it and if I don't like it I can take it back for a refund. Just to be as safe as possible I even filled the tubes with fine sand and packed it tight before I attempted to bend the tubes. Well the first try was not good, It was ok and I also used the conduit bender to help but the radius of the 3/4 HF pipe bender form tool was just too tight and so the tube started to kink. I tried a couple more times alternating back and forth with the conduit bender which works great but just not tight enough bends to the pipe bender which I still ending up kinking the tube. So I took it back.
Ok so I stopped off at Home Depot to pick up 2 sticks of 1/4" x 1-1/4" x 3' foot cold rolled steel for the swing arm of the puller and some 3/8 inch bolt, nuts and washers. I also cut and drilled the two aluminum plates and angle iron for the bottom half of the bender. I did have to trim about 1/16 of an inch off both sides of the angle iron so it would not touch the main tubing die. I want to have it sitting just over the top of the main die to hold the tube in place while it is being bent. I also have some square tubing that I am going to use to shoulder the two plates (keep them separated) the same distance as the main die. I will then notch the back side of the angle iron just wide enough and weld the angle iron to the square tubing. I added more pictures and more coming soon.
02/07/10
Today I got the smaller pulley done and it only took me about an hour to make, It was a lot less material I had to take off, plus I already had the just of how to do it faster. I drilled the center hole to be 3/8 of an inch so I could use 3/8 inch bolts. I spent the rest of the day making up another set of dies for 7/8 tubing which is used on the skybolt.
02/06/10
Ok so I started on the pulley or tubing bender die for the tube bender today. The first main big die is just under a 4 inch radius bend. It took about 5.5 hours to make on my lathe and it is a very close fit. Man I wish I had a cnc milling machine but I had to do it the old fashion way which takes longer but it still gets the job done. Work on the smaller die to start tomorrow.