Just wondering if you seen this build?...............Curt
http://motorbicycling.com/showthread.php?t=37011&page=3
http://motorbicycling.com/showthread.php?t=37011&page=3
Hi from the UK - INDIAN Board Tracker tribute, my first build
- Thread starter PeteMcP
- Start date
NEW FRAME MATERIAL PURCHASED...
Made a decision to construct the new frame for this build from mainly 25.4mm (1") aluminium tube. Ordered-up the 3 x sizes of frame tubing needed today. My welding experience is limited to steel fabrication, so I won't be welding this alloy frame myself. Found a tractor repair/engineering shop ten minutes away who are certified to weld aluminium - so no worries. Busy drawing-up a schematic to help knock-up a frame jig that'll hold everything in alignment.
Made a decision to construct the new frame for this build from mainly 25.4mm (1") aluminium tube. Ordered-up the 3 x sizes of frame tubing needed today. My welding experience is limited to steel fabrication, so I won't be welding this alloy frame myself. Found a tractor repair/engineering shop ten minutes away who are certified to weld aluminium - so no worries. Busy drawing-up a schematic to help knock-up a frame jig that'll hold everything in alignment.
INTAKE MANIFOLD DONE & CARB INSTALLED...
Merry Christmas & Happy New Year to everyone. After almost a week marooned in Chrimbo Limbo, I felt the urge to resume work on my No. 3 build.
As a Christmas prezzy to myself I had purchased a 26mm flat slide carb for my vintage Gnome & Rhone 125cc motor. After wasting close on two weeks-worth of time searching online for a suitable intake manifold that would locate the carb anywhere near correctly on my motor, I gave up looking and decided the best way forward was to modify an existing manifold. All the 26mm manifolds I looked at featured flanges with fixing stud centres 45mm apart at one end and 48mm at the other and featured a 90 degree bend. But I needed an intake with stud centres 48mm apart at both the carb and motor ends of the manifold and with a bend nearer 45 degrees. In the end I purchased two different manifolds and cut off the parts I needed, discarding the off-cuts.
Having found it easy to fabricate the aluminium gas tank for my previous DECOLINER project using Alubuild 300 brazing rods, I figured it would be a cinch to 'weld' the two pieces of my new alloy intake manifold using the same process. And so it proved. I simply pre-tinned the joint surfaces of both pieces of the intake manifold with the Alubuild 300 then joined them together - using nothing more than my butane torch. All very low-tech. and very simple. The first pic shows my perfectly formed intake manifold posed alongside the unwanted off-cuts from the pair of manifolds I started with. Look closely and you'll see the brazed joint securing the flange at the top right of the photo.
The remaining three pics show the intake manifold and carb bolted to the motor. My new intake was fabricated with the intention of locating the carb offset to the left for two reasons. Firstly, the underside of the carb's float bowl had to avoid contact with the alloy gear cover atop the motor, and secondly, the carb's air cleaner obviously will need to clear the frame's centrally located coil spring.
The carb's air cleaner cover is presently sprayed in grey primer awaiting whatever finish colour I'll opt to paint this project.
Mission accomplished...
Merry Christmas & Happy New Year to everyone. After almost a week marooned in Chrimbo Limbo, I felt the urge to resume work on my No. 3 build.
As a Christmas prezzy to myself I had purchased a 26mm flat slide carb for my vintage Gnome & Rhone 125cc motor. After wasting close on two weeks-worth of time searching online for a suitable intake manifold that would locate the carb anywhere near correctly on my motor, I gave up looking and decided the best way forward was to modify an existing manifold. All the 26mm manifolds I looked at featured flanges with fixing stud centres 45mm apart at one end and 48mm at the other and featured a 90 degree bend. But I needed an intake with stud centres 48mm apart at both the carb and motor ends of the manifold and with a bend nearer 45 degrees. In the end I purchased two different manifolds and cut off the parts I needed, discarding the off-cuts.
Having found it easy to fabricate the aluminium gas tank for my previous DECOLINER project using Alubuild 300 brazing rods, I figured it would be a cinch to 'weld' the two pieces of my new alloy intake manifold using the same process. And so it proved. I simply pre-tinned the joint surfaces of both pieces of the intake manifold with the Alubuild 300 then joined them together - using nothing more than my butane torch. All very low-tech. and very simple. The first pic shows my perfectly formed intake manifold posed alongside the unwanted off-cuts from the pair of manifolds I started with. Look closely and you'll see the brazed joint securing the flange at the top right of the photo.
The remaining three pics show the intake manifold and carb bolted to the motor. My new intake was fabricated with the intention of locating the carb offset to the left for two reasons. Firstly, the underside of the carb's float bowl had to avoid contact with the alloy gear cover atop the motor, and secondly, the carb's air cleaner obviously will need to clear the frame's centrally located coil spring.
The carb's air cleaner cover is presently sprayed in grey primer awaiting whatever finish colour I'll opt to paint this project.
Mission accomplished...
WORK BEGINS ON THE NEW FRAME...
Had hoped to be a little further on with the new frame but heavy snow and freezing temps here have slowed-up delivery of the hydraulic tube bender I ordered. Not really a problem given the sub-zero temps in my unheated garage would have prevented me from doing much work in there anyway.
So anyhooo, after several attempts, I finally drafted a workable sketch for a frame layout that works for me. The top two frame bends may yet end up a little more curvacious....I'll figure it out when my tube bender shows up.
First pic shows the layout I've come up with. The other two pics show components laid over the drawing to give an idea how she'll look. Now I just need to cut parts to fab a jig from square aluminium tube to align everything up for the guy doing the frame welding.
Had hoped to be a little further on with the new frame but heavy snow and freezing temps here have slowed-up delivery of the hydraulic tube bender I ordered. Not really a problem given the sub-zero temps in my unheated garage would have prevented me from doing much work in there anyway.
So anyhooo, after several attempts, I finally drafted a workable sketch for a frame layout that works for me. The top two frame bends may yet end up a little more curvacious....I'll figure it out when my tube bender shows up.
First pic shows the layout I've come up with. The other two pics show components laid over the drawing to give an idea how she'll look. Now I just need to cut parts to fab a jig from square aluminium tube to align everything up for the guy doing the frame welding.
Hooray!!! Ten minutes after posting the above message, the delivery driver showed up with my hydraulic tube bender. Bit of a a struggle for him hauling it to the door on a sack barrow in foot deep snow.
No excuses now. Freezing or not, I'll be in the garage tomorrow giving it a try-out.
No excuses now. Freezing or not, I'll be in the garage tomorrow giving it a try-out.
Gives us a show of that bender when you've a chance. Looks like a good design in progress. Rick C.
Rick, here's a generic shot showing the bender I purchased for this frame build.
Made a few modifications to get it to work properly with the 6061 aluminium tube I'm using. Been doing a few practice bends today to get the hang of it. Definitely NOT a tool you just whack some tube in and start making perfect bends. I reckon I now have the hang of it - so I'll share my experiences in the next post.
HYDRAULIC TUBE BENDER - SOME OF MY FINDINGS...
Spent a couple of hours yesterday familiarizing myself with my newly acquired bender.
Whilst waiting for it to be delivered I'd already spent time watching umpteen youtube videos showing this tool in use. First up, what comes across loud and clear from those who know about these things is that this tool is a PIPE bender - not a TUBE bender. They stress there IS a difference. The main difference to be aware of is that PIPE and TUBE diameter measurements differ, in that PIPE is specified according to its internal diameter and TUBE is specified according to its external diameter. It's important you're aware of this prior to laying out for the tool - mainly because the five different bend radius dies supplied with the bender are sized for PIPE, not TUBE. Oh, and the tool is specifically designed to bend malleable steel pipe. If you've reached this point without yawning, read on...
Of all the youtube vids I watched, one in particular grabbed my attention 'cause it outlined and addressed the problems any purchaser of this bender is likely to come up against if they want to use it for bending tube. Or in my case, 24.5mm (1") dia. 6061 aluminium tube. This guy's youtube vid showed how he recommended modifying one of the smaller diameter dies to accommodate the nearest available sized tube. To clarify, the die intended for bending 1" PIPE is way oversized for 1" tube. So is the 3/4" die. The 1/2" die was closest to being the correct die for bending my 1" aluminium tube, being marginally undersized to allow the tube to snug right down in the die's channel. The youtube guy recommended opening-up the die's channel a little and gently chamferring/rounding the channel edges so it didn't bite into the tube's surface. Following his tips, I planned on doing this - but first I planned on making a few test bends just to get the hang of operating the bender. Unsurprisingly, I've learned practice is the secret. Don't expect to get results right out of the traps.
Probably best to refer to the pics below. First pic shows the first bend I made. Disaster, or what!? Oh yeah, the tool has it's limitations - and I reached them pretty early on doing this bend. I just put the tube in the bender, cranked away at the pump handle a few times, and CRACK! What radius bend is that? About 15 degrees before the alloy tube well and truly cracked. Yeah, that's what'll inevitably occur if you don't take it easy and in stages. And notice the gouge in the tube's sides where the raw edges of the die bit in.
Second pic shows how I modified the 1/2" die so it accommodated the 1" aluminium tube I'm using. I used an abrasive ball in a power drill to clean out and enlarge the channel marginally then I rounded-off the channel's sharp edges so the tube was a snug fit into the die. Compare this modified die to the 3/4" die alongside to see the difference.
Third pic shows how I began bending the frame's curved downtube - but sadly, even this ended up failing when I was just short of completing the bottom bend. SH-----T!!! That was nearly two hours worth of bending - a degree or two at a time - using the segmented marks I'd made on the tube as guides when the tube was placed in the bender. I must have had the tube in and out of the bender 50 times while performing that bend. It's just I got cocky at the last minute and cranked the pump handle a few too many times in my eagerness with the end of the bend in sight. I won't make that mistake next time.
Fourth pic is a close-up showing the downtube's fracture. Because the tube is a snug fit in my modified die, it generally maintains its shape without deforming or creasing at the bend's inner radius. The crack failure occurs on the most stressed area of the bend, it's outer radius. That's because aluminium is nowhere near as malleable as the steel tube intended for use with this bender.
Later this afternoon I'm up for re-attempting a mk2 version of that pesky downtube. And the upper bend will definitely have to be smoothed out some. It definitely won't form as sharp as I've drawn it. Gentle bends are the secret. Stay tuned to find out how I get on. Finger's crossed....
Spent a couple of hours yesterday familiarizing myself with my newly acquired bender.
Whilst waiting for it to be delivered I'd already spent time watching umpteen youtube videos showing this tool in use. First up, what comes across loud and clear from those who know about these things is that this tool is a PIPE bender - not a TUBE bender. They stress there IS a difference. The main difference to be aware of is that PIPE and TUBE diameter measurements differ, in that PIPE is specified according to its internal diameter and TUBE is specified according to its external diameter. It's important you're aware of this prior to laying out for the tool - mainly because the five different bend radius dies supplied with the bender are sized for PIPE, not TUBE. Oh, and the tool is specifically designed to bend malleable steel pipe. If you've reached this point without yawning, read on...
Of all the youtube vids I watched, one in particular grabbed my attention 'cause it outlined and addressed the problems any purchaser of this bender is likely to come up against if they want to use it for bending tube. Or in my case, 24.5mm (1") dia. 6061 aluminium tube. This guy's youtube vid showed how he recommended modifying one of the smaller diameter dies to accommodate the nearest available sized tube. To clarify, the die intended for bending 1" PIPE is way oversized for 1" tube. So is the 3/4" die. The 1/2" die was closest to being the correct die for bending my 1" aluminium tube, being marginally undersized to allow the tube to snug right down in the die's channel. The youtube guy recommended opening-up the die's channel a little and gently chamferring/rounding the channel edges so it didn't bite into the tube's surface. Following his tips, I planned on doing this - but first I planned on making a few test bends just to get the hang of operating the bender. Unsurprisingly, I've learned practice is the secret. Don't expect to get results right out of the traps.
Probably best to refer to the pics below. First pic shows the first bend I made. Disaster, or what!? Oh yeah, the tool has it's limitations - and I reached them pretty early on doing this bend. I just put the tube in the bender, cranked away at the pump handle a few times, and CRACK! What radius bend is that? About 15 degrees before the alloy tube well and truly cracked. Yeah, that's what'll inevitably occur if you don't take it easy and in stages. And notice the gouge in the tube's sides where the raw edges of the die bit in.
Second pic shows how I modified the 1/2" die so it accommodated the 1" aluminium tube I'm using. I used an abrasive ball in a power drill to clean out and enlarge the channel marginally then I rounded-off the channel's sharp edges so the tube was a snug fit into the die. Compare this modified die to the 3/4" die alongside to see the difference.
Third pic shows how I began bending the frame's curved downtube - but sadly, even this ended up failing when I was just short of completing the bottom bend. SH-----T!!! That was nearly two hours worth of bending - a degree or two at a time - using the segmented marks I'd made on the tube as guides when the tube was placed in the bender. I must have had the tube in and out of the bender 50 times while performing that bend. It's just I got cocky at the last minute and cranked the pump handle a few too many times in my eagerness with the end of the bend in sight. I won't make that mistake next time.
Fourth pic is a close-up showing the downtube's fracture. Because the tube is a snug fit in my modified die, it generally maintains its shape without deforming or creasing at the bend's inner radius. The crack failure occurs on the most stressed area of the bend, it's outer radius. That's because aluminium is nowhere near as malleable as the steel tube intended for use with this bender.
Later this afternoon I'm up for re-attempting a mk2 version of that pesky downtube. And the upper bend will definitely have to be smoothed out some. It definitely won't form as sharp as I've drawn it. Gentle bends are the secret. Stay tuned to find out how I get on. Finger's crossed....
Have you tried to annul the tube first, to soften it? Just a thought..........Curt
I bought this one, it is good to 1". Haven't tried it on aluminum yet.
https://www.northerntool.com/shop/t...raqK9BvVaxc3xIinfZN7QoknvrFHuggBoCSyIQAvD_BwE
I bought this one, it is good to 1". Haven't tried it on aluminum yet.
https://www.northerntool.com/shop/t...raqK9BvVaxc3xIinfZN7QoknvrFHuggBoCSyIQAvD_BwE
As you discovered Pete bending any tube in a pipe bender isn't easy. Even schedule 40 pipe used in plumbing work is somewhat deformed on relatively modest bends. Aluminum by it's basic nature is, depending on it's alloy, very resistent to bending without fracture, unlike most common steel alloys. The result of a significant bend in formed aluminum is to greatly weaken it'structure. Heating (annealing) metal requires a re-temper process which can, on steel, be done pretty well in a home shop, but not with aluminum.
Back in the the fifties and sixties we did it the "poor boy" way, filling the tube to be bent with fine sand and capped off the tube ends, then proceeded with the caution the bending process. This worked quite well to prevent deformation with thin wall steel but I don't recall ever "packing" aluminum tube in those days, though it should be helpful on any metal tube. I hope this is of some help. Rick C.
Back in the the fifties and sixties we did it the "poor boy" way, filling the tube to be bent with fine sand and capped off the tube ends, then proceeded with the caution the bending process. This worked quite well to prevent deformation with thin wall steel but I don't recall ever "packing" aluminum tube in those days, though it should be helpful on any metal tube. I hope this is of some help. Rick C.
Curtis that is a great value in a tube bender. I think you are going to be very pleased. Rick C.
Actually got it a tad cheaper ( last year ). LOL. Woodward Fab has good tools, used it a couple times and very happy so far. Bought there bead roller also, still in the box, waiting on new bench top, and vise before i go any further. Going to somehow incorporate a receiver hitch, so i can use these and then put away when done, on a rack.........Curt
I've also done this in the past......worked fairly well.
Thanks for all the input and feedback guys.
Let me respond to a few points raised regarding the lower bend I'm forming on my frame's aluminium downtube.
The 3 x test bends I've tried forming so far all fractured on the outside radius of the bend, without the slightest signs of deforming, ie creasing, on the tube's inner radius; no doubt thanks to the tube fitting so snug in the die. For this reason, I assume filling the tube with sand wouldn't be of any appreciable benefit?
Started gradually forming the mk2 version of my downtube late yesterday. I'm about halfway there bending it incrementally, and so far all's good, but very time consuming. That said, my time comes free. I'll continue this afternoon.
That's a very nice tube bender Curt. But again, maybe not designed for aluminium. Be interesting to know what bender could make easy work of a job like this.
If all else fails and it proves impossible for me to form this bend successfully, my Plan B would be to use my Gnome & Rhone 125cc motor as a stressed member like in its intended original frame. Then insert a cosmetic section of steel frame slung under the motor.
Let me respond to a few points raised regarding the lower bend I'm forming on my frame's aluminium downtube.
The 3 x test bends I've tried forming so far all fractured on the outside radius of the bend, without the slightest signs of deforming, ie creasing, on the tube's inner radius; no doubt thanks to the tube fitting so snug in the die. For this reason, I assume filling the tube with sand wouldn't be of any appreciable benefit?
Started gradually forming the mk2 version of my downtube late yesterday. I'm about halfway there bending it incrementally, and so far all's good, but very time consuming. That said, my time comes free. I'll continue this afternoon.
That's a very nice tube bender Curt. But again, maybe not designed for aluminium. Be interesting to know what bender could make easy work of a job like this.
If all else fails and it proves impossible for me to form this bend successfully, my Plan B would be to use my Gnome & Rhone 125cc motor as a stressed member like in its intended original frame. Then insert a cosmetic section of steel frame slung under the motor.
Yes the sand helps distribute the forces of bending the tube evenly through length and circumference. Thin wall tube requires more help than thick wall, though the effort to bend heavy wall will be greater it resists fracture better.
The ratio of bend at the maximum of commonly available commercial aluminum alloy, thin wall tube is 3.5 to 1... radius to diameter. Stay inside this and damage to the metal will be minimal with proper bending technique.
The bender Curt has is a tube bender And the dies are designed for o.d. dimensions of tube material not withstanding. These the style he bought can bend long sections of tube without the pump restriction blocking the material. Rick C.
The ratio of bend at the maximum of commonly available commercial aluminum alloy, thin wall tube is 3.5 to 1... radius to diameter. Stay inside this and damage to the metal will be minimal with proper bending technique.
The bender Curt has is a tube bender And the dies are designed for o.d. dimensions of tube material not withstanding. These the style he bought can bend long sections of tube without the pump restriction blocking the material. Rick C.
Yeeha! I finally managed to form the frame's downtube at the third attempt.
Well, they do say practice makes perfect. Just needed to ease the bend radius a fraction and it turned out fine with zero fracturing. I sure wasn't about to let this thing beat me.
Just tried to take a pic but my camera shut down saying new batteries required - so I'll need to pick up some fresh ones before I can post the results.
Just one thing....I used more tube than intended on my earlier failed bending attempts, so I'll need to purchase some more for the pair of top tubes.
Plan B? Phah! Who needs a plan B?
Well, they do say practice makes perfect. Just needed to ease the bend radius a fraction and it turned out fine with zero fracturing. I sure wasn't about to let this thing beat me.
Just tried to take a pic but my camera shut down saying new batteries required - so I'll need to pick up some fresh ones before I can post the results.
Just one thing....I used more tube than intended on my earlier failed bending attempts, so I'll need to purchase some more for the pair of top tubes.
Plan B? Phah! Who needs a plan B?
Plan B? Phah! Who needs a plan B?, Yep if it don't work the first time rework or remake it till it does. May have a pile of scrap, but scrap is usable sooner or later. LOL
Sometimes have to start all over to get it right ..............Curt
Sometimes have to start all over to get it right ..............Curt