CHEAP aluminum tubing for bike trailers, etc, etc, etc

[DougC]

If you live near any major city, look in the phone book for metals suppliers, call them up and ask if they have any drops (or scraps) to sell in the sizes you are wanting.

The scraps are a bother to store and inventory; many places will sell them cheap for cash, sometimes for not much more than scrap-metal value.
~

 

[kevbo]

Kevbo, what kind of axle does it have or are there just stubs for the two wheels.
Doc

It uses regular (almost*) 20" bicycle front wheels and axles, supported both inboard and outboard by the frame. The dropouts are aluminum angle stock bolted to the bottom of the frame, and slotted for the axles.

Here is a DIY trailer plan that uses pretty similar wheel mounting. (but with flat plate dropouts instead of angle)


*The wheels are slightly dished, to put the tires a little farther outboard for stability, and to make it harder for a kid to push the fabric sides of the enclosure against the tires.

 

[Dockspa1]

Wow Kevbo,
That gives me all kinds of ideas. Thanks for the link. Looks like all thinwall conduit. The benders can be expensive though. Like most single axle trailors, you will have to center the weight distribution over the wheels. Of course, I would have to put a cooler in it ahem, for cold groceries, don't ya know!
Doc

 

[Esteban]

Our local hardware store will bend tubing for you for a very small cost,, or I have seen pretty neat conduit bending SLOWLY done between trees !!LOL

 

[Abeagle]

One tip on bending tubing is wrap the area you want to bend with insulated copper wire (at least 12 gauge or larger). The wire needs to be wraped tight and kept tight, with no room between wraps, it should be extended on both sides well past the area you want to bend. Bend slowly, I have used this method on 1/2 inch elec. conduit.

 

[ibdennyak]

One tip on bending tubing is wrap the area you want to bend with insulated copper wire (at least 12 gauge or larger). The wire needs to be wraped tight and kept tight, with no room between wraps, it should be extended on both sides well past the area you want to bend. Bend slowly, I have used this method on 1/2 inch elec. conduit.

Agreed.....electrical conduit benders are a handy accesory. The wrapping method helps to keep it from collapsing. Another old fabrication technique I learned from an old fabricator is to fill the tubing with processed sand. (silica sand etc that has been sized and graded rather than beach sand) Pack it tightly, and it keeps the tubing from kinking. Another little technique that might be useful here it to bend PVC conduit. I've used it for like surrey top bows etc. I think a piece of 2" bent and slit in half would make a nice fender. The trick is to heat up a 50/50 mixture of water and antifreeze. Put the conduit in it until it becomes pliable. Bend it, and when it cools, it will retain its shape. It can be neated with a propane torch, but it is hard to keep from scorching one area, and another area is still too cool. Be careful with the antifreeze though around children and pets. It tastes sweet, but is very poisonous.

Denny

Ooops, almost forgot the original reason for posting. If you have a large sturdy table, you can make a lobuck bending table by screwing or bolting hardwood templates to it, with another block for a stop. Then just bend the conduit around the template after filling it with sand. You will want to cut your template a little smaller to allow for springback. About 1/2 inch on a 6 inch radius.

 

[fetor56]

Neat trick about the 50/50 mixture of water and antifreeze....i'll have to remember that.

 

[stude13]

bed rail are cheap good angle iron

 

[Dockspa1]

So I guess Abeagle, that 12 guage wire sorta works like the smaller spring benders for smaller copper tubing, huh?Cool!
Doc

 

[SimpleSimon]

Lots of ways to bend tubing. For simple bends of thinwall conduit, I have in the past simply plugged one end, filled the tube with sand (bouncing it as you fill, to pack it well), driven a wooden plug in the other end, and bent it between two fixed posts. A very simple jig can be made to bend conduit and most thinwall tubing from plywood and two chunks of strap or angle iron.

Take a sheet of 3/4" plywood, cut it into two 4' x 4' squares. Find the center of one square (draw two diagonals using a good straight edge, where they cross is the center), put a 3/8" hole through at the center, insert a 3/8" x 2" carriage bolt, drive it home.

Take the other half, and cut from it whatever radius circle you want for your corners (the smaller the radius, the tighter the corner, the harder it is to make the bend) - you'll need two circles for each desired radius, one the same diameter as the radius of the larger circle. Drill 3/8" holes at the center of each circle. Take your strap iron, drill a pair of 3/8" holes the radius of the pair of wooden circles apart, plus the diameter of your tubing, in each of two equal length pieces (which need to be at least one foot longer than 2.5X the radius of the curve you are making), and a third hole near the other end.

E.g. - if you want a 1' radius bend in 3/4" EMT tubing, the holes in the strap iron need to be 1' + 6" + 3/4" = 18 3/4" inches apart, on centers. I reccomend 1/8" x 1 1/2" flat steel bar stock, minimum, which needs to be a minimum of 2.5' long.

Drop one bar on the center pivot in the 4' square, and put a shim piece the same thickness as your bar stock down, tangent to the desired circle, put the 1' radius circle on the pivot bolt, slide another carriage bolt thru the hole at 18 3/4" (pivot pin for the smaller circle), then put that circle on the pin. Place the other bar on the pins, and washer/lock washer, double nut it in place snugly, but not so tightly it prevents either wheel from turning.

Next step is to put an at least 6" carriage bolt thru the holes at the free end of the bars (put a 3/4" spacer between the bars the bolt slides thru), put on a comfortable sized handle drilled for the long bolt to pass thru, and you are ready to bend tubing.

Affix the EMT to the shim plate, tangent to the larger circle, and sliding between the two pieces of bar, and between the two wooden circles. Best way I've found is to use two or more U conduit mounts, screwed down hard. You want the tail stock of your tube to be fixed in place.

Then grab the handle, and pull - hard. In my experience this jig works best screwed to a solid wall, as high as you can comfortably mount it. Pulling on that handle while the jig is horizontal is a good way to ruin your back. Vertical, your weight does the work.