Hello everyone, and Happy New Year!
I have a little problem. I have created an A-Frame lift topped by an electric hoist. This is a very light duty (<100 lbs) lift, but it is rather tall. It also needs to be stored until use, so it has to break down easily. The design I have works pretty well, except for one thing. In order to be able to erect the lift in the relatively restricted areas where it gets used, I made the collapsed lift 16 feet tall with a telescoping section that extends to make the lift a total of 26 feet tall. The rails on the telescoping section are made of 3/4" x 3/4" square Aluminum tubing with a 1/16" wall. In order to raise the telescoping section, I reel out the hoist cable, run it through a pulley attached to a cross-bar at the bottom (in black below) of the extension rails (in red below), and attach the end hook to an attachment point a few feet above the maximum height of the cross-bar. I then reel in the hoist, which easily raises the telescoping section towards it maximum height, where the rails are secured with lynch pins. (See the cross bar 4 feet below the bushings.) The problem is the rails are too flexible. Since the hook cannot be perfectly centered, there is always a small lateral force which causes the rails to flex way too far. I am going to relieve the plastic bushings at the top of the A-Frame and grease them, which should help considerably, but I think the rails still need to be stiffened.
Since the center bore in the rails is 1/2", I think the perfect stiffener would be a pair of 12mm steel rods about 9 feet long. Cold-rolled square bar stock would be excellent, but round stock should work. Stainless steel would be even better, of course, but would be much too expensive. The rods also do not necessarily have to be monolithic. Three rods about 3 feet long in each rail should be fine. I am having trouble finding any 12mm steel of an appropriate length and a reasonable cost.
Does anyone have a good source for some 12mm steel bars / rod? A US seller is preferred - I can't wait forever.
Does anyone perhaps have a better idea for stiffening the rails? I could put in another cross-bar lower down, I suppose.
I have a little problem. I have created an A-Frame lift topped by an electric hoist. This is a very light duty (<100 lbs) lift, but it is rather tall. It also needs to be stored until use, so it has to break down easily. The design I have works pretty well, except for one thing. In order to be able to erect the lift in the relatively restricted areas where it gets used, I made the collapsed lift 16 feet tall with a telescoping section that extends to make the lift a total of 26 feet tall. The rails on the telescoping section are made of 3/4" x 3/4" square Aluminum tubing with a 1/16" wall. In order to raise the telescoping section, I reel out the hoist cable, run it through a pulley attached to a cross-bar at the bottom (in black below) of the extension rails (in red below), and attach the end hook to an attachment point a few feet above the maximum height of the cross-bar. I then reel in the hoist, which easily raises the telescoping section towards it maximum height, where the rails are secured with lynch pins. (See the cross bar 4 feet below the bushings.) The problem is the rails are too flexible. Since the hook cannot be perfectly centered, there is always a small lateral force which causes the rails to flex way too far. I am going to relieve the plastic bushings at the top of the A-Frame and grease them, which should help considerably, but I think the rails still need to be stiffened.
Since the center bore in the rails is 1/2", I think the perfect stiffener would be a pair of 12mm steel rods about 9 feet long. Cold-rolled square bar stock would be excellent, but round stock should work. Stainless steel would be even better, of course, but would be much too expensive. The rods also do not necessarily have to be monolithic. Three rods about 3 feet long in each rail should be fine. I am having trouble finding any 12mm steel of an appropriate length and a reasonable cost.
Does anyone have a good source for some 12mm steel bars / rod? A US seller is preferred - I can't wait forever.
Does anyone perhaps have a better idea for stiffening the rails? I could put in another cross-bar lower down, I suppose.
Last edited:
