Pete.
Member
- Messages
- 14,810
- Location
- Kent, UK
New workshop, new crane. I need this so that I can swap out the different tables, and milling/slotting heads on my milling machine, which I have yet to use what with one thing and another.
I got some nice slotted box-section rail from @Windy Miller, which I figure dI could use to make a lightweight rolling beam for this swing crane. All I needed was somebearings and thick plate to make a truck to do the rolling. A bag of cheap 6201's were a perfect fit and only a quid each.
I drilled the plate and turned up 3 spigots for the bearings. The spigots are 12mm diameter with a thin shoulder one end and a 7mm internal hex broached with a club hammer and 7mm socket allen key. The other end is just some M8 countersunk screws holding the bearings on tight.
The truck rolls nicely along the inside of the box section, after I cleaned out the rust and cobwebs.
Now the channel section on it's own is not strong enough over the full length, it would end up twisted and deformed so I had to put a doubler on top. I figiured that the doubler would be fine for the end half then I could bend it up to make a triangle over the inside 800mm. I have some lightweight 40x40 box which is ideal so I just needed to figure out the angle to do a pie-cut and bend it upwards. I drew it out on the bench and dug out my line of chords rule.
If you don't know what a line of chords rule is I'll explain how it works. The rule has two dimples on the face which you can use to set a divider, and a scale that you can put the divider onto in order to read the angle.
So you set the rule to your angle (in this case, from my lay-out on the bench)
Then you set your divider so that the points sit in the two dots on the rule
Then you take the divider to the scale and read the angle - 26.5 degrees or thereabouts
Now I set my bevel gauge to 13 degrees and marked it up to cut a wedge out of the doubler tube.
Here's the channel and doubler welded together and a sturdy bit of 40x40mm box to finish the triangle.
I also made a simple H frame to mount it to the wall but I didn't take and pics of that being fabricated. In the meantime I cut down the truck, drilled some holes in it and re-purposed my little hoist from the mk1 crane to bolt up to the truck. I made it removable just in case something better comes along later and I can get rid of this cranky little worm-drive winch.
I got some nice slotted box-section rail from @Windy Miller, which I figure dI could use to make a lightweight rolling beam for this swing crane. All I needed was somebearings and thick plate to make a truck to do the rolling. A bag of cheap 6201's were a perfect fit and only a quid each.
I drilled the plate and turned up 3 spigots for the bearings. The spigots are 12mm diameter with a thin shoulder one end and a 7mm internal hex broached with a club hammer and 7mm socket allen key. The other end is just some M8 countersunk screws holding the bearings on tight.
The truck rolls nicely along the inside of the box section, after I cleaned out the rust and cobwebs.
Now the channel section on it's own is not strong enough over the full length, it would end up twisted and deformed so I had to put a doubler on top. I figiured that the doubler would be fine for the end half then I could bend it up to make a triangle over the inside 800mm. I have some lightweight 40x40 box which is ideal so I just needed to figure out the angle to do a pie-cut and bend it upwards. I drew it out on the bench and dug out my line of chords rule.
If you don't know what a line of chords rule is I'll explain how it works. The rule has two dimples on the face which you can use to set a divider, and a scale that you can put the divider onto in order to read the angle.
So you set the rule to your angle (in this case, from my lay-out on the bench)
Then you set your divider so that the points sit in the two dots on the rule
Then you take the divider to the scale and read the angle - 26.5 degrees or thereabouts
Now I set my bevel gauge to 13 degrees and marked it up to cut a wedge out of the doubler tube.
Here's the channel and doubler welded together and a sturdy bit of 40x40mm box to finish the triangle.
I also made a simple H frame to mount it to the wall but I didn't take and pics of that being fabricated. In the meantime I cut down the truck, drilled some holes in it and re-purposed my little hoist from the mk1 crane to bolt up to the truck. I made it removable just in case something better comes along later and I can get rid of this cranky little worm-drive winch.
