knoba
...break a leg!
- Messages
- 863
- Location
- Sussex, England
This has been on my mind for over a year now and I finally made it this week. ...I LOVE it!
I'm sure most folks here will know how it's made etc. But; I'll include as much as possible for interest. WARNING: Some people, I'm sure, will find this boring, so just look at the pictures instead.
I like my bench; it's great for laying out projects and ...other stuff, but when it comes to shaping metal (grinding, filing, plasma'ing, sawing etc.) I find it sometimes a bit ...restrictive! What I really need, I thought, was something that would enable me to get 270 degree access to the work piece.
I wanted from it:
- A standardised, heavy section, metal work bench.
- A strong, adaptable, base for any other tooling that I could devise for it (bending brake, press, etc.).
- To be made from expendable & commonly available materials.
- To be very tough & heavy, but movable.
- Free edges - to clamp to.
- To be upgradeable to 3m long.
- To be dismantle-able.
- Fire proof.
- A strong & flat surface.
- To remain permanently outside.
Tall order or tool order... I love a challenge!
What put me off the project for so long, was that ideally, I'd want the leg sections to be cut as double compound mitres. However, I don't have the time, tooling or capability to perform such complicated cuts. It took 2 weeks in the 'back of my mind' to decide if 1 mitre would do.
I'm glad I took the leap in the end as, I only realised later, double mitre cuts would have introduced "a lot of other issues".
The "I Beams", I was after, have outer parallel flange sections joined by a web. If I joined two smaller beams together to form a 20 degree apex; what size beam would fit into the apex area, while still being supportive? I'd want the largest beam section I could afford! Weight wise; about the same as my Sjoberg - 440lbs.
CAD is a sort of "photoshop like" package, but it's for engineers ...only, it's much, much easier! Drawing a 10" x 10" beam, and playing about, meant that I would need, at least, 8" x 5" for the legs. Great!
Phoning around got me:
4 @ 1000mm x 203mm x 133mm x 30kg/m - self colour
1 @ 1000mm x 254mm x 254mm x 73kg/m - self colour
I picked up the beams locally - new & cut for £180.
CAD also gave me most of the measurements (lengths & angles) I needed to make them.
I used a 125mm angle grinder with Norton thin metal cutting discs (ScrewFix) to cut to the line and just, carefully, followed the cut through by eye, until I had the four sections.
The legs are marked as pairs, so they stay together from now on. Putting the pairs together and resting the top I beam, end on, over the apex gave me a profile that I scribed around. I cut outside the line, since the legs are to sit at an angle to the top beam, as they will need that extra clearance.
Drilled a 3mm pilot hole, on the line, where the flanges terminated, stepped up to a 13mm drill bit (used the garden hose for cutting coolant). Same Norton thin metal cutting discs for cutting out the profile and finished out the radius's with a Garryson TCT de-burr. De-burring and smoothing the profile was done with a Norton flexible Zirconium disc ( I sometimes use the proper backing disc or for extra flexibility just 2 or 3 discs 'stacked' together).
All four legs done.
The tops of the legs also needed mitring, 20 degrees, so they would tilt without touching the underside of the top flange.
Welding areas are stripped back to pristine metal. All clamped up and ready for welding... I'm using the MIG, but the ark would have been good too (if I can find it ....under its coating of dust ...ohh the shame!).
Root pass. I see the legs aren't the only things that are a bit rusty
Re cleaned & 2nd pass...
Re cleaned & 3rd pass.
Turned the legs upright to finish welding the flange radius's. There was quite a gap to make up, but it couldn't be helped. The welds were blended using a Cibo variable speed angle grinder and Cibo's ceramic flap discs.
Underside too...
The trial fit-up was good. But the cheap vice is too poor on quality to stay.
The legs needed securing and some extra support ("Top dog" - the horse is already helping me!
). Cut 8 10mm x 25mm flat bar, each with a parallel 20 degree angle on both ends. Cleaned up cut faces and radiused. Drilled a 3mm hole (in one end only) in all the pieces, then used the drill bit as a guide and drilled the other ends with a 2.5mm bit so the holing was identical in all pieces. Marked out & copied drilling sizes to top beam. Finished all out with a 12mm bit. I used M12 x 50mm BZP hi tensile nuts and bolts with plain BZP washers and tried all supports for fit.
Right... I've had this old Epco 3.5 ton jack sitting around for too many years (ram rusted solid), which; has some very nice wheels and handle!
The bottom of all the legs were mitred to the floor's level. I wanted to 'keep it simple' for ease and maintenance, so the wheel spacings are cut out easily and the axle ends are just slotted. (The 2" thick, solid, axles are cut off an old Antqueen main winch spindle. "Angle grinder!!!") De-burred and cleaned up.
Handle in picture was off jack too. Found 8 inches of oversized tube to fit over the handle and used some scraps to make the supports for it. All cleaned up and welded in. After fitting; the handle then had a large washer on the free end with a split pin to suit.
Added some 'skids' to the other legs (8' x 5' x 1/4" flat plates) to stop the rot creeping up them. Since most of the work is in legs (to make the top expendable) I want the legs to stay good.
Everything is meticulously cleaned (M14 twisted knot wire brush, Flexy discs, soap & water, thinners etc.) and ready for painting. I used Hammerite Direct to Rust smooth. Topped out with a cheap Wilton 6" swivel vice. The unpainted top is finished with Colron Finishing wax (It's superb, lubricating, non-oily, sticks like... I use it on all my tools to stop the rust.)
200 quid all in. 460lbs of movable metal. Yarrr horsey!
Thanks for reading! (or even just looking...
)
looks good & strong 
bugger, why didnt I think of that. 
