Saturday, June 16, 2018

The Hoist Post Brackets

So moving on with this project. I was just going to use over sized washers, on the outboard side of the bracket bolts, but wood moves and cells crush under high press, a better idea is to use a full size plate on the backside of the post. Since I now have lots of 1/4" plate material, I decided to go this route. First job is to get the four plates cut out. The front plates need to accept a heavy weld and be heavy enough to resist deformation in use, 3/8" more than meets these requirements.

The 6" I beam will actually handle up to a 3 ton hoist, so I am going to over build the rest of it to also accept a 2 or even 3 ton hoist, if the need presents itself. To that end I will be using 4 - 5/8" bolts on each end, the I beam end plates will be 3 inches longer than in the drawing to 9", and the bottom two bolts will be moved to below the bottom of the beam, for a larger support stance.

So this was the first good test of my rebuilt Startrite bandsaw. It performed beautifully, cuts were very fast, a function of the premium blade and lots of power, and the cuts perfectly square. Sure beats fighting with my 4 X 6.

Next operation was to drill the plates. I first drilled the two I beam end plates stacked and clamped, to 3/8". Then using these plates, clamped and drilled the back plates also to 3/8". Changed out the drill bit to 5/8" and enlarged all the holes to 5/8". You will notice I use a vise grip plus the table clamp. When drilling a stack, one clamp must always be in place to prevent movement in the stack. If your new to this, you will avoid spoiling work, if your an old hand, excuse my preaching. Job worked out great, I found I could interchange all the plates, and the holes always lined up well.

If your like me you'll know how difficult it is to drill a perfectly straight and level hole through a 6 X 6 post, standing on a ladder. For this reason I drilled the backplates one size larger to 11/16", to compensate for minor misalignment and keep my cursing in check, ha ha.

So here are the two end assemblies loosely assembled. 

Another view.

Here the I beam is cut to length and the loose assemblies in position.

Here a closer look at the I beam end assembly before welding.

So hopefully we will get the welding done tomorrow morning. And if the lightening and thunder don't scare me to bad, even get it installed in the afternoon.