(Sorry for crappy first few pics, my good camera-phone's battery was dead)
Big splat of dykem with profile outlines used to locate a paper template and and punch hole-locations onto the platform.
Three motor/shaft alignment holes drilled and tapped for 1/4-20 bolts.
Lenox bi-metal hole-saw deployed for big shaft hole (har har har). This is needed because the shaft pokes all the way through the gearbox. I need access to the lower-end of the shaft, and the ability to slide it up/down to mate the lovejoy halfs together (later, below). Also, there's enough of the shaft poking through that I could maybe use it to drive some accessory later (w/ lifting mechanism disengaged).
Here you can see the alignment bolts, two are installed (poking up). That big bolt will be used to clamp the motor-mount down onto the platform...
Yay! It's completely finished! Oh wait...there's more.
Upper limit switch tacked in place, along with it's actuation rod on the lifting carriage. The switch has a spring-loaded button, but if something goes wrong, it's able to be forced upwards past a hard-stop. At that point a shear-pin will break or a fuse will blow. I haven't added the hard-stop yet.
Lower limit switch mounted on the lower frame. The lower lifting frame acts as the hard-stop, contacting the carriage on the front-side if it tries to go too low.
Mounted a small 105*c thermal-fuse I scavenged from a microwave. This protects the gearbox and motor (to an extend) from getting overheated, and auto-resets once they cool down. Still debating whether or not I need/want this. It's easy to take off if not, but would have been a bear to mount later.
My good camera charged up now, my friend Thom and I to finished cutting the lead-screw keyway this weekend. Here's all the drive-train parts ready for assembly.
The top-frame carries the load through a thrust pin-bearing (600lb rated), and a flange-mount roller-bearing under the frame locates the shaft.
The screw passed through the lifting carriage, through a brass DIY sleeve-bearing. The acme-bolt on the underside will get welded (or otherwise connected) to the frame later.
Lower-frame flange-mount roller-bearing, used to locate the bottom of the screw.
Underside of the lower-frame, here the top-half of the lovejoy gets mounted to the lead-screw.
Before mounting the other lovejoy half (and spider), the shaft is installed into the gearbox because...
...the alignment is quite bad.
Cranking this adjusting screw (under the platform) jacks up the tail end of the motor and...
...the shaft aligns (close enough). The other lovejoy is mounted, and the buna-n spider goes between. The coupler's tolerance is 1.5* (out-of-parallel), so I don't even need to bother with measuring.
A few taps from a rubber-topped "persuasion-device", on the bottom of the shaft, mates up the lovejoy coupler, and the set-screw is tightened. I'm going to need to add a collar of some sort, above the gearbox to prevent the shaft from working it's way downward. It's a tight, sliding fit, but certainly not rigid by any stretch.
There are still a lot of tacked parts in the lifting-assembly that I need to finish weld, but the drivetrain is together enough for some light (~20-lb) load testing. Yay! Now I need to get back to the electronics / wiring so I can make 'er chooch, to find any binding/rubbing problems.