Twin-screw vise questions . . . .

[Alan in Little Washington]

For those of you who have twin screw end vises or are just mechanically inclined, I have two questions-

1. Has anyone investigated adding sprockets and chain to link two standard acme lead screws to make a twin screw vise like the Lee Valley end vise? (how did it work?)

2. Other than leaving a bit more space below the table for the sprockets and if the Acme screws are long enough, is there any reason that you couldn't mount the sprockets on the ends of the lead screws that are under the table?

You would probably need a spreader bar with bearings so when you tensioned the chain (to remove backlash) you would not bend the the lead screws and cause them to bind against the mount.

Just thinking ahead to the day I finally get around to building my traditional WW bench.

[Gotcha6]

I'd thought about such an application, but with the dust in a typical shop I'd think some sort of dry drive would be better than an oiled chain. Had you thought about a gear belt & sprockets instead? As for backlash, why not set the shafts at a distance apart that a standard belt length would be taut? A bearing block at the sprockets would eliminate the binding.

[Jim Murphy]

Alan,

You could frequent the junqueyard and pick up a lightly used starter motor, pick up a nice lawn tractor battery from WallyWorld, an inexpensive battery charger from FleaBay, an old model railroad switch switch (the little twin push button thingie with red and green buttons that opened and closed the rail switch) and a few other things to automate the vise. With that working, you could shop around for a laser based optical comparator and proximity sensor that could plug in to a PLC, so you just show the material to the comparator, it reads the thickness, opens the vise, and when you place the whatever into the jaws, the proximity sensor triggers the PLC to close the jaws. Of course, you might need gently jog the tighten button depending on the compressibility of the material you seek to hold firm. PIcs soon?

[Alan in Little Washington]

Originally Posted by Gotcha6

I'd thought about such an application, but with the dust in a typical shop I'd think some sort of dry drive would be better than an oiled chain. Had you thought about a gear belt & sprockets instead? As for backlash, why not set the shafts at a distance apart that a standard belt length would be taut? A bearing block at the sprockets would eliminate the binding.

I don't think dust would be much of a problem under the bench using dry lithium grease. I used that stuff on the table adjust chain on my new/old planer after I cleaned it. The bearing blocks would need to move as the lead screws go in and out. The big question (always!) will the cost of parts end up being as much as just buying a Veritas?!?!?!

Originally Posted by Jim Murphy

Alan,

. . . Of course, you might need gently jog the tighten button depending on the compressibility of the material you seek to hold firm. PIcs soon?

Jim, I know you jest here(?) (Hmmm, an application for another gear motor? ) but your post brings up two related items about my recent tinkering-

I just replaced the barely suitable, Rube Goldberg, jury-rigged, drill motor I had been using to power my motorized WP router lift with a nice little 250 rpm gear motor from the Surplus Center. Now, the motorized lift operates at a more constant speed, is smoother, and quieter. For fine adjustment, all I do is tap up or down on a panel-mounted paddle switch - I don't need to use the crank handle at all!! (Note the expensive motor mount brackets! )




Also, while working on my DC autogates I discovered that even at the low 15 to 20 psi needed to overcome friction and operate the gates, they moved too fast! I could sharpen the inside edges of the slides and use the gates as guillotines to trim cigars, cut logs, remove fingers, arms, legs, etc. so I installed flow restrictors on the pneumatic solenoids. Now I can control the speed of gate actuation- from a VERY FAST, AND JARRING- ZIP-CLANK, to a more leisurely, gentler, whoosh-thud. With no tools running the slide and accompanying pneumatic air noise sound like the automatic doors on the Starship Enterprise!

[sapwood]

Nice upgrade on the router lift

Roger

[ptt49er]

The master tinkerer is back at it! Your posts and questions always have my brain twitching to catch up with ya. maybe one day nice work though!