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Re: It's triplets

Posted: Wed Aug 30, 2023 3:29 pm
by docmirror
I think JPG said one of my machines has a 510 or 520 double tilt table? So I can 'go both ways' as they say. I'm sure a double tilt table could be found online for a few Rubles. Reproduce the logo with the "Mark VII" badge too. lolz

Two things won't get is the reversible drive, and the vac setup. I have used that reverse drive for polishing alum so the rotation spins down. I could just as easily run it in fwd direction and polish from the back side of the power head.

Re: It's triplets

Posted: Wed Aug 30, 2023 4:09 pm
by JPG
MVII table tilts ±90°.

Re: It's triplets

Posted: Thu Aug 31, 2023 11:11 am
by edma194
docmirror wrote: Tue Aug 29, 2023 6:03 pm When the unit is tipped up in drill press, it is moderately unstable, and any side loads could push it over pretty easy. I almost suffered this indignity a while back moving in drill press mode. There's a clear warning about this in the manuals. Making it offset pivots would only make this worse.
I've been looking at pictures and the manual in Everett Davis' Google Drive. I can't clearly tell but the bench and way tubes appear to be the same length as a Model 5xx Shopsmith. On those the base casting extend fairly far out from the tubes, and then the legs angle outward further on each side. The feet contact the floor at the corners of approx. 19" X 71" rectangle. In the pictures it looks like the Mark VII feet don't extend much further than 48" for the tubes and a couple more inches at either end. Can't tell the distance of the feet front to back, but a reduction in length could lead to that instability when the headstock is at full height in drill press mode, even at the lower height limit on the Mark VII. It doesn't look like it would make much difference but I've found heavy assemblies have a sort soft tipping point where it doesn't take much before it reaches the hard tipping point where it would fall.

So, if you don't mind satisfying my curiosity, could you measure the foot print of the Mark VII legs some day?

Re: It's triplets

Posted: Thu Aug 31, 2023 11:23 am
by edma194
JPG wrote: Wed Aug 30, 2023 4:09 pm MVII table tilts ±90°.
The manual has a diagram of the tie bar that allows that on the Mark VII. The tie bar gets in the way of 90° either way on the 500 and 510 tables, and of course the tie bar cant run straight from one table leg to the other without getting in the way of saw blades, drill bits and the like.

In the drawings the Mark VII tie bar looks like sorta like this:

Code: Select all

___      ___
    \__/ 
It's mounted very close to the center of the table legs but leaves enough room for a saw blade and the dip in the middle would let the quill or a drill pass through it at 90°.

Did I come up with a good description of it there? I'm wondering why they didn't move forward with this on the 510. The 510 tie bar is heavier, probably resists torsion on the table legs better, but seems to me that could have found other solutions and this would have made under table mode easier to deal with.

Re: It's triplets

Posted: Thu Aug 31, 2023 11:46 pm
by docmirror
I will be down at the hangar on Fri and I'll measure up the base, and also the lower ways. Should get it back here Fri night or Sat afternoon. I'm going to a Porsche meet Sat am.

Re: It's triplets

Posted: Mon Sep 04, 2023 2:15 pm
by edma194
Considering a Mark VII type base for a Shopsmith has been an interesting diversion. Constructing the bottom frame with casters would not be all that difficult and I have enough materials. The cabinet can be made from wood and/or metal at reasonable cost. Mounting a Shopsmith on it and using the tilting method of the Mark VII gets complicated.

I might like to do this for my sanding machine, but I'll do it the easy way and put a long reinforced bench top on the cabinet and attach the Shopsmith end castings to that. It won't tilt like a Mark VII does. Any tilting will depend on the regular single-tilt mode or a double-tilt upgrade.

It would be kinda cool if they made those Mark VII end cabinets and end castings to mount Shopsmiths on.

Re: It's triplets

Posted: Mon Sep 04, 2023 3:57 pm
by JPG
You need Mark 1 parts.

Re: It's triplets

Posted: Mon Sep 04, 2023 8:56 pm
by docmirror
Guys, it's still hotter than the surface of the sun here. I haven't gone down to the hangar yet. Try to get there on Wed am.

One significant difference on the tilt process, and I'm not a Mk V expert at all but the Mk V only tilts two of the tube ways, and the two lower ones stay stable to mount the bases. On the Mk VII, all four ways tilt, and the fulcrum is the cross shaft in the cammed notch on the bottom set of ways. I would thing, but not sure that this would be the right way to convert to Mk VII type base, is to see that all four of the ways tilt at once.

Not knowing the Mk V base ways process, I"m going to defer to others, but guessing the tilt of all four at a time would be preferred.

Re: It's triplets

Posted: Tue Sep 05, 2023 8:53 am
by HopefulSSer

Re: It's triplets

Posted: Tue Sep 05, 2023 4:21 pm
by docmirror
That video is pretty good. However, I have a few edits. When the unit is not tilted, best to keep the cammed shafts turned to the lock position. I've leaned on the headstock end, and with the ways cam lock not in lock position, just by leaning on the headstock at the end of the ways will tip the whole mess a bit. Sort of a "whoa!" feature.

Add to that, even more important when the gadget is in tilt mode, it's fairly important to turn the base latch to lock the gadget in the tilt position. I've also had it in drill press mode, and again - went to push on the headstock for some reason, and realize that the whole thing is just sitting free, with no position latch in place.

If one builds a tilting setup for a Mk V to mimc the VII, I would strongly recommend a pivot like the Mk VII and some kind of locking in the vert position.

My experience is that I get in a bit of a rush, and want to do either drilling or sanding without engaging the locks, and realized that they are there for a good reason. In fact, the tilted up lock or latch should be a 'positive' latch that catches like a gate latch automatically, and must be manually released before the gadget is lowered back to flat.