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Repaired Garage Sale Mark VII

Posted: Fri Jul 08, 2016 1:59 pm
by alohacnc
Continuing on a post I made about a great weekend of garage sale Shopsmith bargains I submit these photos and descriptions of a repair job I did on a $40 Mark VII I picked up.

The head was quite gunked up so I tore it apart and replaced the bearings belts and got everything cleaned up.
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I read about people having issues with the plastic speed cam so I took the old one, which was still good, and measured it out in Solidworks and cut an aluminum speed cam. Unfortunately I lost the photos of that one but here's a screen shot of the 3D model.
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The plastic rack was broken from years of neglect and it looked like they used pretty crummy plastic anyway so I measured out the rack and ordered a metal one from McMaster Carr PN. 6295K132, 14 1/2 degree 12 pitch Rack. I clamped the rack in my CNC, cut the width to match the plastic, then cut the height down with the tube diameter shape so it all matched up nicely. I used the same holes in the main tube and used pop-rivets to hold it all together.
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Now that the head and rack were all working I compared the two tables between the 1980s Shopsmith 5 and this 1970??? Mark VII. The table on the Mark VII is superior in my opinion. It uses a cam lock fence, is larger, and has dual slots for the saw blade. I also noticed the MVII and MV have controls on opposite sides. This actually is a great space saver for me since I can use them back to back BUT the superior table could not be used interchangeably. The table legs have grooves on only one side.
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So I took a look at the lathe rest holder on the news MV and saw they used 1 1/4 - 7 UNC threads. I got some metal tubes, whipped out my trusty Machinery's Handbook, and cut full length threaded legs to put on the tables. This took a while but now I can swap tables between the two machines. With the threaded table legs this also allows a provision to change the angle of attack by rotating one leg. I don't know if I would ever so that but you never know.
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Now everything is put back together and all I need now are to add some casters. I was hoping the casters off my ER10 would work but they will require too many modifications so I will just make some that screw down rather than cam actions. You can see a broken piece of the rack in the dust bin.
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Some notes:
I don't understand why Shopsmith abandoned this design. With improvements of materials this would have been 40 years ahead of their current Mark 7 (minus the speed control motor) It is quite nice having the ability to tilt the frame in both directions. Having the fine adjust head position with a rack and pinion makes it very easy to adjust. Even with the head vertical adjusting the head height is easy with the crank. Adjusting the speed is much easier than the MV. This machine did not come with the integrated dust collector so I can not comment on that but it seems a novel idea if they could figure out how not to draw so much from the motor. The motor reverse is not found on the newer MV either. I have placed all the attachments I have, bandsaw, joiner, sander, biscuit jointer, on both machines with no issues at all. This machine will probably be more dedicated to drilling and routing because of the fact it can tilt in either direction.
Cost:
Casters $40
Rack $50
Belts $25
Bearings $30
Steel (table legs) and Aluminum (speed cam) $15
Threading Inserts $15 (broke one)
Time, about 30 hours including cleaning and polishing the frame tubes.

Re: Repaired Garage Sale Mark VII

Posted: Fri Jul 08, 2016 2:10 pm
by ERLover
A FINE job!!!

Re: Repaired Garage Sale Mark VII

Posted: Fri Jul 08, 2016 10:57 pm
by BuckeyeDennis
Outstanding!

I would love to do the same, but I figure it would take me a good couple of years to acquire the necessary skills and equipment. :(

Re: Repaired Garage Sale Mark VII

Posted: Fri Jul 08, 2016 11:19 pm
by rjent
What a fabulous job!

The Mark VII is an intriguing design. I too am surprised that they abandoned it .... :/

Re: Repaired Garage Sale Mark VII

Posted: Fri Jul 08, 2016 11:42 pm
by alohacnc
BuckeyeDennis wrote:Outstanding!

I would love to do the same, but I figure it would take me a good couple of years to acquire the necessary skills and equipment. :(
Thanks. You would be surprised how quickly you can pick up machining skills. The only problem I can think of is the equipment is quite expensive. If you need any advice just let me know. From what I've seen there are "Maker Spaces" popping up all over the country where you can join a club with all the equipment.

One thing I just noticed tonight is the shaper / router guard from the Mark V does not fit the larger table of the MVII. I shall have to make a new one since there is not enough "meat" with which to modify the MV guide.

Another day. I'll keep everyone posted.

Re: Repaired Garage Sale Mark VII

Posted: Sat Jul 09, 2016 1:16 am
by JPG
alohacnc wrote:
BuckeyeDennis wrote:Outstanding!

I would love to do the same, but I figure it would take me a good couple of years to acquire the necessary skills and equipment. :(
Thanks. You would be surprised how quickly you can pick up machining skills. The only problem I can think of is the equipment is quite expensive. If you need any advice just let me know. From what I've seen there are "Maker Spaces" popping up all over the country where you can join a club with all the equipment.

One thing I just noticed tonight is the shaper / router guard from the Mark V does not fit the larger table of the MVII. I shall have to make a new one since there is not enough "meat" with which to modify the MV guide.

Another day. I'll keep everyone posted.
Shaper fence?

If so there are two holes in the table for mounting a MVII version(i.e. it does not clamp over the ends of the table like the MV).