Mark VII Gear Rack Replacement

[alohacnc]

Nice. I made a new rack with off the shelf steel rack from McMaster Carr. I have a thread on it somewhere here. I CNC cut the back for the radius and match drilled holes for the hole rivets in the tube. Shopsmith should have continued this design. The double tilt and reversible motor made this version flexible. Obviously they were cutting corners using junk plastic parts to increase profit. The plastic speed cam was junk and the rack is junk. I made a new aluminum cam on my CNC as well.

[WLKuhns]

Missing speed dial and gear rack

AACAE587-4118-4FB7-96C7-ABB3596E1C71.jpeg (34 KiB) Viewed 12948 times

Gents, I bought a trashed Mark VII and did a novice refurb but I need a speed dial control and the gear rack...any leads?

[lahola1]

Do you have the speed dial for it and do you have any piece of the rack?

As you probably know you don't need the rack to operate it.
Also, are you trying to refubish it like original or are you just trying to get it operable?

[WLKuhns]

Thanks for the quick response. No, there were no dial pieces included in the sale. You can see that I wired an open box wrench to hold the cam shaft in low speed...something I have to keep a constant eye on. I’ll check the scrap box for anything left of the rack but I don’t recall seeing anything. The cam works well and I’ve serviced the headstock and it works real well. The way tubes weren’t much trouble to clean up as well.

[rpd]

$matches[2]


Gents, I bought a trashed Mark VII and did a novice refurb but I need a speed dial control and the gear rack...any leads?

If you open the first topic at the top of this forum "Shopsmith Large Format Drawings, Illustrations and More", in the first post click on the red "My Google Drive", then open the folder "Mark VII - 1960's vintage" .
In the folder you will find a manual for the Mark VII and other information including a .skp file for the cam.

I also found these files to 3D print the parts on the Facebook Shopsmith Owners Group, https://www.facebook.com/groups/684461538311971/about/

it won't accept the file type to post here. Join the FB group and the links will work to down load the files from there.

Gear rack
https://www.facebook.com/groups/6844615 ... 626253819/

Speed control cam
https://www.facebook.com/groups/6844615 ... 448192670/

[WLKuhns]

Excellent! Thank you kickstarting me into the Shopsmith world!

[lahola1]

I think you are going to have a hard time finding a speed control dial for your mark VII. Very few mark VII parts come up on ebay or anywhere.

to get it operable I would try something like this:
Screw a piece of 1/2" plywood or 1/4" aluminum to the the headstock with a hole cut in it for the speed control.
Drill 1/8" holes around the speed control approx. 1" spacing for a pin/nail.
Attach a small vicegrip to the speed control shaft.
Now you can adjust the speed with the vicegrip up or down and put the nail in the vicegrip to hold that speed.
drawing attached; hope it's readable.

[WLKuhns]

Excellent suggestion, I’ll enjoy using the Shopsmith to fabricate pieces for it!

Also found a piece of the rack...

[WLKuhns]

201764CA-CBB6-4CE6-A4EE-5C43D2413E01.jpeg (33.77 KiB) Viewed 12874 times

[lahola1]

I've attached a drawing of rough rack dimensions I took from my rack a couple years ago with a dial caliper. I hope it's readable.
A previous poster said you can get a rack from Macmaster carr and that's true.
If repairing the rack is important to you, you should call Macmaster carr and talk to someone to help you get the proper rack that will work on your mark VII but you will still have to machine the radius on the back of the rack (machine shop?) to get the proper height on the rack (could be expensive).
Good luck with your project. I would like to see as many old mark VII's kept running as possible.