VII Headstock overhaul

[jhatfield]

I bought a VII a few days back and have plans to replace it's set of bearings. I'm having trouble understanding the parts I need? The best I can tell it is a 1979 unit. Is a Mark V headstock the same as a VII headstock? Any help would be much appreciated.

[DLB]

Posting a photo here would be a good idea. If the headstock is a '79, I think that makes it a Mark V headstock. There is an older Mark VII from the 60's and a newer Mark 7 from ~2010 and on. So for this one we need to be careful to distinguish between VII and 7, they are completely different. You could conceivably have a mixture between headstock and the rest of the unit. Someone here can answer most any questions you have on any of those units. If you have a Mark V (or older Mark 5) headstock and you want to buy a complete set of bearings, including the motor, you'll need to know which motor it has and possibly the quill version (possibly upgraded to one of the two-bearing quills).

- David

[chapmanruss]

As David said there is a difference in what you described. The Mark VII was only made in the 1960's and is the Shopsmith shown below.

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MARK-VII_SS Inc.jpg (10.62 KiB) Viewed 1307 times

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Below is a picture of a Mark V 500 with the original Table System. There has also been a mark V 505, 510 and 520 but differ only in the Table/Fence Systems to the 500. Currently only the Mark V 520s is still available and the other models have been discontinued.

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Mark V Model 500.jpg (7.09 KiB) Viewed 1307 times

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The Mark V headstock can fit on a Mark VII if the Racks (tracks with teeth for moving the headstock) are removed. The Headstocks are different and the Speed Controls in particular are different. The Mark VII Headstock can run in forward and reverse. The Mark V Headstock only runs forward. The Mark VII when it came out was more or less a completely re-engineered tool. It can use many of the parts and accessories as the Mark 5 of the time can but does have items specific to it and accessories for the Mark 5 it cannot use. You may have noticed I used Mark 5 in the last sentence as opposed to Mark V. Until the beginning of 1980 they were Mark 5 and not Mark V. Still the same tool just a change from a number to a Roman Numeral. I know it is confusing just as there is a Mark VII and a Mark 7. As David said the Mark 7 was introduced in 2010. If you have a Mark VII as shown in the top picture above with the original Headstock you will notice it has Mark VII and Mark 7 on the machine in different places. More confusion. The new Mark 7 is based off the Mark V and Mark 5/V's can be upgraded to be a Mark 7.

Suffice it to say identifying which Shopsmith you have will help us give you the correct information you need to work on your new to you Shopsmith.

[jhatfield]

Thank you Dave and Russ for your input. I assure you, it is much appreciated since I have had very little experience with these machines. I think my purchase appears to fall into the first of the two graphics Russ posted. "MARK-VII_SS Inc.jpg". I've used the lathe a few times over the last couple of weeks, and feel a sense that there may be more noise then should be. I would rather be safe than sorry (something gained with age or experiences perhaps) I've felt around some of the areas around the bearing I can reach without going inside the case, and think one could be a problem child perhaps. If I need to replace one, it seems logical to replace them all at the same time. I will attempt to post my graphics now.



Above is an overall picture of my machine.



This speed controller appears to be of nylon.



Here is an up close shot of the headstock with the access cover off.



And here is a shot of the serial number plate.

I am so looking forward to spending quality time in my garage with this machine.

[chapmanruss]

Jerry,

It is a Mark VII and from the pictures it looks like the Lathe Tool Rest and Arm are form a Mark V. Probably the original ones got lost along the way. From the serial number and what little I do know about them yours was likely made in 1964. The Mark VII was produced from the 1963-1964 fiscal year to the 1968-1969 fiscal year. 10,671 units were sold with sales decreasing each year of production.

In your second picture you show the speed control cam. You are correct about the material it is made from. The Cam has a tendency to melt during use. Replacing any bad bearings will help reduce heat buildup and thereby reduce the chance of melting the Cam. There have been replacement cams made and for sale on ebay in recent years. Most are 3D printed but I have seen a metal cast one someone made to sell.

Replacing all the bearings will include the Motor, the Idler Shaft Bearing, the rear Idler Control Sheave bearing, the Drive Sleeve Bearings and the Quill Bearing. If all the bearings are original that makes them 57 years old. I don't know what sizes of bearings it needs since I have not owned a Mark VII yet. Others may have that answer. My best advice on that would be to remove those assemblies from the Headstock to get to the bearings. In doing so you can check the condition of the bearings in each assembly. In checking the part numbers the bearing and spindle shaft have the same part number as the Mark 5 part. Other part numbers for those assemblies with bearings didn't match. The Idler Control Sheave Bearing will have the greatest effect on the cam if it is in bad condition since it has the closest contact.

[JPG]

This may be of interest.
viewtopic.php?f=10&t=11373

List of bearing sizes in first post.

[chapmanruss]

Jerry,

I was hoping JPG would jump in on this one and he did. He has a lot of good information on the Mark VII since he owns them and has done restoration work on the Mark VII. He will be a great help to you. What I know about the Mark VII is what I have read and what others like JPG have passed on to me.

[jhatfield]

JPG, this is a wealth of knowledge. I so appreciate this vital information thread.

This may be of interest.
viewtopic.php?f=10&t=11373

List of bearing sizes in first post.