Shopsmith Forums

In another thread the other day we started talking about the Mounting Posts for the Magna/Shopsmith SPT's. So this is the information I have found in Owner's Manuals/Parts Lists and measurements I have made.

The Jointer, Jig Saw, Belt Sander, Bandsaw and Air Compressor that all originally came out in the 1950’s started with straight mounting tubes. The Jointer, Jig Saw and Belt Sander tubes had snap rings to rest on the Mark 5 headrest mounting holes. The Bandsaw and Air Compressors (both the original Magna and later Campbell Hausfeld) had collars to set the height. The Air Compressors had mounting tubes with a threaded insert at the top of the tube for attaching with a bolt to the compressor frame and only used this type of mounting tube. The original Magna Air Compressor mounting tube was hollow and the later CH Air Compressor had solid mounting tubes.

The following information has been corrected with new information I have found about the Jig Saw mounting tubes and the original Air Compressor.

The Scroll Saw and Strip Sander which came out in the 1980’s have only had eccentric mounting posts. Later the Scroll Saw changed from Gray to Teal paint. The mounting post information below is for the gray Scroll Saw. Later parts lists leave off the mounting posts for some unknown reason. At some point the Jointer, Jig Saw, Belt Sander and Bandsaw changed to eccentric mounting posts. The Bandsaw has an optional offset mounting post to allow it to stay on the Mark V when it is put up into drill press mode. This off set mounting post is not included in the information about posts below.

SPT – straight post Overall Length Length from top to ring/collar* (sorry the information doesn't line up under the headings)

Jointer 3-7/8” 1-5/16” P/N A3094, 3094
Jig Saw 8-7/8” 6-3/4” P/N 502289
Belt Sander 6-1/4” 4-1/8” P/N B3532, 503002
Band Saw 7-1/2” 4-3/4” P/N A3466
Air Compressor – M 6-1/8” 2-1/2" P/N 66100, 502568
Air Compressor – CH 5-1/2” 3-3/4” P/N 516533
*Collars are measured from the top of the post to the bottom of the collar. Lengths may vary by individual set up.
The Air Compressor posts are left original Magna and right later CH.

SPT – eccentric post Overall Length Length from top to eccentric offset
Jointer 3-1/2” 1-3/4” P/N 502080, 5020809
Jig Saw 8-7/8" 6-3/4" P/N 513776
Belt Sander 6-1/2” 4-1/2” P/N 513777, 5137779
Band Saw 6-1/2” 4-1/2” P/N 513777, 5137779
Scroll Saw 6-1/2” 4-1/2” P/N 513777
Strip Sander 8-7/8” 6-3/4” P/N 513776, 5137769

The Eccentric Mounting Post for the Jig Saw is not shown in the picture below but is the same as the one for the Strip Sander.
I have an additional pair of straight posts with snap rings that are 8” long and 6-7/16” to the ring that may be for the Jointer from the Power Mount Adapter Kit Item Number 11 920 made in the mid 1950’s for using SPT’s on the Shopsmith Model 10’s. This is something I will have to try at a later date to confirm.

I forgot to include this yesterday. One of the reasons for using collars on the Bandsaw and Magna Sprayer (Air Compressor) straight mounting posts instead of the snap ring appears to be for use on the Model 10 Adapters. SPT's used on those adapters whether the "A" or "B" adapter may sit at different heights to the Model 10 Drive Sleeve Pulley Hub than those on the Mark 5 Drive and Idler Shaft Hubs. The 2nd Adapter Kit included the "A" and "B" Adapters plus long posts for the Jointer. The Air Compressor was introduced about the same time as the 1st Adapter Kit and collars were used on its posts to allow for that adjustment. The Bandsaw was introduced about the same time as the 2nd adapter kit. The Jointer and Air Compressor mount on the "A" Adapter and the Jig Saw, Belt Sander and Bandsaw mount on the "B" Adapter. The original Power Mount Adapter Kit only had the "A" Adapter. It was for mounting the Jig Saw and the Air Compressor (Magna Sprayer) with no provision made for mounting the Jointer. Because the "A" Adapter sits higher the Jig Saw's snap Ring posts were inverted and collars used to set the height. There wasn't a mounting option for the Jointer with the 1st Power Mount Adapter Kit since Magna still sold the Model 10 Jointer mounting kit with the special headrest. Like the Model 4E Jointer the Model 620 jointers still had the mounting holes for that kit until the Jointer changed to the Model 620-C.

As I said in my first post for this thread

I have an additional pair of straight posts with snap rings that are 8” long and 6-7/16” to the ring that may be for the Jointer from the Power Mount Adapter Kit Item Number 11 920 made in the mid 1950’s for using SPT’s on the Shopsmith Model 10’s. This is something I will have to try at a later date to confirm.

I did try those posts and they are indeed the ones for the Jointer included in the second Power Mount Adapter Kit. As I said yesterday the first Power Mount Adapter Kit did not have a provision for mounting the Jointer on SPT posts but instead relied on the Model 10 Headrest Mounting Kit. With the later mounting kit the SPT mount Jointer can run on a Model 10 but after trying it on those tall posts I prefer the Model 10 Jointer Mounting kit or using a Mark series tool to power it. For those who do not have that much interest in the SPT's mounting on Model 10's I apologize for going on more about them but the mounting of SPT's on Mark series tools is pretty straight forward after comparing the post lengths. As far as mounting goes alignment of the hubs is the key to a problem free use of the SPT's on the Mark series tools and even the Power Station.

I am away from the shop for the day but just curious if anyone has tried the longer strip sander mounting posts on the bandsaw.

redleg wrote: Wed Nov 18, 2020 5:38 pm I am away from the shop for the day but just curious if anyone has tried the longer strip sander mounting posts on the bandsaw.

I have not but I do not believe they would work. The bandsaw would set too high to align the hubs. There are mechanical stops that would limit how far the legs are inserted.

What sort of a problem do you experience that can not be resolved with the intended mounting posts?

I'm not really having any issues with the bandsaw. I thought I remembered posts some time ago about the bandsaw mounts not going far enough into the bandsaw. Mine don't go very far into the top ring. I was thinking about getting a strip sander set and cutting them down just to see if it would be solve issues others had.

The Bandsaw posts are fine even if they do not touch the cast in stop. The stops have always been in the Main Frame casting and originally the Bandsaw used the straight posts with collars. At that time the stops had a purpose but are really no longer needed. The Main Frame has changed very little if at all since the Bandsaw introduction. The only thing I have noted as a change to the Bandsaw Main Frame assembly is originally the table bushings were pressed in and are now slip in bushings that are separate parts from the assembly.

redleg wrote: Wed Nov 18, 2020 8:19 pm ... Mine don't go very far into the top ring. I was thinking about getting a strip sander set and cutting them down just to see if it would be solve issues others had.

I think it is typical that the eccentrics don't go very far into the upper ring on the Bandsaw, and of course they are radiused so there is not much engagement there. I'm no fan of the Bandsaw Eccentrics, I found them very unstable when I first tried them compared to the straight tube with stop collar that I had always used. IIRC there were three parameters that I determined added to instability: 1) length above the mounting shoulder was shorter than the straight tube, 2) length below the shoulder was shorter, and 3) diameter was smaller. (Note that none of these have anything to do with it being eccentric.) Unfortunately, a modified Strip Sander set only addresses the first of these. Because of that, I don't think much improvement in stability can be realized. In my case I felt that most of the instability was coming from the mount below the shoulder, in other words how the eccentric tube's fit compared to the straight tube's fit into the Headrest.

But what I think you can do, if you 'measure twice and cut once,' is engage the stop in the casting and eliminate both the need and ability to adjust the BS vertically for at least one mount. The questions I would have about that are whether it is worth it and whether the non-adjustable vertical value is portable to other machines including Marks, Power Stations, Power Stands, etc.

- David

David,

As to what you have said above. The straight Bandsaw Mounting Posts were 7-1/2" long whereas the eccentric posts are 6-1/2" long. The straight posts can go all the way up to the stop in the Bandsaw and goes farther into the Headrest mounting holes. You asked about mounting on other power sources for the Bandsaw. The alignment should be very close to the same for any Model of the Mark 5/V as the headstock has remained the same for the idler and drive shaft in relation to the headrest mounting holes. The same is true for the Mark VII, Mark 2 and Mark 7, The Power Station has two pairs of mounting holes to position the SPT's relative to the normal mounting on the Mark 5/V's to the Idler or Drive Shafts. For a Power Stand the Mounting Post length is less relevant since it would be belt driven. For example you could use much shorter posts for a Strip Sander or a Jig Saw on a Power Stand since there is no hub to align to. As for SPT's on Model 10's I have already covered that in a previous post here.

These solid eccentric mounts came on my Greenie Jointer. They mount short end up, are steel, and have about half or a little less 'eccentricity' compared to the more recent version, shown for comparison. I presume they are original, though this unit has only been mine since the early 1980's. In terms of timeline they must they fall between the snap-ring straight tube and the current eccentric. - David