setscrew/arbor loosening on spindle

historia · Post by **historia** » Thu Jun 23, 2011 9:11 am

Bought used SS in 1999; Mark V 510 made in 1991. Have tried several arbors/blades with different length setscrews and after stopping SS found arbor/blade very loose. About 1/2 inch in vertical plane. Arbor has moved to right from headstock. Need help? Any suggestions? Did not detect problem until 2011 even though purchased it used in 1999.

JPG · Post by **JPG** » Thu Jun 23, 2011 8:15 pm

The flat on the arbor shaft is tapered. If the arbor is not pushed firmly towards the headstock and the setscrew is tightened with the screw at the lowest point of the flat, the setscrew will not be tight enough to maintain that position and will 'work loose'.

To prevent that, press the arbor towards the headstock until it is as far as it will go, then while tightening the set screw, rock the arbor until the setscrew seats at the low point.

There has been some discussion here regarding set screws wearing and periodic replacement was regarded as a 'solution'.

P.S. I do not understand the "1/2 inch in vertical plane" statement. Hopefully you are not mounting a 1 1/4" blade on a 5/8" arbor!

historia · Post by **historia** » Thu Jun 23, 2011 8:43 pm

Many thanks to the "first responders. The arbor has been secured inward toward the silver collar as far as possible. Yes, it has been rocked and the setscrew tightened again for a slight turn. However, after running the SS, it's unpluged, and at that point the arbor/blade (it doesn't make any difference if it's a 1 1/4 arbor or 5/8) the darn thing can be rotated back and forth in the plane of rotation of the cut. The left hand is holding the upper shaft/hub on the left of the headstock while the right hand grasps the arbor/blade. Have found a similar situation somewhere on the Internet. After the spindle was replaced, the respondent claims there never was a problem afterwards. A local SS owner physically examined the SS in question and said he was puzzled.

JPG · Post by **JPG** » Thu Jun 23, 2011 9:03 pm

historia wrote:Many thanks to the "first responders. The arbor has been secured inward toward the silver collar as far as possible. Yes, it has been rocked and the setscrew tightened again for a slight turn. However, after running the SS, it's unpluged, and at that point the arbor/blade (it doesn't make any difference if it's a 1 1/4 arbor or 5/8) the darn thing can be rotated back and forth in the plane of rotation of the cut. The left hand is holding the upper shaft/hub on the left of the headstock while the right hand grasps the arbor/blade. Have found a similar situation somewhere on the Internet. After the spindle was replaced, the respondent claims there never was a problem afterwards. A local SS owner physically examined the SS in question and said he was puzzled.

The method is not rock then tighten, but rather lightly tighten while rocking, then tightening firmly after bottoming out.

The knurled 'silver' collar has its own smaller tapered flat on the arbor shaft. It must also be tightened while firmly pushed towards the headstock and its setscrew tightened using the rock technique. If the setscrew hex hole is plugged, it must be cleaned out to get the allen wrench inserted. The quill shaft should be pulled outward to eliminate in/out play when doing this.

charlese · Post by **charlese** » Thu Jun 23, 2011 11:01 pm

historia wrote:....it's unplugged, and at that point the arbor/blade (it doesn't make any difference if it's a 1 1/4 arbor or 5/8) the darn thing can be rotated back and forth in the plane of rotation of the cut. The left hand is holding the upper shaft/hub on the left of the headstock while the right hand grasps the arbor/blade. Have found a similar situation somewhere on the Internet. After the spindle was replaced, the respondent claims there never was a problem afterwards. A local SS owner physically examined the SS in question and said he was puzzled.

Referring to the underlined portion of your quote - you may be experiencing some rotational play. It is not uncommon to develop some free rotational play after a lot of use. My old headstock had 1/8" free play measured at the outer edge of a saw blade. This was only noticeable when holding the axillary spindle and rocking the main spindle while a saw was attached. There is a thread somewhere in this forum where a few of us discussed this play.

My new headstock had absolutely no play for a while, but lately has developed a small amount of play - about 1/32". There is nothing worrisome about this rotational play. If the play becomes excessive, it can be fixed with a replacement of a relatively inexpensive part.

For reference here is a link to a good exploded diagram and part numbers. http://www.shopsmith.com/ownersite/productmanuals/MKVSTDPartsList%20_1_14.pdf

Such play stems from the play between the fluted shaft of the quill and the flutes in the Drive and Ring Assembly (part number 514083) In assembly of my PowerPro and associated disassembly of the old headstock I took particular interest in those parts and could notice the difference in tightness between the two parts.

The only reason I can think of to cause the arbor to move away from the headstock is a loose arbor set screw.

JPG · Post by **JPG** » Thu Jun 23, 2011 11:16 pm

The left hand is holding the upper shaft/hub on the left of the headstock while the right hand grasps the arbor/blade.

I misread this at first. I thought he was holding the collar. The upper belt pulley set screw may be loose on the main shaft. It can be accessed by removing the belt cover.

charlese · Post by **charlese** » Thu Jun 23, 2011 11:29 pm

JPG40504 wrote:The left hand is holding the upper shaft/hub on the left of the headstock while the right hand grasps the arbor/blade.

I misread this at first. I thought he was holding the collar. The upper belt pulley set screw may be loose on the main shaft. It can be accessed by removing the belt cover.

Where is this upper belt pully set screw on a 1991 model?

JPG · Post by **JPG** » Fri Jun 24, 2011 12:46 am

charlese wrote:Where is this upper belt pully set screw on a 1991 model?

Age irrelevant - unless Gilmer!

[ATTACH]13461[/ATTACH]

Now that I have posted this pix, I must retract my previous 'guess'. A loose pulley will not cause play between the sawblade on an arbor and the upper rear output shaft. The coupler could(the white thing) although not likely(1/2" slop).

One thing not brought up is the two piece two bearing quill. I am not familiar with them.

The key to solving this puzzle, is what doesn't move when the blade 'slops'?

scollins · Post by **scollins** » Mon Aug 01, 2011 7:11 am

I have a problem with the set screw loosening on the saw arbor and on my Nova chuck insert, The does not happen with any other attachment.

My solution has been to tighten the screw and run the SS for a brief minute, retighten and go to work. I figure the screws may not be machined to the correct tolerance and have wondered about using some plumbers tape, but not enough to try that solution.

dusty · Post by **dusty** » Mon Aug 01, 2011 8:13 am

scollins wrote:I have a problem with the set screw loosening on the saw arbor and on my Nova chuck insert, The does not happen with any other attachment.

My solution has been to tighten the screw and run the SS for a brief minute, retighten and go to work. I figure the screws may not be machined to the correct tolerance and have wondered about using some plumbers tape, but not enough to try that solution.

When I find an arbor set screw (that I know I have tightened) loose, I replace it. The replacement set screws that I have have a small spot of something like Loctite on them. These set screws remain tight for many setups but they do work loose (especially if you use the wrong style set screw).

The Shopsmith set screw for the arbor is part number 222458 which is a 5/16"-18x1/4" Flat. This part number when ordered from Shopsmith may not have the Loctite that I mentioned.