PSI 1-1/8 to 5/8" adapter fix ???

reible · Post by **reible** » Thu Mar 08, 2012 2:43 pm

Some years back I purchased a PSI (Penn State Industries) L5818 headstock spindle adapter.

It had a set-screw issue, it would keep loosening up. Various phone conversations and attempts to get it to the point of me feeling safe using it never happened. The thing was plane not safe at any speed even without anything mounted on it. I will not go into more detail but it has been a few years now so maybe the issues with the early models has been fixed.

If however you happen to have one of those early models and feel unsafe using it I may have a solution for you. I have intended to do this for years now since I hate having it show up in one of my drawers under my shopsmith every so often and knowing it needs work.

The first thing I did was check to see if the existing tapped hole was at an angle or at 90 degrees. I was pretty sure of the answer, yep 90 degrees.

The next task was to see what angle shopsmith uses on their saw arbors. To do this I put a tap into the saw arbor set screw hole, this is a nice tight fit. I then put the tap in the drill chuck and tilted to the table as shown below.

[ATTACH]16598[/ATTACH]

When the arbor was laying flat on the table the angle had to be pretty close. The table indicated 3 degrees, could be a little off from that but good enough for what I wanted.

Left the table locked there and then drilled a hole opposite the original hole but now at 3 degrees which should match the flat on the shopsmith spindle.

[ATTACH]16599[/ATTACH]

While still at the 3 degrees I then tapped the hole using the shopsmith as a tap tool. I used a 5/16-18 tap.

[ATTACH]16600[/ATTACH]

Removed the burr inside after running a setscrew in to make sure the hole was fully tapped.

Initial testing shows this to be working, so far it is 100% staying tight an no sign of the setscrew loosening.

The open hole I think I will put the setscrew back in then epoxy in place including filling the hole for the wrench so I don't try to take it out.

So far it has been a good day in the shop.

Ed

dusty · Post by **dusty** » Thu Mar 08, 2012 4:53 pm

reible wrote:Some years back I purchased a PSI (Penn State Industries) L5818 headstock spindle adapter.

It had a set-screw issue, it would keep loosening up. Various phone conversations and attempts to get it to the point of me feeling safe using it never happened. The thing was plane not safe at any speed even without anything mounted on it. I will not go into more detail but it has been a few years now so maybe the issues with the early models has been fixed.

If however you happen to have one of those early models and feel unsafe using it I may have a solution for you. I have intended to do this for years now since I hate having it show up in one of my drawers under my shopsmith every so often and knowing it needs work.

The first thing I did was check to see if the existing tapped hole was at an angle or at 90 degrees. I was pretty sure of the answer, yep 90 degrees.

The next task was to see what angle shopsmith uses on their saw arbors. To do this I put a tap into the saw arbor set screw hole, this is a nice tight fit. I then put the tap in the drill chuck and tilted to the table as shown below.

[ATTACH]16598[/ATTACH]

When the arbor was laying flat on the table the angle had to be pretty close. The table indicated 3 degrees, could be a little off from that but good enough for what I wanted.

Left the table locked there and then drilled a hole opposite the original hole but now at 3 degrees which should match the flat on the shopsmith spindle.

[ATTACH]16599[/ATTACH]

While still at the 3 degrees I then tapped the hole using the shopsmith as a tap tool. I used a 5/16-18 tap.

[ATTACH]16600[/ATTACH]

Removed the burr inside after running a setscrew in to make sure the hole was fully tapped.

Initial testing shows this to be working, so far it is 100% staying tight an no sign of the setscrew loosening.

The open hole I think I will put the setscrew back in then epoxy in place including filling the hole for the wrench so I don't try to take it out.

So far it has been a good day in the shop.

Ed

I gather then that you believe the original set screw did not remain tight because the flat of the set screw was not mating properly with the flat on the spindle taper. Because MAYBE it wasn't intended to encounter a taper but rather a flat shaft.

JPG · Post by **JPG** » Thu Mar 08, 2012 5:33 pm

dusty wrote:I gather then that you believe the original set screw did not remain tight because the flat of the set screw was not mating properly with the flat on the spindle taper. Because MAYBE it wasn't intended to encounter a taper but rather a flat shaft.

Makes sense to me!:)

Amazing the things you learn here!

reible · Post by **reible** » Thu Mar 08, 2012 5:56 pm

Hi,

Now it could be that I just got a bad adapter but I know of at least a few people who got them that had similar issues. PSI was reluctant to replace it, which ended up with me canceling an order for a chuck from them but that is another story.

The first issue I had began with the set-screw they had installed, it was short and wrong fit for the threads. A longer and better fit set screw(more major dia.) helped but did not fix the issue. I then added a thread tape which also helped. All of these issues could have been fixed by how the hole was drilled and tapped and what set-screw was chosen. I put on my engineering hat and provide them (PSI) with information of how to speck it. No idea if they used the information.

Now this is with the adapter on the shopsmith and nothing else, I could turn the machine on and within minutes I could shut it off and check the set-screw, it would be loose. From there the changes I made extended the time but still it wouldn't be very long and the set-screw would be loose again. I was afraid to mount anything for fear of the whole thing taking a walk.

I'm no longer seeing the setscrew loosening up, so, the new drill and tap job at the angle as well as a new setscrew seems to have fixed it. I have a project later this summer which will subject this to additional testing. I can't say for sure which part of the change had the most effect, and I can't really test anyway.

Ed

billmayo · Post by **billmayo** » Thu Mar 08, 2012 6:51 pm

I have 3 different metal chucks which mount on the 5/8" quill shaft adapter. I quickly learned that installing 2 additional set screws spaced 120 degrees apart on each chuck adapter really help me to insure the chuck was centered plus additional security to prevent the chuck from loosening on the quill shaft. I used blue (semi-permament) LocTite on the set screws and quill shaft as I have left each chuck mounted for a series of operations over time. This Shopsmith is a dedicated metal turning lathe and tube cleaning machine. This Shopsmith has a 3/4 HP Gilmer Drive headstock with a double bearing quill I machined and installed. I find it to be as accurate as my 7X10 metal lathe.

cincinnati · Post by **cincinnati** » Thu Mar 08, 2012 10:13 pm

I just received a PSI chuck adapter last week. I have used it for a few hours now and not an issue at all with it. The set screw that came with the adapter was bad. the hole for the 5/32' wrench was off center and a little too big. I replaced it with a new one from the Shopsmith Help Kit.

[ATTACH]16624[/ATTACH]

reible · Post by **reible** » Thu Mar 08, 2012 11:26 pm

cincinnati wrote:I just received a PSI chuck adapter last week. I have used it for a few hours now and not an issue at all with it. The set screw that came with the adapter was bad. the hole for the 5/32' wrench was off center and a little too big. I replaced it with a new one from the Shopsmith Help Kit.

[ATTACH]16624[/ATTACH]

Unless they have changed the set screw it is metric... the 5/32 wrench would not be the correct size and if you replaced the set screw with a 5/16-18 that is not right either, it is really a 8-1.25 metric.

You might want to check it out before doing much more.

The metric size and imperial size is very close here. The metric body size is .3150" and 20.3 threads per inch vs the .3125 body and 18 threads per inch.

Ed

larryhrockisland · Post by **larryhrockisland** » Fri Mar 09, 2012 2:42 pm

dusty wrote:I gather then that you believe the original set screw did not remain tight because the flat of the set screw was not mating properly with the flat on the spindle taper. Because MAYBE it wasn't intended to encounter a taper but rather a flat shaft.

I am practicing my thread response skills. Hopefully this thread will show up, http://www.shopsmith.net/forums/showpos ... stcount=82 I like knowing why things work/are designed.

I bought my chuck from SS so I quess the adapter that came with it was drilled at an angle. I haven't used it enough to discover a loosening issue.

Larry
Rock Island, OK

reible · Post by **reible** » Wed Aug 14, 2013 1:03 am

Update

I have contacted 3 supplies of 1" x 8 tpi for shopsmith which are all made in China. They have metric set-screws, please see above for the size and how close it is to a shopsmith standard 5/16 - 18. They all have the set screw coming at a perpendicular to the shaft. Keep in mind everything shopsmith makes have the set screw coming in perpendicular to the taper flat.

I had requested information from shopsmith as to the angle but they are not willing to give out that information.

"Good morning. The set screw tightens 90 degrees to the flat on the spindle of the Mark V. We do not release exact specifications and tolerances on our tools."

So I spent some time trying to measure the angle with the tools I have. The best method I could come up with was to use the output shaft with the tapered flat. This is a change for the postings I had earlier where I used a threaded element. In my playing today it was clear there was too much slop in the threads and the angle would vary depending on were pressure was applied.

I used the shaft on my powerpro as it is the newest I have. I measured at the very end of the shaft, I then measured 1" in (deeper in the flat) and took a second measurement at that point. With that data and taking several measurements to make sure I was getting good readings I solved for the angle. This method gave me 3.1 degrees. I'm pretty sure no one specified that angle but I can believe this could be 3 degrees.

I am in contact another supplier who currently sells adapters but had no idea that should have the angle applied to the set screw. I am in the process of having one made for myself with the 3 degree angle.

Of course the best method to have a shopsmith quality item is to have shopsmith do the design and sell them to us. So far they have not stepped up to the plate for an adapter into the rest of the world. I'd like to see them do so.

Since I'm planning on adding another adapter I still like it to be as close to shopsmith product as it can be. By getting the set-screw and angle corrected this is about as good as it gets for now. Heck the price even seems like a shopsmith price.

When I get the adapter I will have a close look at it. If it meets my approval I can share more details if people are interested.

I'm also in contact with yet another person relating to an adapter. This version would be a down and dirty, might I add also cheap. His current design has a 1/4-20 no angle set screw. He is sending me one minus the set screw drilling so I can do that part myself. I should have that soon too.

Anyway if you are interested keep checking back for more updates.

Ed

billmayo · Post by **billmayo** » Wed Aug 14, 2013 3:15 am

Ed.
I switched to using knurled cup point set screws for almost all places that Shopsmith uses set screws. I have not had any of these set screws come loose over time. I feel I can live with what little damage is done to the quill, drive sleeve, idler or SPT shafts. I use a small flat metal file to clean the shaft if I remove the attached part. I keep a close watch on these set screws and replace one if the knurled ridges have become smooth. I am not aware of any of the 100s of these set screws I used coming loose. To me it was a fair trade-off I made many years ago.