Shopsmith Forums

I know the headstock will become warm with use. But I think mine gets too warm. After running on FAST for about two minutes (during routing several pieces), the headstock becomes really warm. After a few more minutes of off and on use, the headstock is so hot I only want to put my hand on it for a few seconds. When I tried to turn the auxiliary shaft, I jerked my hand back as soon as I touched it. I don't ever recall it being this hot over the years I have owned it (1983). If getting this hot is out of the norm, then here is what I have seen and done to the headstock recently.

I took off the belt cover and watched everything inside when running from slow to fast several times. Everything seems to operate fine. There are no abnormal noises like bearings squeeking. Speed changing was smooth.

I read the owner's instruction manual, and here are my answers to the overheating section in Maintenance and Troubleshooting:
1. Poly V-belt improperly tensioned: When I lightly push in on the belt it only moves about 1/8 of an inch
2. Air flow clogged: the inside of the machine is clean. When running, there is good airflow out from the slot at the bottom of the unit.
3. Motor overheating: I don't know how to tell if it is, but the top of the headstock seems hotter than the lower section.
4. DriveSleeve/IdlerShaft missing lower auxillary hub: I have no idea on what this even means, but everything seems to be spinning.
5. Quill Feed bearings worn: I had a new two-bearing quill installed by the factory about 3 years ago. I only use the machine occasionally on weekends and a moderate amount during the summers.

During the last cleaning and lubricating maintenance I did this summer, I took out the quill and feed mechanism, speed changing mechanism, and slipped the motor belt off the motor sheeves. I did nothing to disturb the poly V-belt or aux spindle and drive sleeve.

If this heating is not the norm, can anyone offer suggestions as to what to investigate next?

Thanks.

tryinhard wrote:I know the headstock will become warm with use. But I think mine gets too warm. After running on FAST for about two minutes (during routing several pieces), the headstock becomes really warm. After a few more minutes of off and on use, the headstock is so hot I only want to put my hand on it for a few seconds. When I tried to turn the auxiliary shaft, I jerked my hand back as soon as I touched it. I don't ever recall it being this hot over the years I have owned it (1983). If getting this hot is out of the norm, then here is what I have seen and done to the headstock recently.

I took off the belt cover and watched everything inside when running from slow to fast several times. Everything seems to operate fine. There are no abnormal noises like bearings squeeking. Speed changing was smooth.

I read the owner's instruction manual, and here are my answers to the overheating section in Maintenance and Troubleshooting:
1. Poly V-belt improperly tensioned: When I lightly push in on the belt it only moves about 1/8 of an inch
2. Air flow clogged: the inside of the machine is clean. When running, there is good airflow out from the slot at the bottom of the unit.
3. Motor overheating: I don't know how to tell if it is, but the top of the headstock seems hotter than the lower section.
4. DriveSleeve/IdlerShaft missing lower auxillary hub: I have no idea on what this even means, but everything seems to be spinning.
5. Quill Feed bearings worn: I had a new two-bearing quill installed by the factory about 3 years ago. I only use the machine occasionally on weekends and a moderate amount during the summers.

During the last cleaning and lubricating maintenance I did this summer, I took out the quill and feed mechanism, speed changing mechanism, and slipped the motor belt off the motor sheeves. I did nothing to disturb the poly V-belt or aux spindle and drive sleeve.

If this heating is not the norm, can anyone offer suggestions as to what to investigate next?

Thanks.

The claim is that the auxiliary hub acts as a heat sink, so if it is not attached to the shaft, you may have increased heat issues.

If you know that it is properly lubricated, I recommend that you install hubs on both shafts (left side of headstock). They act as heat sinks to dissipate the heat that build up on the shafts.

Then I would slightly reduce the tension on the poly-v. If this does not help then you'll have to look deeper for the source of heat. Run it till it gets hot. Turn it off and unplug it. Reach inside and feel around. What is the hottest? Brutally fundamental but it works.

Have a dry clean rag handy for a compress for when you touch the source and jerk your hand out.

I doubt that the motor could be causing the heat build up on the upper headstock and shafts the much that quickly. I would suspect the motor last.

dusty wrote:If you know that it is properly lubricated, I recommend that you install hubs on both shafts (left side of headstock). They act as heat sinks to dissipate the heat that build up on the shafts.

Then I would slightly reduce the tension on the poly-v. If this does not help then you'll have to look deeper for the source of heat. Run it till it gets hot. Turn it off and unplug it. Reach inside and feel around. What is the hottest? Brutally fundamental but it works.

Have a dry clean rag handy for a compress for when you touch the source and jerk your hand out.

I doubt that the motor could be causing the heat build up on the upper headstock and shafts the much that quickly. I would suspect the motor last.

During my DC motor conversion days, I would cut a 4" round hole (4" carbite teeth hole saw) in the end of the motor pan so the DC motor would fit (a few inches too long to fit inside the motor pan) and it provided extra cooling for the DC motor and controller. After storing all my DC motors and controllers a few years ago, I placed a 4" square louvered vent (half of an AC vent) with screen over the 4" round hole on each motor pan.

I was very surprised that the headstock, idler shaft and drive sleeve shaft operated many degrees cooler now, never even got more than warm now. This increased the air flow from the motor pan bottom vent many times over the normal flow. Also, after a few years of using this vent, when I checked the headstock, there was no sawdust/crud collected inside the headstock. Shopsmith management was not interested in following up on this change.

Contact me if interested in any of the above changes.

Hi Bill
Any chance that you could post a pic showing the location of the vent -

thanks
nath

tunznath wrote:Hi Bill
Any chance that you could post a pic showing the location of the vent -

thanks
nath

Sorry, I sold the headstocks and did not take any pictures at that time. The 4" hole top edge was about 1/2" from the pan top edge and centered from the sides at the front (vertical) of the motor pan.

I found another vent in my DC pile so will try to take a picture about where the hole was on the motor pan. The DC motors were not attached to the motor pan. I used a 1/4" flat alumnum plate in the bottom of the headstock casing to attach the motor and controller.

I was only making use of the motor pans that I had modified for the DC motors and did not want to throw the motor pans away after all the work to cut the holes and paint the motor pans. I had the vents from a previous project as I throw very little away. The extra cooling was a bonus.

Warning: The motor pan is a very hard metal to cut/drill and can jam whatever you are using to drill or cut. You need some method for holding the motor pan when cutting on it.

This probably isn't Shopsmith approved maintaince but I remove the belt guard from the back of the headstock and then tilt the headstock into drill press mode.
I then drip more than a few drops of Mystery Marvel oil (very thin very low surface tension (read this to say it spreads everywhere, I'm convinced that left long enough one drop would cover the world)) around the two exposed bearings. Before I do this I run the SS until it gets hot. Then I apply the oil, I figure the cooling down process will draw in the oil. I keep a bead of oil around the bearing. About half way through the cooling process I mix in some 30 W oil. I figure it gets carried into the bearing with the mystery oil. 30w is a good lub for those bearings.

After the headstock is cool I wipe off all excess oil and run the machine again wiping away any excess.
Since I have started doing this I have noticed my headstock runs noticably cooler.
Everytime I notice it starting to run hot I do the procedure again.
Works for me.

For what it is worth I do this to many of my bearings. I do this often to my mower deck idler bearing. After I mow the lawn I bath the hot bearing in oil. As it cools down it seems to draw the oil right in. Before I did this I replaced an idler bearing every year or two, since doing this I haven't had to replace the bearing.

The above are all good responses to you problem. I particularly like Ed's! Mystery Marvel oil is good stuff!

Now I have to ask a stupid question - Were you working in temps above 90F? Also were you working in sunlight? These things will cause bearings in the headstock to heat more than normal.

To answer Charlese, I work outside so the temperatures can vary. The days in question were probably in the low 90s. I work under a tarp so the machine is shaded from the sun.

I tried Dusty's idea to barely loosen the poly-v belt. The slight loosening led to belt slipping when I started it with the sanding disc attached. So I set the eccentric back to where it was. With "light pressure," the belt deflects about 1/16".

I did another test. With the headstock dead cold and nothing attached, I started it, ran it up to FAST, and let it run for one minute. The temperature increase on the top of the headstock was very slight. The upper auxiliary shaft (which has a hub) was barely warm , but the lower auxiliary shaft (no hub) was so hot I could only leave my fingers on it for two seconds. So, even though I am not hearing any noises, I wonder if there is a bearing problem (even though the idler shaft was replaced maybe 5 years ago when I had the two-bearing quill installed, and the machine has had relatively very little use).

So I am asking for your guys help. I am asking for you to check your machines to see how hot the lower shaft gets after one minute of FAST starting from a dead cold headstock. If mine is the only one, then I guess I need a new idler shaft.

Thanks, Mike

tryinhard wrote:To answer Charlese, I work outside so the temperatures can vary. The days in question were probably in the low 90s. I work under a tarp so the machine is shaded from the sun.

I tried Dusty's idea to barely loosen the poly-v belt. The slight loosening led to belt slipping when I started it with the sanding disc attached. So I set the eccentric back to where it was. With "light pressure," the belt deflects about 1/16".

I did another test. With the headstock dead cold and nothing attached, I started it, ran it up to FAST, and let it run for one minute. The temperature increase on the top of the headstock was very slight. The upper auxiliary shaft (which has a hub) was barely warm , but the lower auxiliary shaft (no hub) was so hot I could only leave my fingers on it for two seconds. So, even though I am not hearing any noises, I wonder if there is a bearing problem (even though the idler shaft was replaced maybe 5 years ago when I had the two-bearing quill installed, and the machine has had relatively very little use).

So I am asking for your guys help. I am asking for you to check your machines to see how hot the lower shaft gets after one minute of FAST starting from a dead cold headstock. If mine is the only one, then I guess I need a new idler shaft.

Thanks, Mike

If you have the eccentric that has a set screw holding the bearing by a groove in the middle on the outside of the bearing, it may be too tight. It should be just snugged up into the groove.