phone  (937) 890-5197

Shopsmith Forums

%nbsp;

24 posts 1 2 3

melted/broken power coupler

#262109 by hfmann » Sun Aug 18, 2019 3:46 pm

After nearly 30 years of using my Shopsmith off and on (now upgraded with Power Pro headstock), I got some new power couplers as backup. Using a new coupler for the first time on my bandsaw today, after a few minutes of heavy resawing it seemed to melt and then break apart. Same thing with the second one but caught it before it broke. In both cases I found the end attached to the bandsaw was extremely hot. But the shaft on the bandsaw was not. The hub was firmly attached to the bandsaw shaft and the hubs are aligned vertically and horizontally.

Anybody else had this problem? What up?

pix attached.
power coupler.jpg
first new coupler
power coupler.jpg (63.3 KiB) Viewed 1100 times

Attachments

power coupler 1.jpg
power coupler 1.jpg (57.61 KiB) Viewed 1100 times

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262115 by wa2crk » Sun Aug 18, 2019 5:11 pm

Curious. The guys in our woodworking shop recently stripped the end of the inside of the end attached to the headstock.
They were using the belt sander and were doing some heavy sanding on our Toys for Tots project. I believe that they were pushing too hard on the item being sanded and as a result exceeded the strength of the coupler.
In the 36 years that I have had my machine I have never had a coupler fail. I gave the shop one of my old ones and the club bought a replacement which I have. I have a project that will require some heavy sanding so I will use the new coupler to see if it fails.
It seemed to me that the material was different from the original. It looks like that it could be repaired with a short piece of PVC pipe. In any case let the group know what happens after you contact customer service.
Bill V

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262119 by garys » Sun Aug 18, 2019 6:11 pm

That is interesting. I have a couple of those newer ones as spares in my box. I'm still using an older one so I haven't tried to use the new ones. I hope that isn't what I can expect to happen when I get to them.

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262120 by mountainbreeze » Sun Aug 18, 2019 6:13 pm

How's the alignment of the two hubs? If misaligned, I'm wondering if this could cause heat buildup in the coupler where it flexes with each rotation.

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262122 by dusty » Sun Aug 18, 2019 6:30 pm

I too have recently experienced a broken power couple. Mine occurred at the very moment I turned on the bandsaw. I rationalized that I probably did not have the hubs properly seated. I have not attempted to use the bandsaw since but I will tomorrow.

I have extra power couplers, included that are nearly brand new. I will use a new one when I run this "test". I'm hoping this was a setup issue and not a quality issue.

I had no indication of a heat problem except that the temperature in my open air work shop (garage) was over 100 degrees.

---

"Making Sawdust Safely"
Dusty
Sent from my Dell XPS using Firefox.

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262123 by jsburger » Sun Aug 18, 2019 6:33 pm

mountainbreeze wrote:How's the alignment of the two hubs? If misaligned, I'm wondering if this could cause heat buildup in the coupler where it flexes with each rotation.


That was my first thought but, he says the hubs are aligned. If the hubs were not aligned I would think you would have the same heating on both ends. Even more so on the SS end since the head stock does get warm.

This is totally unheard of. I would think that almost 100% of long time SS users will say that the couplers don't break and they have never had one break.

---

John & Mary Burger
Eagle's Lair Woodshop
Hooper, UT

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262128 by hfmann » Sun Aug 18, 2019 8:16 pm

I too thought the heat could be from misaligned hubs. But the hubs seemed pretty well aligned both vertically and horizontally. After the first coupler failed, I inspected the alignment and thought maybe they were off by a little less than 1/64 inch. I realigned and couldn't feel or see anything off. Still failed.

If the hub wasn't secure on the bandsaw shaft and spun I thought that could build up the heat. But dang, that thing was tight. Besides, if the hub was spinning, I thought the blade wouldn't be driven enough to cut through the 5 inches I was resawing.

Anxious to talk to customer service tomorrow.

hal

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262129 by hfmann » Sun Aug 18, 2019 8:17 pm

The new hubs are definitely a different material/construction.

Interesting idea you have about using pvc pipe to fix it.

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262130 by hfmann » Sun Aug 18, 2019 8:21 pm

I only got these new couplers to use if my original failed. The safety cover on the jointer gouged the original hub enough to make me think it might fail one day.

I'll see what SS says tomorrow. Just didn't want to go back to the original coupler and find out I was doing something wrong and destroy that too.

Post a reply  Reply with quote 

Re: melted/broken power coupler

#262132 by wa2crk » Sun Aug 18, 2019 8:39 pm

The interesting thing about this discussion is the fast that the bandsaw hub got hot. It could be that the water pump bearing on the bandsaw drive wheel got contaminated somewhere and got hot. That would be a very rare occurrence however. I have never seen one of those bearings go bad but there is always a first time. My bandsaw is mounted on the power stand and not driven by a coupler so I have no problems and this time of year is when our woodworking club is making Toys for Tots stuff and I use my bandsaw a lot. I have a suspicion but I will refrain for now and wait to see where this discussion goes.
Bill V

Post a reply  Reply with quote 

Who is online

Users browsing this forum: smith2tx and 54 guests

Board indexDelete all board cookies

Welcome to Shopsmith. Please fill in this form and we'll send you more information about the Shopsmith MARK 7 and other woodworking topics.

Subscribe to our mailing list

* indicates required