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Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 12:24 am
by bainin
Well-I've been making reindeer lately and with the continuous running of the bandsaw ..I came into an issue.

Not sure the name for the thing-but the coupling ring mounted on the bandsaw shaft (black ring in my pic) ..which is held in place with a set screw
is coming loose during operation. I've put as much tension on the set screw as i'm comfortable with, but still over time
it will come loose.

Once this happens, it drifts away from the plastic coupling ..which usually ends up chewing up those little plastic ridges
inside the plastic coupling.
bandsaw-shaft.jpg
bandsaw-shaft.jpg (43.58 KiB) Viewed 1035 times
I was thinking of drilling a recess in the bandsaw shaft for the set screw to sit in which "should" keep the ring from slipping along the shaft.

Perhaps someone has encountered this and found a better solution ? Any problem with making a recess in this shaft ?

thank you,

b

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 1:28 am
by beeg
Try some lock-tight on the set screw.

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 4:29 am
by JPG
Try more torque when tightening the set screw. A longer set screw will help.

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 7:36 am
by dusty
The same thing happens with the saw arbor. A "touch" of lock tight and/or new set screws. Once I am aware that a set screw has come loose, it is replaced with a new one and I don't save the old ones.

I use the long handled hex driver and was taught to flex it three times when setting screws. Tighten until you feel resistance and then tighten (flex the handle) three more times.

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 11:46 am
by db5
"Tighten until you feel resistance and then tighten (flex the handle) three more times."

That is such a simple and outstanding suggestion. Why didn't you post this years ago? You could have me and others so much frustration with other things too such as the sanding disc. Somewhere I saw a post on what type set screw was used where. I think you posted it and learned that the PO of my 510 just put in set screws probably purchased at Ace and wouldn't tighten sufficiently. Thanks for posting.

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 12:35 pm
by JPG
When tightening a set screw on a flatted shaft(straight or tapered) it is imperative that the screw be positioned at the middle(low point so to speak) of the flat. Rocking the arbor will help assure that centering. I usually rock with the wrench while slowing advance the screw. Requires 'co-ordination'. :D

A tapered flat(quill) requires also firmly bottoming the arbor on the shaft.

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 1:08 pm
by chapmanruss
Let me throw my two set screws worth in here. Cup Point Set Screws are the most common ones found. It is the type that was used at one time to hold the hub (for the Power Coupler) in place on your Bandsaw's drive shaft. Note, in your case the shaft already has an indent from a Cup Point Set Screw. As Dusty suggests replace the set screw. I would use a new Cup Point one of the proper length no longer than the thickness of the hub between the inside bore diameter and outside diameter. Tighten as Dusty suggests with the cup into the indent already on the shaft to hold it in place. I don't recommend using Cup Point Set Screws to hold Arbors, Chucks and other attachments on the Quill's Spindle end. That is a location you do not want to have set screws creating indents. For that I would use either Oval Point or Flat Point Set Screws. Hubs have come with either Cup Point Set Screws (older) or Flat Point Set Screws (newer) and the same is true for Arbors, Chucks and other attachments. For any older Arbors, Chucks and other attachments that have Cup Point Set Screws I would recommend replacing them with Oval Point or Flat Point Set Screws.

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 1:24 pm
by JPG
AMEN!

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 2:06 pm
by DLB
bainin wrote: Sat Aug 07, 2021 12:24 am ...Not sure the name for the thing-but the coupling ring mounted on the bandsaw shaft (black ring in my pic) ..which is held in place with a set screw
is coming loose during operation. I've put as much tension on the set screw as i'm comfortable with, but still over time
it will come loose...
I thought I had found some nylon patch setscrews for use on/around the PowerPro from Fastenal but the right sizes and types were all out of stock at the time. I picked up some nylon tip setscrews to evaluate, but have not put any real miles on them yet. For this application I'd think blue loc-tite or equivalent, as recommended earlier, would be a great choice. I recall a couple of threads here where a small number of users were having a large number of problems combining the PowerPro and BS. I would combine the correct setscrew, preferably new, with blue loc-tite or similar thread locker, and plenty of tightening torque.

- David

Re: Bandsaw coupler coming loose.

Posted: Sat Aug 07, 2021 2:34 pm
by chapmanruss
Although the Power Coupler Hubs now come with a Flat Point Set Screw this is a case I feel would benefit from using Cup Point Set Screws due to the flat on the SPT's Shaft being even the entire length of the flat. The pressure put on the hub pushing it towards the SPT itself by the Coupler/Headstock, as shown in bainin's case, creates a need for a more positive lock than the friction a Flat Point Set Screw on a flat surface can give. A Flat Point Set Screw does a great job of keeping the hub from rotating on the drive shaft but not as good of a job keeping it from moving inward on the drive shaft. Using a Cup Point Set Screw here is not a big problem even when causing an indent/dimple on the SPT's drive shaft when centered on the flat. Notice on bainin's Bandsaw's drive shaft the indent/dimple is centered and should not interfere with removing or installing the hub.

Depending on the age of my SPT's some have Cup Point Set Screws while others have Flat Point Set Screws. If any end up having the problem bainin is having I will switch it to a Cup Point Set Screw.