• It's time to cast your vote in the April 2025 Turning Challenge. (click here for details)
  • Congratulations to Steve Bonny for "A Book Holds What Time Lets Go" being selected as Turning of the Week for 28 April, 2025 (click here for details)
  • Welcome new registering member. Your username must be your real First and Last name (for example: John Doe). "Screen names" and "handles" are not allowed and your registration will be deleted if you don't use your real name. Also, do not use all caps nor all lower case.

Hose clamp chuck for round objects

Dave Fritz

Dave Fritz

Joined
Jul 24, 2008
Messages
743
Likes
212
Location
Montfort, Wisconsin
I want to drill a straight hole through a ball. I've seen a home made chuck that has slits cut in the end and a band clamp is placed around it and tightens around the ball but I can't find the video or plans for making such a thing. Can anyone help please?
 
Haven't been on his site lately but have you seen David Reed Smith's site. He shows plans for a number of homemade jigs & fixtures.
 
DSC00782.JPG
This is one of several that I have made over the years. I didn't have a plan I just turned a piece of wood made the inside contour to fit the piece I wanted to hold then made the cuts and added a hose clamp. The biggest problem with this type chuck is that the hose clamp does not pull the fingers tight evenly so the piece you are holding ends up slightly off center.
 
I have turned many custom jaws using the Oneway strong hold flat jaws. Instead of the hose clamps, you may try hollowing a set of cove-like jaws near the diameter of the spheres you are holding. I have not tried this but it appears that it may be a worthwhile alternative.
 
Don Wattenhofer said:
View attachment 36624
This is one of several that I have made over the years. I didn't have a plan I just turned a piece of wood made the inside contour to fit the piece I wanted to hold then made the cuts and added a hose clamp. The biggest problem with this type chuck is that the hose clamp does not pull the fingers tight evenly so the piece you are holding ends up slightly off center.
Click to expand...

Don, to offset the pulling of the hose clamp (absence of continuous pressure due to the screw) you can try two hose clamps with the locking mechanism 180 degrees of each other. You would alternately tighten each one to get even spacing between the slots thus getting your piece closer to center. What do you think?
 
Dennis Weiner said:
Don, to offset the pulling of the hose clamp(absence of continuous pressure due to the screw) you can try two hose clamps with the locking mechanism 180 degrees of each other. You would alternately tighten each one to get even spacing between the slots thus getting your piece closer to center. What do you think?
Click to expand...

I was thinking about some wax on the outside of the chuck and on the inside of the hose clamp.
 
You have some good suggestions for making slotted jam style Chuck.

whenever possible I drill holes before the turning. Pretty easy to line up a block with a hole drilled though or partway and then turn a sphere with a hole already in it that goes through or toward the center.

another easy solution is a vacuum Chuck if you have one

also a straka Chuck or donut Chuck will do well if you can center the ball or if it is not a through hole.
I use one for hollowing the big ball to do a ballin a ball.
 
I did drill some on the drill press, and 100% accuracy was not critical. I drilled a recess in a waste block with a forstner bit, maybe 1 1/4 inch diameter, and then without moving anything, changed bits to drill through the sphere. It was pretty close.

robo hippy
 
Dennis Weiner said:
Don, to offset the pulling of the band clamp(absence of continuous pressure due to the screw) you can try 2 band clamps with the locking mechanism 180 degrees of each other. You would alternately tighten each one to get even spacing between the slots thus getting your piece closer to center. What do you think?
Click to expand...
That would undoubtedly be an improvement if you connected two smaller clamps together, but that would leave two quadrants questionable.
I will not be making or using any of this type again since I have started going the scroll chuck route.
 
Don Wattenhofer said:
Excuse me but I don't understand what a "slotted jamb style chuck" is.
Click to expand...
Below is a nice looking Jam Chuck with slots cut in it to let It open and close. And a hose clamp to keep it closed.

When I took a class with Christian Burchard we cut patterns on spheres and hollowed them using Jam chucks.
Those were cylinders hollowed to hold the balls. No slots the balls were a tight fit and pushed or tapped in.
After hollowing the balls usually came out when the side of the Chuck was hit with a tool handle.
sometimes the chucks had to be split with a chisel to free the hollowed sphere

upload_2020-12-31_15-47-32.jpeg
 
hockenbery said:
Below is a nice looking Jam Chuck with slots cut in it to let It open and close. And a hose clamp to keep it closed.

When I took a class with Christian Burchard we cut patterns on spheres and hollowed them using Jam chucks.
Those were cylinders hollowed to hold the balls. No slots the balls were a tight fit and pushed or tapped in.
After hollowing the balls usually came out when the side of the Chuck was hit with a tool handle.
sometimes the chucks had to be split with a chisel to free the hollowed sphere

View attachment 36649
Click to expand...
Yup a jam chuck is something that you have to "jam" the work piece into where as a collet chuck can be opened and closed to grip or release the work piece. Question would you call the collet chucks being sold which use multiple sizes of steel spring collets a slotted jam chuck?
 
Don Wattenhofer said:
Yup a jam chuck is something that you have to "jam" the work piece into where as a collet chuck can be opened and closed to grip or release the work piece. Question would you call the collet chucks being sold which use multiple sizes of steel spring collets a slotted jam chuck?
Click to expand...


No because a collet chucks close by being compressed into a taper.

When a wooden chuck is turned just like a jam chuck and would work as such and then modified,
I think slotted jam is as good a name as finger Chuck. They do hold similarly to a collet Chuck so that is a reasonable name too although they close differently.

just another example of the lack of standard definitions in woodturning.
 
Don Wattenhofer said:
Yes because a collet needs to close uniformly whether it be a taper or scroll !@#$%^ so there
Click to expand...

I don’t understand. I assume you are joking and I’m missing the joke.

The way your post comes across to me is that you are now saying a machined collet should be called a jam Chuck based on the question you asked.

Don Wattenhofer said:
Question would you call the collet chucks being sold which use multiple sizes of steel spring collets a slotted jam chuck?
Click to expand...


Really doesn’t matter what you call a home made Chuck as long as it holds good enough to do the job.
 
I have a question for Al. I thought about sending an email but then I thought, there may be others that have a similar problem to the one I'm having with a Straka chuck. I downloaded your plans and followed them. When turning them round on the lathe I held them together with short bolts, marked both parts as top and bottom and drew a registration mark across both. The problem came when I replaced the short bolts with the carriage bolts. For some reason the registration mark isn't lined up exactly anymore and it's really hard to adjust the outer ring as there's a lot of binding with the bolts. I was wondering about opening the holes on the bottom plate a little bit and tighten everything in place making sure the registration line is where it should be. Interested in your thoughts about where I may have gone wrong and what the fix might be. I'm drilling a hole through a 1.5 inch ball and will be doing at least a dozen so I'd rather not take so long to put one in and take it out.
 
Dave Fritz said:
I have a question for Al. I thought about sending an email but then I thought, there may be others that have a similar problem to the one I'm having with a Straka chuck. I downloaded your plans and followed them. When turning them round on the lathe I held them together with short bolts, marked both parts as top and bottom and drew a registration mark across both. The problem came when I replaced the short bolts with the carriage bolts. For some reason the registration mark isn't lined up exactly anymore and it's really hard to adjust the outer ring as there's a lot of binding with the bolts. I was wondering about opening the holes on the bottom plate a little bit and tighten everything in place making sure the registration line is where it should be. Interested in your thoughts about where I may have gone wrong and what the fix might be. I'm drilling a hole through a 1.5 inch ball and will be doing at least a dozen so I'd rather not take so long to put one in and take it out.
Click to expand...

My answer may be disappointing.- thought of a couple of things. Maybe some one else has a thought.
not sure what is wrong.

If it fits and lines up with the short bolts then I think it has to line up with the long bolts.
I’m sure you watched the alignment of the outside faces- they face outward and then they face inward.

I have done 20 - 30 this way for workshop sets and have given several away.
They all lined up with the long bolts. And most have been field tested by students.


One thing that I thought of is if the holes are not drilled square it could cause a “twist” with the long bolts.
Check the long bolts for square with the top plate.

I do struggle sometimes with the bolts not sliding easily through the bottom plate when opening and closing it.
there is a stiffness in the beginning and I may have to tap the bolts some with a tool handle. This may be from the MDF absorbing moisture or the drill leaving a fuzzy hole. The threads on the bolts will clean the hole with a tap.

You could drill the base plate holes a 1/16 larger - you have a washer on that end.
 
Last edited:
Not being square holes could definitely be the problem. My drill press appears to be square but when I drill a ball on that the hole is off center, that's why I made the chuck. I wonder why you use four bolts and not three? I think Alon Lacer uses 3 in his. Wouldn't three be easier to register sort of like a three legged stool compared to a four legged stool?
 
Dave Fritz said:
I wonder why you use four bolts and not three? I think Alon Lacer uses 3 in his. Wouldn't three be easier to register sort of like a three legged stool compared to a four legged stool?
Click to expand...
.

I just felt more comfortable with 4 bolts. With most balls I don’t have to remove a bolt to get the balls in and out.
Also I get the top plate perpendicular top the bed and tighten all the nuts the same (torqued to the same finger pressure). So registration isn’t an issue.

three bolts are a big advantage for bowls. With 3 bolts you can get bowls in and out with removing 1 bolt or maybe none. With 4 bolts you have to take 1 and probably 2 bolts out to get bowls in and out.

Probably a small advantage for registering with 3. The three bolts would register better with the top plate at an angle if there were a need for that.
 
You must log in or register to reply here.
Back
Top