Square blank to collet Chuck

[InkyMike]

Hey all - question for the collective.

A lot of tutorials I've seen, specifically in section turning, start with using a round blank in a collet chuck. Thanks to the generosity of some folks here, I have a good number of square blanks to practice with. I'm curious how many of you turn down your square blanks to round, and then use a collet chuck - and for those that do - if you have any tips on how to get the rounded portion as true as possible to use in the chuck - on a wood lathe (I have a Taig micro lathe but I'm trying to go end to end on the wood lathe.)

Thanks!
Michael

 

[KenB259]

I don't turn them round or use a collet chuck for pens, so not much help there, but I can tell you if you put a piece of wood between centers and turn it round, it will find it's own center. Not sure if that's what you're asking though.

 

[Paul in OKC]

Use a drive center in the headstock and the live center in the tailstock and turn round. If you have a four jaw chuck, you could chuck it up and just turn a long enough tenon to put in the collet.

 

[Valleyboy]

I use a metal lathe and I use collets. My approach (which depends on the size of the bore in your headstock) is to remove the collet and nut and then wedge one end of the square blank into the bore. I bring up the live centre on the other end and then turn down around 5mm to the correct diameter. Then put the collect back on and flip the blank over with the rounded end in the collet and you can then round the rest of the blank.
Cheers
Ash

 

[InkyMike]

I use a metal lathe and I use collets. My approach (which depends on the size of the bore in your headstock) is to remove the collet and nut and then wedge one end of the square blank into the bore. I bring up the live centre on the other end and then turn down around 5mm to the correct diameter. Then put the collect back on and flip the blank over with the rounded end in the collet and you can then round the rest of the blank.
Cheers
Ash

This is where I was thinking I was going to have to head to be the most accurate. My fear was that even using a square carbide bit it might be difficult to get the exact same diameter the length of the tenon to put in the collet.

 

[its_virgil]

You mentioned sections which makes me think you are making non-kit fountain pens. For me, I turn square blanks round between centers. Then hold the blank in a collet chuck to so the drilling and taping. I then transfer the parts to a mandrel which I also hold in the collet chuck. BTW, the entire blank does not have to be turned round. Just a couple of inches turned round for the collet chuck. The rest of the blank can be rounded on the mandrel.
Do a good turn daily!
Don

 

[InkyMike]

You mentioned sections which makes me think you are making non-kit fountain pens. For me, I turn square blanks round between centers. Then hold the blank in a collet chuck to so the drilling and taping. I then transfer the parts to a mandrel which I also hold in the collet chuck. BTW, the entire blank does not have to be turned round. Just a couple of inches turned round for the collet chuck. The rest of the blank can be rounded on the mandrel.
Do a good turn daily!
Don

Well, I'm exploring non kit pens - I just wasn't sure if I could get accurate enough turning a tenon for the collet chuck between centers - I suppose like anything else it just takes practice with a gouge and a caliper.

 

[Valleyboy]

This is where I was thinking I was going to have to head to be the most accurate. My fear was that even using a square carbide bit it might be difficult to get the exact same diameter the length of the tenon to put in the collet.

So metric collets give you a 1mm diameter margin of error (which is quite a lot) the nice thing about this approach on a metal lathe is you turn the tenon down to, say 18.5mm to fit in a 19-18mm collet then zero your cross slide dial and when you flip it you just turn down until you reach zero again knowing you've now got a rod that will fit the same collet.
Does that answer your question?

 

[InkyMike]

So metric collets give you a 1mm diameter margin of error (which is quite a lot) the nice thing about this approach on a metal lathe is you turn the tenon down to, say 18.5mm to fit in a 19-18mm collet then zero your cross slide dial and when you flip it you just turn down until you reach zero again knowing you've now got a rod that will fit the same collet.
Does that answer your question?

Yeah - makes perfect sense. I have standard sized collets but a metric set on the way. I can't zero the slide on the Taig but I can count the rotations and use the indicator marks.

 

[dogcatcher]

If I want a 3/4 diameter I use a 3/4 open end wrench as my guide. Same for other sizes.

 

[InkyMike]

If I want a 3/4 diameter I use a 3/4 open end wrench as my guide. Same for other sizes.

I'd seen something like that before - thanks for the reminder.

 

[monophoto]

Hey all - question for the collective.

A lot of tutorials I've seen, specifically in section turning, start with using a round blank in a collet chuck. Thanks to the generosity of some folks here, I have a good number of square blanks to practice with. I'm curious how many of you turn down your square blanks to round, and then use a collet chuck - and for those that do - if you have any tips on how to get the rounded portion as true as possible to use in the chuck - on a wood lathe (I have a Taig micro lathe but I'm trying to go end to end on the wood lathe.)

Thanks!
Michael

Collet chucks are intended to hold tenons; there is no way to mount a square blank in a collet chuck without first making the blank round.

The best way to make a square or rectangular blank round is to mount it between centers. Since collet chucks don't have a large expansion range, sizing the tenon is critical. I don't have any specific size that I use regularly, so I use calipers. But if you are converting square to round on a regular basis, you could always make a go/no-go gauge. Start with a thin scrap of timber - plywood or mdf would be fine. Drill a hole the size of the desired tenon (a forstner bit would be the best tool for this), and then cut through the board exactly through the center of that hole. Then, as you are turning the tenon, you can use the gauge to know when you are approaching the target diameter. In my experience, a skew is the best tool for fine-tuning the tenon diameter, but it is also possible to get close, and then use coarse sandpaper to finish-size the tenon.

 

[InkyMike]

Collet chucks are intended to hold tenons; there is no way to mount a square blank in a collet chuck without first making the blank round.

The best way to make a square or rectangular blank round is to mount it between centers. Since collet chucks don't have a large expansion range, sizing the tenon is critical. I don't have any specific size that I use regularly, so I use calipers. But if you are converting square to round on a regular basis, you could always make a go/no-go gauge. Start with a thin scrap of timber - plywood or mdf would be fine. Drill a hole the size of the desired tenon (a forstner bit would be the best tool for this), and then cut through the board exactly through the center of that hole. Then, as you are turning the tenon, you can use the gauge to know when you are approaching the target diameter. In my experience, a skew is the best tool for fine-tuning the tenon diameter, but it is also possible to get close, and then use coarse sandpaper to finish-size the tenon.

Right - which is why I was asking about the rounding. My only concern was ensuring the tenon isn't tapered. I like the go/no go. Could also use the wrench for that, too.

Also - as an FYI for the collective, Turners Warehouse has a tenon cutter that you mount in the tailstock. I was just wanting to do it w/o an additional tool.

 

[MPVic]

I avoid turning the square blank round BEFORE drilling. Someone here on IAP recommended that it's best to leave as much material on the blank while drilling to give it more strength & support.

 

[InkyMike]

I avoid turning the square blank round BEFORE drilling. Someone here on IAP recommended that it's best to leave as much material on the blank while drilling to give it more strength & support.

Makes sense. I think most of the videos I've watched, they started with round blanks to begin with.

 

[jttheclockman]

I mainly leave blanks square. When I need to I round over between centers. You really should get to know your tools and turning a blank round just by looks should become second nature. I use the open end wrench trick but never sharpened to actually make it a tool Pretty nice idea, I use the, as a gauge more or less.

 

[anthonyd]

I use a step centre and a live centre to turn the entire square blank end to end. Exactly as the video on the attached link. Then I use a collet chuck on the barrel, cap and section.
1414

 

[anthonyd]

Correction Steb Centre. Darn autocorrect.

 

[rixstix]

I use a metal lathe and I use collets. My approach (which depends on the size of the bore in your headstock) is to remove the collet and nut and then wedge one end of the square blank into the bore. I bring up the live centre on the other end and then turn down around 5mm to the correct diameter. Then put the collect back on and flip the blank over with the rounded end in the collet and you can then round the rest of the blank.
Cheers
Ash

WOW, what a novel idea @Valleyboy . I did that this afternoon. What a timesaver & much smoother operation than my dead center/live center arrangement.

THANK YOU.

I have er32 collets in 32" increment through 3/4" but metric would be a brain saver.

 

[InkyMike]

I mainly leave blanks square. When I need to I round over between centers. You really should get to know your tools and turning a blank round just by looks should become second nature. I use the open end wrench trick but never sharpened to actually make it a tool Pretty nice idea, I use the, as a gauge more or less.

I can turn it round no problem - turning it round the same identical diameter without tapering it was my concern.

 

[jttheclockman]

I can turn it round no problem - turning it round the same identical diameter without tapering it was my concern.

I hear you and that is why I say with some practice you can turn equal dimension all the way. The key is the angle you look at the blank. Your eye should be able to pick up a straight line as it spins. My little cheat is to zero in both ends to exact same diameter and then even the center out. When I get close I stick a straight edge across the blank and can tell high spots. But whatever works to get the job done is fine. Happy turning.

 

[dogcatcher]

You do not have to turn the whole blank, just turn a tenon on one end to fit the collet.

During my "thinking time" I grab some blanks and turn then round. With wood blanks doing this I get a better idea of what they will look like in a pen. The grain, burns, etc. can have a different look in the round than they do square.

It is also a stress reliever, both for the wood and the woodturner' mind. Pool cue makers do a lot of small cuts over days to allow the wood stress to slowly adjust to the removal of wood. Is it necessary for pens? Not really but it gives the turner time to clear his/her own stressors.

 

[InkyMike]

You do not have to turn the whole blank, just turn a tenon on one end to fit the collet.

During my "thinking time" I grab some blanks and turn then round. With wood blanks doing this I get a better idea of what they will look like in a pen. The grain, burns, etc. can have a different look in the round than they do square.

It is also a stress reliever, both for the wood and the woodturner' mind. Pool cue makers do a lot of small cuts over days to allow the wood stress to slowly adjust to the removal of wood. Is it necessary for pens? Not really but it gives the turner time to clear his/her own stressors.

This is probably what I'm going to start doing - I have a ton of blanks to play with.

 

[Valleyboy]

My pleasure Rick.

If you run off collets on a metal lathe then this is a game changer in terms of time saving and efficiency.

I do them in batches because once you're dialled in for the first one it's just a case of rinse and repeat. I've also found that it happens to work for the majority of blank sizes.

Cheers
Ash

 

[InkyMike]

My pleasure Rick.

If you run off collets on a metal lathe then this is a game changer in terms of time saving and efficiency.

I do them in batches because once you're dialled in for the first one it's just a case of rinse and repeat. I've also found that it happens to work for the majority of blank sizes.

Cheers
Ash

Luckily my collet system fits both my wood lathe and my metal micro lathe. I'm just not nearly as efficient on the micro lathe yet. I'm still working through all my initial design and process ideas. I'm sure it will take several iterations.

 

[Valleyboy]

Luckily my collet system fits both my wood lathe and my metal micro lathe. I'm just not nearly as efficient on the micro lathe yet. I'm still working through all my initial design and process ideas. I'm sure it will take several iterations.

That's handy. The thing about the collet system on my metal lathe is that the face plate has to be bolted on with 4 bolts. To remove it is quite awkward and it's very time consuming to change it over for, say, a 3 jaw chuck that can hold a square blank. Hence this approach.

 

[darrin1200]

I can turn it round no problem - turning it round the same identical diameter without tapering it was my concern.

This is why most Kitless makers either have a metal lathe or want to move to one.
While I've made many kitless pens on my woodlathe, the accuracy needed takes more time on wood lathe. Also, depending on your model, the wood lathe is not concentric enough for some of the detailed work you will get into.

 

[InkyMike]

That's handy. The thing about the collet system on my metal lathe is that the face plate has to be bolted on with 4 bolts. To remove it is quite awkward and it's very time consuming to change it over for, say, a 3 jaw chuck that can hold a square blank. Hence this approach.

Yeah - I have the PSI set and an adaptor that fits the Shopfox and the Taig. It's quick to swap it between the two if needed.

 

[Curly]

My metal lathe is large enough to have a D1-5 headstock which means it is quick to change chucks. The collet chuck I bought for it is a 5C type that can use collets made for round, hexagonal or square collets as needed. The down side to them is they need to be very square in order to fit right, a condition most banks don't come in. Therefore I use a self centring 4 jaw chuck to hold the very end of the square stock and the tailstock to turn round. Then switch over to the collet chuck. It wouldn't be all that hard to skip the chucks altogether and turn the blanks round between centres, then switch to the collet chuck. A centre made for the collet chuck would take care of that.
One just has to find a way to get where they want to go with what is available.

 

[mredburn]

Ran across this thread and it made me think about 3d printing one. I had actually drawn this Er32 collet years ago but never printed it. I have 3d resin printers but the cost of resin for them was too expensive to bother to play around at the time. I just picked up another resin printer that is Chinese made and the resin is only $20 a bottle instead of $350 for a liter of resin. I'm not sure how strong it is for actual work but it should be ok for normal use and light cuts. This one is .700 square. 3/4 square would take the corners out to the edge of the collet. I can easily make then in smaller dimensions. 5/8,1/2, 1/4 etc. Think I'll play with it just cause I can.

 

[InkyMike]

This is why most Kitless makers either have a metal lathe or want to move to one.
While I've made many kitless pens on my woodlathe, the accuracy needed takes more time on wood lathe. Also, depending on your model, the wood lathe is not concentric enough for some of the detailed work you will get into.

I bought my Taig years ago with just that thought in mind. But life got in the way and I haven't become even close to proficient on it yet.

Ran across this thread and it made me think about 3d printing one. I had actually drawn this Er32 collet years ago but never printed it. I have 3d resin printers but the cost of resin for them was too expensive to bother to play around at the time. I just picked up another resin printer that is Chinese made and the resin is only $20 a bottle instead of $350 for a liter of resin. I'm not sure how strong it is for actual work but it should be ok for normal use and light cuts. This one is .700 square. 3/4 square would take the corners out to the edge of the collet. I can easily make then in smaller dimensions. 5/8,1/2, 1/4 etc. Think I'll play with it just cause I can.

That's a very cool idea!

 

[mredburn]

You do know they make a 4 jaw scroll chuck for the Taig. I use them on a steel mandril mounted in my 6
inch 3 jaw to round square stock. Its one of the other reasons I never pursued the square collets. The 4 jaw is faster to mount and adjust to what ever size im working with.

 

[rsieracki]

My metal lathe is large enough to have a D1-5 headstock which means it is quick to change chucks. The collet chuck I bought for it is a 5C type that can use collets made for round, hexagonal or square collets as needed. The down side to them is they need to be very square in order to fit right, a condition most banks don't come in. Therefore I use a self centring 4 jaw chuck to hold the very end of the square stock and the tailstock to turn round. Then switch over to the collet chuck. It wouldn't be all that hard to skip the chucks altogether and turn the blanks round between centres, then switch to the collet chuck. A centre made for the collet chuck would take care of that.
One just has to find a way to get where they want to go with what is available.

Tell me more about this scrolling 4 jaw... I have a Precision Matthews with a D1-4, and a South Bend heavy 10 lathe... and of course a 'few' wood lathes. I've been looking for a 4 jaw that scrolls for the same purpose of going square to 3/4 or so round and keep comming up empty

 

[Curly]

I bought the 4 jaw scroll chuck from Grizzly and as it is a plane back, a D1-5 backing plate that I had to machine to fit.

6" 4-Jaw Plain Back Scroll Chuck at Grizzly.com

<h1>T32463 6" 4-Jaw Plain Back Scroll Chuck</h1> <h2>A scroll chuck means that all jaws close together and are self-centering.</h2> <p>The T32463 6" 4-Jaw Plain Back Scroll Chuck has a semi-steel body and two sets of hardened jaws.</p> <p>4-jaw self-centering chucks have firmer hold on the...

www.grizzly.com

6-1/4" D1-3 Back Plate at Grizzly.com

<h1>SB1391 6-1/4" D1-3 Back Plate</h1> <p>Sized to fit D1-3 chuck mounts, the SB1391 6-1/4" D1-3 Back Plates are precision made and mount to your chuck with minimal modifications.</p> <p>All South Bend back plates are made of fine-grain cast-iron.</p> <p>Whether you need a blank or semi-finished...

www.grizzly.com

Other companies sell similar if you poke around.

 

[Penultimate]

Tell me more about this scrolling 4 jaw... I have a Precision Matthews with a D1-4, and a South Bend heavy 10 lathe... and of course a 'few' wood lathes. I've been looking for a 4 jaw that scrolls for the same purpose of going square to 3/4 or so round and keep comming up empty

Hi
You should be able to mount 5C collets on your SB 10.