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Luke Maddux
15th May 2015, 05:50 PM
Call me lazy, but I do NOT like changing the jaws on my chucks. I think it's enough of a pain to move the bumpers on my cole jaws, but that's a necessary evil which I accept. Kind of like flossing... I like my mounting and remounting to be a "wham, bam" scenario. If the wood isn't spinning, time's a wastin'.

I have a G3 which I use with the standard jaws, and a Vicmarc VM90 which is my dedicated cole jaw chuck. Additionally, I have a NOVA Precision Midi which came with my current lathe. This chuck is currently sitting idle (with standard jaws equipped).

So recently I've been doing a bit more turning. I went through a several month period of extensive furniture-making, and I bounce back and forth, but right now I'm loving some turning.

I keep finding myself in a situation where I've turned something which is too small to reverse mount onto my cole jaws to finish. My proposed solution to this is to buy either the NOVA 100mm or 130mm jaws and use those for mounting tiny "dish" sized pieces, likely with some carpet padding in there to prevent damage to the (already sanded) piece. I've seen someone doing this extensively at a demo and it seemed to be working great.

Now the problem... I don't want to swap the jaws on either the G3 or the VM90, so I'm left with the Precision Midi. Unfortunately, however, Teknatool's website says that using this chuck with either of those jaw sets is "Not Recommended".

Can anyone provide any commentary on why this is the case? I can virtually guarantee that this chuck will be used exclusively in contraction mode for finishing off small faceplates, and I doubt I will ever use it for a large footed piece. If I ever needed to, I could, reluctantly, swap the jaws onto the G3... or just get on here and whinge about it to you guys :2tsup:

I'd also be interested in commentary from people who finish the bottoms of small pieces in a different manner.

Thanks in advance,
Luke

Gabriel
15th May 2015, 06:07 PM
How about a Longworth chuck?
Mine fits onto standard jaws, so no changing required.

I purchased mine, but I'm pretty sure there are plans about to make them.

I know this wasn't the question you were asking, but it saves jaw changing. The only real limitation is the speed at which you can turn (max about 600 rpm they recommend)

Cheers
Gab

Luke Maddux
15th May 2015, 06:29 PM
How about a Longworth chuck?
Mine fits onto standard jaws, so no changing required.

I purchased mine, but I'm pretty sure there are plans about to make them.

I know this wasn't the question you were asking, but it saves jaw changing. The only real limitation is the speed at which you can turn (max about 600 rpm they recommend)

Cheers
Gab

Thanks Gab. You're right, that does seem drastically easier on jaw adjustment. I will look into it!

Also right that it doesn't help me with the smaller stuff. The quest for knowledge continues.

Cheers!
Luke

Luke Maddux
15th May 2015, 06:33 PM
Ok, wow... I just watched a video on them. I had NO IDEA this existed. I am absolutely sold. I think I could buy the smaller one and it would solve my entire problem AND it would free up my VM90 for some other set of jaws. Incredible.

issatree
15th May 2015, 06:53 PM
Hi Luke,
I have been rather lucky as I now have 4 Black Nova Chucks, all with different Jaws.

If you ask, you may even pick another chuck up, to take the other jaws.

I saw a Lathe for sale, had 2 chucks, asked & I was able to by one of them, with 100mm. jaws, & almost new. Lucky me.

Luke Maddux
15th May 2015, 07:01 PM
Ok actually... The longworth chucks still only go down to 115mm. But they mount in standard jaws. So if I buy the longworth and leave the standard jaws in the G3, then get rid of the vicmarc bowl jaws and replace them with the vicmarc step jaws, that covers the entire range of faceplate turning operations without the need to ever change jaws, and any bowl which finishes to greater than 115mm doesn't even require me to remove the chuck!

This, friends... Is a good day.

Rod Gilbert
15th May 2015, 10:09 PM
Hi Luke,
For most rechucking to finish bowl bottoms I just put a screw chuck in whatever jaws I have in the lathe and attach a piece of 19mm pine to it and turn a jam chuck recess to suit whatever size I need a nice tight fit(either internal or external whatever suits best) and you can clean up the bottom of whatever you need especially if as it seems you are working on smaller objects.
Regards Rod.

Luke Maddux
15th May 2015, 10:48 PM
Hi Luke,
For most rechucking to finish bowl bottoms I just put a screw chuck in whatever jaws I have in the lathe and attach a piece of 19mm pine to it and turn a jam chuck recess to suit whatever size I need a nice tight fit(either internal or external whatever suits best) and you can clean up the bottom of whatever you need especially if as it seems you are working on smaller objects.
Regards Rod.

Hi Rod,

Are you just talking about a board of 19mm pine? Do you have a photo of what you're describing?

Sturdee
15th May 2015, 10:51 PM
Have you looked at making a donut chuck using a small face plate. With a number of covering rings giving you a number of different openings you're home and hosed.

Just google "donut chucks" for how to make them.

Peter.

Luke Maddux
15th May 2015, 11:15 PM
The donut chuck is a novel idea. I could see it being the only option in certain scenarios, namely something which tapers inward at the top so drastically that mounting it in bowl/cole/longworth jaws is not an option, so I will keep it in mind. It does, however, seem convoluted, prone to error, and time consuming to use.

And that video... geez... that dude could've explained that in like four minutes.

Thanks for the information though. I have learned quite a bit as a result of this post.

Cheers,
Luke

Mobyturns
16th May 2015, 08:28 AM
Luke I have two Midi's that I rarely use now because I much prefer the Vicmarc dovetail jaw design.

Have a look at my "sneak peek" post to see how I reverse jamb chuck goblet cups using the "mummy technique" with low tack masking tape. It works well and is safe IF you use tail stock support where necessary and use light cuts with sharp tools. I use a purpose made custom fitted recess in the jamb chuck for each goblet or bowl rim dia. Up to 100 to 150 dia is quite OK. Most of my goblet cups have less than 2mm wall thickness.

I usually have a number of discs of varying diameters pre-prepared and I also keep any parted off tenons so I can quickly place a tenon in the chuck jaws, face it off, hot melt glue on a disc, let it cool, then true the rim (safety) & face off the disc, then cut the recess to suit. Sounds involved but in reality it only takes a few minutes.

Big bonus is there are no chucking marks and very little risk to the turner. Biggest risk is damaging the bowl or goblet cup through being to aggressive.

Rod Gilbert
16th May 2015, 09:03 AM
Hi Luke,
Yes just a piece of 19mm board or whatever comes you have laying around this is the only photo that I have to hand normally I don't add the tabs but this bowl had a very thin edge and I didn't want to pull it out of the recess.
Regards Rod.

Mobyturns
16th May 2015, 09:11 AM
Hi Luke,
Yes just a piece of 19mm board or whatever comes you have laying around this is the only photo that I have to hand normally I don't add the tabs but this bowl had a very thin edge and I didn't want to pull it out of the recess.
Regards Rod.

Nice setup. I also use bits of 19mm pine as its economical and usually a pretty known quantity they way they process it these days. It does pay to check that you don't split the jamb chuck with the screws when using 19 mm pine, very easy to do if you haven't got much rim margin. Rod's looks pretty good though.

One thing with the tape - the bowl won't spin, with the screw tabs if it even moves slightly it will mark the finish. But then Ive used the wrong masking tape and pulled off some finish - Oh shucks! :(

Rod Gilbert
16th May 2015, 06:53 PM
Hi again,
I don't usually use the tabs screwed in to the board but (as stated with this bowl the edge was very thin and didn't trust friction alone) usually just a tight fit in the jam chuck I quite often just split the jam chuck to release the work that is why I usually just use whatever is lying around the workshop for the chuck any scrap will do. There are times when I use tape also to hold into the jam chuck if the fit isn't as tight as I would like.
Regards Rod.