# 4 Jaw Stand offs and the quest for concentric lathe work



## Janderso (Aug 17, 2020)

Hi all,
I am learning, all the time. I really thought I made these stand offs well. They are made out of tool steel and getto hardened.
I can adjust the depth simply by turning the tapered allen screws in or out based on the indicator reading. They lock with a brass set screw.
I failed to put the screws in a collet and face the mating surface. I was not successful in machining two perfectly concentric faces. I bored a piece of round stock, slid the part on the shaft and I could see lateral movement.
If I want to work on a hub, collar, pulley, etc. I need to have a way of holding the piece with something like a lathe mandrel.
I had in my mind these stand offs would allow me to surface/feature a part without a hole concentrically (is that a word?). I guess I could do the same on the mill.
Anyway, I'll try an end mandrel. The way the screw expands the mandrel to hold the part seems like it would not be consistent. I guess if the expansion is uniform? it will hold the part without worrying about lateral movement.

What are your thoughts on this method vs. turning between centers using an arbor?

learning every day.


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## Grinderman (Aug 17, 2020)

Could you remove the chuck jaws and take a skim cut off of the 4 faces of the adjustment screws?


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## pontiac428 (Aug 17, 2020)

Don't you have a surface grinder, Jeff?


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## Janderso (Aug 17, 2020)

Grinderman said:


> Could you remove the chuck jaws and take a skim cut off of the 4 faces of the adjustment screws?


I’m thinking they would need to be screwed into an arbor of sorts? I don’t think they would be supported enough for a skim as is. Maybe, with light cuts?


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## Janderso (Aug 17, 2020)

pontiac428 said:


> Don't you have a surface grinder, Jeff?


I sure do! Now your thinking!
Maybe screw them into a block that has been set up in the mill, drilled and tapped with care.
Good idea. I’m always looking for a Good excuse to fire up the B&S.


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## Grinderman (Aug 17, 2020)

Joe Pi had a good video on making standoffs for a chuck. Not easily adjustable but simple.


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## mickri (Aug 18, 2020)

I am trying to understand how these standoffs are supposed to work.  As best as I can tell is that each screw is screwed in or out until they are all in the same plane when you check them with a DI.  If that is the case then why can't you just face off the top of each screw in a 3 jaw chuck to make it flat?  What am I missing? 
And how much time will it take to dial these in each time you want to use them?  Having several different heights of Joe Pi's standoffs seems like a better and quicker solution.


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## davidpbest (Aug 18, 2020)

Adjustable Chuck Stops
					

Making adjustable chuck stops for 3-jaw and 4-jaw chucks.   Click photos for descriptions




					www.flickr.com
				




More info here:   https://www.hobby-machinist.com/thr...stops-for-3-and-4-jaw-chucks-long-post.61766/


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## C-Bag (Aug 18, 2020)

Grinderman said:


> Joe Pi had a good video on making standoffs for a chuck. Not easily adjustable but simple.


Joe Pie to the rescue, thanks for posting that link Grinderman. I don’t have slot in either my 3jaw or 4jaw and this fixes the whole problem. Simple fixes for a simple guy.


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## Janderso (Aug 18, 2020)

mickri said:


> Having several different heights of Joe Pi's standoffs seems like a better and quicker solution.


I have several different length screws but yes, this is the best idea. I will acquire or fabricate a series of standoffs that are identical. No need to adjust.
Sometimes I can't see what's in front of my face. I think i got side tracked. Oxtools, Robin Renzetti and Joe Pi all made a version of this. They were adjustable so I assumed I could pull it off.
I'm also thinking the delrin is expanding at the chuck jaw position, therefore cutting deeper at those points.
I have a plan now. Thanks guys.


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## mickri (Aug 18, 2020)

Why couldn't you face off the face of the chuck to be perpendicular to the spindle and then use 123 blocks or something similar to position the work.  I have not faced off any of my chucks but often place something against the face of the chuck to square the work to the chuck.  Thinking off of the top of my head (or maybe the bottom) we all have multiple 3 and 4 jaw chucks.  For a given chuck you can only spread out the jaws so far.  Dedicate a chuck to be used with standoffs, make a stepped standoff to conform to the steps in jaws and leave it permanently mounted on the chuck.  I can think of multiple variations of this.  One thing with removable standoffs is that you have to keep them protected when not in use to keep them from getting dinged up.  You can't just throw them in a drawer and hope for the best.


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## Janderso (Aug 18, 2020)

I have seen holes drilled in chucks for various accessories. There seems to be more than one way to skin this cat.
The old parallel system works too but I have to dig them out of the chip pan.


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## C-Bag (Aug 18, 2020)

Janderso said:


> I have several different length screws but yes, this is the best idea. I will acquire or fabricate a series of standoffs that are identical. No need to adjust.
> Sometimes I can't see what's in front of my face. I think i got side tracked. Oxtools, Robin Renzetti and Joe Pi all made a version of this. They were adjustable so I assumed I could pull it off.
> I'm also thinking the delrin is expanding at the chuck jaw position, therefore cutting deeper at those points.
> I have a plan now. Thanks guys.


I can totally relate to the complication blinders. I see something my hero’s do and get stuck on that track. I’ve only needed standoffs a couple of times got through by using parallels then pulled them out after it was clamped in the jaws. Yeah, not perfect but it was within .001. I would be all over adjustable standoffs if I had the slots for them because no matter what it seems I don’t have exactly what I need. Joe Pie’s method you just face it to what you need. And facing it every time means it’s as accurate as it can be. Brilliant.


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## Janderso (Aug 18, 2020)

C-Bag said:


> Joe Pie’s method you just face it to what you need. And facing it every time means it’s as accurate as it can be. Brilliant.


He is an amazing machinist. Smart as a whip!
I always look forward to his new videos. Most of them are way over my head


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## C-Bag (Aug 18, 2020)

Janderso said:


> He is an amazing machinist. Smart as a whip!
> I always look forward to his new videos. Most of them are way over my head


Agreed. For whatever reason his explanations don’t intimidate me like Tom or Robin. I can’t think of a simple time saving thing I’ve ever gotten from Tom or Robin, not to say they aren’t brilliant and an incredible inspiration. But Joe is all about “get ‘er done” and his explanations are that way too.


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## talvare (Aug 18, 2020)

Joe Pi's stand-offs are a nice simple solution as long as the part you are machining is a large enough diameter to sit against the stand-offs. If not, you will have to resort to something else like maybe parallels.

Ted


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## Grinderman (Aug 19, 2020)

I use something similar for smaller parts. I took a MT3 drill chuck arbor and machined the chuck end off. Inserted into the spindle and held with a drawbar you can use a bolt/ nut for really small stuff or bolt on the aluminum standoff and machine to length/diameter.


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## ACHiPo (Aug 19, 2020)

Janderso said:


> I have several different length screws but yes, this is the best idea. I will acquire or fabricate a series of standoffs that are identical. No need to adjust.
> Sometimes I can't see what's in front of my face. I think i got side tracked. Oxtools, Robin Renzetti and Joe Pi all made a version of this. They were adjustable so I assumed I could pull it off.
> I'm also thinking the delrin is expanding at the chuck jaw position, therefore cutting deeper at those points.
> I have a plan now. Thanks guys.


Joe Pie also recently had a video about getting "stuck" in your approach--it's easy to start, then things get harder and harder, when maybe you should stop and restart in a different direction.  It was a good critique of BlondiHacks' challenges boring the casting for her steam engine model.  Not directly related to your issue, Jeff, but I found it pretty insightful.






Learning is what I love so much about this hobby!


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## davidpbest (Aug 20, 2020)

ACHiPo said:


> Joe Pie also recently had a video  . . . . .   It was a good critique of BlondiHacks' challenges boring the casting for her steam engine model.


I respect and have learned a lot from Joe Pie, but I regarded his "critique" of as an unnecessary misogynistic mansplaining outburst directed specifically at Quinn (BlondiHacks).


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## ACHiPo (Aug 20, 2020)

davidpbest said:


> I respect and have learned a lot from Joe Pie, but I regarded his "critique" of as an unnecessary misogynistic mansplaining outburst directed specifically at Quinn (BlondiHacks).


David,
I struggled a bit with that as well, but I also think he was adding to the collective knowledge base.  I’m not sure of YouTube etiquette.  I certainly learned a lot.  I hope Quinn is ok with it as well as I think she does a great job from the advanced student perspective.


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## Janderso (Aug 20, 2020)

This is getting interesting.
I'll have to check out both videos. I have learned from both machinists, they have different styles.
I think Quinn is an outstanding teacher. She seems to cater more to the inexperienced audience. IMHO


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## ACHiPo (Aug 20, 2020)

Janderso said:


> She seems to cater more to the inexperienced audience. IMHO


Jeff,
I agree and it's one of the reasons I like watching her.  She brings the audience along on her journey, foibles and all.
Evan


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## ErichKeane (Aug 20, 2020)

ACHiPo said:


> Jeff,
> I agree and it's one of the reasons I like watching her.  She brings the audience along on her journey, foibles and all.
> Evan



Yep!  I love Quinn's videos!  She's definitely not a pro machinist, but she 'takes you along' as she learns, which to me is much more effective.  I could never get into JoePi's videos, too much blathering on in front of a whiteboard rather than showing /explaining as he went (A number of Youtube machinists have this problem!).


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## ttabbal (Aug 20, 2020)

I didn't see his video as being rude/sexist. He's done the same type of "response" videos with Adam Savage and a couple others I believe. He's just showing another way to do it that might be faster, safer, more accurate, etc.. He even started the video with a note that there are lots of ways to do any particular job and what matters is that you get there in the end. As a hobbyist, I appreciate seeing different ways to do the same job. It gives me ideas for how I might make a part.


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## ACHiPo (Aug 20, 2020)

ttabbal said:


> I didn't see his video as being rude/sexist. He's done the same type of "response" videos with Adam Savage and a couple others I believe. He's just showing another way to do it that might be faster, safer, more accurate, etc.. He even started the video with a note that there are lots of ways to do any particular job and what matters is that you get there in the end. As a hobbyist, I appreciate seeing different ways to do the same job. It gives me ideas for how I might make a part.


I was just going to mention the Adam Savage "critique" video.  I learned a lot from that one, too.


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