Date
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Spindle to collet adapter run out.
Steven Karvelis
I had started a project awhile ago that got put on hold for a bit. Returning to this project today I noticed that the workpiece held in a step collet had run out that I could see. I tried resetting the workpiece but it was to no avail. So I put an indicator on the workpiece and found that there was 0.0035 T.I.R. at the face of the step collet and the part. What's going on? I broke everything down re-cleaned and inspected all the mating surfaces i.e. spindle bore and collet adapter O.D. put it all back together and the same thing. Went back and checked the spindle for run out < 0.0003 T.I.R. I'm thinking to myself what is going on here? There is roughly 10X the amount of run out between the spindle bore and the angled bore of the collet adapter. This also holds true for the O.D. at the nose of the spindle / collet adapter. Can anybody tell me what I missed? I can't see or feel anything that would cause this loss of concentricity. Could I grind the 12 degree taper in the nose of the adapter into concentricity as this is only a few thousandths per side? Any and all input would be greatly appreciated
Sincerely,
Steve K.
Certainly sounds as though the collet is the faulty part. I would mark the position of the high point, and try the collet in the spindle at different angles to confirm that the high point is always the same poosition on the collet.
If the collet is not absolutely hard, you could bore the working face of the collet rather than regrinding the taper. Clamp something in one of the other steps while boring so that the collet is in the working position.
BUT before you start, check for snigs, burrs etc!
Eddie
From: "steven_karvelis@... [SOUTHBENDLATHE]"
To: SOUTHBENDLATHE@...
Sent: Tuesday, 13 February 2018, 5:40
Subject: [SOUTHBENDLATHE] Spindle to collet adapter run out.
I had started a project awhile ago that got put on hold for a bit. Returning to this project today I noticed that the workpiece held in a step collet had run out that I could see. I tried resetting the workpiece but it was to no avail. So I put an indicator on the workpiece and found that there was 0.0035 T.I.R. at the face of the step collet and the part. What's going on? I broke everything down re-cleaned and inspected all the mating surfaces i.e. spindle bore and collet adapter O.D. put it all back together and the same thing. Went back and checked the spindle for run out < 0.0003 T.I.R. I'm thinking to myself what is going on here? There is roughly 10X the amount of run out between the spindle bore and the angled bore of the collet adapter. This also holds true for the O.D. at the nose of the spindle / collet adapter. Can anybody tell me what I missed? I can't see or feel anything that would cause this loss of concentricity. Could I grind the 12 d
egree taper in the nose of the adapter into concentricity as this is only a few thousandths per side? Any and all input would be greatly appreciated
Sincerely,
Steve K.
Michael Camire
Steve, any chance of getting your hands on a different collet. If not perhaps try a different size with a different piece of stock to mount. This should eliminate the question of a collet problem. Mike
On Tuesday, February 13, 2018 03:44:52 AM, Edward Draper eddie.draper@... [SOUTHBENDLATHE] <SOUTHBENDLATHE@...> wrote:
Certainly sounds as though the collet is the faulty part. I would mark the position of the high point, and try the collet in the spindle at different angles to confirm that the high point is always the same poosition on the collet.
If the collet is not absolutely hard, you could bore the working face of the collet rather than regrinding the taper. Clamp something in one of the other steps while boring so that the collet is in the working position.
BUT before you start, check for snigs, burrs etc!
Eddie
From: "steven_karvelis@... [SOUTHBENDLATHE]" To: SOUTHBENDLATHE@...
Sent: Tuesday, 13 February 2018, 5:40
Subject: [SOUTHBENDLATHE] Spindle to collet adapter run out.
I had started a project awhile ago that got put on hold for a bit. Returning to this project today I noticed that the workpiece held in a step collet had run out that I could see. I tried resetting the workpiece but it was to no avail. So I put an indicator on the workpiece and found that there was 0.0035 T.I.R. at the face of the step collet and the part. What's going on? I broke everything down re-cleaned and inspected all the mating surfaces i.e. spindle bore and collet adapter O.D. put it all back together and the same thing. Went back and checked the spindle for run out < 0.0003 T.I.R. I'm thinking to myself what is going on here? There is roughly 10X the amount of run out between the spindle bore and the angled bore of the collet adapter. This also holds true for the O.D. at the nose of the spindle / collet adapter. Can anybody tell me what I missed? I can't see or feel anything that would cause this loss of concentricity. Could I grind the 12 d
egree taper in the nose of the adapter into concentricity as this is only a few thousandths per side? Any and all input would be greatly appreciated
Sincerely,
Steve K.
Lapping doesn't correct alignment. It only provides a finish and possibly some profile correction on the existing alignment.
Eddie
From: "armne@... [SOUTHBENDLATHE]"
To: SOUTHBENDLATHE@...
Sent: Tuesday, 13 February 2018, 19:54
Subject: Re: [SOUTHBENDLATHE] Spindle to collet adapter run out.
I would run a lap threw it !
Alec
Nick Jonkman
This may sound silly but most collet holders have a small key and
collets have a key way at least all the ones I have do. If they
are not engaged your collet will wobble. Was this checked?
Nick
On 18-02-13 1:43 PM, Michael Camire
nh_sawyer@... [SOUTHBENDLATHE] wrote:
Steve, any chance of getting your hands on a different collet. If not perhaps try a different size with a different piece of stock to mount. This should eliminate the question of a collet problem. Mike
On Tuesday, February 13, 2018 03:44:52 AM, Edward Draper eddie.draper@... [SOUTHBENDLATHE] wrote:
Certainly sounds as though the collet is the faulty part. I would mark the position of the high point, and try the collet in the spindle at different angles to confirm that the high point is always the same poosition on the collet.
If the collet is not absolutely hard, you could bore the working face of the collet rather than regrinding the taper. Clamp something in one of the other steps while boring so that the collet is in the working position.
BUT before you start, check for snigs, burrs etc!
Eddie
From: "steven_karvelis@... [SOUTHBENDLATHE]"
To: SOUTHBENDLATHE@...
Sent: Tuesday, 13 February 2018, 5:40
Subject: [SOUTHBENDLATHE] Spindle to collet adapter run out.
I had started a project awhile ago that got put on hold for a bit. Returning to this project today I noticed that the workpiece held in a step collet had run out that I could see. I tried resetting the workpiece but it was to no avail. So I put an indicator on the workpiece and found that there was 0.0035 T.I.R. at the face of the step collet and the part. What's going on? I broke everything down re-cleaned and inspected all the mating surfaces i.e. spindle bore and collet adapter O.D. put it all back together and the same thing. Went back and checked the spindle for run out < 0.0003 T.I.R. I'm thinking to myself what is going on here? There is roughly 10X the amount of run out between the spindle bore and the angled bore of the collet adapter. This also holds true for the O.D. at the nose of the spindle / collet adapter. Can anybody tell me what I missed? I can't see or feel anything that would cause this loss of concentricity. Could I grind the 12 d egree taper in the nose of the adapter into concentricity as this is only a few thousandths per side? Any and all input would be greatly appreciated
Sincerely,
Steve K.
Boris Gaspar
I'm not super experienced but I also have 5C collets in my lathe and the spindle and adaptor are perfect which I believe you alluded to in you post was the same for you. So by logic, the collet or the stock isn't round or have some non concentricity.
Don't grind your adaptor try other collets perhaps different brands.