R8 chuck problem

[richard 2Participant @richard2]

Hi everyone – trouble again!

I have a Warco Vario VMC mill with an R8 spindle.

Several times I have had to really tighten the ER32 collet chuck to hold a mill.

How do I hold the chuck body to unscrew the cap?

There is no spindle lock on this mill and I would like to know if anyone else has this problem and how they solved it.

Has anyone made a spindle lock for this mill?

Many thanks for any help.

Richard 2.

[richard 2Participant @richard2]

[TSHParticipant @tsh73987]

Hi Richard,

I have a Chester Super Lux with an R8 spindle. The ER32 collet chuck (sourced from Hong Kong) has a pair of flats on it. An old 13/16" W spanner fits nicely. I think I would have trouble tightening the chuck without this.

Regards,

Trevor

[Mark P.Participant @markp]

Hi Richard, I hold the front pulley on my VMC to tighten my er chuck.
Mark P.

[VicParticipant @vic]

My ER32 chuck has four flats on it for a spanner, can’t remember the size off hand but it’s quite large. I bought one of those black DIN spanner’s from eBay to fit it quite cheaply.

[John HaineParticipant @johnhaine32865]

Ball bearing ER closer should help.

[Jon GibbsParticipant @jongibbs59756]

+1 for bearing nut closer & +1 for holding the top pulley/belt

but if it's still tight I sometimes use the draw-bar soft hammer to tap the end of the spanner to slacken off the collet nut. This technique is needed more often for my Clarkson and Posilock chucks with plain closers.

The inertia and belt gearing effect usually provides enough resistance to work.

HTH

Jon

Edited By Jon Gibbs on 11/01/2018 09:39:21

[VicParticipant @vic]

Posted by John Haine on 11/01/2018 09:01:56:

Ball bearing ER closer should help.

Yes, I’ve got those on two of my chucks. In some circumstances hand pressure alone is enough to hold the work.

[WindyParticipant @windy30762]

I bought a new Warco VMC supplied with an ER32 collet chuck with no spanner flats on the chuck.

Using a carbide end mill (a good deal from Ebay) machined some flats on the chuck.

Its tough steel so an HSS cutter probably wont cut.

Accuracy is the same as before cutting the flats. .

[michael mParticipant @michaelm]

Hi Richard

I experienced the same problem with my ER chuck and some two years ago became sufficiently exasperated to resolve the problem. I machined a steel ring to be a push fit on the chuck body and then prior to fitting machined two C-spanner slots into the ring. Having lightly abraded the chuck body at the place where the ring was to fit I loctited it in. It's been fine ever since, but with the wisdom of experience if I were to do it again I would incorporate three C-spanner slots for greater utility in use.

Regards

Michael

[michael mParticipant @michaelm]

Sorry Richard, forgot to post picture but it's in my album ER Chuck.

Michael

[John HaineParticipant @johnhaine32865]

Possibly unpopular, but you could always use R8 collets in your R8 spindle, as it was designed for….

[David Standing 1Participant @davidstanding1]

Posted by John Haine on 11/01/2018 17:33:44:

Possibly unpopular, but you could always use R8 collets in your R8 spindle, as it was designed for….

Absolutely true, but as you will well know, ER collets will do things R8 won't, like cater for both imperial and metric shank cutters

[Malcolm HarwoodParticipant @malcolmharwood97364]

Hi Richard 2

read the following. Almost identical problem, not helped by the supplier!

http://modeleng.proboards.com/thread/11999/collet-tightening-wth-draw-system

Regards

Malcolm

Sorry about the PB edit of pics

Edited By Malcolm Harwood on 11/01/2018 18:59:11

[John HaineParticipant @johnhaine32865]

Posted by David Standing 1 on 11/01/2018 18:02:12:

Posted by John Haine on 11/01/2018 17:33:44:

Possibly unpopular, but you could always use R8 collets in your R8 spindle, as it was designed for….

Absolutely true, but as you will well know, ER collets will do things R8 won't, like cater for both imperial and metric shank cutters

Um… I've got both metric and imperial R8 collets? Yes, I know that ER cover a range, but actually you really need at least a few imperial ER collets to hold some of the imperial sizes properly. Anyway, one only uses a few cutter shank sizes – 6 / 8 / 10 / 12 mainly in my case though I have a few surplus imperial cutters.

[Tony RayParticipant @tonyray65007]

[David Standing 1Participant @davidstanding1]

Posted by John Haine on 11/01/2018 19:40:46:

Posted by David Standing 1 on 11/01/2018 18:02:12:

Posted by John Haine on 11/01/2018 17:33:44:

Possibly unpopular, but you could always use R8 collets in your R8 spindle, as it was designed for….

Absolutely true, but as you will well know, ER collets will do things R8 won't, like cater for both imperial and metric shank cutters

Um… I've got both metric and imperial R8 collets? Yes, I know that ER cover a range, but actually you really need at least a few imperial ER collets to hold some of the imperial sizes properly. Anyway, one only uses a few cutter shank sizes – 6 / 8 / 10 / 12 mainly in my case though I have a few surplus imperial cutters.

John

I've got both metric and imperial R8 collets too, as well as an ER40 set.

I perhaps didn't make my earlier post clear – I meant that to cover both metric and imperial cutter shanks in R8, you need both metric and imperial R8 collets, whereas in ER, as you say, one set will largely cover a range.

[Tony RayParticipant @tonyray65007]

Now the text. The tooth disc is attached to the top surface of the spindle drive pulley. The detent is sized to fit the teeth and in practise much shorter than drawn. The pivot is attached to the pulley cover as is the spring attachment point. The actuating arm projects through a horizontal slot milled in the side of the pulley cover. The spring retracts the detent so it self releases. You would have to play around with the pivot etc. until you find a solution where the detent locks and retracts smoothly. I built a similar system for my SX3 that locks on the toothed drive pulley it works a treat and was designed by an Aussie on the forum. I would use steel for the indexing disc.

[richard 2Participant @richard2]

Many thanks everyone for all your help.

Have found an R8 Er chuck with flats on the body so problem solved.

Richard 2.

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