Thread: ER40 collets for 260 lathe?

This is a preliminary reply to "Localele" who sent me a PM on the subject.
Micheal, I will speak to you by phone in detail soon, however for your immediate consideration there are a few alternatives regarding collets for the Hercus 260
1 The use of a draw bar & collet insert of a no 4 morse taper into the headstock spindle to use 4c collets they have a capacity of 3/4 inch dia but are very hard to obtain
2 The use of a draw bar & collet inset to accept 3c collets into the headstock spindle. These collets are readily available through "Tools 4 Cheap" in the USA however the no 4 morse taper insert to accept the 3c collets are very expensive from Hercus Australia.
An alternative would be to get a no 3 morse taper insert to accept the 3c collet & fit it with a 4 to 3 morse taper reducer (modified) from "Tools 4 Cheap" in the USA.These adaptors are about $30 from them. The 3c collets have a range of 64th inch up to 1/2 inch dia.The draw bar is also available from them.
I have a full set of 3c collets & find them very handy & accurate.
3 The use of a special collet chuck to use 5c collets. These chucks are available from "The Little Machine shop" in the USA along with a set of 5c collets & have a range of 1/16 to 1 inch & a 16th" I think this would be my choice if I was going to set up this system again. All you would need is a backing plate machined accurately to size to accept the chuck. The threaded backing plate for the chuck is available from Hercus Australia but rather pricey. The alternativer is to machine your own in cast iron & cut the internal thread on the lathe. I did this & with care it can be done, but it easy to mess it up.
4 To pursue the ER Collets as you mentioned, however I have had no experience with these. I noticed "Pipeclay"on this forum has been making & providing these.
Trusting this will give you food for thought & I will arrange a time to speak with you, after you consider the above alternatives.
Best regards
Bruce

Hopefully "Pipeclay" will give us some info on his version.I don't want to re-invent the wheel if I can get out of it.
Will be good to have a chat on the phone Bruce.There is a lot to be learned from having bought a lathe finally.

An alternative would be a MT4 ER40 collet chuck. ER40 MT4 MK4 M16 SPRING COLLET CHUCK CNC MILLING LATHE TOOL & WORKHOLDING #A82 | eBay

Of course on top of that you still need to buy a set of ER40 collets.

I use an MT3 ER32 collet chuck on the smaller 9" Hercus and it's VERY accurate. I can turn a part, remove it and reverse it to turn the other end, then not even be able to see precisely where the junction was. The QC on these is traditional Chinese (ie zilch) so maybe I just got a good one. But most people seem happy enough with the accuracy of the collet chucks.

Pete

The disadvantage of using an MT style collet chuck is that you lose the ability to push longer items through the headstock.

For that reason I bought a backplate mounted ER chuck and once mounted and indexed properly it is as accurate as the MT3 chuck I used before.

I also have an ER chuck for my wood lathe that screws on to the spindle (M30x3.5) and it is also accurate but if one buys one of these and it isn't accurate there is no adjustment, unlike a backplate mounted one.

Of course on the metal lathe one could turn one of these spindle mounted chucks in situ on the lathe it is going to be used on and it should be very accurate.

Using the hollow spindle to its full size is the reason for not going with a morse taper collet.I would like to be able to feed lengths through and also hold longer lengths for deep hole drilling.
I have a set of ER40 collets that are under utilised on the milling machine so they can do both jobs.
I haven't found any back mounted ER40 chucks yet which is why I thought it may have to be made.

You can turn your own chuck. It isn't hard it just takes some time. I made the first ER40 collet chuck for a lathe about 6 years ago and everyone thought i was nuts for wanting it. I do use the bigger collets even though my spindle hole isn't as big as the biggest collet. I have lots of pics here in my Yahoo group if you want to join and have a look...Bob
southbend10k : SouthBendLathe10k and lathe projects.

Are you capable enough to turn the OD thread and bore 8 degrees?

Now that I see it has been done I am keen to have a go at it. I think the resulting chuck and accuracy will be well worth it.
Definitely open to all offers of help and or buying part turned components to then finish off in my lathe for the ultimate accuracy.

I can supply you a ID machined blank,threaded 1 3/4 x 8 could be either 4140 or 1045 not sure.

Sounds like a great way to get started on this job. I take it that you have been building a few of these to suit these 260 lathes?

Originally Posted by localele

Sounds like a great way to get started on this job. I take it that you have been building a few of these to suit these 260 lathes?

I think this would be a great method of holding small parts accurately.
Although I have not had experience with ER collets, I have read of many rave reviews about them.
This would be a logical solution to your problem.
This time of year includes a lot of running about everywhere, are you home during the day, if so I can give you a phone call Monday ?
regards
Bruce

Hi Bruce, I work at home and so you can ring anytime. Today if you wish.
I use a set of ER40 collets in my milling machine to hold cutters and have a few that have 1 inch shanks with 1 1/4 inch cutters and they are held with no problems so I think there is plenty of power and accuracy for small turning jobs.

I have made a few complete for the 260 and 9".
The 9" are not to much of a problem as I finish them on a 9".
The 260 gives me a problem with repeatability as I machine it on a spigot,it is much easier if they are finish machined on the lathe that they are to be used on.

Hi Pipeclay, I would like to take you up on the offer of a threaded blank and ordered a pair of nuts to suit. If you would like one of the nuts to build another with that is fine.I will only need the one.
Please give me a ring to discuss the timing and costs involved.Ph 6628 4385.