By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by Allendale Nov 29

Er32 chuck for Fortis lathe

All Topics | Latest Posts

Search for:  in Thread Title in  
sean logie10/11/2018 17:12:24
avatar
584 forum posts
86 photos

Been a while since I've had time for my wee workshop ,so today I decided I would make the er32 chuck I've wanted for a while now ,so I used a chunk of stainless I had ,probably not ideal but it's what I had . It's not perfect but it's accurate where it matters . I put a tenths indicator on the inside of the collet taper and it barely moved which kinda surprised me a bit 😁 but I'll take it . The only negative is the cheapo collet set I bought have 0.002 run out ,I tested using three different sized carbide End mills in the collects. .

20181110_135622.jpg

20181110_135618.jpg

20181110_135552.jpg

20181110_135527.jpg

Martin Connelly11/11/2018 07:39:02
avatar
763 forum posts
75 photos

ER chucks were developed for holding tooling and for most cases the runout you have would be fine. Home workshop users have started to use them for workholding and this may then give unacceptable results. If you have a 4 jaw independent chuck you can get the runout required for what you are doing if it needs to be lower and as a compromise, if you want to also use your ER collets, you can mount a collet holder in a 4 jaw chuck. A square ER32 collet chuck may be your next piece of tooling to make or buy. They are also useful for holding round parts in a vice for milling so not limited to one infrequent use.

Martin C

sean logie11/11/2018 09:03:48
avatar
584 forum posts
86 photos
The run out I have in the er32 collet is good enough for what I do . It's true that you get what you pay for . I do have a four jaw independent. I wanted to make er32 chuck to use/have and also as an exorcise to see if I could make something that had to be accurate ,up till now I've just been mucking about . 😊 I have a square block er32 holder which is a very handy piece to have .

Sean
Emgee11/11/2018 10:39:18
956 forum posts
189 photos

Hi Sean

Have you modified the collet closing nut in some way as all of my ER collet nuts wrap around the front face of the collet which hinders working close to the collet face.

Does the nut still engage the slot in the collet to assist removal ?

Thanks, Emgee

Michael Gilligan11/11/2018 10:53:56
avatar
12283 forum posts
538 photos

Well-spotted, Emgee

Whatever that modification might be, it could be useful !!

MichaelG.

JasonB11/11/2018 11:04:39
avatar
Moderator
14309 forum posts
1380 photos

Or more likely the nut has just been tightened down a bit on the empty collet which makes it stick out.

Same 12mm collet one with a cutter the other tightened down a bit by hand with nothing in it

dsc03366.jpg

dsc03365.jpg

Edited By JasonB on 11/11/2018 11:04:59

Michael Gilligan11/11/2018 11:12:26
avatar
12283 forum posts
538 photos

crying 2

sean logie11/11/2018 13:28:58
avatar
584 forum posts
86 photos
Emgee I've not made any alterations to the nut ,the release of the collet works the same as the original. It pops out like it should 😉 . The collet is a beautiful fit .

Sean
ega11/11/2018 13:55:03
995 forum posts
85 photos

sean logie:

For 'tis a jolly good lathe!

Here is my shop-made version showing also a GHT-inspired dividing attachment for use with milling and drilling spindle:

dscn1447.jpg

Not obvious in the photo but I have made the chuck body long enough to be able to work up close despite the gap.

sean logie11/11/2018 14:00:04
avatar
584 forum posts
86 photos
My old Fortis is a bit rough around the edges but it's accurate enough for me 😉

Sean
ega11/11/2018 14:28:01
995 forum posts
85 photos
Posted by sean logie on 11/11/2018 14:00:04:
My old Fortis is a bit rough around the edges but it's accurate enough for me 😉

Sean

Tony Griffiths gives them a good write-up as you are no doubt aware.

Clive Brown 111/11/2018 14:31:53
185 forum posts
5 photos

Don't necessarily put the run-out down to your "cheapo" collets. I made a similar ER25 chuck and at first had a few thou. run-out, similar for all my collets despite the taper running true. I thought that this might be due to making the screw-thread a wee bit too tight, so took off a shaving. Sure enough, the run-out reduced to less than a thou. at which I'm quite happy.

Clive

Edited By Clive Brown 1 on 11/11/2018 14:33:07

Russell Eberhardt11/11/2018 16:31:52
avatar
2371 forum posts
82 photos

I was thinking the same Clive. The nut should centre itself on the front of the collet, not on the thread.

Russell

sean logie11/11/2018 16:33:46
avatar
584 forum posts
86 photos
Food for thought gents .

Sean
ega11/11/2018 16:35:14
995 forum posts
85 photos
Posted by Clive Brown 1 on 11/11/2018 14:31:53:

Don't necessarily put the run-out down to your "cheapo" collets. I made a similar ER25 chuck and at first had a few thou. run-out, similar for all my collets despite the taper running true. I thought that this might be due to making the screw-thread a wee bit too tight, so took off a shaving. Sure enough, the run-out reduced to less than a thou. at which I'm quite happy.

Interesting point; my Quick Step Mill with ER20 spindle came with a rather loose collet nut. The designer/manufacturer may have had the same idea in mind.

Emgee11/11/2018 17:47:52
956 forum posts
189 photos

After checking further all Emco made ER25 collet chucks I use have the front of the nut extended to always be about 2mm in front of the collet face .
The other makes including Schaublin (RH front in pic) do allow almost flush facing if in the lathe.

emco f1 tooling.jpg

Emgee

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

Want the latest issue of Model Engineer or Model Engineers' Workshop? Use our magazine locator links to find your nearest stockist!

Find Model Engineer & Model Engineers' Workshop

Support Our Partners
Eccentric July 5 2018
méridienne Nov 18
Ausee.com.au
ChesterUK
Sarik
Warco
Shapiro
TRANSWAVE Converters
emcomachinetools
Eccentric Engineering
Allendale Electronics
Subscription Offer

Latest "For Sale" Ads
Latest "Wanted" Ads
Get In Touch!

Do you want to contact the Model Engineer and Model Engineers' Workshop team?

You can contact us by phone, mail or email about the magazines including becoming a contributor, submitting reader's letters or making queries about articles. You can also get in touch about this website, advertising or other general issues.

Click THIS LINK for full contact details.

For subscription issues please see THIS LINK.

Digital Back Issues

Social Media online

'Like' us on Facebook
Follow us on Facebook

Follow us on Twitter
 Twitter Logo

Pin us on Pinterest