ER40 vs. 5C collets accuracy in a lathe?

[Bob Korves]

(SNIP)5 While 5C can be held in the spindle taper, to use either collets with through bar, you need some sort of collet chuck.(SNIP)

Not true, Ron. A 5C to Morse taper adapter (to match spindle internal taper) and a hand wheel or lever type collet closer will take work up to 1" through the collet and through the spindle, if the spindle has a big enough bore (1-3/8" or more typically.)

 

[ronboult]

Thanks for the correction Bob
My limited observations(I have never used a 5C collet) was that a 5C collet changer mounted on the outside of the spindle and used a rotary motion using the collet external thread to close the collet. I wasnt aware of the tubular draw bar option.
I still think that for hobby use the ER system is more versatile and cheaper. Given the price and number of 5C collets it could become very expensive. We wouldnt want to buy anything less than Hardinge
Cheers
Ron

 

[darkzero]

I loved getting to use a lever type collet closer. I don't think there's anything quicker that will release & reengage a piece of stock, well that I'm aware of anyway (CNC machining centers don't count). It's great for production/repeatative work. What's also cool is if you're careful & know what your doing, you can even swap a piece out without even having to turn the spindle off.

 

[ronboult]

Cool definately ! Usefull in home shop Maybe.
My current project involves making 1/2 doz identical short pieces made from 30mm bar. A lever action collet closer would save time but in the overall scheme maybe less that 1-2% of the actual time spent machining all the seperate operations.
Normally my jobs are one off and I am more than likely to change the stock and the holding method between jobs. A collet closer would add virtually nothing to my workshop.
On the other hand good manual collets are great because of the ability to quickly remount without significant runout. I dont yet have a set true 6 jaw A external mount ER50 collet chuck that allows through stock is the most economical solution.
Ron

 

[mikey]

A external mount ER50 collet chuck that allows through stock is the most economical solution.
Ron

Hey Ron, do you have an ER-50 system? If not, have you looked at the prices for the collets? I have an ER-40 chuck and would own an ER-50 if they made a direct mount (I don't want it badly enough to cobble one up) and just buy the ER-50 collets over 1", but they don't. Actually, the most economical solution is a 3 or 4 jaw chuck because truth be told, a hobby guy really doesn't NEED a collet system. My 3 jaw chuck isn't as fast as a 5c collet lever closer but its close enough.

 

[darkzero]

I dont yet have a set true 6 jaw A external mount ER50 collet chuck that allows through stock is the most economical solution.

If you get a 6-jaw Set-Tru, the only reason to get a collet setup is if you don't want to bust your knuckles doing hand work close to the chuck. My Bison 6-jaw"s accuracy is more than I can ask for. I rarely even use my ER4o chuck. I use the 6-jaw most of the time.

I see a lot of people mentioning ER50 lately & personally I don't see why. ER50 are very uncommon. Sure they'll give you 1/4" more capacity over ER40 at 1.25" but keep in mind they only go down to 1/2" & most places only only carry them in the "common" sizes. TG150 is so much more common. Just search on ebay, barely anything found for ER50 used but you'll see a good selection of TG150 collets. Not important I guess if you're buying new but ER50 ain't cheap!

TG150 goes up to 1.5" and the way the collets close are similar to ER. But they too will only go down to 1/2" but they are available in a all sizes in between "common". TG150 are also designed for workholding, you won't see any TG150 collet chucks in R8 or Morse Taper so you'll have to make your own chuck for the lathe.

Before & I'm sure I've said somewhere else that if I could start over & if I wasn't using ER40 for my mill that I would go TG150. Well I take that back now, I'll stick with ER40. I did not realize TG150 also did not go smaller than 1/2". That would be a deal breaker for me not being able to go smaller than 1/2". But then again I could always just stick my ER16 straight collet chuck in a 1" TG150 collet, like this:

 

[ronboult]

Mike
No I dont have an ER50 external mount chuck. It was next on my list. Just ordered a ES 12B readout to upgrade my lathe DRO?
I just searched for an ER 50 chuck without success. Didnt realise they were hard to get. Might have to settle for a ER40.

Will
Thanks for the heads up on the TG150 collets. Will have to do some research. I was not aware they existed -learn something new everyday.
PS ER50 collets are available down to at least 6mm and I am sure I have seen down to 1mm advertised somewhere.

The OP might like to check out the TG 150's also.

Will I assume that the ER40'chuck you show above has an D1-4 backplate. Since you have TWO lovely Bison 6 jaws the ER is clearly no use to you. Just post it over to me - I would be glad to pay the shipping
Ron

 

[darkzero]

Will
Thanks for the heads up on the TG150 collets. Will have to do some research. I was not aware they existed -learn something new everyday.
PS ER50 collets are available down to at least 6mm and I am sure I have seen down to 1mm advertised somewhere.

Will I assume that the ER40'chuck you show above has an D1-4 backplate. Since you have TWO lovely Bison 6 jaws the ER is clearly no use to you. Just post it over to me - I would be glad to pay the shipping

Ah I see, don't know that. I only just checked Techniks website & didn't bother to look at Maritool & the other affordable quality brands. Thanks for clarifying.

I think I mentioned earlier in this thread though, with the large size collets, holding on the smaller diameters can give you problems with slippage. Although you probably won't be taking heavy cuts with a small end mill you really have to crank down on the nut to get them secure. So with ER50 it may be even worse. 3/8" dia is my prefered cutoff for the ER40, then I go down to ER16. And for clearance, ER40 holding a small litte endmill is awkward. But that's for tool holding.

Yes my ER40 is D1-4, it's not the integrated plate, I machined a backplate to fit & made it a "tap-tru" so I can adjust runout if/when needed. But sorry, not letting it go. That's one of 2 ER40 plates that I got from Jeff at tools4cheap which is no longer around.

Oh and my old avatar that showed the 2 Bison 6-jaws. One is a 6.3" that I have now, the other was a 5" that I had on my mini lathe. The 5" chuck is gone, I sold it when I gave the minilathe to my brother. I just had to a get a group pic of it. Well now that I'm back spending too much time again here, maybe I should throw my avatar back up.

 

[bss1]

Regardless of what collet system you choose, make sure you get a set of collet blocks to use in your mill vise. MKSJ recommended that to me when I got my 5 C set and it opened up an entire secondary use for the collets that I didn't have before.

 

[Alan H.]

Thanks for all the feedback.

Here's some of what I have learned with your help:

1. 5C is for work holding

2. ER's are for tool holding

3. Many have applied ER’s in work holding as well

4. Get a good chuck for 5C

5. Lathe chucks for ER are hard to come by

6. Get decent holders for ERs – mill and lathe application

7. Nice to have ER holding capability for the tailstock of the lathe for tools

8. 5C is narrow in clamping range for an individual collet

9. Buy a complete set of 5C collets up front and get it over with

10. ER's come in multiple ranges

11. May need fewer ER collets due to their flexibility in clamping range

12. Buy decent quality collets

13. Get collet blocks for use in the mill

14. Both 5C and ER are accurate - depending if you apply them as intended and you buy good quality hardware

15. Figure out how to store all these freaking collets

I have once again confirmed what I knew already – “A little here and a little there and soon you have spent some real money.” One of my buddies here called it right via a pm, buy it all!

Thanks for all the help, this forum is a great community.