MT3 Emergency or Soft Collet?

[Robo_Pi]

I would like to get some MT3 Emergency or Soft collets that I can drill holes into for special applications. I haven't been able to find any MT3 emergency collets. Anyone know where I could get one? Or perhaps it would be easier to make my own?

I just watched this video by Joe Pie. And I like the idea for making parts for small engines, like crankshafts, and cam eccentrics, etc. My lathe uses MT3 collets and won't accept 5C collect.

I can, however, use ER collets. which might actually be better since I can get these in larger sizes. Is there such a thing as an ER series emergency or soft collet that can be modified like in the above video?

I think it's a pretty cool idea and would be far faster for a small production run of parts than having to set up each part in a 4-jaw independently.

Actually I'm thinking that I could probably make my own ER custom collets if I have to. But I thought I'd post this question to see if anyone knows where to obtain MT3 or ER emergency or soft collets.

Thanks.

 

[darkzero]

I've never seen or heard of MT or ER emergency collets but then again I've never specifically looked.

FYI, most lathes don't normally accept 5C collets directly. They use a collet closer with nose adapter or a 5C collet chuck. Although I have seen people use just the nose adapter & make their own drawbar but if your spindle is MT3 it's not big enough.

If collets & emergency collets are something you will need to use often it may not be a bad idea to invest in a 5C collet chuck. MT collets aren't that common to use for workholding as other style collets but then again people use ER for for workholding as well.

 

[Robo_Pi]

I saw this 4-part series on building an ER 40 collet chuck for a lathe. I thought it was pretty interesting.

It's amazing what these machinist YouTubers come up with. Great ideas.

I also see that there are larger ER-50 collets too. So I've been thinking about building an ER-50 collet chuck for my lathe. I figure that way I would have more capacity for larger parts.

I'll probably just end up making my own ER-50 collets then. The only thing I would ultimately need to buy would be the ER-50 collet nut. Then just make my own custom soft collets. I see the hardened precise ground ER-50 collets are quite expensive.

 

[darkzero]

ER-50 collets aren't that common either so they're expensive. Last I checked China wasn't making them either. I use Techniks brand ER collets & ER-50 collets are twice the price of an ER-40 collet. I just went with ER-40 cause I use them for my mill too & cause ER-40 plates are availble to give you through hole.

I've seen people machine their own ER chucks but never heard anyone want to make their own ER collets before. Sounds like quite the project & very interesting. Please post/share with us when you.

Here's my ER-40 chuck the day I finished it. Sadly I never use it.

 

[Robo_Pi]

I've seen people machine their own ER chucks but never heard anyone want to make their own ER collets before. Sounds like quite the project & very interesting. Please post/share with us when you.

If I make them I'll definitely post the process. This isn't something I'll be doing anytime soon. I'm just toying with ideas right now. However, I do plan on making various production products that might use parts that could be made using the method Joe Pie showed in the video in the OP.

If I make my own ER collets they would be soft collets. I'd probably cut the tapers and ring groove first. Then actually put them in the ER chuck to mill out the special shape for my part. Finally cut the flex slots designed around the custom part I'd be holding.

There may be other ways that would be easier. For example, I also saw an idea of making "Custom Collets" that actually fit in a 3-jaw chuck. It's basically just a piece of round stock milled out to hole the custom part. Then slotted (I think only in 3 places) so that when it is placed in a 3-jaw chuck it closes on the custom workpiece. That method would save having to build the ER chuck itself. In that case all you need to make are the collets. And there's no tapers involved at all. It's actually a collet that is being closed by the 3-jaw chuck.

Let me see if I can find that video,...

Yep here it is,...

You can actually make the 3-jaw chuck collets deeper and turn the back end down a bit smaller. That way you can have 3 slots in the collet so it closes more evenly. Of course you'd most likely want to put it into a 4-jaw chuck to do any concentric shapes for the part you want to hold first. Then cut the closure slots for the 3-jaw chuck. This way you can just pop it in the 3-jaw anytime you want to use it and it should be pretty close to where you want it.

Using a full ER-50 collet chuck would probably provide a bit higher tolerance for repeatability, and might be a tad bit easier to use if you're doing a large quantity of production parts.

 

[darkzero]

I make collets out of delrin all the time to hold odd parts & knurled parts. They come in very handy. I'm lucky to have 2 Set-Tru chucks so they run pretty true, I rarely need to use the four jaw for holding these unless it's for something larger in dia.

 

[Robo_Pi]

That 6-jaw chuck looks like it would hold that collet with real nice even pressure too. Nice set up!

 

[mmcmdl]

Robo . Slow down and think out your jobs . Soft jaws are always an option . Do you own a lathe and if so what spindle mount is it ? There are people on here that will help you out .

 

[Robo_Pi]

Robo . Slow down and think out your jobs

Sorry. I didn't mean to give the impression I was in a rush to do anything.

Taking my time to think out the jobs is exactly what I am doing. I like to explore all the possibilities. I just watched the video by Joe Pie and thought that using a speciallized collet for a job like that does make a lot of sense. Especially if you plan on making a lot of the same part.

I'm just now tooling up an old Enco Lathe/Mill combo that I've had for some 20 years now. I haven't really used it lately. In fact, it was covered in rust due to the moisture it accumulated sitting in an unheated shop. Fortunately I caught it in time and it cleaned up really well.

Do you own a lathe and if so what spindle mount is it ?

The spindle mount really sucks, so be prepared for a long rant here.

Here's a photo of the naked spindle:

Not a real good picture, but maybe good enough to explain my rant.



I actually took the above photo as part of a project. I'm making a backing plate for a 4-jaw chuck. I have centers in everything because I'm actually getting the bolt pattern measurements transferred over to the new chuck backing plate. The chuck is held on by 3 M8 bols. I actually have a center punch in the tool holder I was using to get the bolt patter diameter. You can see there is a raised section in the middle of the spindle. That's the register for the chuck.

My big complaint here is that the original 3-jaw chuck was bolted on from the back side. The problem with this is that those bolts are extremely difficult to get at. There's barely any room to work between the spindle and the headstock. So it's a real pain to remove and replace the chuck. I'm currently in the process of changing this. Or at least I hope to. I'm going to drill three new holes in the spindle plate and thread them and bolt the chuck on from the chuck side. Making it much easier to remove and replace. I say that I hope to do this because I'm hoping that I can drill and tap this mounting plate. Hopefully it's not hardened. It doesn't appear to be. I cut into it with a file and it seemed to cut easily. So hopefully it will drill and tap easily too.

So I'm in the process of changing things up a bit. I like to remove the chuck when using the mill. And I also like to be able to swap back and forth between the 3-jaw and 4-jaw chucks. And I just recently bought a set of MT3 collets for it too which I would also like to use.

So I'm trying to modify this lathe and make it easier to change tooling on. The 3-jaw chuck that came with it is only 4". The new 4-jaw chuck I just bought is 6". So I'll have the larger chuck capacity too.

As far as using soft jaws I don't know what I would need to do to be able to do that. Both the chucks I have are equipped with hardened jaws and I have no idea where I would obtain soft jaws for them. Both chucks to have reversible jaws though. Well, the 3-jaw chuck actually has two sets of jaws. Both sets are hardened. I change the jaws often. Changing jaws is easy. Far easier than changing out the entire chuck. At least with those bolts behind the chuck. Hopefully I'll be able to drill and tap the spindle so I can bolt the chucks on from the front. That would make life a whole lot easier.

In fact, it beats me why anyone would have designed this thing the way it is. It must have been designed by a sadist. They must have figured that no one would ever want to change out the chuck. But like I say, I even like to remove the chuck when I use the milling head. So I'm taking this chuck off all the time.

I'll be trying to drill out the spindle plate here shortly. We'll see how that goes. I hope it's not a disaster. If it's hardened I won't be able to drill and tap it. Then I'll be stuck with having to bolt everything on from behind for the rest of my life. That would suck big time.

 

[mmcmdl]

Wow ! Gotta make a quick trip , but I'll get back with you . Your objective is to have quick change tooling correct ?