R8 Collets at Enco

[rake60]

For anyone who owns a Harbor Freight or Cummins Mini Mill,
or any mill with a R8 taper in the spindle for that matter.
Enco has a 6 piece set of R8 collets, sizes 1/8" to 3/4" by 1/8"s
on sale for $20.95 until December. They have the standard 7/16-20
draw bar thread. Enco Sale Item
It's actually not marked down much from it's standard price, but it
caught my eye in a sale catalog that was looking on my lunch breaks today.

Rick

 

[DICKEYBIRD]

Hi Rick, et al

I bought a 23 piece R-8 set from LMS for $79.95 back when I bought my X-3 simply because the per collet price ($3.50) was so good. It's 1/16" through 3/4" by 32nds. Oddly, the one shown now starts at 1/8" but I think that's a typo. 1/8" through 3/4" by 32nds would only be 21. http://www.littlemachineshop.com/products/product_view.php?ProductID=2872&category= The set I have is very nicely finished, accurate and after almost a year of hard use show little, if any wear.

At the time, I didn't think I would use more than just a few but man, was I wrong! The thing I never use now is the drill chuck that came with the mill. I chuck all my drills, reamers & edgefinders in collets and the difference in rigidity and accuracy is (to me) worth the trouble of changing collets all the time.

 

[wareagle]

DICKEYBIRD, I have to agree about the accuracy of drilled holes using collets instead of chucks. I have found that it really depends on what I am doing as to which method I drill a given hole. For brackets and such, the drill chuck gets the go, but for a precision hole, I have much better success with using a collet.

I, too, have a "Cheap" set of collets for my mill, and have found them to be very accurate. I origionally bought them to get started, but haven't seen the need to upgrade them.

 

[Lew Hartswick]

question for dickeybird.
Do you use number drills in the 1/32 collets? It seems that some of them
would be further off than recomended variation for a collet. I've heard
only + or- a few thousanths.
...lew...

 

[rake60]

Lew the collets in our machines at the plant are all metric.
We use them for SAE size tools all the time. If the drill bit, end mill,
reamer or other tool will slide in, and the collet doesn't bottom out on the
cuts when it's closed to tightly hold the tool it will center and securely
hold the tool. It DOES have to be close!
I would hope common sense would kick in when setting up a tool in
an off size collet application.
It would be great to have the perfect collet for every applications tool size.
In real life there are times that it isn’t practical to buy a collet for a size that
you may never use again when you have one in the holder that is .015” larger
that will do the job.

Experiment a little yourself. Try a collet that is .015 oversize and check the
tool for security and run out. Then try one that is .030 oversize the same way.
Try it with an end mill taking a shallow cut across soft metal and measure the
width of the “keyway” that it cuts. The oversize will be double the
actual running run out of the tool. I think the results will surprise you.

Rick

 

[Cedge]

Great price on the collets!!. It's almost a shame that I'm tooled up with MT2 and MT3 stuff here...LOL One thing for sure... I've learned collets are definitely the way to go on the mini mill. Much more control over the way the tool cuts.

Steve

 

[DICKEYBIRD]

Hi Lew,

I use collets for number drills as well. Some are a little more undersize than I'd like but all the sizes (tap drill sizes) I have chucked so far have clamped up tight with no damage to the collets or bits from slipping.

I just check the decimal size of the bit against a fractional chart and pick the closest one. To make sure I haven't picked up the wrong one, I slide the bit in the collet and squeeze it by hand to make sure it grabs OK. Crude, yes, but so far it works fine for me.

 

[Lew Hartswick]

Thanks. We only have 1/8 " sets at school for the students (that covers all
the cutters ) and a few 1/16 " ones for special uses. (bummer)
I guess I'll have to keep an eye out for some of the smaller increment ones
for personal use. I have used 1/4" one and it sure is nice to not have to
crank the knee way down to get the chuck in.
...lew...

 

[rake60]

The CNC machine I run every day for a paycheck has three ER-32 collet
holders in it. When placing tools in the tool changer, I use those ER-32's
first, for both drill bits and end mills. They will grip a drill bit better than
any chuck ever could. They will also hold an end-mill dead nuts on center.
I have never had one suck out.

I just might go that route myself for my mini mill.

Thanks for the wake up call Phil! :wink:

Rick

 

[rake60]

I took a chance on an eBay auction.

I bought an ER 32 chuck with an R8 shank for the mini mill.
It comes with an 18 piece set ER 32 collets from 1/8" to 3/4"
It will be a few days before I receive it. I won't know until then
if I got a deal or a beating. LOL

This is the sellers photo. It shows a Morse shank, not the R8 shank.

I have never from this vendor before, so we will find out just how they
perform.

Rick

 

[cfellows]

I took a chance on an eBay auction.

Please do report back on the quality. I see the vendor has more sets available on eBay.

Chuck

 

[rake60]

I will do that Chuck

It is my understanding that this vendor is not a quick shipper.
Given their sales volume that is understandable.

Rick

 

[Philjoe5]

Rick,
I'm also interested in the quality of the ER collet set you bought. From the picture you sent it looks like the collet chuck has two flats on it for holding a wrench to counter the force used to tighten the collar nut. That's important to Grizzly X3 mill owners because when the ER collet chuck they sell is installed you can't get the spindle lock wrench into position. I found an oil filter strap wrench wrapped aroundthe mill spindle works OK but it's awkward to use.

 

[DICKEYBIRD]

Hi Phil,

A 23 mm 12 point wrench or socket fits the splines at the top of the spindle perfectly. It took me about 30 sec. to grow weary of the little pin spanner that comes with the X3.

 

[cfellows]

I see the same vendor has a set of er-40 collets starting at $99. I like the extra capacity afforded by this size. Anybody see any potential issues with er-40 compared to er-32?

Chuck

 

[rake60]

I received the collet set today from eBay seller 800Watt It was 10 days, but coming from the opposite coast, that was not unreasonable. Exactly as described by the seller.

I didn't like the look of that single hook spanner wrench so after winning the auction I also bought a proper ER 32 collet chuck wrench.

I was impressed with what I got for an $80 bid. The spindle of my mini-mill runs out .0005" With a 2" long piece of 3/8" drill rod chucked in the collet I measure .0007" run out on 1" below the chuck. I do believe I can live with that. Another positive is the collet chuck is .900" shorter than the drill chuck I had been using.

I'm happy with the whole deal!!!

Rick

 

[cfellows]

Thanks, Rick, good information. I'm actually contemplating the er40 set that the same guy sells...

Chuck

 

[tattoomike68]

Nice deal!

Now you need a nice neat rack to hold the collets and label them for size.

I worked in a shop where there was a huge rack with every size you could get, it was ridiculous. I had to label the top rows of the common ones and left the weird ones to gather dust. I think the maintenance machinist before me had a collet fetish.