R-8 Collet Set

[AR15DCM]

I found these at Grizzly... What do you all think of this set?

http://www.grizzly.com/products/T10067

[Inspector]

Is there a reason you are not using the R8 collets or is this in addition to them?

Pete

[mechanicalmagic]

I have a set like that. Rarely use it, since it is a R8 shank. Only used for holding tools, and moderate diameters get shoved away from the spindle bearings. I much prefer solid holders, more rigid, for about the same money you can setup several cutters, and leave them fixed in place.

Mechanicalmagic

[AR15DCM]

Is there a reason you are not using the R8 collets or is this in addition to them?

Pete

This is a R-8 Collet set.

[AR15DCM]

I have a set like that. Rarely use it, since it is a R8 shank. Only used for holding tools, and moderate diameters get shoved away from the spindle bearings. I much prefer solid holders, more rigid, for about the same money you can setup several cutters, and leave them fixed in place.

Mechanicalmagic

Wouldnt be easier if you are switching out the tooling to use this set to speed up the switch?

[Inspector]

Is there a reason you are not using the R8 collets or is this in addition to them?

Pete

This is a R-8 Collet set.

Actually Dean it is an R8 shank holder for ER collets.

R8 collets look like these.

http://www.shars.com/product_categories ... ollet_Sets

http://www.grizzly.com/products/12-pc-P ... -Set/G1646

They hold your tools directly in the arbour.

Pete

[AR15DCM]

Is there a reason you are not using the R8 collets or is this in addition to them?

Pete

This is a R-8 Collet set.

Actually Dean it is an R8 shank holder for ER collets.

R8 collets look like these.

http://www.shars.com/product_categories ... ollet_Sets

http://www.grizzly.com/products/12-pc-P ... -Set/G1646

They hold your tools directly in the arbour.

Pete

Okay correct me please if I am wrong... I understood this set to allow you to mount the R-8 collet holder in the spindle and then all you need to do to change tools is just loosen the R-8 collet holder in stead of having to loosen the spine and replace the R-8 shank tool holder each time... Correct?

There is some gunsmith tooling that only comes in certain sizes and when performing multiple operations I am thinking this would be easier???

[Inspector]

Okay correct me please if I am wrong... I understood this set to allow you to mount the R-8 collet holder in the spindle and then all you need to do to change tools is just loosen the R-8 collet holder in stead of having to loosen the spine and replace the R-8 shank tool holder each time... Correct?

There is some gunsmith tooling that only comes in certain sizes and when performing multiple operations I am thinking this would be easier???

The R8 collets grip the tools directly. The up side to them is that there is less hanging below the arbour so you have more working room below the tool and should be more concentric than the holder and collets (fewer tolerances for each part). If you just get the R8 collets you need for the cutters you use you will spend less and have more for other goodies you want. The ER holder might be the slightest bit faster to switch from tool to tool but if they are all 1/2" or 3/8" shank tools I doubt by much. The advantage of the ER holder being that you can hold up to 1" tool shanks but is your mill capable of driving 1" tools to full feeds and speeds that cutters that big can handle? If you can get some bigger tools from friends etc., then the ER holder is useful. The other advantage of the ER collets is that they have a slightly larger range of diameters they will grip. If you had 1/2" and 12mm shank tools then the one ER collet will work, whereas you might want both a 1/2" and 12mm R8 collets. Some gunsmiths would have better insight as to which is of more use.

Pete

[mechanicalmagic]

Okay correct me please if I am wrong... I understood this set to allow you to mount the R-8 collet holder in the spindle and then all you need to do to change tools is just loosen the R-8 collet holder in stead of having to loosen the spine and replace the R-8 shank tool holder each time... Correct?

There is some gunsmith tooling that only comes in certain sizes and when performing multiple operations I am thinking this would be easier???

Yes, that is the typical operation.
Where you lose time is resetting the cutting tool height, each time you load the tool in the quill. A bunch of solid holders can be replaced easily.
As to your need for an odd shank size holder, solid or collet R8's are typically available in common sizes.

[spro]

It is easier and it will work, we're not using toys. There is the combination of outset of many parts of the mill which would make this wander and be inaccurate. Nobody can say it is wrong. If you are using a collet in this head instead of an R-8 in the spindle, there is around 2-3" set over from the bearing support. A small endmill will wander and flex before the setup in some cases and not in others. That depends on the speed and lateral pressure applied to it. All this ties together. If someone has the quill extended pushing a large end mill, they will experience the same thing. The worst combination would be a large end mill in a large collet extended 3" beyond the freakin nominal support achieved by a collet inside the spindle.

[AR15DCM]

Here are the specs for my Mill.... Its a ZX25 from Bolton Hardware.

Max. Drilling capacity: 1.
Max. Face milling capacity: 2-1/2.
Max. End milling capacity: 4/5.
Head tilt: ±90° Spindle travel: 3-7/64 Max. Distance between spindle to table: 17-1/2.
Distance between spindle to column: 8.
Spindle taper: R8.
Spindle speed: 115,220, 320, 600, 1120, 1700 RPM.
T-solt: 3 @ 1 1/32" 5/8" wide.
Work travel of table: 5-1/2 x 11-3/8 Table size: 20-1/2~6- 3/10.

[arthur.marks]

A few clarifications and corrections. What is shown above is not an ER collet holder. The collets are visual equivalents of TG collets, but I've heard rumor that sets like these which don't specifically mention "TG" are not interchangeable with the standard. I can't confirm or deny this rumor, but it gives me pause. TG collets will only hold their marked diameter. ER collets have a collapsible range -- typically 1mm -- which allows them to grip continuous diameters between marked collet dimensions. Single angle collet types, TG being one, are suitable for gripping one diameter only. There is no range.

I own a Rong Fu 31, which is similar to your size machine from the spec's listed. In fact, yours is slightly smaller. It is my experience the realistic, comfortable and practical limit is 3/4" end mills with a mill of this size. Larger tools can be sometimes beneficial, of course, but not utilized to their full potential. The majority limiting factor is mass/rigidity moreso than power -- although I have encountered some of that issue when working with steel and larger cutters.