R 8 Spindle Drawbar Torque

[Jack772]

I just received my Grizzly mill/drill G0463. My question is how many ft. lbs of torque should apply to the spindle drawbar when tightening?
I will be using the drill chuck that came with it and end mill holders.

Also can grease/oil be applied to the tapered surfaces?
Thanks,
Jack

[seal killer]

Jack--

To install tooling in your G0463 . . .

1. Remove the drawbar cover.
2. Place the tooling in the proper R8 collet.
3. Slide the collet up into the spindle all the way; it will only go all the way if it lines up with the internal stud in the spindle that aligns the collet via the slot in the collet. It is vital that the internal stud and the collet slot DO line up!
4. Tighten the drawbar by hand until it is uncomfortable while holding the tooling with your other hand so it does not fall out of the spindle. (If that happens, not good! Not good at all!)
5. Place the 17mm wrench on the drawbar hex head at the top of the mill.
6. Hold the tooling with your hand and tighten the drawbar with the wrench until you cannot hold the tooling with your hand. If you are a little worried about how tight it is, use a wrag to hold the tooling.
7. Replace the drawbar cover.

To remove the tooling . . .
1. Remove the drawbar cover.
2. Place the 17mm wrench on the hex head of the drawbar.
3. Hold the tooling with your other hand, supporting it so that it does not fall out when you unscrew the drawbar.
4. Give a yank on the wrench. This should easily loosen the drawbar so that you can unscrew it by hand. HOLD THE TOOLING SO THAT IT DOES NOT FALL OUT OF THE SPINDLE!!!
5. Allow the weight of the tooling to drop it from the spindle while your hand is under it. (NOTHING should ever touch that table unless it is designed to touch the table!)
6. Replace the drawbar cap.

Mill and be happy!

--Bill

[steamin10]

Hey Seal. And Jack. Uh, that method doesn't work on my Rockwell. I have to give the wrench a whak with a rubber mallet to make sure that snug is, well... SNUG! I have had problems with 3/4 inch 4 fl cutters rising up in the R-8 while cutting. Got caught in this trap a coupla times. Removed finished part from the Vice or setup only to find movement caused a tapered cut, or the calculated stock removal to be off or uneven. R-8's just dont grip that strong, and the pin or key on my machine is long gone. It is the grip alone that stops the collet or tool from turning.

oh, and dont oil, never sieze or grease the R- taper. A small tap on the drawrod is all it takes to drop the tool out. If I think oil is a problem, I will lightly dust the taper with chalk dust, or talcum powder to give a little bite, and remove any influence oil may have. A short Bridgeport drawrod is the Ideal replacement for me, as the original broke on the second job. Losing the collet during a cut is interesting, but I can do without all the extra drama.

And yes, I make scrap that doesn't look like chips. Uh, just every now and then.

[seal killer]

Dave--

Thanks for the correction. It does work on my larger Grizzly. Although, I do pay extra attention to face mill tightness. And, I (usually) have to hit the top of the drawbar to loosen everything up, as well. But, I hit it with my open palm.

As far as grease and oil is concerned, I store all my cutters and collets in oil to prevent rust. THAT works well! <g> However, I then have to use something to thoroughly remove the oil when I use things. I have found that Birchwood-Casey Oil and Grease Remover works wonders. I just spray all surfaces. The literature says you do not need to wipe it down afterwards. However, I always wipe the exteriors of the collets.

Time-wise, my method is a killer. But, I only build one-offs and have plenty of time to clean. Still . . .

Thanks for the clarification, Dave.

--Bill
ps My oil bath storage technique is vast over-kill. But, nothing rusts, either. I am THINKING of replacing the plastic-drawer, oil-bath storage with a either a dehumidified wooden or metal structure. It would save a lot of time. <g>

[Bill Shields]

It's interesting that someone actually has an R8 that releases without having to smack the end of the drawbar with a lead mallet.

I even have a commercially made tool that is a drawbar wrench on one end, a lead hammer on the other..must have had it 30 years or so.

I cannot say that I have ever worked at a Bridgeport where I DIDN'T have to smack the drawbar to get a tool to release - even with oil on everything...but then I have only worked at Laguns, Bridgeports and Wells-Index machines, not on any of the variants you have mentioned. Perhaps it is a situation of tolerance in the spindle that makes this so?

As for R-8s not holding all that well for big cutters...absolutely true, only my experience is more on the lines of he end mill pulling OUT of the collet into the work rather than tools pushing into the collet, but I can easily see how that would happen with the approirate type of tool.

[seal killer]

Bill--

I am here to learn. (I am too old to have an ego.)

Please feel free to critique anything and everything I do and write. It is the cheapest and highest quality education I can get.

I am more than willing to accept the idea that my collets are not appropriately tapered. If this is a bad situation, it seems it could be cured by acquiring better collets. (Mine are all ChiCom. My entire toolset is converting to made in the USA. I never thought about the collets, however.)

Thank you.

--Bill

[millman5]

The drawbar that came with my BP Clone ENCO was soft & the threads promptly stretched then stripped.

I've been through all the R-8 tooling coming loose, end mills creeping in or out, etc.

I cut the hex head off a grade 5 bolt, pincil pointed the drawbar & the bolt, lined them up & TIG welded the GR5 bolt to the drawbar.

I do use a very very small amount of never-sieze on the drawbar threads.

To tighten I engage the back gear & use a short handle 3/8" drive rachet wrench & give several jerks (sort of an impact wrench affect). In other words tighten the crap out of it. Loosen them the same way. It always requires a tap on top of the drawbar after loosening 3-4 turns, then twist out by hand.

[seal killer]

millman5--

Weird, ain't it?

I tighten the drawbar with a wrench while holding the tooling with my other hand. If it is a big tool, I hold it with a rag so I can apply more torque with the wrench.

But, no matter what tooling is installed, all I have to do to remove it is to hold it with my hand and unscrew the drawbar. If the tooling does not fall out when I tap the top of the drawbar with my open palm, I lift the drawbar about an inch and a half and drop it. That never fails to nudge the tooling down into my waiting hand.

This is bothering me. If things SHOULD be tight, then something is fishy. I am going to buy a set of American made collets from 1/8" to 3/4". Do you have any brand recommendations?

Thanks.

--Bill

[mechanicalmagic]

My style for R-8, B'port clone.

Tighten the draw bar by hand, attach 12" long box end wrench.
Grab brake in left hand, pull, jerk wrench lightly.

Remove, grab brake, pull, attach wrench, unscrew 1/4 turn.
Whack top of draw bar with edge of wrench, releases R-8.
Unscrew by hand.

This is for solid tooling, I don't use collets often. Not a strong preference, but I like to repeat tool heights. And I don't like dropping cutters from a collet.

Dave

[Harold_V]

Remove, grab brake, pull, attach wrench, unscrew 1/4 turn.
Whack top of draw bar with edge of wrench, releases R-8.
Unscrew by hand.

Heh!

Kindred spirits we are, Dave. I've used that exact method since buying my first Bridgeport in '67. When you're trying to make a living, you don't often hunt down a soft hammer for the drawbar release--especially when changing tools regularly.

Harold

[mechanicalmagic]

Kindred spirits we are, Dave. I've used that exact method since buying my first Bridgeport in '67. When you're trying to make a living, you don't often hunt down a soft hammer for the drawbar release--especially when changing tools regularly.

Harold

Harold,
Thank you for the comment.
I value your opinion.

I also have my 3/4" wrench hanging from the front T slot, on the far right. The nylon rod, with a ridge holds my 2 wrenches, one for the T nuts, one for the quill. I could find them in the dark. NOT on the table, or bench. They return to the nylon ------, ALWAYS.

Same for the lathe chuck wrench. I have a fork on the chip pan, chuck wrench goes there, NOT on the tray, or bench. I try to make it easier to put the tool in the proper place, then putting it in the wrong spot.
Dave

[millman5]

I too use the rachet handle to whack the top of the drawbar. I store the socket & wrench bu sliding the socket over one of the dovetail locking bolts on the ram. Very convienient & the same wrench handle gets used for a hammer that way