Re: [mill_drill] Re: Boring head?
- Seems like a good time for some noob questions about boring heads in general. Using this one in the link as an example, see if I understand correctly:
This one says "max 5/8" offset, I assume that's the center hole so that means that using the 9/16 boring bar gives a max diameter of .625x2+9/16 or 1.8125? Then the outer hole is, say, another 5/8 off so that'd be an additional 1.25 for a max 3.0625 hole diameter? At which point you can use the cross hole and go still wider?
If you use the cross hole do you use the same boring bar or do you need a different one with different rake for end cutting?
I've also been told that one can use a boring head for OD turning (I don't have a lathe) by turning the boring bar around. To do this you either need to reverse the mill's direction of rotation (not immediately possible on mine, though I haven't looked at the wiring) or a reverse cutting boring bar. I've never seen such a "backwards" boring bar advertised; are they actually available?
At 10:51 AM 3/15/2013, Paul wrote:
Here is another option that includes the tooling. I have one and it works great, at least for me. Also, LittleMachineShop stands behind their products and will exchange or refund if there are any problems.
http://littlemachineshop.com/products/product_view.php?ProductID=3662&category=--I.R.S.: We've got what it takes to take what you've got!
- My bifocals like more graduations..... it's a lot easier for me.
My lathe has non direct dials....not much matter anymore. I installed a DRO years ago.
Date: Fri, 15 Mar 2013 17:22:59 +0000
Subject: [mill_drill] Re: Boring head?
Direct reading might be *slightly* more convenient mentally, but there is no change in precision. The adjustment thread is still 20 TPI. The screw head is simply marked in 100 steps rather than 50.
I have no trouble at all in splitting the marks on my non-direct reading boring head.
But then I am using an old SB lathe with non-direct dials as well.
--- In firstname.lastname@example.org, Bill Armstrong <bill_1955@...> wrote:
> I would bet the Harbor Freight boring head IS NOT direct reading. ie; .001 on the dial is .001" on the diameter. Non direct reading means .001 movement on the dial is .001" on the radius.
> Many of the made in China boring heads are not direct reading. Makes it a pain to stay precise. Depends on how close of tolerance you want I suppose.
> I think the Shars (Discount Machine) eBay propaganda has a typo too. .0001".....No..... How about .001"
> I have an Enco, direct reading. I like it.
> I also have a Grizzly, non direct reading....that gathers a lot of dust.