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Thread: Which r8 boring head
01-19-2012, 04:52 PM #1
Which r8 boring head
HI, ALL COULD ANY OF YOU GIVE ME SOME ADVISE ON WHICH BORING HEAD TO BUY FOR MY BRIDGEPORT SERIES 1.
MY MATE WHO IS AN EX TOOL ROOM MAN SAYS I COULD DO WITH ONE WITH A 50mm HEAD, METRIC GRADS AND MADE OF A ONE PIECE CONSTRUCTION ( TO STOP CHATTER, PLUS IT WILL NOT LOOSEN ITS SELF OFF IN REVERSE ).
THE ONLY ONES I CAN FIND AS A ONE PIECE ARE IN IMPIERAL FROM WHAT I HAVE SEEN.
ANY ADVISE WOULD BE GREAT..
01-19-2012, 10:59 PM #2
I have about 4 different heads for my BP and my favorite is the #2 BP made one about 3"=75MM dia and 5/8 tools.
01-20-2012, 12:05 AM #3
There's a lot to be said for a 2" (~50mm) boring head. Short extension, can use 1/2" shank tools for smaller holes, can bore larger holes with bar out the side, etc. Any of the cheap ones work fine, some are harder to read than others. I'm not sure how often you would need to reverse a boring head on a mill. I do it sometimes, usually when using a boring tool to turn a boss. Using the inside tool to cut an OD makes the geometry "reverse" and hence the rotation needs to be too. Beyond that, most tools are going to be RH anyway unless you make them for yourself.
But unless you only do small stuff, you might eventually like a range of boring heads up to about 3" for the BP.
The primary difference between a "good head" and mediocre ones are 1.) the ease of reading an accurate dial, 2.) the ease of adjusting combined with a smooth action that will repeat/always move the same for the same dial increment. Criterion heads are a common simple head in the USA that are very good at this.
I agree with John that BP's own head is a pretty nice one. Relatively huge dial (easy to read, easy to adjust) for the size head, one piece head and rugged. The 5/8" bar size is kind of unique, most are either 1/2" or 3/4" (or larger). 5/8" is kind of intermediate and if you do work in the range, it is a convenient size though possibly the bars are less commonly available. They don't have much offset, but that does not have to be a hindrance; move the bar out to the outer hole or stick it out the side instead of using a large unbalanced offset. Mine's beat to heck by the previous factory, but good tool to have on hand. I sold a Criterian to keep this one, but in fact often just reach for the cheap chinese 2" unit when a small bar size is needed.
Wohlhaupters are nice. Less convenient for routine moderate tolerance holes. But when you want to dial them in a few tenths at a time, it is easy. Includes facing capability. UPA3 size (~3") is about right for a BP
A bit esoteric these days, but if you want to bore tapered holes or bosses, a Tree boring head will do the job. Most are also "tenths setting" with the ring, for straight up and down boring work. Of course with the angle slide, even the non-tenths units can be set to dial "tenths" based on the sine principle. A bit ponderous of a tool for routine boring, though. Also don't take "normal" bars. You have to grind tool bits to fit the proprietary set of 3 bars that come with every Tree unit.
Just to confuse the issues.
01-20-2012, 08:30 AM #4
The "Caps Lock" key is to the left side of your keyboard. Don has rules against posting in all caps. I have trouble reading them
You don't say what size holes that you plan on boring. I've got 2 Criterion boring heads, a DBL-202 and 204.
dbl boring heads
I can go from about 3mm up to 300mm.
01-21-2012, 09:43 AM #5
Here are 4 boring heads that I have managed to end up with.
Described L-R ...
Gamet 3.5", made in France, sold by Ralmikes, Enco, etc. Takes 3/4 boring bars. This came w/ my Bridgeport however I have never used it so can't comment on it. Has capability to do facing and I think even automatic stops? As boring heads go its quite a complex mechanism. Some more pics of the Gamet, I really need to try this boring head out:
Gamet/Ralmikes Pic 1, Gamet/Ralmikes Pic 2, Gamet/Ralmikes Pic 3, Gamet/Ralmikes Pic 4
APT 2.5" BH34C. My first boring head, bought at cabin Fever years ago works well, takes 5/8 bars. But the graduations are very closely spaced and difficult to try and hit a tight diameter tolerance.
Maxwell E-Z Set #30 2.25". This is the boring head I usually reach for. Its size works well for the work I do when I occasionally need a boring head. Takes 1/2 boring bars. Its got generous spacing between graduations and has a vernier. So its pretty easy to hit your mark when you are looking for an accurate diam.
Bridgeport #1, Diam 2.25". Takes 3/8 boring bars. The baby brother to Stephen's Bridgeport #2 (shown in his post above). I bought this from a vendor at Cabin Fever because I wanted graduations that were easier to read than the APT. And we have a Bridgeport #2 (3.375") boring head at work that I like. Its a nice smaller boring head.
Hear is a photo to show you why I like the Maxwell #30 boring head. The graduations have very generous spacing and it has a vernier. One complete revolution of the upper straight knurled ring is .10 on a radius, each division .001 on the radius. Vernier grads are .0001 on a radius. Of course those division values double on a diameter. I do wish they were diameter reading graduations.
Last edited by morsetaper2; 01-22-2012 at 09:23 AM.
01-21-2012, 11:22 AM #6
Just to add, don't buy a boring head any bigger than you really need. The difference in vibration between a 2" head and 3" head is very noticeable, if you get the thing offset to any degree. Don't underestimate the importance of being able to read a big clearly marked dial.
01-22-2012, 05:41 AM #7
Thanks for all of your replies and the time you have taken to post photos.
Anybody got any views on the Vertex heads ?
PS- sorry about using caps im not up on forum etiquette
01-22-2012, 08:34 AM #8
Morse, try the Gamet, I think you will like it. Also known as a clicker or ratcheting head, it is not a continuous feed. One of the nicest features is the z shaped hex key that came with it. The key is used for adjusting for size, locking the bar, locking the slide, and winding the slide to size. Many other heads require more than one key to operate.
In the top ring there are three pawls that can move the slide. Two can be retracted by turning the hex socket, the third one is fixed. This controls the feed rate per revolution.
The knurled ring is meant to be held by hand when facing. If you must use something to help hold the ring make sure it will break easily. You don't want it to swing around and hit your hand when the slide reaches its travel limit.
The Maxwell looks like a nice head. Erickson Tenthset heads are the only other heads I know of with an external setting ring like that.
01-22-2012, 07:53 PM #9
One thing I like about the bridgeport boring head is that the screw is stationary which allows the index mark to be on the top. On another one I use the screw moves with the slide so the index mark is on the bottom on the slide. Annoying and a little harder to read.
01-22-2012, 10:46 PM #10
Gamets (french made, dunno about the later ones) are smooth, and work better than they ought to. But they are too damn big for routine use on a BP size mill. Nice to have on hand for some stuff, but too much overhang and bulk for straight boring most holes. A wohlhaupter UPA3 size is much shorter, more rigid, "finer" working, ring dial for easier reading (like Maxwell or Tree) and can feed both directions. The G-brand only feeds out/turns RH for feeding. (though of course you can straight bore turning either direction if the screw-in shank is adequately retained)
Here's what the insides look like, as Gbent mentioned, with the retractable ramps for the pawl.
Cheap enough way to get a nice enough facing head, simple; just a lot of bulk and overhang to carry on the machine when facing capability is not needed.
The shorter the overhang, the better for cut quality.
I like that Maxwell! Don't need it, (obviously ) But worth watching for!
01-25-2012, 04:41 PM #11
I happen to like my Criterion #202 pretty well.
It takes a 1/2" tool so I use a shortened 1/2" lathe boring bar with inserts.
01-29-2012, 04:36 PM #12
Here's my Gamet/Enco (made in France) boring a hole in a solid brass charge bar for a rebuilt 1960's shotshell reloader! It is smaller than Stephen's and does everything I've needed so far.
02-16-2012, 10:30 AM #13
Since we're talking about boring heads.........
Are any of you using a boring head with a Bridgeport to bore (motorcycle, ATV, etc.) engine cylinders?
Range I am looking it may vary from 2.44" bore x 1.6" stroke, to 3.7" bore to 3.07" stroke.
If so, what brand/model would you recommend for the sizes I've listed above?
02-16-2012, 12:16 PM #14
I've bored "big" "deep" holes on flimsy machinery, but not specifically automotive related.
Sound doable, but you have an interesting problem to work around the rigidity (lack of) issues.
You mention the stroke, but not the bore depth. Can it be assumed depth = "somewhat more than 2x stroke?"
The R8 gage dia is for all practical purposes, 1.25" dia. Depth = 5 x dia (6-1/4")for relatively "easy" boring puts you in the ball park depending on the tool overhang.
The small bore should be easy. I'd use a 2" dia head, and stick the bar out the side hole. If necessary to to get to depth and clear the spindle, i'd make a 1-1/2" to 2" dia extension arbor to screw in the 2" boring head socket, and turn the other end to R8 to fit the machine. I would not make it any longer than necessary.
For the 3"+ hole, I'd do the same, favor 2" + dia extension arbor. A compromise would be if you can use a 3" head with a 3/4" bar out the end, but the whole combination is buried up to the spindle at full depth. A boring head that won't enter the bore with a 3/4" bar straight out the end that is 6+" long will have too much extension from the spindle nose. Though it could work, it might either take a long time to bore a straight hole, or it could drive you nuts. With a larger head that will take 1" bars out the end, the total extension of the whole combination out of the spindle (~pushing 10"+?) is going to be long enough to potentially give you fits.
Are you planning to bore with knee up? or horizontal with the table?
02-16-2012, 12:35 PM #15
That's why I was asking. The bore depth of the smaller cylinder would need to be approx. 3-1/2". Not sure of the larger one since it is still on a bike.
Rigidity is a concern, so I would assume the table would need to be up as high as practical and still be able to accomplished the depth of bore I'd need. Getting everything lined up would also be a concern to assure a straight and concentric cut.
I'm still a noob with this machine, so I tend to ask some whacky questions. I do however, have an immediate need to bore out a bike's twin cylinders of the smaller dimension, so just thought I'd ask. For this first one, I may wind up carrying it to an automotive machine shop with the proper boring tool.
In the "old days," used to use a course-stoned Sunnen hone (dry), followed up with a couple finer ones that were used wet until the proper piston clearance and cross hatch was obtained. But, those puppies aren't cheap either, which is why I was looking at an alternative method with some of the tools I have on hand now.
Thank you tho'. You've been most helpful.
02-16-2012, 03:30 PM #16
02-16-2012, 04:51 PM #17
Auotomotive cylinder boring equipment has been refined over many years to do that specific job to the required tolerance in the shortest time with minimum skill requirement, the equipment is suitable for little else but is very refined for purpose ....automotive honing equipment is much the same.
02-17-2012, 01:28 AM #18That's why I was asking. The bore depth of the smaller cylinder would need to be approx. 3-1/2". Not sure of the larger one since it is still on a bike.
Have you been following this thread? Lots of info and opinions on same subject. There are no stupid questions? Boring small cylinders in my garage..
There's even an example of what I was referring to as boring with the table (with the head swung around parallel, or with a horizontal attachment for the head)
02-17-2012, 07:14 AM #19
Stephen, I did not see that thread.
Wish I had 'cause it answered my question.
Appreciate your pointing it out.
03-15-2012, 11:08 AM #20
Hi all, thanks for all the info i am now the new owner of a Gomar 75mm and a small Bristol Ericson Tenthset boring heads, tried to post the photos but could not make it work, thanks again.