R8 Blanks

admin

I made 24 of these to be used for whatever.....I started out with a 12' length of 1.5" diameter stressproof.  I set up the compound with an indicator on what I thought was a good arbor.  As it turns out, I don't own an arbor that seats with 100% contact.  Now I own 24 more that aren't perfect.  Very close, just beyond what I can measure.  I can only tell they are off by bluing and test fitting in the mill spindle.  I think I need to order up a sine bar and a collet set up for the fine tuning of the taper.Got the process down to an even 20 minutes each from raw to what is pictured here.  All machining done manually without a DRO.  I made a full garbage can of swarf and no scrap parts.Most will prolly end up as endmill holders. Attached ImagesMy name's not Jim....
Reply:cool....i bought two lathes in 95-96 and was machineing round stock as much as i could , but i never thought of that , wow.  What about notching the ends of a couple of them at different angles to hold an insert...then you'll hav different angled  fly-cutters . just one thought        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Anything is possible, but fly cutters are cheap...My name's not Jim....
Reply:Nice. I'm waiting to hear back from a guy who has a 10 x 36" Clausing he wants to sell. I can't wait to have my own lathe. I'm bookmarking this even though I really don't have a need for any more R8 endmill holders for my little mill..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:Do not know if you need one but here is a jig I devolved to slot shafts on a lathe.   have funTom
Reply:Nice Tom. Now I have one more project to add to my growing list of things to build for the lathe as soon as I get it. Thanks..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:you planning on hardening them?  i would think stressproof might be a little soft for a tool holder..Last edited by brucer; 03-17-2012 at 01:06 PM.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Originally Posted by bruceryou planning on hardening them?
Reply:I would think stressproof would be too soft for a tool holder.. Its only like 22-30rc.. Fatigueproof might be a little better choice..  When I use to make holders, generally for some custom cnc application,  we usually made holders from 4340 and usually heat treated them...In a smaller mill stressproof might be ok, because you wont be loading the holders as much..  also when stressproof breaks it can fragment if i remember correctly.. Over time I would also worry about pulling the threads with the drawbar because its soft..tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Originally Posted by brucer Over time I would also worry about pulling the threads with the drawbar because its soft..
Reply:I like the idea but have to pop your bubble..These come hardened and ground from any manufacturer..These must run within .0005 to be useful for anything other than roughing out material and even then they will not last..The end mill itself will chew these up in no time at all from the inside out..Those mills are HARD and any vibration and it's all over.Even a drill chuck will do these in..Don't say I did not warn ya.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:Originally Posted by zapsterI like the idea but have to pop your bubble..These come hardened and ground from any manufacturer..These must run within .0005 to be useful for anything other than roughing out material and even then they will not last..The end mill itself will chew these up in no time at all from the inside out..Those mills are HARD and any vibration and it's all over.Even a drill chuck will do these in..Don't say I did not warn ya.....zap!
Reply:I have been a machinist for 34 years.Those are hardened..I did not say it won't work..I do say they will not last.Google R-8 colletts....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I know collets are hardened, they have to be.  I'd bet all commercially made arbors are hardened also unless specified "soft".These aren't collets and they will see a lot less use than in a full time shop.  All I've got to lose right now is the $5 each in material and 20 min of time.I'm not trying to argue or say you're wrong Zap, just saying I think they'll suit my needs which are different from your needs.My name's not Jim....
Reply:cut a dovetail into the end of one of them , make a boring bar. Drill and tap a couple for end mill extensions....i cant wait to see what your going to do with some , but i know its going to be good        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:Boostinjdm Its probably even more critical with holders like your making because they project a few inches out of the nose of the spindle and put more load/pressure/stress at the end of the holder and at the nose of the spindle which creates about twice the pressure a normal r8 collet would..  The typical r8 collets that stick up into the spindle the r8 collet is within the spindle not hanging 3 inches out the end of the spindle..   the holders your making will also be hard on spindle bearings in bridgeport type mills.. I also agree with zap, I wont say they wont work, but I wouldnt care to use them...  they might be ok for light work and such but no way would I sink a rougher into a cut and let it eat. Also when your using an endmill there is always a pulling force on the collet/holder so soft threads arent idea..Zaps a bit older than me evidently,  I have about 25yrs experience certified machinist/tool&die/mold maker..Last edited by brucer; 03-17-2012 at 08:52 PM.tackleexperts.comwww.necessityjigs.comhttps://www.facebook.com/groups/mach...dingequipment/
Reply:Well "not Jim", in my opinion what you did today was not a waste of time.ImpressedMatt
Reply:you sound like hes makeing them out of glass.  I needed to make collet extensions for certain jobs , didnt have an issue. They made nice clean cuts. Looking at his r8s made me think a solid one piece collet through is better than extensions...the cutting rules still 30 thou. id'nt it?        thermal arc 252i  -  millermatic 350P -   miller XMT, cp300ts, 30a 22a feeders, buttload of other millers, handfull of lincolns, couple of esabs  -   Hypertherm 1250 G3
Reply:You say they are concentric, but have not added the hole yet. Also, test fitting with blue shows seating issues? Sometimes a slight burr/piece of whatever can caise problems. Have you compared the fit with another R8 collet from another source?Always try to eliminate the obvious.As far as adding the hole, this could be done while blank is held in mill spindle.IIRC 16* 51 ' is spec angle with.951" body dia.  Of course, check against yours.
Reply:From the Niagara Lasalle Steel website. I underlined the important parts.http://www.niagaralasalle.com/product-stressproof.html"STRESSPROOF® is made by a patented process which consists of drawing the bar through a special die under heavy draft, then stress relieving it in a precisely controlled furnace.When Niagara LaSalle developed STRESSPROOF® in 1938, it changed the economics of part production. Because for the first time, users could get an improved wearability without case hardening, strength without heat treating, plus excellent machinability and tool life.STRESSPROOF® is electro-magnetically tested using eddy currents. Other benefits include resistance to fatigue and stress, balanced working and minimum warpage and distortion. STRESSPROOF® can also be induction hardened, but should be watched for quench cracks.It is strongly felt that in our modern computer age, uniformity in machinability of a product has become a key factor in improved productivity, and Niagara LaSalle will continue to be responsive to the needs of its customers.STRESSPROOF not only meets the minimum properties of ASTM A311, but it also has controlled low stresses, reliable machining, and improved surface quality. Result is longer part life with less manufacturing costs."115,000 psi tensile100,000 psi yieldRC 26I went out and checked....I've got right at 1" of thread engagement of the drawbar.  The drawbar will fail before arbor does.  I know that from first hand experience.  I added more meat to these arbors than what the weldon holders have.  The added overhang Bruce is so worried about isn't that much.  Maybe 1"-1 1/2" over what a collet has.My name's not Jim....
Reply:Interesting stuff.  The joy of having equipment is making your own tools.  I've needed a couple metric r-8 holders for a while and they are hard to come by in the US. I was thinking of making some tool holders but didn't have a heat treat oven. I'll have to try some of that stressproof.Interestingly, I started "baby sitting" a friends heat treat oven yesterday... he needed a dry place to store it... and I was happy to make space.
Reply:Well, the good news is that I can make a nice fitting concentric hole.  Bad news is that my hand looks like it got attacked by a ream of paper.  Lesson for the day....put on your damn leather gloves before handling an end mill.  The fit is so close, you have to push it half way in then wait a second before pushing it the rest of the way.  When pulling it out, you have to fight a vacuum.  That is bone dry.  No oil film sealing it.I used a 3/8" fine set screw for the 3/4" holder.  I may go up a size or two on the set screw.  I've also got room to shorten the holder a bit.  As pictured it has 1-1/2" more over hang than a collet.  Actually a little less than that because my drawbar hits the 3/4" double ended end mill if I put it in the collet all the way to the flutes. Attached ImagesMy name's not Jim....
Reply:I forgot to add....correcting the taper took about 3 swipes with a file and some scotch bright to polish it up.  I'm assuming it's correct now anyway.  All of the blue in the contact area looked scuffed, but none of it rubbed off.  Before, the small areas making contact rubbed off the blue showing shiny metal.My name's not Jim....
Reply:Originally Posted by forhireInteresting stuff.  The joy of having equipment is making your own tools.  I've needed a couple metric r-8 holders for a while and they are hard to come by in the US. I was thinking of making some tool holders but didn't have a heat treat oven. I'll have to try some of that stressproof.Interestingly, I started "baby sitting" a friends heat treat oven yesterday... he needed a dry place to store it... and I was happy to make space.
Reply:Originally Posted by dunemetalTry www.plazamachinery.comJoe has had Bridgeport branded metric R8 collets listed for a while.Forhire:Guess I need to read a bit more carefully.
Reply:"Well, the good news is that I can make a nice fitting concentric hole. Bad news is that my hand looks like it got attacked by a ream of paper. Lesson for the day....put on your damn leather gloves before handling an end mill."    next lesson is to remember to remove the leather gloves before operating the mill. i think it was about 30 years ago that i was wearing mine while running my bridgeport in a non-heated building. went to brush a heavy drill chip out of the way and it grabbed my glove. twisted off about half of my left index finger. i was happy to escape with the rest of my hand and arm.miller thunderbolt 250vlincoln square wave tig 175 prolincoln idealarc mig sp250everlast tig 210EXTeverlast power plasma 50chicago electric (hf) 130 tig/90 arcchicago electric 90 amp flux wire3 sets oxy/acet
Reply:Originally Posted by boatbuoynext lesson is to remember to remove the leather gloves before operating the mill. i think it was about 30 years ago that i was wearing mine while running my bridgeport in a non-heated building. went to brush a heavy drill chip out of the way and it grabbed my glove. twisted off about half of my left index finger. i was happy to escape with the rest of my hand and arm.