http://www.todaysmachiningworld.com/forum/forum/screw-machine-issues Brought to you by Todays Machining World en-US Fri, 30 Jul 2010 03:11:40 +0000 http://bbpress.org/?v=1.0.2 q http://www.todaysmachiningworld.com/forum/search.php http://www.todaysmachiningworld.com/forum/topic/c038m-pickoff#post-686 Thu, 29 Oct 2009 19:09:29 +0000 Anonymous 686@http://www.todaysmachiningworld.com/forum/ <p>We are looking for an internal chamfer. We will try Buelldogs suggestion. </p> http://www.todaysmachiningworld.com/forum/topic/c038m-pickoff#post-685 Thu, 22 Oct 2009 15:18:58 +0000 Anonymous 685@http://www.todaysmachiningworld.com/forum/ <p>letitrun, are you looking to do an internal or external chamfer?<br /> Buelldog, I like your plan 'B'. That's a great fix. It reminds me of an illutration in a tooling catalog ( <a href="http://www.slatertools.com/davenport17.htm" rel="nofollow">http://www.slatertools.com/davenport17.htm</a> ). The illustration shows the recess chamfer before cut-off. </p> http://www.todaysmachiningworld.com/forum/topic/c038m-pickoff#post-684 Wed, 21 Oct 2009 06:54:44 +0000 Anonymous 684@http://www.todaysmachiningworld.com/forum/ <p>As my experience on the 62's, the best way to make a nice &#38; constant back chamfer on a variety of parts, is by using a Schlitter recessing attachement mod# 58-1 at the same position of the cut-off. I'm not familiar with the 52's, but if your machine work with 125 deg. of feed. The recessing cam muts not exceed 190 deg. total lengh with approx. 4 5/8" stroke. the tool lengh must not exceed 3 1/8" or you'll get vibration. And to eliminate the cut-off burr, the tool should have a strait edge of .010" at the end of the chamfer aligned with cut-off. With this king you can do any thing, chamfer, groove within ±.005" </p> http://www.todaysmachiningworld.com/forum/topic/c038m-pickoff#post-677 Thu, 01 Oct 2009 20:20:50 +0000 Anonymous 677@http://www.todaysmachiningworld.com/forum/ <p>I don’t have any experience with the Model 52, but I had a somewhat similar situation on an ACME machine. I'm not sure if this will help you, but this is what we did:<br /> We needed to cut-off our parts and add a chamfer with a specific size &#38; angle to the cut-off end. We had two machines for this job, but neither of them had any back-working capabilities.<br /> We received quotes for upgrading the machines, but they were very expensive so we had to rule that option out. For the first couple months of production, we did the back-working on a secondary operation (drill press &#38; mill). The results weren’t very good; we had parts missing the operation and too much dimensional variation. We needed to come up with something else.<br /> We had a ramp-type tool slide on hand, so we designed a custom carbide boring tool to mount in it. We then went in from the front, through the bore, and cut the recess in the back of the part (before cut-off). When the cut-off tool came through the part, it would intersect the recess, removing part of it, leaving the needed chamfer behind after cut-off.<br /> This isn’t a perfect solution because there is a small cut-off burr left behind, which varies in size depending on the recess angle, tool wear, etc. We were able to take advantage of an operation further on in the process to remove this minor burr. </p> http://www.todaysmachiningworld.com/forum/topic/c038m-pickoff#post-675 Fri, 25 Sep 2009 12:58:50 +0000 Anonymous 675@http://www.todaysmachiningworld.com/forum/ <p>Has anyone ever adapted a C&#38;M pickoff to fit a 1 1/4 52 New Britian? We need a reliable solution to back chamfer and back machine a variety of parts on a Model 52 New Britian. </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-close-enough-tolerance-on-acme-using-c12l14#post-327 Sun, 29 Mar 2009 14:12:52 +0000 Anonymous 327@http://www.todaysmachiningworld.com/forum/ <p>our guys just grind some of the reamer flutes off.. seems to work. too many flutes build up and force the reamer to one side or other. try two or four flutes, else have an odd number, like 3. seems to work on ours.<br /> Ray </p> http://www.todaysmachiningworld.com/forum/topic/high-pressure-coolant-for-screw-machines#post-316 Thu, 26 Mar 2009 13:24:35 +0000 Anonymous 316@http://www.todaysmachiningworld.com/forum/ <p>You can also try Keith Urban at Daniel L. Bowers Co., Inc (DLB) in Michigan. I have used them on a few occasions and the latest on a CNC Lathe with twin spindle and three turret machine from Miyano. They did a great job! 248-656-3600 - <a href="http://www.dlbmbci.com/" rel="nofollow">http://www.dlbmbci.com/</a> </p> http://www.todaysmachiningworld.com/forum/topic/high-pressure-coolant-for-screw-machines#post-289 Mon, 16 Mar 2009 20:23:54 +0000 Anonymous 289@http://www.todaysmachiningworld.com/forum/ <p>Talked Mr McConkey at Brittani and he needs to know machine size. Bigger than 1 inch takes a 15 hp motor. 43 gallons. 55o psi generated. </p> http://www.todaysmachiningworld.com/forum/topic/axial-threadrolling#post-288 Mon, 16 Mar 2009 19:46:10 +0000 Anonymous 288@http://www.todaysmachiningworld.com/forum/ <p>A thread of this size should not be a problem we have ran up 5"-6" long but you must have your cams and gears right.<br /> Fette has the best customer support give Dick Hagenbach a call 216-403-4853 </p> http://www.todaysmachiningworld.com/forum/topic/high-pressure-coolant-for-screw-machines#post-287 Mon, 16 Mar 2009 19:01:37 +0000 Anonymous 287@http://www.todaysmachiningworld.com/forum/ <p>Try Brittani Technologies in Delta, Ohio, 419-822-3500. They produce a superior product but are quite expensive. Graco is another option with a less pricey air pump approach but it is less powerful. Cool Baster is a good solution for Swiss but not real powerful </p> http://www.todaysmachiningworld.com/forum/topic/high-pressure-coolant-for-screw-machines#post-278 Mon, 16 Mar 2009 14:23:40 +0000 Anonymous 278@http://www.todaysmachiningworld.com/forum/ <p>Can anyone recommend an add-on high pressure coolant system for a multiple-spindle screw machine? </p> http://www.todaysmachiningworld.com/forum/topic/axial-threadrolling#post-215 Thu, 05 Mar 2009 22:47:06 +0000 Anonymous 215@http://www.todaysmachiningworld.com/forum/ <p>The blank was shaved with carbide tooling, held well. The head although it was rated at 1.125 fine pitch seems a little small. Fette 233400, this head works fine on CNC lathes. I suppose the aux. feed cam was not exactly right, the mechanism flexs... </p> http://www.todaysmachiningworld.com/forum/topic/axial-threadrolling#post-214 Thu, 05 Mar 2009 20:36:13 +0000 Anonymous 214@http://www.todaysmachiningworld.com/forum/ <p>Are you holding your diameter to size? You might try putting coolant to the cutting area because it gets extremely hot. You need a shave tool holder or ground stock. The feed to the cam in the gear ratio may be incorrect. You also should check whether the machine horsepower is adequate. That thread roll which must be a mighty big one.</p> <p>I would suggest looking at a Wickman and do the part with a single point threading attachment off the cross slide. 1144 material is brutal to try to thread roll. Too abrasive and stringy. </p> http://www.todaysmachiningworld.com/forum/topic/axial-threadrolling#post-213 Thu, 05 Mar 2009 20:36:09 +0000 Anonymous 213@http://www.todaysmachiningworld.com/forum/ <p>Are you holding your diameter to size? You might try putting coolant to the cutting area because it gets extremely hot. You need a shave tool holder or ground stock. The feed to the cam in the gear ratio may be incorrect. You also should check whether the machine horsepower is adequate. That thread roll which must be a mighty big one.</p> <p>I would suggest looking at a Wickman and do the part with a single point threading attachment off the cross slide. 1144 material is brutal to try to thread roll. Too abrasive and stringy. </p> http://www.todaysmachiningworld.com/forum/topic/axial-threadrolling#post-209 Thu, 05 Mar 2009 03:11:28 +0000 Anonymous 209@http://www.todaysmachiningworld.com/forum/ <p>How long a thread can be rolled with a axial 3 roll style thread head on a screw machine? We tried but get a very poor looking start, and the pitch diameter varied too much to run successfully. Tried a 1.125-12 thread 1.75 long in 1144 CD. Thread size what right in the middle of what the manufacturer rated the head for. Has anyone tried this? </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-good-finish-on-1018-part-running-on-acme#post-121 Tue, 17 Feb 2009 10:33:48 +0000 Anonymous 121@http://www.todaysmachiningworld.com/forum/ <p>I've machined a lot of 1018 over the years. This material is gummy and likes to tear rather than cut. I've found that using a high chlorinated and sulfinated oil helps quite a bit. </p> <p>To get a nicer finish, use a sizing tool that takes .005-.010 finish cut on diameters and .003-.004 per side. This will clean up the galling left by the form tool. You should also be machining this at 100-110 SFM if you are using any type of high speed cutting tools. For high speed tools, I recommend using Rex 76. </p> <p>If you are using carbide tooling, then I can't imagine having a problem getting a good finish unless you are feeding too hard....carbide does very well in 1018.</p> <p>BTW, if you are looking to maintain a 62 RMS finish or better on this, then best of luck to you. It can be done, but it requires a lot of tool sharpening. I machine 1018 and get it to look as good as 12L14 once in a while, but it doesn't stay there long. </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-close-enough-tolerance-on-acme-using-c12l14#post-116 Mon, 16 Feb 2009 11:57:01 +0000 Anonymous 116@http://www.todaysmachiningworld.com/forum/ <p>First you must make sure your drilled hole is holding to a tight spec before the reaming will hold. I'm not a big fan of bought reamers--Sounds like you need a good shop made carbide flat reamer or drill to hold that tight.<br /> TRR </p> http://www.todaysmachiningworld.com/forum/topic/surface-finish-problem-material-gummy-welding-to-edges-of-tooling#post-114 Sun, 15 Feb 2009 23:39:27 +0000 Anonymous 114@http://www.todaysmachiningworld.com/forum/ <p>I would look at your coolant. If material is welding to your cutting tool, you are not removing enough heat. This is either from the lack of sufficient coolant or poor chip evacuation. Be sure the coolant is mixed to the right proportions and you have enough pressure delivering the coolant. </p> http://www.todaysmachiningworld.com/forum/topic/no-central-system-for-chips-and-oil-coolant-oil-is-mixing-with-hydraulic-oil#post-111 Sun, 15 Feb 2009 11:23:45 +0000 Anonymous 111@http://www.todaysmachiningworld.com/forum/ <p>I use a Castrol synthetic and the lub/hydraulic oil will not mix with the coolant. In fact, I leave the tramp oil in the sumps to inhibit evaporation. The coolant is Castrol Syntilo 9954.<br /> Regards, Ray in FLA </p> http://www.todaysmachiningworld.com/forum/topic/termanology-definition-concentricity-vs-run-out-vs-position-requirement#post-106 Fri, 13 Feb 2009 20:40:52 +0000 Anonymous 106@http://www.todaysmachiningworld.com/forum/ <p>Runout tolerances (circular runout and total runout) control the form, orientation and position of individual features - datum axis required.- Circular runout is a two dimensional, surface to an axis contol.- Total runout is a three dimensional, surface to an axis control.<br /> Concentricity tolerances control the location of opposing median points of a feature (datum axis or median plane required)- Concentricity is a three dimensional tolerance.<br /> Position for coaxial features is a three dimensional, axis to axis control.<br /> I suggest you refer to ASME Y14.5M-1994 <a href="http://catalog.asme.org/Codes/PrintBook/Y145M_1994_Dimensioning.cfm" rel="nofollow">http://catalog.asme.org/Codes/PrintBook/Y145M_1994_Dimensioning.cfm</a><br /> Understanding the differences in these specifications will allow you to assure compliance. </p> http://www.todaysmachiningworld.com/forum/topic/no-central-system-for-chips-and-oil-coolant-oil-is-mixing-with-hydraulic-oil#post-93 Fri, 13 Feb 2009 17:03:50 +0000 Anonymous 93@http://www.todaysmachiningworld.com/forum/ <p>It could be but a little more info would be helpful first. How old are the Acme's and what kind of shape are they in. It could also be a difference in the condition of the spindle bearings, differences in the gib adjustments on the different machines or something of that nature. To rule out the coolant, you might want to clean out 6 or so machines and start from scratch with fresh coolant..run the same job.. and watch the results. </p> http://www.todaysmachiningworld.com/forum/topic/no-central-system-for-chips-and-oil-coolant-oil-is-mixing-with-hydraulic-oil#post-92 Fri, 13 Feb 2009 16:55:52 +0000 Anonymous 92@http://www.todaysmachiningworld.com/forum/ <p>depending on the type of oil you are using. many of the current cutting oils on the market are tri-purpose.</p> <p>meaning they can be used in the sump of the machine and the hyd. system.</p> <p>check with your oil supplier.</p> <p>we use a Shell product - new / reclaimed oil in the sumps, and new oil only in the hyd systems.</p> <p>this way the leaks into the sump will not weaking the additive package of the cutting oil. </p> http://www.todaysmachiningworld.com/forum/topic/termanology-definition-concentricity-vs-run-out-vs-position-requirement#post-90 Fri, 13 Feb 2009 16:07:55 +0000 Anonymous 90@http://www.todaysmachiningworld.com/forum/ <p>We are a job shop manufacturing turned parts on screw machines and CNC lathes for a variety of customers and industries.</p> <p>On parts with multiple diameters some customers call out a concentricity specification. Others will use run-out and some show a position requirement. Aren’t they really all asking for the same thing? Why do they say it three ways, and can they be used interchangeably? </p> http://www.todaysmachiningworld.com/forum/topic/no-central-system-for-chips-and-oil-coolant-oil-is-mixing-with-hydraulic-oil#post-89 Fri, 13 Feb 2009 16:01:23 +0000 Anonymous 89@http://www.todaysmachiningworld.com/forum/ <p>We have a shop with 70 acme multi spindles, but we have no central system for chips and oil. In the course of the machining operation, our coolant oil mixes with the hydraulic oil. We are getting different results on similar machines using the same tooling. Is the mixing of the oils the cause of this? What should we do? </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-good-finish-on-1018-part-running-on-acme#post-86 Fri, 13 Feb 2009 14:12:39 +0000 Anonymous 86@http://www.todaysmachiningworld.com/forum/ <p>1018 is a tough bird, I know you can't do this on an Acme, but we use cermet tools from Iscar, run it at 1000 SF, and the finish comes out like a mirror. 1500 pieces on an Acme seems a little short to me. </p> http://www.todaysmachiningworld.com/forum/topic/surface-finish-problem-material-gummy-welding-to-edges-of-tooling#post-83 Fri, 13 Feb 2009 13:03:27 +0000 Anonymous 83@http://www.todaysmachiningworld.com/forum/ <p>I use an air grinder to angle the cutting edge so as to direct the chip away from the work. The finished chip curler is usually conical with the large end away from the work.<br /> Careful attention to the cutting edge, as mentioned before, is critical. Use a fine stone to finish all edges, and hone by hand.<br /> Oil coolant is recommended.<br /> Tom </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-close-enough-tolerance-on-acme-using-c12l14#post-79 Fri, 13 Feb 2009 11:44:01 +0000 Anonymous 79@http://www.todaysmachiningworld.com/forum/ <p>I don't know this type of metal, or how deep the hole is, whether it's blind, but I've been able to hold .0002 with a nice rigid boring bar in a variety of stainless steels and other metals. I had a job in cupronickel from bar stock that ended up with a .002 wall, where by the +/- .001 tolerance it could vanish and still be in tolerance. We held .0001 id and od by using 2 tools, one inverted for the od and normal for the id in one pass.<br /> If the hole is long and deep then honing or ballizing are good choices. Think peaks and valleys in the finish. With ballizing the peaks are pushed into the valleys.<br /> Tom </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-good-finish-on-1018-part-running-on-acme#post-78 Fri, 13 Feb 2009 11:23:26 +0000 Anonymous 78@http://www.todaysmachiningworld.com/forum/ <p>I agree with Engineeringtech except with regard to the rake angle. I use an air grinder to angle the cutting edge so as to direct the chip away from the work. The finished chip curler is usually conical with the large end away from the work.<br /> Careful attention to the cutting edge, as mentioned before, is critical. Use a fine stone to finish all edges, and hone by hand.<br /> Tom </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-good-finish-on-1018-part-running-on-acme#post-61 Wed, 11 Feb 2009 20:52:21 +0000 Anonymous 61@http://www.todaysmachiningworld.com/forum/ <p>Again, no experience with acme bar machines, but just thinking of good machining practices. Steeper back rake, side rake, and front clearance angles are going to remove mass from the tool. You don't want that. With less mass to wick away the heat buildup there will be more welding of the stock to the tool, causing dimensional changes. You can shallower angles, but you have to control your feed rate accordingly. I don't know what profile you're cutting, but you probably need a bigger radius on the tip of the cutter, or you get that "sewing needle" effect. With HSS I see lots of improvement in finish when I stone in a little radius on the cutter (without dulling the edge0. I'd check the rigidity of your setup (part holder, tool holder, and gibs). And are you using a water soluble cutting fluid? I'd try some heavier stuff. Can you use a sulfurated cutting fluid without running into trouble with the OSHA people? Tends to smoke a bit. Finally, some time in the heat treat oven might make that stuff cut better. 1018 CRS can have a lot of built in stresses. </p> http://www.todaysmachiningworld.com/forum/topic/trouble-getting-close-enough-tolerance-on-acme-using-c12l14#post-60 Wed, 11 Feb 2009 20:16:08 +0000 Anonymous 60@http://www.todaysmachiningworld.com/forum/ <p>I'm no expert on reaming, and not even sure what a 6 spindle acme bar machine is. But I know .0005 is not outrageous for a reaming operation. What is the size of the hole you are reaming to? What length reamer are you using? (Longer shanks self align with the pilot hole better when you have tiny misalignments between tailstock and headstock.) Is the collet or chuck holding the part and the collet or chuck holding the reamer clean and burr free? Is the reamer shank smooth and concentric? Is the reamer ground properly? Is the the reamer online with the headstock? Is sufficient coolant applied to prevent the reamer from heating up and cutting oversized? Is the pilot hole large enough that the reamer will not be overloaded and cause chips to pile up in the flutes? Or is the pilot hole so large that the cutting lips of the reamer have no support during the cutting operation? </p>