ball mill finish calculator - martin chick & associates
The Ball Mill Finish Calculator can be used when an end mill with a full radius (a ball mill) is used on a contoured surface.
The tool radius on each side of the cut will leave stock referred to as a scallop. The finish of the part will be determined by the height of the scallop,
amd the scallop will be determined by the stepover distance between cuts.
To calculate the stepover distance, enter the scallop height and click Calc Stepover
To calculate the scallop height, enter the stepover distance and click Calc Scallop
ball mill liner function | wear parts for industry | qiming casting
Ball mill is a major equipment in the production of power plants, cement plants, mines, chemical industry, metallurgy and other industries, the liner is one of the components of the mill, the main role is to protect the cylinder, the cylinder from the grinding body and Material direct impact and friction, help to improve the mill grinding efficiency, increase production and reduce metal consumption. As the liner in the harsh conditions of long-term conditions, maintenance and replacement of considerable volume, not only requires human, material and financial resources, but also a direct impact on productivity.
Ball mill liner plays a major role in protecting the inner wall of the anchor windlass. Different shapes of the ball mill lining plate can improve the grinding effect of the ball mill and improve the working efficiency of the ball mill.
1, flat ball mill liner, the surface smooth, suitable for installation in the fine grinding warehouse.
2, the pressure of the type of ball mill liner, suitable for coarse grinding warehouse, for low speed ball mill.
3, ladder-type ball mill liner, ladder liner is better than the pressure liner, suitable for installation in the coarse grinding warehouse.
4, small corrugated liner crest and pitch are small, suitable for fine grinding and coal mill.
5, end cover liner installed in the grinding head cover or cylinder cover to protect the end cover from wear and tear.
6, ring groove liner in the lining of the T surface for casting a circular groove, after installation to form a circular groove, suitable for multi-warehouse grinding of the first and second positions, dry, wet grinding Machine can be.
7, grading liner, grinding mill for the ideal state should be large particles of material with a large diameter grinding body to impact and crush, that is, in the direction of the mill feed with large diameter grinding body, with the material The direction of the material to the gradual reduction of the grinding body should be sequentially reduced.
Qiming Casting is one of the largest manganese steel, chromium steel, and alloy steel foundry in China. Products include crusher wear parts, Crusher spare parts, mill liners, shredder wear parts, apron feeder pans, and electric rope shovel parts.
surface finish calc - villa machine associates, inc
As one can see, in the two pictures below, an end mill with a corner radius on a shallow slope produces much shallower scallops than a ballnose end mill would. This results in a better surface finish and much faster machining time. The FAKE BALL NOSE DIA CALC is designed to give you an accurate calculation of the adjusted diameter for calculating surface finish. The SURFACE FINISH calculator also includes a stepover adjustment calculator for internal, and external radii. A ballnose end mill makes smaller scallops on an internal radius, and larger scallops on an external radius, and so it must be adjusted to maintain consistent surface finish. Click the pictures for a larger version.
analysis of milling surface roughness prediction for thin-walled parts with curved surface | springerlink
In manufacturing industry, parts contain curved surface are widely used to meet specific needs like better performance, beautiful appearance, and light weight. Surface roughness is an important part of machining surface topography. The milling surface roughness prediction of thin-walled parts with curved surface and physical factors are studied in this paper. Based on the theory of milling process, modeling theory of differential geometry and computer graphic, a milling surface roughness prediction model is deduced. This paper futher discretized the ball end milling edge, and built the tool feed model, cutting edge conversion model, and tool axis control model, based on differential geometry theory. Z-map model is used to mesh the workpiece. Combining tools motion model during milling process with workpiece meshing model, the basic milling surface roughness prediction model is deduced. Considering the physical factors influence, based on the micro-unit cutting force modeling theory and two-segment cantilever beam tool deformation theory, ball end milling cutters forced deformation model is deduced by analytical calculation. Considering the tool wear in milling process and analyzing tool wear in the initial wear stage, the tool wear correction model is built. The comprehensive milling surface roughness prediction model is established by introducing the tool wear model and tool forced deformation model into basic surface roughness prediction model. An experimental verification is set up by the central composite design method, the result show that error of surface roughness prediction model is less than 13%. This experiment verifies that the milling surface roughness prediction model based on milling theory established in this paper is of high precision, and surface roughness can be quantitatively predicted.
Koreta N, Egawa T, Kuroda M, Watanabe K, Ii Y (1993) Analysis of surface roughness generation by ball endmill machining. Seimitsu Kogaku Kaishi/Journal of the Japan Society for Precision Engineering 59 (9):15371542
Hao, Y., Liu, Y. Analysis of milling surface roughness prediction for thin-walled parts with curved surface.
Int J Adv Manuf Technol 93, 22892297 (2017). https://doi.org/10.1007/s00170-017-0615-4
do you know these common senses about nc milling machine tools? - meetyou carbide
The common diameters of metric (mm) knives are: 0.5, 1, 1.5, 2, 2.5, 3, 4, 5, 6, 8, 10, 12, 16, 20, 25, 28, 30, 32, 35, 40, 50, 63 The common diameters of inch knives are: 1 / 8, 1 / 4, 1 / 2, 3 / 16, 5 / 16, 3 / 8, 5 / 8, 3 / 4, 1, 1.5 and 2
(1) High speed tool steel tool is the most common tool, cheap, easy to buy, but easy to wear, wear and tear. Some Jinwei high speed tool steel tools with 3Co, Mn and other alloys have good wear resistance and high precision, such as LBK, YG and other types of tools, but the price is relatively expensive.(2) Alloy toolIt is made of common alloy materials, high temperature resistance, wear resistance, high spindle speed, high processing efficiency and processing quality. It can process high hard materials (such as welded mould), so it is expensive. It is generally used in high precision and high quality processing occasions(3) Discarded bladeThis kind of cutter is made of alloy, which can be replaced, has good wear resistance and moderate price, so it is widely used in steel processingThe shape of the blade is square, diamond and round. The two corners of square and rhombic cutter grains need to be replaced after wear, while the ring surface of round cutter grains can be used. Therefore, it has good durability. The commonly used models are 25r5, 30r5, 32r5, 35r6, 16r0.8, 20r0.6, 25r0.8, 6R1, 8r0.5 and 10r0.5
maximize hard milling with balanced machining process factors |
Many solid carbide ballnose end mills feature coatings such as aluminum titanium nitride (AlTiN) that combat the high temperatures associated with hard-milling applications. Images courtesy of Seco Tools.
Successful hard-milling operations require the perfect balance of all the factors present in a system, including cutting tools, CAM software and machine tools.
Solid carbide end mills can help bring high productivity and reliability to mold shops that machine a large portion of their products from hardened steels.
To maximize productivity and reliability, mold shops often machine a large portion of their products from hardened steels. Historically, hardened steels have been rough milled at low feeds and speeds, with large depths of cut and stepovers. The process is agonizingly slow and can produce deep stair-steps on the part, which necessitate multiple semi-finishing and finishing operations. Alternatively, shops will rough mill a soft block, have it heat-treated, and then bring it back to the milling machines for a number of setups for semi-finishing and finishing. Another approach to hardened steel machining has been EDM, a process that is also very time-consuming.
These lengthy processes are increasingly being replaced by high-speed hard milling, which involves taking light depths of cut and using high feed rates. This process enables shops to drill holes and water lines in a block, perform heat treatment, and then apply the high-speed strategies to rough and finish in one setup. Metal removal rates are high, and semi-finish and finish operations are minimized, because the hard-milling process results in near-net-shape parts. Surface finishes in the range of 10-12 rms are possible. The result is increased productivity, and decreases in the costs of setup and repetitive part handling.
The measured hardness of typical hardened steels is in the range of 48-65 HRC. However, when it comes to real-world machinability, the Rockwell number does not represent the whole story. For example, D2 tool steel hardens to about 60-62 HRC, but it machines more like 62-65 HRC due to a chromium content of 11-13 percent that increases toughness. For D2 and similar multi-constituent alloys, it is necessary to apply machining parameters from the tooling supplier that are intended for harder materials.
A key to tool life and part quality in milling, and especially in high-speed milling of hardened steels, is maintaining constant chip load on the milling tools cutting edges. Chip load equals the feed rate divided by the spindle speed multiplied by the number of cutting flutes, and chip load that varies widely or is too low or too high will cause tools to wear out too fast, chip or break.
Maintaining constant chip load is a particular problem when machining the 3D contours that are characteristic of moldmaking. Programming a straight high-speed, high-feed tool path generally is routine, but in milling complex shapes, the load on the tool changes and the machine may not be able to maintain the desired chip load. For example, when a cutter arrives at a 90-degree corner, the tools engagement angle doubles and cutting forces increase. If the feed rate is not reduced, the tool will wear rapidly or break. Machinists can manually reduce feed via feed-override controls, or the CAM program and machine tool control can combine to back the feed rate down in order to machine varying mold contours.
A machinist can confirm if the specified feed rate is being achieved by loading the CAM program and tools into the machine and setting the tools Z height about 1 inch above the part. A dry run will reveal the actual feed rates. Basic physics dictates that maintaining the desired feed rate and chip load 100 percent of the time is not possible. A good rule of thumb is: If the programmed feed rate is not maintained for 80 percent of the cycle time, then spindle speed must be reduced accordingly to maintain consistent chip load.
For example, in an application where a feed rate of 100 inches per minute at 30,000 rpm will produce the desired chip load, the correct feed may be achieved for some portion of the operation but may fall to 40 inches per minute for other parts of the process, producing an average feed of 50 inches per minute. In this case, cutting the speed in half will most likely produce the desired chip load. Lowering the spindle speed will nominally increase cycle time, but tool life will increase in turn. Milling calculators are available to provide the parameters needed to achieve constant chip load.
Another critical but often overlooked factor in milling operations is tool runout. In general, runout greater than about 0.0004 inch (one-seventh the diameter of a human hair) can cut tool life in half. Minimizing runout grows in importance when employing very small tools. For some small tools, 0.0004-inch runout will double the chip load on a single tooth, causing accelerated wear on the tools cutting edge. Using expensive machine tools and expensive cutting tools but employing bargain toolholders is a recipe for problems. High-precision holders, including shrink-fit and hydraulic, among others, will essentially eliminate runout as a negative factor.
Many shops make the mistake of leaving excess part stock for finish milling. For cutters of about 1/8-inch diameter and larger, leaving about 1 percent of the cutter diameter for finishing is recommended. For example, when applying a -inch-diameter tool, stock for finishing should be about 0.005-inch, or for a 1/8-inch-diameter cutter, finishing stock should be 0.002-0.003 inch.
For smaller tools, determining a sufficient amount of stock for finishing may be a case of feel, or trial and error. One percent of a 0.020-inch-diameter ballnose cutters diameter is 0.0002 inch, but the amount of stock may be insufficient and the tool may rub the workpiece material instead of shearing it, thus hastening tool failure. For the 0.020-inch-diameter cutter, finishing stock of 0.001 inch or 0.0008 inch would probably be more appropriate.
With small tools in particular, excessively large steps between finishing tools will cause problems. Starting with a 2-mm tool (1-mm radius) to create a 0.2-mm radius in a corner, some machinists will next apply a tool with a 0.4-mm radius. Under those circumstances, the chance that the tool will break is high. A better progression might be to next use a 0.8-mm-radius tool, then a 0.6-mm, and finally tools with 0.4-mm and 0.2-mm radii. This conservative method will consume a few more tools, but tool life will be greater for the tools that are applied, and the risk of breakage is small.
Programming software is critical in maintaining chip load. Top-of-the-line CAM systems employ a larger number of individual points to define a tool path than less-capable programming systems. The CAM program also manages tool entry and exit to moderate forces on the cutting edge. Although more capable CAM software is usually also more expensive, the benefits generally outweigh the initial higher cost.
Machine controller capabilities play a role in efficient milling as well. To efficiently carry out high-speed milling strategies, a machine must have the computing power to look ahead and smoothly handle the rapid changes in machining parameters dictated by the CAM program. Older controllers and servos cant necessarily process as many blocks per second as are needed to follow the complex machine movement commands of high-speed milling.
Close consideration of chip load, runout and other issues such as machine rigidity can produce surprising results regarding tool life in high-speed milling. Properly applied tools can last hours when milling hardened steels. Of course, the definition of tool life is a factor as well; the demands of the customer receiving the mold regarding surface finish may limit the amount of time that a tool can be run before being changed.
Extreme heat negatively impacts tool life, so the light depths of cut used in high-speed milling can boost tool life by maximizing the amount of time the cutting edges have to cool while outside the cut. To avoid thermal shock, air blast or oil/air mist generally replaces coolant when materials harder than 48 HRC are being milled. Although in some cases liquid coolant flow can clear chips and prevent recutting, an air blast is a better choice because it does not subject the tool to rapid, large changes in temperature.
The industry-wide trend toward tighter tolerances includes moldmaking products, and those demands are reflected in the tools used to machine the molds and their components. A few years ago, a typicalradial tolerance for a ball mill was 10 microns; now it is closer to 5 microns. Aballnose end mill that is not true to formwill produce parts that do not match. Avoiding that kind of error is critical in moldmaking where, for example, liquid silicone rubber can form flash in mold mismatch gaps as small as 2 microns.
Because milling hard materials generates a significant amount of heat, many of the carbide end mills used in hard milling feature thermal-barrier coatings such as aluminum titanium nitride (AlTiN). These tools generally have hard micrograin carbide substrates (8 percent cobalt content) for heat resistance and strength, and negative cutting edge rake geometries to resist chipping. Cubic boron nitride (CBN) tools can be used in finishing operations, and inserted end mills are effective in roughing.
Very small milling tools can create features that formerly were only achievable with EDM. Tools as small as 0.1 mm (0.0039 inch) in diameter are available, and even such tiny tools can be effectively applied at high speeds with short flute lengths.
Precision tools, sophisticated CAM software, high-capability machine tools, premium toolholders and details such as coolant alternatives should be applied together to maximize the productivity and quality of hardened steel milling. Tooling, machine tool and workpiece material suppliers typically are more than willing to provide their expertise to help shops achieve a true process balance and meet their productivity goals.
Our automatic production line for the grinding cylpebs is the unique. With stable quality, high production efficiency, high hardness, wear-resistant, the volumetric hardness of the grinding cylpebs is between 60-63HRC,the breakage is less than 0.5%. The organization of the grinding cylpebs is compact, the hardness is constant from the inner to the surface. Now has extensively used in the cement industry, the wear rate is about 30g-60g per Ton cement.
Grinding Cylpebs are made from low-alloy chilled cast iron. The molten metal leaves the furnace at approximately 1500 C and is transferred to a continuous casting machine where the selected size Cylpebs are created; by changing the moulds the full range of cylindrical media can be manufactured via one simple process. The Cylpebs are demoulded while still red hot and placed in a cooling section for several hours to relieve internal stress. Solidification takes place in seconds and is formed from the external surface inward to the centre of the media. It has been claimed that this manufacturing process contributes to the cost effectiveness of the media, by being more efficient and requiring less energy than the conventional forging method.
Because of their cylindrical geometry, Cylpebs have greater surface area and higher bulk density compared with balls of similar mass and size. Cylpebs of equal diameter and length have 14.5% greater surface area than balls of the same mass, and 9% higher bulk density than steel balls, or 12% higher than cast balls. As a result, for a given charge volume, about 25% more grinding media surface area is available for size reduction when charged with Cylpebs, but the mill would also draw more power.
grate discharge liner for ball mill - eb castworld % grate discharge liner
Leading supplier of high alloy castings and forgings. There are 4 companies with sales of more than 100 million yuan, across the 4 major areas of wear resistance, heat resistance, corrosion resistance, and machinery
We produce every Grate Discharge Liner with strict control procedures, must by the quality inspection department quality inspection before deliveryto ensure that each factory the quality of the products. The use of Discharge end Liners, reduce cost of investment castings and wear, more can reduce due to often shutdown losses asa result of the replacement parts,greatly improve the work efficiency. We can according to individualized requirements of customers. Products through scientific and strict smelting, casting, heat treatment process,greatly improving the wear resistance. Contact us: If you haveinterest, please do not hesitate to contact me. Pls send the drawing, technical requirements to us by email. Looking forward to receiving your inquiry andreply. Thank you.