Getting into wire EDM, machine suggestions?
Close
Login to Your Account
Results 1 to 11 of 11
  1. #1
    Join Date
    Dec 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    248
    Post Thanks / Like
    Likes (Given)
    36
    Likes (Received)
    85

    Default Getting into wire EDM, machine suggestions?

    As the title says, I'm new to wire EDM and looking to buy. Coming from 2 decades of experience in 4 and 5 axis milling and turning. Most parts will fit in your palm and will be under 1/8" thick.

    Looking at the Makino U3 and U32j. What are the real world, practical differences? U32j claims to be more accurate, but how accurate are we talking here? My experience with "super precision" mills and lathes with glass scales is that they make a bigger difference over large distances, but no difference over individual features and small parts. The only parts where I need to split tenths will be under 1" x 1".

    I like that the U32j can use very thin wire for essentially square inside corner features. Any issues running 0.002" wire in thin parts? How thin can I go on a U3?

    Surface finish capability on the the U3 vs U32j? I'm okay taking 5-6 passes in either case. Cycle time is not an issue and parts are small anyway.

    What's the life expectancy of a WEDM? No cutting forces - is there even any noticeable wear and tear other than consumables like wire guides? What's the long term cost to operate?

    Also, thoughts on installing one of these in a clean, office-type environment on a polished concrete floor? I'd like to convert some of our unused office space into a micro machining area, which will include the EDM.

  2. #2
    Join Date
    Apr 2008
    Location
    Auburn Hills, MI
    Posts
    239
    Post Thanks / Like
    Likes (Given)
    34
    Likes (Received)
    53

    Default

    Radar987,

    I am the EDM Product Manager at Makino, and the (x2) machines you have identified are both capable of producing the work you have outlined. I believe you will have difficulty in telling the two models apart from an accuracy standpoint, especially since your parts are very small. Both machines utilize a similar structure and design, but the U32j machine is the higher-level model. Below are a few differences between the U3 and U32j machines...

    U3:
    - Standard with 0.010" wire (0.004", 0.006", 0.008, and 0.012" Guides are optional)

    - Standard configuration can achieve surface finishes in Steel to 8~10uinRa (Optional Crystal Fine Finish Circuit can achieve surface finish to 3~4uinRa)

    - Utilizes a Stationary Work Table design (this improves accuracy, as the machine is always moving the same mass regardless of work piece weight and fluid fill height)

    - The water reservoir is built into the base casting of the machine to minimize floor space, and this design also improves thermal stability

    - The machine uses a pneumatic Rise/Fall Front Door for Work Tank access, and Work Tank allows you to access the underside of the work piece from underneath the table

    - Standard with HyperCut settings (this is a special Makino technology that achieves a fine 16uinRa surface finish with 3 Pass Machining)

    - Standard with the Pro-Tech circuit (this is an active anti-oxidation/anti-rust system that protects the entire work piece and work tank)

    - Utilizes 0.05um Glass Scale Feedback

    - Machine Specifications state a Dynamic Shape Precision of 5 microns (0.0002”), which is a combination of feature size and location over the full stroke of the machine (all parts moving & working together)



    U32j:
    - Standard with 0.010" wire (0.002”, 0.003”, 0.004", 0.006", 0.008, and 0.012" Guides are optional)

    - Standard configuration includes the Crystal Circuit, which can achieve surface finish to 3~4uinRa

    - Utilizes a Stationary Work Table design (this improves accuracy, as the machine is always moving the same mass regardless of work piece weight and fluid fill height)

    - The water reservoir is built into the base casting of the machine to minimize floor space, and this design also improves thermal stability

    - The machine uses a mechanical 3-Sided Rise/Fall Work Tank that is fully programmable, and Work Tank allows you to access the underside of the work piece from underneath the table

    - The machine is designed for greater thermal stability, and includes additional active cooling of the entire machine structure and a higher accuracy Chiller Unit

    - The machine mechanical construction alignment accuracy is held to a finer tolerance

    - Standard with HyperCut settings (this is a special Makino technology that achieves a fine 16uinRa surface finish with 3 Pass Machining)

    - Standard with the Pro-Tech circuit (this is an active anti-oxidation/anti-rust system that protects the entire work piece and work tank)

    - Utilizes 0.05um Glass Scale Feedback

    - Machine Specifications state a Dynamic Shape Precision of 3 microns (0.0001”), which is a combination of feature size and location over the full stroke of the machine (all parts moving & working together)



    Summary:
    - The U32j is capable of operating with smaller diameter wire

    - The enhanced accuracy of the U32j will be difficult to see and measure considering the small size of your parts (higher accuracy pitch positioning over the full stroke of the machine is not needed for your application)

    - The U32j Out-of-the-Box settings are designed for high accuracy, whereas the U3 favors the Speed size of the spectrum (this just means that you might have to adjust offsets a bit more on the U3)

    - The U32j and U3 (with optional Crystal Circuit) can achieve the same surface finish



    Questions:
    - A smaller diameter wire will produce a small inside corner radii, but what are your part requirements?

    - Running 0.002” wire is more difficult (especially wire threading) than running the traditional industry norm of 0.010” wire. When running 0.002” wire, Makino recommends using pure tungsten wire for best performance.

    - Life expectancy of Wire EDM is long…because there are little mechanical forces in EDM, and most machines are replaced due to performance and electronic obsolescence.

    - Wire EDM machines do require TLC, and structured pro-active maintenance is a key operating factor for reliability.

    - Wire EDM’s do have consumable components that require replacement over time (Wire Guides, Filters, Di-Ionization Resin, Rollers, etc.), and the amount of parts and intervals on replacement vary GREATLY between the different machine tool OEMs and also the type of application and accuracy requirements being performed.

    - From the type of work you have described, the maintenance and life of the consumable components should be minimal, but the life of a typical Wire Guide is 2,000 to 3,000 machining hours.

    - The long-term cost of Wire EDM operations (includes costs of wire, wire guides, filters, rollers, resin, etc.) should be in the range of $5 to $6 per hour

    - The installation of the machine on a polished concrete floor in a clean office-type environment is EXCELLECT!

    - Please let me know if you would like to have a direct discussion to talk in greater detail…I can be reached at 248-921-2474

    - Here are some additional helpful links:
    Makino Webinar on Wire EDM Maintenance: The true operational impact of wire edm maintenance. | Makino

    EDM Today article on Machine Installation: EDM_Today_Winter_2018


    - Brian

  3. Likes hanermo, Radar987, JTB3 liked this post
  4. #3
    Join Date
    Jan 2013
    Location
    Plainfield, Indiana, USA
    Posts
    1,680
    Post Thanks / Like
    Likes (Given)
    1255
    Likes (Received)
    899

    Default

    Excellent comparison Brian! But you did not address the op's desire to split tenths . . . which is a lapping operation, not a machining operation, at least in mho.

  5. #4
    Join Date
    Sep 2009
    Location
    barcelona, spain
    Posts
    2,478
    Post Thanks / Like
    Likes (Given)
    493
    Likes (Received)
    1323

    Default

    Brian f. Makino ..
    On the base model.

    what is the single-axis resolution and repeatability please ?

    What tir should be expected from an interpolated hole say 10 mm D in steel, say 303SS, 10 mm deep, through ?
    How long to cut the hole, ballpark.

    When looking for best-available, rather than fast output.

  6. #5
    Join Date
    Dec 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    248
    Post Thanks / Like
    Likes (Given)
    36
    Likes (Received)
    85

    Default

    Brian, thanks for the very helpful information.

    Inside corner requirements are adaptable - "as small as practically possible" would be my best description. 0.004" should be sufficiently small to make an inside corner relief invisible to the naked eye, I think.

    Perusing the Makino website a bit more, I see you also have the UPV-3 that uses oil dielectric for even finer surface finishes. Other than surface finish, how do these machines compare in precision and cycle time? Is maintenance of the oil an issue for some people? I'm envisioning something along the lines of a CNC tool and cutter grinder with a fire suppression system and oil chiller.

  7. #6
    Join Date
    Dec 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    248
    Post Thanks / Like
    Likes (Given)
    36
    Likes (Received)
    85

    Default

    Quote Originally Posted by Red James View Post
    Excellent comparison Brian! But you did not address the op's desire to split tenths . . . which is a lapping operation, not a machining operation, at least in mho.
    We would only need to split tenths for geometric features, e.g. round and square holes under 1/4" diameter.

    But speaking of lapping, I wonder if the oil dielectric models can slice raw materials into "wafers" with a 1uinch surface finish?

  8. #7
    Join Date
    Apr 2008
    Location
    Auburn Hills, MI
    Posts
    239
    Post Thanks / Like
    Likes (Given)
    34
    Likes (Received)
    53

    Default

    The UPV-3 machine is structurally identical to the U32j machine, but the mechanical alignments are held to even stricter tolerances to achieve finer accuracies. The UPV-Series generator has also been modified for use with an oil di-electric fluid, and the machine is standard with a Flame Sensor and Fire Suppression System (identical to Makino's Sinker EDM machines).

    The use of de-ionized water as the di-electric does have limitations with the minimum amount of discharge power that the fluid will support, which is in the 3~4uinRa range. The use of oil di-electric fluid overcomes these limitations, as the oil is a true insulator, providing finer control over the machining spark gap. It is the oil’s di-electric properties that allow machining with considerably lower power levels than water and allows the ability to achieve even finer surface finishes down to and below 1uinRa.

    Oil Di-Electric PRO’s:
    - Oil does not require any de-ionization resin, so this maintenance consumable item is eliminated
    - Cleaning of the work tank is easier, as the dirt & debris does not scale-up like it does on water-based machines as the water evaporates (oil keeps the debris loose and slimy)
    - Surface Finish and part Accuracy are be improved
    - Ultra-Fine Surface Finishes can be achieved that are considerably finer than what water is able to produce
    - Work Piece metallurgical quality is also improved, especially for Carbide materials (oil eliminates the water from chemically attaching the cobalt binder in the Carbide)
    - Oil never rusts or stains the work piece, and chemical cleaners do not need to be used when the part is removed from the machine


    Oil Di-Electric CON’s:
    - Any oil splashing or spray-over can create a slip hazard (water can too, but water evaporates by itself…oil must be cleaned up)
    - Oil will stain your clothes (it is very common for water-based WEDM’ers to wipe their hands off on their clothes after pulling a slug)
    - Oil does have a Cycle Time penalty, especially in the Rough Cut (this is due to the smaller spark gap that is created with oil)
    - Oil’s cycle time differences compared to water become less as the surface finish becomes finer (equilibrium point is around 10uinRa)

    - Brian

  9. #8
    Join Date
    Apr 2008
    Location
    Auburn Hills, MI
    Posts
    239
    Post Thanks / Like
    Likes (Given)
    34
    Likes (Received)
    53

    Default

    @Hanermo,

    The Axis Positioning and Repeatability of the Makino U3 machine is +/- 0.001mm over the full stroke when equipped with 0.05 micron glass scales.

    The U3 machine configuration for the North American market includes the 0.05 micron scales as standard, but I believe they are an option in the European market.

    As for part Roundness/Circularity of an actual machined part, the U3 Specifications state 0.005mm of a machined 20mm Diameter Hole 40mm think in SKD-11 material (0.787" Diameter Hole 1.575" thick in D2 Tool Steel).

    This part was machined using a Precision 5-Pass Process (1 Rough, 4 Skim Cuts), and was machined to a 0.3umRa (12uinRa) Surface Finish using 0.200mm (0.008") Diameter Brass wire.

    Here is a ballpark Cycle Time estimate to machine a 10mm Diameter Hole thru a 10mm thickness on a standard equipped Makino U3:

    - 0.200mm (0.008”) Diameter Brass Wire
    o Machine a 10mm Diameter 10mm thick in Steel (0.400” Diameter x 0.400” thick)
    o 6 Pass Precision Process (1 Rough, 5 Skims)
    o Surface Finish = 0.2umRa (8uinRa)
    o Cycle Time = 16 minutes

    - The Surface Finish can also be improved to 0.1umRa (4uinRa) if the U3 is equipped with the Crystal Fine Finish Circuit option


    - Brian

  10. #9
    Join Date
    Dec 2011
    Country
    UNITED STATES
    State/Province
    Texas
    Posts
    248
    Post Thanks / Like
    Likes (Given)
    36
    Likes (Received)
    85

    Default

    Quote Originally Posted by Brian Pfluger View Post
    @Hanermo,

    The Axis Positioning and Repeatability of the Makino U3 machine is +/- 0.001mm over the full stroke when equipped with 0.05 micron glass scales.

    The U3 machine configuration for the North American market includes the 0.05 micron scales as standard, but I believe they are an option in the European market.

    As for part Roundness/Circularity of an actual machined part, the U3 Specifications state 0.005mm of a machined 20mm Diameter Hole 40mm think in SKD-11 material (0.787" Diameter Hole 1.575" thick in D2 Tool Steel).

    This part was machined using a Precision 5-Pass Process (1 Rough, 4 Skim Cuts), and was machined to a 0.3umRa (12uinRa) Surface Finish using 0.200mm (0.008") Diameter Brass wire.

    Here is a ballpark Cycle Time estimate to machine a 10mm Diameter Hole thru a 10mm thickness on a standard equipped Makino U3:

    - 0.200mm (0.008”) Diameter Brass Wire
    o Machine a 10mm Diameter 10mm thick in Steel (0.400” Diameter x 0.400” thick)
    o 6 Pass Precision Process (1 Rough, 5 Skims)
    o Surface Finish = 0.2umRa (8uinRa)
    o Cycle Time = 16 minutes

    - The Surface Finish can also be improved to 0.1umRa (4uinRa) if the U3 is equipped with the Crystal Fine Finish Circuit option


    - Brian
    How much do accuracies and cycle time improve as material thickness decreases?

    In the first example, I'd imagine better roundness spec if the same 20mm hole were done in 5mm thick material and a 5th skim cut to a finer finish.

    In the second example, again if the material were 5mm thick, how much would cycle time should decrease? How about 2mm material?

  11. #10
    Join Date
    Apr 2008
    Location
    Auburn Hills, MI
    Posts
    239
    Post Thanks / Like
    Likes (Given)
    34
    Likes (Received)
    53

    Default

    Radar987,

    Your assumptions are correct...the Cycle Time becomes shorter as the work piece thickness becomes smaller, but the part accuracy does not necessarily improve with additional skim cuts or with thinner parts.

    Generally speaking from a Wire EDM perspective, part Accuracy does not improve once past the 4th Machining Pass, but the achieved Surface Finish will improve if the machine and settings support it.

    The reason for the thicker 40mm (1.57”) work piece accuracy statement on the U3 machine is to establish a real-world and realistic performance expectation for the most common type of work that is performed on the equipment using Out-of-the-Box conditions. This is again ACTUAL verified measured results of a real machined part. The 0.005mm (0.0002”) Accuracy of the 20mm (0.787”) diameter hole is a combined TIR Straightness and Circularity measurement (Dynamic Precision), which tells more about what the machine is capable of with all its parts moving and working together than a Linear Positioning and Repeatability specification. The accuracy of thinner and smaller parts can of coarse be improved, and the Makino U3 machine is capable of achieving accuracies finer than 0.005mm (0.0002”), but some common sense needs to be applied to this statement.

    OEM’s sometime show Ball-Bar Circularity results of just machine movement, which are OK, but these values are not the same level of precision that you can expect to achieve and deliver to every part.

    For reference, I’ve attached an image with an example of a 20mmØ x 20mm thick (0.787”) Tungsten Carbide part machined on the Makino UPV-3 (oil-based machine) with actual measured results of 0.0008mm (0.00003”) Roundness.

    - Brianupv-3-roundness.jpg

  12. #11
    Join Date
    May 2011
    Country
    UNITED STATES
    State/Province
    New Jersey
    Posts
    1,533
    Post Thanks / Like
    Likes (Given)
    143
    Likes (Received)
    781

    Default

    I'd give a look at the Mitsubishi mv advance plus machines as well. I've held under 2 tenths repeated with an older fa model...last part measured .0002 from nominal on one feature and nominal on the second feature. Maintenance is easy and the touch screen navigates easily.

    I've held similar on mv advance machines as well. The auto threading is reliable as are the general mechanics of the machines.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •