Intro
This CNC machining center is also known as Dyna Myte DM1007 and was manufactured by Dyna Mechtronics Inc in the USA till they went out of business in 2018. There is still excellent support available from a former employee which hosts the Dyna Mechtronics website and can be contacted through the website. The DM1007 machine has a DYNA 4M PC control with color monitor and is equipped with AC servos, the headstock spindle has also an AC servo motor.
The predecessor of the DM1007 is the DM2900 and had a so called Single Key Input Programming “SKIP” control which can hold about 900 program lines, the XYZ axis from the DM2900 are driven with stepper motors and the spindle with a brushless DC motor. The same mechanical machine body but without the automatic tool changer and a smaller chip cabin is the DM2800. The DM2800 had as well a SKIP control with stepper motors.
The electronic design was made in the USA and the mechanical design and parts where made in Taiwan, several buy components are made in Japan.
Specifications
The machine specifications can be found on the Dyna Mechtronics specification page. According the Dyna Mechtronics website general castings are made out of FC30 which corresponds with EN-GJL-300 also known as DIN GG30. The dovetail guide ways are hardened and precision grounded, the slides are milled and scraped. The XYZ axis uses Ø16×2.5 ball screws, the ball screws are indirectly driven by AC servos with a 2:1 HTD timing belt transmission. These machines are designed metric and uses also metric fasteners.
Machine history
The construction year of the machine is not listed on the attached machine type plate. This particular machine is assumed to be built in 1999 because of countless “quality check” stickers found on nearly all electronic boards and components, which showed 1999 as the most common and recent year. The installed Dyna 4M CNC software showed 1999 as date. This machine came in 2023 in my possession and was since 2009 in the possession of the previous owner. The machine history since its built till 2009 is rather unclear.
Fixes to do & risks
The machine is about 25 years old and came with some issues to get solved. Maintenance work need to be carried out as the machine was not used for a long time. Plastic air lines has become brittle at the fitting ends, the ends can be trimmed off, however for safety to prevent suddenly burst air lines these will be replaced completely.
After starting doing maintenance work and cleaning the machine, I decided to go for a functional overhaul of the machine, by doing so it would be back in top condition and can be used with pleasure for the next 25 years.
Challenging issues to get solved is the monitor not displaying anything at all and the spindle servomotor makes an unhealthy sound at the encoder end.
The electronic controls used on the machine are 486 PC based, when developed this was state of the art but are nowadays outdated and no longer available. The risk by obtaining a CNC machine with obsolete electronics is ending up with a machine that in the worst case scenario will need the monitor, PC, controller board(s), power supplies, servomotor amplifiers and servomotors to be replaced with contemporary models.
The video card has two connectors one suitable for VGA and the other one for its predecessor EGA. Next a functioning VGA monitor was connected to the video card, the connected monitor didn’t displayed anything. However after disconnecting the flat cable of the Dyna Myte LCD monitor from the video card, the external monitor started displaying.
After taking out the monitor, PCB and video card for inspecting, cleaning the contacts with air and when put back the monitor came alive, hurrah! The joy was however from short term, the next power on cycle of the machine the monitor was again black. After investigating it turned out to be the connector of the black flat cable at the back of the video card. Cleaning these contacts twice with contact spray seemed so far adequate to fix the problem.
The focus at the moment of writing is the mechanical overhauling of the machine and with that the spindle servomotor as well. Depending on the outcome how the spindle servomotor and monitor will function, the decision will be made to keep or replace the current electronics with new ones. Preferred is to keep the servo motors and analog servo drives as this will save a lot of parts like the motor mounting plate, motor pulley and off course the servo motors with drives.
In case the electronics will be replaced LinuxCNC will be used as controller. As controller hardware a Mesa 7i92TH Ethernet board in combination with a Mesa 7i77 daughter board is a logical choice, as the 7i77 is suitable for six analog servo’s and has six encoder inputs. At the time of writing the 7i77 boards are in back order for months with an unknown lead time. From this point of view the analog servo motors and drives might be replaced for modern ones with direct drive at the ball screw spindle and use a Mesa 7i76 or similar which is suitable for Step-Dir and is available of the shelf.
The spindle servo motor has been fixed and is properly running without noise. The issue turned out to be the encoder which was barely touching the inner side of the protection cover. After creating more clearance by turning out the cover the sound was disappeared. Still very strange that it occurred as the encoder was still fully mounted on its shaft.
Spare parts and substituted parts
Spare parts are no longer available from Dyna Mechtronics since they went out of business. Nearly all buy and norm parts are still available from different industrial suppliers or a replacement can be searched for. Parts which are specifically designed and made for these machines are a challenge as these have to be repaired or replaced with a substitute part.
In this first simple case the for these machines designed and made felt wipers of the Z-axis part number 00507002 needed to be replaced. To create replacement parts the felt wiper was drawn in 3D and 3D printed. The 3D print serves as a template to cut out accurately the shape. For these wipers is 100% wool felt used according DIN 61200-F2 with a density of 0.36g/cm³. The 3D STP and STL files of the wiper template can be downloaded here.
Illumination of workspace
The workspace was illuminated with a halogen spotlight and is replaced with a modern update in the form of LED bars. The two 800 Lumen LED bars are mounted to sheet metal plates which also act as a reflector and some what as additional chip guard. The bended length is created in such way that the light do not blind when working with the machine.
Inside the electrical cabinet is also a LED bar mounted with an integrated on/off switch.
The electrical cabinet is originally equipped with a fan to reduce heat load generated in the electrical cabinet. The original air intake and fan outlet position where very close to each other which is not ideal for air flow through the cabinet. The first owner had already replaced the original unit for a unit with a double fan and internal heat exchanger which is intended for dusty environments, this replacement fan is a very noisy unit so the electrical cabinet receives a new quite fan.
The electrical cabinet door had some damages and a broken lock, a replacement lock was not available for a reasonable price and as the fan opening was also not on an ideal position, it was more appropriate to design a substituted improved part with VDE locks and fabricate a new door with laser cutting and get it powder coated.
XYZ axis
The ball screw spindles used are for all three axis Ø16×2.5 and where made by Hiwin. The bearings used for the ball screw spindle are two (unpaired) NSK 7001A angular contact ball bearings. The bearings in the X-axis had no decent shielding and where exposed to coolant and chips, as the grease was washed out and chips entered the bearing these needed to be replaced. A suitable shielding to protect the new bearings will be added to keep coolant and chips away.
The Y and Z-axis spindles and slides can be removed without relatively a lot of disassembling. The Y-axis however needs disassembling of the chip cabin otherwise the Y-axis slide will bump against the chip cabin, when the door opening of the chip cabin was designed a little lower it would be much more convenient for servicing.
Central oil lubrication
The DM1007 is equipped with an electrical central oil pump. From the electrical oil pump a PA Ø4xØ1.5 line goes to an oil distributor from which individual PA oil lines go to their respective lubrication points.
The oil distributor is however mounted underneath the machine body which is resting on the chip basin and is totally inaccessible without dismantling and lifting the whole machine body from the chip basin. Unfortunately it is the case that this machine has a leaky oil line and because of this service unfriendly design, the entire machine body needs to be lifted from the chip basin. A spiral PU Ø4xØ2.5 oil line is used to feed the Y-axis from which it is distributed to the slide feed channels. The PU line has become brittle over the years and is replaced with a PA-12 oil line made spiral and the gasket was fabricated with a 3D printed template.
Pedestal or base cabinet
The Dyna Myte DM1007 and predecessors are meant to be put on a suitable workbench. A pedestal or base cabinet to put the machine on was not an available option from the manufacturer. This machine came with a pedestal fabricated by a previous owner. As floor space is key in my workshop and is also a reason why I like this machine is that it offers a nice working envelope and tool changer for its floor space.
To optimize the used floor space and actually also for an more ergonomic working height, a base cabinet is designed with a drawer to store cutting tools and other items as well a space with a door to store larger items as a machine vise, fourth axis rotary table. The coolant tank fits in it as well.
Updates
This is a dynamic webpage and content will be added when the project proceeds.
Please note that the available assembly drawings or other files may change without any notification or may no longer correspond with the latest CAD version.
If you are curious about the resurrection of this Dyna Myte DM1007 CNC machining center or want to know more details, feel free to contact at the contact page.