Dyna Mechtronics 4400 (DM4400, dyna myte) reference + brochures & photos

[ckm]

All,

I thought I would start a new thread (vs the 2400 thread) to post some pictures of the DM4400, mostly of the electronics right now.

This post will be divided into three sections, each in it's own post:

• Dyna Mechtronics Overview (this post)
• 4400 Specific Overview
• 4400 Electronics Pictures

Dyna Overview

All Dyna Myte machines were made in San Jose, California by a company called Dyna Mechtronics. They are still around, their website is at http://www.dynamechtronics.com/ and they still support these old machines as best they can. You can still buy manuals and schematics from them.

In the late 80's and early 90's, Dyna was a large provider of smaller CNC machines to all sorts of users, ranging from the small desktop machines (the 2400 and the 2800) to their top of the line 4400 small VMCs. The smaller machines were quite popular and sold in their thousands. They also had a line of CNC lathes, the DM3000 and variants.

One drawback, however, was that Dyna used it's own controls with it's own language (similar to G-code, but not the same). The reason for this was that the machines were designed to be used largely conversationally and the technology of the day was quite limiting (e.g. controller speed in 1987...), so they developed their own series of controllers, SKIP (Single Key Input Programming) which simplified the task of conversational programming. The machines do have RS232 inputs that can be used to upload upto 1000 lines of programming (smaller in the 2400/2800) and can be drip fed using the appropriate software for the PC. When these machines were new, Dyna also sold a sophisticated CAM package as well (no longer available, AFAIK). Using modern CAM tools and appropriate post processors, it is still possible to generate code for the SKIP series of controllers. There are posts available for BobCAM and MasterCAM 9 & 10 and you can used a variety of RS232 utilities to upload the code.

One interesting thing about Dyna machines is that they were all built in a modular fashion from relatively off-the-shelf parts. Their architecture and electronics are fairly open, with all systems, including the 4400, using step-dir style controllers for the axis motors. All the machines use stepper systems with feedback encoders for position monitoring. The steppers are relatively small and are geared (5 to 1 in the case of the 4400) using either plastic gears or belts.

Uniquely for such small machines, they used 30-taper spindles on the 2800 and 4000/4400 series, which provides nice, rigid tooling. The bases were all of cast iron, made in Taiwan. The 2800/4000/4400 machines used ballscrews with dovetail ways, while the 2400 had ACME screws with dovetail was. All systems had one-shot lubrication, automated on larger machines. All the systems were designed from the ground up to be bed-style CNC machines and were never derived from mill-drill style designs. The 2400/2800 series also has a relatively high speed spindle (10k rpms), which is an advantage when dealing with small tooling.

As CNC became more widespread, Dyna changed it's product line. The 2400 was discontinued in the early '90s and controls on the 4000/4400 line switched to more common Mitsubishi G-code (Meldas) in the mid-'90s. AHHA made a conversion kit for most Dyna machines, but it has since gone out of business. Their major value add was a bridge board between existing Dyna electronics and newer control systems, but this is no longer available. A number of people have retrofitted EMC, FlashCut, DeskCNC and Mach3 mostly to 2400/2800 series machines.

Overall, Dyna machines are great candidates for conversions as they are well built, have electronics which can potentially be re-used and were made in fairly large numbers. They are also small enough for the hobbyist to handle while still providing industrial-style tooling, particularly the 2800.

In the late '80s, these machines were nothing short of revolutionary, even if they were expensive and quirky. Given all of the mill/drill conversions currently being done, particularly around Sieg products, there is a growing market for small CNC systems pioneered by Dyna 20 years ago.

Here are some scans of Dyna brochures from back in the day. I only have the 4400 brochures, but you can see the other machines on the last scan.

Also, some threads that might be of interest:

Dyna 2400 Conversion (lots of good info, inspired this thread)
Dyna 2400 Mill update NOT DIALUP FRIENDLY!

Yahoo Dyna Group
http://groups.yahoo.com/group/Dyna_Mechtronics_Users/

4400 Specific -
Dyna Myte 4400 (or other model) owners/users
Dyna Mechtronics 4400

Post Processor Info for 4400
Dyna 4400 pst help

4400 with Mitsubishi Meldas control
Meldas-M3 Dynamyte DM4400M Problem

2400 Conversion pictures
http://www.grifftek.com/images/dyna2400remec/

DM3000
Dyna mechtronics DM3000

Mach3 Forum discussions on Dyna conversions
http://www.machsupport.com/forum/ind...pic,630.0.html
http://www.machsupport.com/forum/ind...ic,3557.0.html
http://www.machsupport.com/forum/ind...ic,5233.0.html
http://www.machsupport.com/forum/ind...ic,4092.0.html
http://www.machsupport.com/forum/ind...ic,3134.0.html

2800 Clone
http://www.minitechcnc.com/vmc10/vmc...ing_center.htm

(note: I have better scans - I need to re-upload the images)

[Caprirs]

Excellent info. I worked for Dyna from '95-'98. At that time, the Mitsubishi Meldas controls (M3 & M520) were being phased out and replaced with Dyna's PC based control. With the Mits and PC controls, Dyna was aiming for the bigger machine market with the largest mill being 43" x 22" travel 40 taper 15hp 16,000lb VMC.

The SKIP control was designed by Sandy Walker at Dyna. It was originally intended for the small benchtop machines Dyna sold. Over time, the SKIP control got adapted to bigger more powerful machines like the 4000/4400. The PC3 control that Dyna eventally released was also originally designed by Sandy. Unfortunately, Sandy passed away while the PC3 was under development and before it was released. The PC3 control is, to a great extent, a SKIP control with servos instead of steppers and a PC for the user interface instead of the proprietary console used on the SKIP controls. Because it was PC based, it used conventional G & M codes, had a hard drive and floppy drive, and color LCD screen. Also unfortunately, Dyna started selling the PC3 machines too soon before all the bugs were sorted and alienated their customers and dealers.

For reference, see attached pictures of my Dyna 4400s with the Mitsubishi M3 controls. These are mechanically the same as the SKIP controlled machines but take advantage of the (at the time) more modern Meldas control with higher rapids (400ipm vs. 100ipm) higher spindle speed (10K rpm vs 7K rpm), rigid tapping, more memory (32KB), and standard G & M codes.

As far as I know, the ballscrews, spindle, ATC, and basic iron are identical between the Mitsubishi controlled machine and the SKIP controlled machine. This reinforces the statement that the early machines are good candidates for retrofits.

[ckm]

Cool! I've never actually seen one with an enclosure. Could you take a couple of more pictures of the enclosure (particularly how it interfaces with the base column) so that I can build one of those?

In post #2, I'm going to post pictures of my 'naked' machine. It's probably not possible, but, if you ever get a chance, I'd love to see what your electronics look like. Does the Meldas control run steppers or servos? 400 ipm, huh? I guess that's what I should shoot for as well.

A little later in this thread, I'm going to post detailed pictures of my current electronics, it'll be interesting to know if those are the same as the ones used on the Meldas machines.

Thx. for the great pictures, my are not as good, might have to re-shoot them... Esp. now that I've cleaned the thing.

Chris.

[Caprirs]

Some of the SKIP control 4400s had the same full enclosures as my M3 machines. Other SKIP 4400s had the smaller "table" guards as shown in your brochure scans. I cannot remember if it was an optional enclosure or something that was added to later built machines. I have seen at least three SKIP 4400s here in the Phoenix, AZ area that had the full enclosures and two that had the table guards.

I will try to take specific pictures of how the enclosure attaches to the base along with the electronics in the back cabinet.

The M3 uses servos and 5mm pitch ballscrews.

[ckm]

The DM4400 is one of the smallest mills you can get with a toolchanger. Although the 2800 is much smaller (it is a benchtop mill), the 4400 is a full size mill, much like a Bridgeport, but significantly stiffer as it is a bed mill, not a knee mill. As stated in a previous post, it was specifically designed for CNC.

Mechanical Details

The DM4400 is cast from Meehanite cast iron in six main sections:

• Base
• Bed
• Column
• Head
• Y-axis Saddle
• Table

Altogether, the mill weighs 4200lbs, and as much as 4600lbs when fully loaded (stock, tooling, coolant). It has hand scraped hardened dovetail ways with Turcite female surfaces. All ways have wipers, way covers, and the axis are driven by pre-loaded ball screws which are also covered. Both dovetails and ball screws are lubricated through a one-shot auto lube system. According to Dyna, the specs are as follows:

• Table Size: 28.7" x 10"
• X Travel: 14"
• Y Travel: 10"
• Z Travel: 14"
• Min. Distance from Spindle to Table: 6.5"
• Maximum table load: 300lbs
• Floor Area: 65" x 65"
• Height: 90"

The spindle is a 30 taper design which can accommodate either CAT30 or BT30 tooling. It has a power drawbar system with a air flush system and a tool changer which holds upto 10 tools.

Electrical Details

The DM4400 has a 4.5hp (6hp max) bi-directional spindle motor driven by a Servo Dynamics PWM amplifier (model 3030) capable of 30A @ 160v. It senses motor performance via a tachometer mounted on the spindle motor. In addition, the spindle motor is equipped with a brake. The spindle is belt drive, with two possible positions, 0-2400 RPM and 0-6500 RPM. The spindle motor has levers to loosen it, but it's not really designed to be done often.

All axis are driven by stepper motors with feedback encoders for closed loop control. The steppers are PMI/Kollmorgen SyncroSteps, their specs are:

X,Y & Z Axis

• 200 steps/rev
• 140 oz. in.
• 125 watts
• Parallel: .13 Ohms 4.6 A
• Series: .52 Ohms 2.3 A
• Shaft: .375" x 1"
• Size: NEMA34
• Overall Length: 3.25"
  (note: motor enclosure has a fan with a 3" dia. hole in enclosure)

The encoder is an HP HEDS-6310, specs are:

• Dual channel
• TTL 1000 count with Index
• Input 5 VDC

The stepper drivers are from Dyna and are apparently step/dir style drives (see photos below). They feed 48v to the steppers, which are then geared via a tooth drive 5:1 to the ballscrew.

The electrical system is feed by a large isolation transformer which requires at least 220v 3-phase. It can by be fed by a Wye/stinger configuration (with a 208v high leg). There are several other transformers in the cabinet, one for the steppers (48v output), one for the electronics (12v & 5v) and a secondary isolation transformer (which feeds the table light, among other things). There are also two timers, one for the e-stop system, another for the auto lube.

The DM4400 was designed to have a number of auxiliary systems:

• Probe
• Coolant
• Rotary Axis (one or more)
• Manual Pulse Generator (MPG/pulser)

The probe was plugged into the a socket in the side of the machine. It was used for tool length measurement as well as stock location.

The coolant system consists of a separate unit at the front of the machine. It is plugged into an outlet controlled by a relay. There are 6 other outlets to control other systems as needed.

The rotary axes are plugged into circular-style waterproof connectors also on the side of the cabinet. These necessitated additional cards in the cabinet to drive the rotary axes.

The MPG (or pulser) was a hand held system for moving axes. It plugged into the bottom of the console.

Tool Changer

The tool changer is a pretty complicated affair by hobbyist mill standards. It has bi-directional rotary carousel controlled by a stepper and a swing arm controlled by a DC motor. The controller sees it as two new axes, A and C. I'm not entirely sure which is which yet, but, basically, the tool change sequence is as follows:

1. Z-axis moves to tool change position (88 mm, apparently)
2. Carousel stepper moves to the correct (empty) tool slot
3. DC arm motor fires up and moves until the limit switch at the top of the arm contacts the spindle casting
4. Power drawbar releases the tool
5. Z-axis moves up to release the tool
6. Carousel moves to the new tool
7. Z-axis moves down onto tool
8. Drawbar clamps tool
9. DC arm motor reverses until hall sensor on column trips

All these movements are controlled by boards in the cabinet. Two of the boards handle the carousel stepper and limit switches, while another board turns and reverses the DC motor (at least, that's what I think).

Controller

The controller is a proprietary system which has the following features:

• Tool compensation
• Backlash compensation
• Pitch error compensation
• 3-axis circular interpolation
• Programmable spindle
• Rigid taping
• Polar and Cartesian coordinates

As stated above, it was designed at a time when computing systems were rather slow, so it's rather primitive. It also uses it's own language, not G-code. While it has two RS232 ports, there are only 999 lines of memory, so one would have to drip feed it for anything larger. One interesting feature was that the controller can be removed from the console for programming at your desk.

Performance

So what can it do? Well, according to Dyna, these were the machine specs when new:

Rapid traverse: 100 ipm
Cutting feed rate: 80 ipm max
Resolution: 0.0001"
Position accuracy: 0.0005" total
Position repeatability: +/- 0.00015"
Boring roundness: 0.0002"
Boring cylindricity: 0.0004"/4" dia
Manual jog: 0.0005" (0.01mm)

That's about it. More in the brochures from the first post. A bunch of pictures below. Mouse over for what it is. Next up, how to fix various broken things on your DM4400 (tracing and fixing wiring, fixing your spindle amp and fixing your hall sensor, plus whatever else I find is broken...), followed by retrofitting the DM4400 with Mach3.

[ckm]

The M3 uses servos and 5mm pitch ballscrews.

You wouldn't happen to know what the specs on those servos would be? I'm particularly interested in the speed and torque that were used. This would be useful in narrowing which servos I might choose for the retrofit.

Right now, I'm looking at Keling's NEMA 34 series (http://www.kelinginc.net/ServoMotor.html), but they come in 600, 850 and 1125 oz.in. versions. I think the 600 oz.in. may be enough (esp. with 5:1 gearing), but I'd like to know what the factory used to get 400 ipm

I think I may be able to mount them straight onto the original mounting structure by boring out the coupling on the original motor and leaving of the cover...

Thx.

Chris.

[Caprirs]

My M3 machines have Mitsubishi HA40CS servos on the X & Y and HA80CS on the Z. No idea on the specs but someone at Mitsubishi should be able to help. I believe the HA80CS on the Z is a "high torque" servo to deal with the Z's higher mass of head & counterweight.

[ckm]

Caprirs: quick question. Did your machines come those colors or where they painted? And if they were painted, how and with what?

BTW, did find the HA40CS here:

http://www.meau.com/eprise/main/sites/public/SERVICE_AND_SUPPORT/TSS_Parts_Catalog/-Part_Detail?matnrid={465F47AB-3423-48AF-9B80-7AB7C3EAE656}

and the HA80CS here:

http://www.meau.com/eprise/main/sites/public/SERVICE_AND_SUPPORT/TSS_Parts_Catalog/-Part_Detail?matnrid={DBEFE200-0342-4ACB-BC33-DA797A7DE778}

The specs of these motors are as follows:

HA40CS
Rated Torque
30.0 kg/cm at stall (2687 oz.in.)
27.2 kg/cm at 1000 RPM
24.4 kg/cm at 2000 RPM
Max. RPM 2000
Weight 8 kg

HA80CS
Rated Torque
60.0 kg/cm at stall (5375 oz.in.)
54.4 kg/cm at 1000 RPM
48.7 kg/cm at 2000 RPM
Max. RPM 2000
Weight 12kg

Attached is the spec PDF.

Damn, those are some powerful motors. Much, much more than the 140 oz. in. steppers on the SKIP-based 4400.

As a side note, I removed the Z-axis stepper today to have a good look at it. After I had taken it off, I freaked out as I suddenly realized that the head was now totally unsupported and I had just taken off the stepper... I remembered hearing that ball screws could be back driven and feared the head would coming crashing down. After running around the shop looking for appropriate wood, I secured the head and tried to see if it would move. Nothing, nothing at all, it would not budge. I didn't push hard, not wanting to tempt fate....

This little adventure, however, leads me to believe that a Z-axis brake is perhaps not necessary. I had been doing some research into this, but it seems that the combination of dovetail ways and a counterweight may be enough to hold up the head. For safety sake, I probably really should have a brake, it's just that I haven't found a suitable solution yet.

The fact that the factory servo comes without a brake also suggests this is an acceptable solution....

[ckm]

[since I can't edit a post that's only 3 days old, here's a new post with new scans]

Updated brochure scans

[ckm]

I'm now wondering if the factory servos on the 4400M are actually geared differently than the steppers on the older 4400C.

If I look at DC servos commonly available and in the same weight range as the AC units from Mitsubishi, they are around 600 and 1100 oz.in. respectively. Geared 5:1, they would be roughly the same power as the AC servos on the 4400M....

[Caprirs]

No gears on the Mits machines. Direct coupled to the ballscrews.

The head likely will not drop with the 5mm pitch ballscrew. On machines with a 10mm pitch ballscrew, the heads can creep down when the power is switched off which generally indicates the gibs need to be snugged up. There is typically enough friction in the dovetail (when properly adjusted) to prevent the head from dropping so there is no servo brake on the Z axis of my machines.

Those colors on my machines are the ones used on all Dyna Mitsubishi machines: 4400, 4500, 4800, 3300 (lathe). There are numerous layers of primers underneath. As the coolant and chips have taken their toll over the years, there are areas where huge chunks of paint are flaking off.

[123CNC]

Is the 4400/4000 a vertical knee mill or vertical bed mill. Just a little confused by location of thread. Nice pics though.