Dyna DM4800 pre purchase questions

[kentster]

Greetings,

I've been interested in CNC technology for years but only recently have I seriously pursued building or purchasing a machine. Until last week I was on track to build a Machine Tool Camp based router, however, my true interest lies in aluminum.

As luck would have it, an opportunity to purchase a Dyna DM4800 with a Mitsubishi M3 controller and tool changer at a very attractive price presented itself last weekend. The machine appears to be in good condition overall and has newer thrust bearings on all axis.

Aside from potential mechanical or systems failures associated with aging units, is there anything particularly negative about this machine that I should be aware of? In the event that it's relevant, I intend to machine aluminum prototypes with it and rarely if ever will it see steel.

In closing, I have a few questions

1. Are there any PC integration options beyond possible simple file transfers without performing a retrofit?

2. Does a 4th axis option exist?

3. Is a faster spindle swap possible?

3. Is any type of special bracing required in order to move the machine? I plan on using an air ride semi trailer as the unit is several hours away.

If anyone can shed a bit of light on the questions I've posed I'll be extremely grateful.

[Caprirs]

The DM4800 is a heavy machine. Box ways, 40mm diameter ball screws, etc. You can cut anything on that machine as it is very rigid.

There are no PC integration options other than what can be done through an RS232 cable. If you are ambitious, the machine can be controlled remotely as part of a flexible machining cell or integrated with an external device like a robot for automated loading/unloading. However, there is no provision to view files stored on the machine from a remote PC, nor can the machine view files stored on a PC.

By 4th axis, do you mean a simple indexer? Or a true live 4th axis? The machine has M codes already to work with an indexer although a couple relays may need to be added. The replays may already be installed on the machine. The M3 control can control 4 axes continuously if you have a true 4th axis with servo and amp. I have a wiring diagram for wiring up a true live 4th axis if using Mitsubishi servo, encoder, and amp.

The machines were available with a 10K rpm option. To covert, you'll need a new spindle, spindle pulley, motor pulley and belts. The standard 6K rpm spindle uses a timing/cog belt. The 10K rpm spindle uses poly-v belts.

To move the machine, start by supporting the counterweight in the column. On the side of the column, there should be a hole where a 1'-2' bar can pass through. Move the head up/down until the bar can pass through the column and through the hole in the counterweight. With the counterweight resting on the bar, raise the head gently using the handwheel to just take the weight off the chains between the counterweight and head and place a block of wood under the head (just behind the spindle). Let the bar in the column support the counterwieght and the block of wood support the head. There should be slack in the chains.

You'll also want to prevent the table/saddle from moving. A couple pieces of angle iron and some t-nuts to the table should be plenty. Also, the tool carousel needs to be restrained as normally it is held in the retracted position by air pressure.

[kentster]

Thank you for the thorough response. Unfortunately due to communications issues the deal fell through, which is unfortunate as I've become quite fond of the machine. This particular example was $4000 for a 1997 model which outwardly appeared to be in great shape.

I intend to continue my search but units with the M3 controls appear to be few and far between. Based on my limited experience, this seems like one of the best values on the market in the sub $10,000 category.

[lathe tech]

If the machine is still for sale please call my cell. I'm looking for a replacement mill. My dm4800 was in a fire lost the control and z servo & spindle740-7011054