Retrofitting a 1986 Maho MH400E

Hi to all, OldTony the reason the tool change is taking to long is probably air in the system, you can keep one of the valve for the z axis locking mechanism, so you don't have to find servo with brake for that axis. And operate the horizontal spindle from a separate valve from the vertical, with this mod the tool change time will be 1/2 of the original.
John

You can even fit a switch that detects the position of the arm that support the vertical head. That switch will tell the controller witch valve to operate.
John

Thanks all, great info! My confidence level in actually pulling this up is slowly rising.
RSMP - thank you for the drawings, looks less intimidating than it does from the outside. Re: video background - zilch! Don't have to go too far back in my videos to see my learning curve. But I appreciate the innuendo.

Andy & drimaropoylos, thanks!

I feel bad hijacking this 400E thread, as I make progress I'll start a separate one.

I haven't put too much thought into controls just yet as I want to tackle the ball screw installation, but I leaning towards trying the 'new' EtherCAT stuff.

-OldTony

Your machine probably also has Heinenhain LS-403 encoders. My mill still had the original calibration reports for the scales in the door. Heidenhain measured the scales at 10mm intervals, and none of the three has a deviation exceeding a single µm. I'd really recommend making your retrofit a closed loop system using these scales. This is pretty easy with Mesa 7i77 (if you use analog servo amps) or 7i76 (for step/dir).

Mark

Talla83 and Nomei's excellent pendant:


...motivated me to get off my butt and make some progress on mine. When I hogged it out of 7075-T6 billet, I failed to notice that the switches on the back of industrial buttons are bigger than the buttons, and didn't make enough space to fit them. Fixed that by simply plunging an end mill to create some more space. (no photos of that

I didn't know of those guys plans to design around the Mesa SSerial interface, and connect with an ethernet cable. Since I have enough I/O pins free on my 7i77, I'm just hardwiring mine.


The E-Stop will wire into the MAHO hardwire provision for their E-Stop pendant.
The button will be tool release. I'll kee the existing tool release button on the control panel, and add a second, so this with need the "OR" comp in HAL.
The two rotary switches are for axis select and jog increment.
Mark

Fine job on the pendant and a great accessory to have on a tool room mill. At some point when I fix my Maho up I will surely take some inspiration from your posts to make my own pendant.

Thanks. I would really recommend building the one from those guys. They have designed a circuit board and written a microcontroller program to output the Mesa Sserial interface. Seems like a really well thought out design, and you can simply 3D print the housing from their model in Thingyverse. Had I known of that project, I would hae done it.

Peter has posted it all (in german) on his website. I am sure he could support questions about it in english.
www.talla83.de/
Mark

Nice! I don't have a 3d printer so I might machine a housing from some scrap or cast a polyurethane version from a tooling board mold. Not in a rush though! My Maho has some issues that need addressing and I'm currently working on a CNC router which is faster and has a larger envelope for sheet stock.

However I detest using the router for aluminum even though it's plenty good in terms of specs (the mist coolant is horrible to use without an air exhaust and with a compressor like mine, and yet without the coolant super expensive endmills break like there's no tomorrow; it doesn't have covers so chips fly everywhere and the work envelope would make it awkward to make regular covers, it sounds almost like a table saw when cutting metal, etc.) and the Maho is also far more precise.

Soon enough I will learn basic German just to take advantage of the wealth of technical information available in the language. I've already assimilated some stuff through internet induced osmosis.

QUICK EDIT: I'm already loving the videos on Talla's site! Machining a three jaw chuck for an SK40 tool holder in a mill using a turning tool in a vise (on a retrofitted tool room mill with an extra side spindle no less) is why YouTube exists

There are plenty of online services to get 3D prints make cheaply. I would be tempted to do a lost PLA casting of the 3D print for a nicely shaped aluminium housing.

I have the components for a mist cooling system, and was planning to install it on the MAHO, alongside the flood cooling, next time I need to pull all the covers off. I like the idea of the air blast for clearing swarf from deep cuts.
Mark

Honestly, IMO flood coolant is leagues better. At least on my machine the pump is good enough to clear chips away from the tool and (this is also very important), the flood coolant actually, you know cools the tool. So there's no risk of chip welding when cutting aluminum.

Mist cooling is great if you have an industrial grade air compressor, preferrably hidden in some wall compartment behind a sound proof wall, and the work area of your machine is fully enclosed like in a modern VMC.

My tank of coolant says I should avoid contact with it, so having it sprayed all over the shop in tiny molecules borne aloft on jets of smelly compressed air is just not my idea of a good day at work.

EDIT: probably should've added that often the air blast is unable to reach deep cuts properly without me constantly finessing the exhaust while the machine is working. It absolutely must reach the endmill or your tool will build up chip weld and break. No such issues with flood coolant, it can run on high speeds without a hassle because the emulsion gets everywhere even if it doesn't hit the tip of the tool.