MAHO'n it in the home shop

hi and welcome back to our channel this week we're going to do a little different programming a lot of people have asked me about my mill so let's talk about mills of course it all started with buying a lathe this was my first lathe and for a long time it was my only machine tool so i did a lot of milling with it as well as you can imagine it's not a great lathe and it's an even worse mill sometime later i got my first real mill yeah no it's it's not actually a mill it's a engraving frame which i got from the scrap dealers for 20 bucks and i just put an overarm on it with a er 16 collet spindle it's also not a very good milling machine better than a lathe but still not great this is a single car garage and like all single car garages no cars fit in it the reason why no car fits in my single car garage is because of this in an attempt to stop this channel's number one fan neko from putting a i don't know some sort of a broken down car into my garage i stuck a 1.2 tonne milling machine in the way yeah you'll be thinking this is all the trend seems these days everyone on youtube is getting a maho what's so special about an e well glad you asked i don't know i think e stood for economy mahu's made a bunch of machines over the last 50 70 years called mh 400 starting with some manual ones this doesn't really tell you too much the four means that it's the size they made series like the 400 5 6 8 i think a thousand series getting bigger as you went through but it's the letter at the end that counts all of the maho mh machines are their take on the classic decal style with a rigid column a y axis going backwards and forwards on the top of that column a saddle which goes up and down and then the table moving sideways as an x-axis on that saddle the interface allows you to drive various accessories like in this case i've got a vertical head or the slotting head well this is the overarm for driving horizontal mills these must have been a pretty typical and common trade school machine back in the day this was made in 1985. the seller said that it came out of the trade school in pasal called the hanvex kamapasa i tend to believe that seeing as i asked dmg and they confirmed it and as you can see it's had very little wear just enough time for some students to screw up a bit but then probably had some sort of a defect in the control the school probably couldn't afford the call-out rates for a commercial cnc service and it probably just got pushed into the corner where it then sat for 30 years at least that's what i'm guessing so what i'd like to do in this video is comparison of retrofitting an old industrial cnc machine versus a retrofit of some sort of a manual machine and the second thing is what i actually did to this i did think about doing a conversion of a rongfu 45 like this awesome one done by 91 tsi guy i'll put a link in the description i even got as far as downloading these awesome ked models that were done by a guy called kcj once again link in the description so i was sort of thinking of doing a cnc conversion but i had a bit of difficulty getting my head around the buying a machine for maybe two and a half three thousand clams and then effectively throwing away everything except for castings and that's what kind of got me thinking about ah maybe there's a better option first up let's talk about the mess of these things right this is an industrial machine i mean look at this look at the thickness of this base casting even the lugs here on the side which are only put there to hold the user interface module are like 15 maybe 20 millimeters thick so three quarters of an inch thick cast iron just to hold a computer there's nothing like mass in a machine tool to aid you with stiffness and damping and things like that that's just the base of course the main casting is also similarly massive my comparisons with the wrongfu 45 because it has roughly the same travels as the maho and it's popular a lot of people are doing it there's simply a lot less mass in this i think this is around 270 kilograms whereas the mahou weighs 1.2 tonnes now you might be thinking that at least there's an advantage in the in the space required and the size of the machine if you go to a mill retrofit but realistically if you're going to use an enclosure it doesn't really matter what the mass or size of the machine is because they all end up with the enclosure taking up most of the space you can see this machine is about sort of a meter and a half wide with the control cabinet on the side it is probably a bit deeper than a converted rongfu because it's about once again a meter and a half deep next up let's talk about cost this beast cost me 2 400 clams and it was brain dead i couldn't test anything all i did is i looked at it the ways looked as new as does the paint and the paint's obviously the original paint job so my goal when buying it was to try and get the original controller working but failing that i figured i had good mechanics and would just need to do like a linux cnc conversion on it didn't have much clue of what that would cost at the time but figured hey this is a hobby let's give it a go this cnc conversion only cost me about an extra thousand on top of the purchase price of the machine now the basic rongfu 45 is going to cost about the same two and a half thousand but if you want it as a cnc you're then going to dump the lead screws buy ball screws make up mounting blocks bearings nut carrier motor mounts have to get a set of motors get a set of motor drivers make up cables between the two the head probably going to be a morse taper head it's a good system some people like it but most people are going to probably convert the head put in a different motor a higher speed range probably put a vfd on a variable speed mode to get a variable speed motor as a cnc with dovetails you really want an oiling system on there to prevent galling you're going to need a stand for it to sit on you're going to need to make up an enclosure for it looking on the cnc zone at some of the awesome conversions people have done of these they all seem to come up with a price range of around ten thousand as a third sort of criteria to think about we get into things that are a little less obvious things like performance let's take a look at the spindle for example industrial machines aren't built down to a price they're built up to a standard the people who designed this were professionals they probably spent their whole career designing machine tools it wasn't like us amateurs look at something like i need an x-axi ball screw what can i fit okay i can fit a 16 millimeter ball screw so that's what i'll use designing a machine like this they would have had a design target for example dynamic stiffness of let's call it 30 newtons per micron of deflection between the work and the tool spindle and they would have gone through the entire design process and iterated to ensure that this machine meets that design goal stiffness of the the bearings stiffness of the housings casings belts between ball screws and motors all of these would have been engineered and analyzed to ensure their performance this is a footy taper spindle with hydraulic tool release and very very high quality bearings now we've all been enjoying this old tony retrofit of his maho 400p model i just thought i'd show this e model just to show that things don't have to be as complicated as uh as tony has to make them see one of the cool things about cnc is it can be pretty simple you know back in the days before cnc you had these hideously complicated machines you know another example is is tony's beautiful show blind machines like this are made similar to swiss watches with a huge bunch of gears and pulleys and to enable you to have feed drives on the axis well once you move to cnc this can all be much simpler because the three axes are just a ball screw a pulley and a big-ass motor to drive them each independent from one another the only thing that holds it all together is the computer here you can see it that motor belt drive ball screw for the x-axis same thing for the z-axis you've got a ball screw driving the saddle up and down pulley back to a motor the only thing different being this motor's got a brake on it same thing on the y-axis same sort of motor belt drive ball screw i must say i found the concept of retrofitting this machine quite daunting i actually remember the discussion i had with my wife sort of along the lines of hey i found this machine and it's really awesome and it's like in perfect condition and it's it's like a fantastic price i mean it doesn't work and she's like you want to pay thousands for a dead machine that weighs 1.2 tons are you crazy and it was daunting because when i got started on this i really had no clue the first time i got into this control cabinet i really didn't understand it the moderator of the practical machinist dekel maho forum milicron always recommends against trying to retrofit a machine like this he feels they're far too complicated there's far too many people start them do a half-assed job give up and end up just ruining the stock of good machines out there and i get that i mean i understand where he's coming from i think one of the most important things to get your head around with a machine like this is that industrial machines are extremely modular in my case this machine obviously has a lot of relays controlling the gearbox and the spindle you've got power coming in three-phase power with a main disconnect switch you've got breakers all in this area then you get into the major relays for switching the main loads like the spindle why does this machine need so many because it's only got a dumb three-phase motor plus it needs to turn it forward and reverse with just 90 volts as sort of a twitching function when it goes into gear the next thing that's awesome about an industrial machine is everything's annotated and there are wiring diagrams so for example this node here 156 is exactly here it's these wires into into terminal 156 all of the nodes are numbered and everything can be found the next area you see here is the actual brain the computer running the machine so this is it the mighty philips 432 weighs a ton and it's a computer with a whole bunch of very very big cards that get stuck in there and a big power supply module at the end a few nerds who are into this sort of stuff let's take a look at the central processing unit down here at the bottom is the central processor it's an intel 8088 this was probably the lowest specification version of the philips 432 that was offered was probably the cheapo for the school system this version's not capable of fully coordinated 3d moves it can only do a two and a half d so two axes at a time i believe there are versions with a a 286 or even a 386 processor that were able to do fully coordinated five axi moves had i been able to troubleshoot this and get it running i probably would have just left it the philips 432 has an excellent reputation as a controller people say it's got a lot of very useful canned cycles i believe it's got a very uh user-friendly way of stopping in the middle of a program and then restarting from the same place however on mine i never managed to get anything other than snow out of the monitor i put an oscilloscope on the video card looking for the hsync and vsync signals but never never found anything and by the time i looked at the price of repaired or even just used cards off ebay it was cheaper to retrofit and this is what replaced that philips 432 this is just a standard itx sized computer i'm not sure what i'm running i think it's just something like a celeron 1500 or something sort of processor nothing too special there's no great expectations on graphics cards it's only got i think two gigabytes of ram in there so it's all pretty simple the main thing i got it for was it's got a pci card and this is a mesa 5i25 pci card the concept is linuxcnc runs on the the main computer but it offloads the trajectory as a set of vectors to the processor on the mesa card and then the mesa card does the actual fine timing of the the machine control the control is over here on this board which is connected directly to the d5i20 and this is a 7i7 now the cool thing about this is it's the interface for analog controllers for your drivers so up here above the brain is the intramed this is just an old analog dc driver unit using plus 10 volt through to minus 10 volt analog signals converts that into a velocity control command for the motor which are just big dc motors dc brushed servos the motors have got resolvers on them so the feedback loop for velocity is closed within the intramad all i had to do for each of the three axes connect up those two wires to two pins on the 7i7 two wires are simply the wires that send the speed control command if it's sending a command between those two of zero volts the thing knows to stay stay still you give it a command of five volts it goes at half speed in one direction give it a command of minus 10 volt tells the motor to turn at full speed in the other direction and there's no feedback back into linux cnc from the intramat however that only closed the velocity loop to close the position loop so the machine actually goes to where it's supposed to go we have position feedback through glass scale linear encoders on all three axes the y-axis encoder is located using a rod made of invar this is an alloy which has almost no coefficient of thermal expansion so it compensates for thermal expansion of the gearbox fun fact heidenhein included the original calibration protocols for the linear encoders with the machine and if we look at the certificate of inspection for this scale for example we can see that the maximum deviation over its half meter measuring length is 0.6 of a micron linear encoders put out a analog sine wave and this board here which is the high dehyde xc is used to do the analog to digital conversion it's a 3xc board unfortunately two of my axes are dead and have had to be replaced i was able to pick up two standalone modules off ebay for only about 75 bucks each they do exactly the same function but the feedback signals from those encoders get fed into this line of 7i77 and allow linox cnc to close the loop so that it actually goes to the commanded position realistically if i was going to do this again i wouldn't bother recycling the 3xc board i just buy three of those now we already talked about all these high voltage 400 volt three-phase motor control relays how do we switch them glad you should ask because hanging on the door is this low voltage relay module each of these is a 24 volt dc relay this is all original these used to be controlled by these two ribbon cables from the philips computer and all i did was butcher those input and output cables put them through a another mesa board this is called the 7ia84 it's just an i o board all of my inputs and outputs are now controlled through this board which is of course plugged into the other mesa boards so the surprising thing i guess is that's it i didn't touch any of the mechanicals of the machine i didn't touch any of the main electrical wiring the original e-stop chain and all of that stuff's still original the motors are still completely untouched still originally as connected to the injurement driver all of the wiring from the low voltage control electrics to control all the high voltage stuff the gearbox etc all of that stuff is completely untouched here you can see the original maho user control module and so i made this it's much thinner it mounts onto the original arm at this stage which is massively overbuilt for this and i may well change it in the future and i use most of the original cables the housings welded together out of three millimeter laser-cut steel and then a stainless steel face plate also laser cut so i designed my control panel around the the linux cnc interface called gmcapi designed by a guy in germany called norbert and it's a truly awesome interface it's set up to allow these soft keys around the edge these ones always have the same function but these ones change function depending on which screen you're in i put a set of physical buttons behind here these two have to be held together to latch the machine into its normal state we can home the machine e-stop drops it this is a purely mechanical e-stop it's the original maho e-stop you can hear in the machine goes on the lube unit runs for about 15 seconds and then it repeats every 20 minutes so once again we can home the machine there are no home switches as such on the machine it uses the index marks on the the linear encoders to find those positions i've got a physical tool release button here just runs the hydraulic pump to kick out the tools the springs return the tools i think i got the engraving wrong on this one there's a couple of these two buttons i got back to front so i just put some stickers on them next time i'm in get inside this i have to go in there and fix those coolant on off works spindle clockwise anti-clockwise work this is all a touchscreen interface so for example for jogging i can change the jogging speed anything up to the max there's a slow jog button so you can jump between the tortoise and the hair plus you can jump in into jogging increments you can set that yourself in the any file i find i don't need anything less than a hundredth of a millimeter so that works fine for me i've got the the buttons on the switches working but i wasn't able to get the encoders working correctly yet i need to troubleshoot those so next up this we're in jog mode let's switch to the mdi mode let's change the speed shootings i quite often use a usb keyboard from doing a lot of writing m3 changes gear analytic goes and we can stop the spindle such as your standard mdi next up we've got the program mode so here we can pull up a program like our telefish there we go here's just a program to run our telefish you can move things around on the with the touchscreen you can look at the isometric view you can look at the side on x and y look at it from the top zoom it down the bottom you've got your run your run program a stop you can put them turn on and off your optional pauses uh you can run single single step or blocks and if you want you can put the picture in the big screen to make it look pretty i used to do that you really want it in the zed mode then it looks real pretty you can also edit programs it pulls up just one of the standard text editors mouse pad or something gmos or something like that it doesn't really matter they all work kind of the same nice thing is it does give you a bit of a ide sort of function highlighting you know whether you've got g codes or m codes or functional codes in there next one down is the settings page you also have like an oscilloscope function in here so which was really useful for tuning in all the axes back out of there the next thing we have is a macro page which i've currently got set up for probing you like with a 3d touch probe but i don't have a 3d touch probe yet what i do want to add to this is a is a plugin called native cam which gives you a way of doing sort of like conversational programming right here on the machine so that's something i need to still set up going back into the jog mode you also have your touch off so you can touch off an x y and z or you can put in a value for x y and z plus you've also got your your whole tool offset table which is setting up all your tooling i've got two ongoing projects one of them is just this tool height setter it's just the standard one you buy off ebay i made a base plate for it that's just needs to be wired in and i need to learn how to use it and the second thing that i made which i really need to finish the wiring on the machine side because this is finished is this pendant it's nice and robust i milled this out of a big block of 7075 t6 aircraft grade aluminium which i bought from boeing surplus a bunch of years ago it's been following me around ever since i recycled the hydraulic button off the original maho controller and also the e-stop button and then otherwise it just got a click between x y z and maybe a future cxc and continuous one millimeter a tenth or a hundredth of a millimeter switches and a jog wheel something i really need to get get up and running but to get this installed i do need to run more wires in between the control cabinet out to my control module and i just haven't got around to it now all in all on this project i learned an awful lot to start with i couldn't even read an electrical schematic i had no real idea of how the thing was set up you know there's a lot of help out there the linux cnc forum guys were just awesome i'll post a link to my thread in there it runs for about 150 pages there's a lot of just discussion in there as well but got fantastic help from all the people on the forums compared with millicron's worst case scenario that you just end up ruining machine like this i guess i got lucky i got a friend who's a professional programmer he programmed the gearbox control module for me rather than ruining this machine i believe i've actually improved it one it's now full 3d capable it can run all three axes at the same time two i'll soon have the provision for a proper jog wheel which phillips never offered for the 432 they only ever had sort of button controlled pendants and this i believe is a real advantage i've got full control of the gearbox through the machine that's put in an s code and it automatically changes gear for you linux cnc being modern of course has none of those issues with limited memory so you can run codes that are tens of thousands of lines long without any problem you don't have to go through rs 232 drip feeding or any of those sort of nonsense i think that gmc pie interface is a great improvement on classic 1980s interfaces on the whole i don't think i've lost any of the original functionality maybe except some of the canned cycles but even there i just need to implement native cam and i should have even better canned cycles the machine still does everything it could do well there you have it thanks very much for watching and look forward to seeing you back here again you

Channel: RotarySMP

Views: 67,354

Rating: 4.9329948 out of 5

Keywords: This old tony, CNC Mill, MAHO MH400E, Filthy, LinuxCNC, Heidenhain, Linear encoder, Gmoccapy, 400P, Rong Fu, RF-45, Milling machine Autopsy, MIlling machine

Id: LXwbRhgq1og

Length: 24min 53sec (1493 seconds)

Published: Sun Sep 20 2020