Maho - gross positioning error Y

[AlfaGTA]

Don't think they (DMG) are setup for walk in trade. The bulk of their customers are industrial accounts and therefore use PO's and billing to an accounting department or the like. I know it is a bit of a headache but just establish the account adn that way when you are ready to buy tat DMU80 you can just call them up and say "Ship it"
Good news about the bellows, and the price is not out of line i don't think.
Cheers Ross

 

[toolmkr]

The price is about what I expected (500+).
As Don said, if you consider time lost designing or redesigning something store bought, price could very well triple.
This machine has bellows, as well as steel blinds on the Y axis. - I think DMG got that part wrong, Y axis should cost more than the two pieces for X axis.

there's a picture of the Y on this post:

http://www.practicalmachinist.com/ubb/ultimatebb.php/topic/1/22826.html

 

[AlfaGTA]

Toolmakr:
Be careful, as the axis designations are different between the Deckel and the Maho. Possibly the parts person is confussed...did you order the parts using a part number that you supplied from a parts book, or did the parts person on the phone come up with the number...might want them to send you a fax of the parts book page showing the part they are quoting.
Cheers Ross

 

[toolmkr]

we were able to find only one part number in the info that came w/ machine that even sounded correct: bellow horizontal
this is in a list of (probably most replaced) spare parts in the back of the operators manual.
we gave that p/n to the DMG phone person.
I think the price was for 3 of the X's.

Do other machines have bellows on the Y axis (vertical)
The one Don posted pics of didn't.

 

[Milacron]

Sam, I've never seen bellows on the vertical of a Maho. In fact I've only owned one Deckel that had vertical bellows...seem more hassel than they are worth to me.

 

[toolmkr]

Yeah, they just about need to be removed if not feasable to replace; before they start to collect, rather than repel.
These are ok, since it has the "blinds".
If it wasn't factory, someone did a professional job.

 

[toolmkr]

it's amazing how that blue coolant makes that enco vise look like a Kurt.

 

[Hal]

Hello toolmkr
What control do you have? On my Maho it says CNC 332. The control is actually a Heidenhain TNC 155.

In the past, I would occasionally get a similar message but on the X axis (X measurement defective). The machine would come to a sudden stop and the only way to get it going again was to turn the power off and on and home the machine.It would run fine for a few days then do it again.
I kept the heat turned down in the winter (I realized this happened only in the winter) so it was a little frosty in here during the cold snaps. I insulated the door near the machine and turned up the heat. I have not had this problem in a couple of years now. It is a wierd one.
On the off chance that you have an air conditioning duct blowing cold air onto your machine, that could be part of your problem.

For D Thomas' amusement, I am including a picture of the Y axis covers on my machine.

Hal

 

[toolmkr]

Hal,
Mine is a CNC 232 - Heidenhain.
I still get this alarm, but if I program a short distance at a feedrate, then rapid- it works.
I removed the bellows to make sure it wasnt just packed with chips- none.
Vertical ways look brand new.
How much way lube does your machine use? I marked the resevior about a week ago, machine has ran close to 8hrs/day avg; level is down about 5/8"
Doesn't seem like enough.
Not sure how to change it, though.
Do you know how to send out parameters via rs232?
Sam

Nice machine, how old? maybe '89-ish?

edit: no email address for you in profile, if you don't mind, I'd like to ask about a million questions; please email me

[ 06-22-2006, 06:38 PM: Message edited by: toolmkr ]

 

[toolmkr]

on the way oil consumption, or lack of--
The way wipers on all axis (like the ways) look perfect.

 

[AlfaGTA]

toolmkr:
Would be tracing every lube oil line on your machine and removing every feed check to see if it was delivering oil at its output. Very hard to tell just from general oil on the ways as the wipers tend to keep the way surfaces pretty dry if they are working properly. Would check to see if the vertical slide was sticking. easy test is to mount a magnetic backed indicator to the way surfaces with the plunger touching the moving part. Move the slide almost full down, wher it does not see much use. Fit your indicator and zero the dial in mid travel...use a plunger style indicator not a lever test indicator. If you have a MPG (electronic handwheel) set it for a coarse move per click. move the slide (Y) one click down and watch the indicator. if the dial moves crisply the required amount, then no slide stick. But if the slide moves in a jump and goes too far and then comes back to the correct position , the slide is sticking and lube, ball screw, thrust bearing or dirty/out of round tacho can be the problem.
You did not say , but what lube are you using on teh machine? There has been some discussion of Vactra on teh general forum. The formula has been changed so the lube is not the same it used to be. The current Mobil product that is as the old Vactra is now Vacouline (sp?) and there are different series numbers for the weight... I am currently using a product made by "General Lubrication" that is called "Diamond". The nice thing about the Diamond 1020 (ISO 68) and Diamond 2050 (ISO 220) is that it is the same as the old Vactra, but lacs the wax that is present in most way lube. The Diamond is almost clear in the 1020 adn slightly amber in teh 2050. This lighter color is nicer on my machine finishes (less staining) and less likely to clog a feed check. I would deffinately try to isolate and cure the fault problem before running the machine any great amount...could be causing excessieve wear.
Cheers Ross

 

[toolmkr]

Ross,
Have done as you suggest with lube system, and have found what is definately a problem-- I dont seem to be getting any oil to the feed lines out of the (1st) manifold, which has 6 lines out, and thru-feeds to other manifolds. The thru feeds work.
the feeds on all the manifolds use this type dist.

I removed and tried to disassy/clean (hrs), but the bottom pistons in the die cast manifold were stuck. Soaking and gently pulling didnt work on three of them. More drastic measures follow---
pressure.

If these bottom seals are damaged, what then?

Should I be looking to replace internals, or the manifolds?

 

[AlfaGTA]

toolmkr:
Now i could be just a spend thrift, but for my nickel it isn't worth taking a chance on "Maybe". Messing with overhauling those checks is iffy at best. O rings get swollen from the oil or waxy build up. Just find where you can buy the replacement units and replace any suspect ones...buying new lube checks $100.00. Correct lube to your machine Priceless!
As an added note i swithched my way lube from Vactra 220 to a product made by Diamond Oil Company called "Diamond 2050" The main reason is that the Diamond still has (i am told) the tackifiers that have been removed from Vactra, and Diamond also lacs the coloring wax that Vactra and other way oils have. This is nicer on the paint and easy on, you guessed it , the sticking feed checks.
Cheers Ross

 

[AlfaGTA]

Toolmakr:
Guess i was typing while you were...If you can i would replace the one piece manifold with a built up unit where you can replace the individual checks. That is the way my Deckel is setup. It has a manifold that the individual checks fit to like the Group 320 on the page you posted. Possibly you can get a repair kit for the checks..new pistons, o-rings etc. Let us know what you find out.
Cheers Ross

 

[toolmkr]

I'm convinced the lube system is working correctly - as it is designed.
We assembled the dist. block (manifold). Cleaned, purged, etc. Used Shell Tonna
Checked pump pressure (300#)
This "spits" about 2 drops each time the pump creates pressure, then looses pressure.
I'm looking into best way to increase-

Cleaned and readjusted scale (DMG said do that first)

I've got the machine in running order with all guards removed, everything visable.

Sometimes, when you jog, y axis motor is wandering- you can see it-- maybe as much as 10-20 degress in both/either direction. other times a crisp stop.

DMG still says it's the scale- probably replace reader (glass scale "looks" ok). But, the guy I talked to wanted to talk to another who knows the most about the older machines - didn't call back today.

Ballscrew "looks" ok,
There may be too much backlash in the differential???

Noticed oil on the timing belt for Y
Belt doesn't feel spongy, but if the belt was stretching, wouldn't that do it?

As I said before, none of these alarms (and for that matter, no alarm I've seen so far)
are mentioned in any documentation I have.
The "Gross Position Error Y C " alarm is not the alarm for a malfunctioning scale.
When indicating the scale, if we moved the scale or reader to much, it would estop and that alarm was something like "Y axis measurement failure"

Belt is looking like an oem part

 

[toolmkr]

It's fixed!
Turn out to be the oiling.
DMG never have called back.
We have checked, indicated, cleaned, adjusted etc.
The more we did, it started wandering after stopping, then later, stick-slip.
We removed the way "clamps"- cleaned back of ways and stoned off the clamp and the turcite just enough to evenly discolor.

There was a fair amount of dried oil/coolant lower than the area the wiper cleans- and maybe the turcite stuff had swelled some. (Karl Reis said that was common, along with the diff/ ballscrew mount loosening up - and mine was)

Thanks for everybody's help!
As always a great forum
Sam

 

[Milacron]

Just found out yesterday that I need 2 Maho bellows for the X axis of an MH400e. Actually a more impressive mounting system than Deckel uses, with 2 rods that extend all the way from one side to the other and each bellow flap has it's own wire hook top and bottom, that rides on the rods. Nonetheless the fabric is kaput on my MH400e... sure hope they are less than $222 each for the smaller e Maho...

 

[Milacron]

Word came down from on high yesterday...$307 each for MH400e X axis bellows

 

[sneebot]

Ouch. I assume that is from DMG. Are they available from that place in Germany that you had quote the multi-axis Maho table?

 

[Milacron]

Ouch. I assume that is from DMG. Are they available from that place in Germany that you had quote the multi-axis Maho table?

Yes, DMG. Re German source..probably, but unlike Singer and FPS, they seem more "high brow" and are less responsive to emails. So while I really don't know what their prices would be, I have the impression they wouldn't be enough cheaper to matter.

Since I'm in no hurry, I contacted Gortite this morning and will see what they have to say. I hope they have some Maho bellow specs in their files already but if not, I have enough of the original material left to send in the mounts and a few pleats for them to quote and reproduce.

http://mmdwm.de/e_home.htm