Thread: Noise from MH 48 mill

Hi Ben,

I'd be interested in the responses to this. I have a 45 size mill and the geared head makes clunkety clunk noises in all gears. I have totally stripped the head, removed all the gears, bearings, cleaned and put back together with clean oil but it sounds the same. Not sure if it's just the slop or backlash where the spline from the quill mates with the final gear?

The machine runs fine but it's not the sort of noise I would expect from a "precision machine tool"

Cheers,

Simon

Thanks for the reply Simon. I kind of got the feeling it's just the way they run. Mind you I have never used a mill before... Kinda makes my opinion a non event!

Hahaha I love H&F's marketing! I got the best I could afford and that was the 48 with all it's plaster and paint coverups... There are so many silly little things wrong with mine. For example, the DRO scales and the power y feed cover up 2 oil ports..actually on that note the oil ports are more like dry paint ports anyway, one of the brackets for the coolant pump is about 25mm to low so the tank rattles. The standard plaster they used to smooth out the base sand castings does not hold onto the paint. Etc etc..

Actually, I think if you sneezed hard enough in the general direction of the base, you would probably strip off some enamel.

Having said all that and even before I mill anything on it, I think I'm going to like it!

Mine sounds like the gearbox is about to have a hernia, but I think it is just a normal thing for them. The sound pitch varies with what gear it is in . It isn't a Swiss made work of art , it's a peoples republic bodge . Mike

A lot of guys over on CNC zone have ripped all the gears out and fitted a belt drive with VFD to there CNCed mills. They run much quieter on the toothed belt.

Dave

Hey guys,

I'm really giving this forum a burn with the questions and I have another!

I was tramming the head on my new mill (HM 48) to adjust the tilt ( left and right) to near zero which I got within .03mm over 240mm. I can play with that later but also checked the runout (nod) and it came out at .11mm higher at the front over 240mm.

Now, I'm not sure I'm reading it right...can someone please check for me?

My dial indicator is read in .01mm increments so I think that is onehundreth's of a mm?

The dial moved 11 increments on the dial.. So that reads .11mm?

By the way there is no adjustment to nod the head... What do you guys think?

No problems with questions, as thats what most of us are here for.

I would check the table/saddle etc first by mounting a dial indicator in the spindle like you have and run the table back and forward in the Y axis and see what it reads. Some times it can be out and it's not the column.
If that check is OK and it is the column you will have to shim the column to bring it into alignment.

Dave

It could be better. Schlesinger (that name again) suggests that "the surface of work table parallel with its traverse movement" should only have an error of 0.02mm per 300mm.
Remember that is for a industrial quality machine, not necessarily a small machine that you or I might purchase. To correct that some disassembly and scraping will probably be needed, although you might be able to shim.
The big question is will that 0.11mm stop you doing what you want to do with the machine and the answer is probably not.

Incidently on noise - any machine driving through straight cut gears will make noise, especially if they are not running in an enclosed gear box. The important thing is that you want a 'uniform noise' (constant sort of volume without thumps and bangs when the spindle is under steady load) that does not have nasty grinding noises, or something that suggests that there is something loose.

Michael

From memory my HM52 test report allows 0.02 per 200mm so 0.11 in 240mm is way out.

If my calculations are right and you where using a 75mm face mill and facing a wide piece in the X axis direction, that would mean a difference in height of around 0.04mm between cuts, which is a pretty big step up.

Another check you need to do is to check the quill travel is parallel with the column as this will throw things out as well.

Dave

Originally Posted by Ben Dono

Hey guys,

I'm really giving this forum a burn with the questions and I have another!

I was tramming the head on my new mill (HM 48) to adjust the tilt ( left and right) to near zero which I got within .03mm over 240mm. I can play with that later but also checked the runout (nod) and it came out at .11mm higher at the front over 240mm.

Now, I'm not sure I'm reading it right...can someone please check for me?

My dial indicator is read in .01mm increments so I think that is onehundreth's of a mm?

The dial moved 11 increments on the dial.. So that reads .11mm?

By the way there is no adjustment to nod the head... What do you guys think?

Did you nip up the Z axis gib screws?

When I was measuring this stuff on my mill I did the measurements with a combination of conditions just to see what difference it made. Turns out it makes heaps of difference if you tighten the table screws and/or Z axis and quill feed. Give it a try. At least you will know what condition will produce the most accurate geometry for your machine should you need it for accurate work.

Simon

Originally Posted by Ben Dono

Thanks for the reply Simon. I kind of got the feeling it's just the way they run. Mind you I have never used a mill before... Kinda makes my opinion a non event!

Hahaha I love H&F's marketing! I got the best I could afford and that was the 48 with all it's plaster and paint coverups... There are so many silly little things wrong with mine. For example, the DRO scales and the power y feed cover up 2 oil ports..actually on that note the oil ports are more like dry paint ports anyway, one of the brackets for the coolant pump is about 25mm to low so the tank rattles. The standard plaster they used to smooth out the base sand castings does not hold onto the paint. Etc etc..

Actually, I think if you sneezed hard enough in the general direction of the base, you would probably strip off some enamel.

Having said all that and even before I mill anything on it, I think I'm going to like it!

I have a love/hate relationship with my lathe and mill. As time goes by and i get more experienced and also make improvements, its more love than hate!

Simon

Originally Posted by simonl

Did you nip up the Z axis gib screws?

When I was measuring this stuff on my mill I did the measurements with a combination of conditions just to see what difference it made. Turns out it makes heaps of difference if you tighten the table screws and/or Z axis and quill feed. Give it a try. At least you will know what condition will produce the most accurate geometry for your machine should you need it for accurate work.

Simon

Thanks Simon,
I did test it both ways with it locked and unlocked. I'm going to check the bolts on the base/stand first before I look at shimming.
To be fair, it was a good half an hour before I locked the gibs.. The reading was a little worse than than .110 out

Dave, I will be checking the quil run out as well.. Actually, that's how I enede up tramming first as I was checking the quill and was getting .30mm runout over 120mm.. I have not rechecked that after tramming yet. The fine lady needed someone to help her train for volley ball tryouts so it took me away from my other love my sweet mill. Well... She did buy it for me!
I live on a farm Bellingen and we get a whole lot of rain! Normally I just get on with work I have to do out side as you get use to it... Besides, when it's not raining your sweating. When it's raining... You just get wet.. Same same really. Now it's been raining for weeks I'm finding any excuse to get back into my workshop!

I was checking the 4 bolts the attach the base of the mill to the stand. By backing off the 2 bolts in the rear of the machine I can eliminate all the nod runout so thanks for the advice on that one guys!

I'm going to shim the back of the mill and leave the column alone and try my luck. Once I tighten the bolts back down hopefully this should reduce the runout to an acceptable amount.

Ok, shim stock. Some forums talk about aluminum foil and drink cans as shim stock.. Am I wasting my time?

Thanks guys.
Ben

Dosent really matter what you use as shim,as long as it is stable and wont compress.