Thread: Hercus Model 0

Hello Michael,

I didn't mean to scare you. I use the broaches in my arbor press.

Regards Bob.

Hello, might be able to help regarding the fine feed/ power feed, I have a Schaublin 13 and access to an Arboga Indian clone, I am not sure exactly what you require however.
On a related topic the Schaublin has a vertical head which sufferers from the overheating issue as well so it is not just a Hercus problem. I would be interested in any comments on this problem.
Regards, Metalman.

Hello Metalman,

We might need to create a Schaublin User's page.

I purchased a No.13 mill two weeks ago. The machine was manufactured in 1962. I have not had it running because I don't have 3 phase power. Because of the limited space available within the base for mounting an alternative motor, I may persevere with the Oerlikon motor and run it via a VFD.

I have become very familiar with the right hand longitudinal feed handwheel, it's dog clutch and it's connection to the leadscrew. At some stage, the handle had been broken off and the forked shaft bent. I've made a new shaft and still need to make a couple of other parts to complete the repair. I am thankful that I have a set of metric transposing gears for my ARL. I will post a couple of photos showing how I machined the slot in the forked shaft.

The overheating head is a concern. The Hercus mill uses lipped seals and I reckon the seal friction is the source of the heat. The Schaublin head appears to utilize a labrinth seal setup according to my operating instruction manual. Your heating could be a bearing issue.

Good luck
Bob.

Hello Bob,
It is nice to know I am not the only 13 owner around, mine is a 1955 model that I puchased about 8 years ago. I have done nothing to it accept lubricate it occasionally and it has worked well other than the overheating.
Using a VFD on your machine could have problems if you replace the mechanical spindle speed control as the table traverses will then vary with the spindle speeds. With the existing system the traverse speed is independent of the spindle speeds.
I have some sales brochures and tech info if needed, would be interested in conversing further but do not want to hi-jack this thread too much.
Regards, Metalman. (Phillip)

Hello Phillip,

Let's move the discussion to the Metalwork Forum.

Regards Bob.

Hi there
Just a quick point regarding your overheating problem, if the head is grease lubricated and fitted with grease nipples it may have been over lubricated. I struck this problem with a couple of Cincinnati machines years ago almost killed with kindness. Too much grease creates a shearing action which generates heat, bearings should never be packed more than about a third full to allow the stuff to flow as temperature changes.
Hope this helps
Ray

Hello Ray,

The instuction regarding oiling was not heeded. Someone pumped grease into every nipple on my mill before I bought it. I dismantled the vertical head to remove the grease and replace the seals. I use Mobil DTE Heavy Medium oil to lubricate the head and main spindle. The head runs hot with seals installed. Remove the seals and there's no heat. I don't know if this is a problem that is common to all No.0 mills or something that occured in the earlier machines. My machine has the serial number 0L-8.

I had been thinking about trying to make some seals out of Teflon, but like a lot of things, it hasn't progressed past the thinking stage.

Do any other No. 0 owners experience a heating problem when using the vertical
head?

Bob.

Hi Bob, et al,

I don' t have a problem with the vertical head running hot on my mill (#362). I have used it for 1/2 an hour at at time and the head is mildly warm, but by no means hot.

Like you, when I got the mill I pulled it apart and cleaned out all the grease (and embedded swarf!) and have only run it on oil since. I use the same oil as I use in my lathe (Hydraulic oil).

Hope this helps

Rodd

Hey Rodd,

Looks like Hercus might have changed something. Is there any chance that you could let me know the brand and part number on the seals that are installed in your vertical head? That's if you can see them.

Regards Bob.

Hi Bob,

I had a quick look at the seals on the vertical head and both don't have any information printed on them that I can see without pulling the head apart.

I did however find in the owner's manual that the vertical head uses 2 off Flaseal 13297.

As I didn't note the maker / part number of the seals when I cleaned up the head, I can't confirm that this information is correct.

Hope this helps.

Rodd.

Hello Rodd,

I just checked out my seals with the aid of a torch and a jeweller's loupe and all they have on them are the manufacturer's name, NAK and the size, 2.500 x 1.875 x .375.

I had bought them from Transeals as replacements for the unavailable Flaseals listed in the owner's manual, I ran them both with and without the spring but the heat persisted. I will buy another brand of seal to see if there is any difference.

Thanks for having a look at yours.

Regards Bob.

As a matter of interest, what was the outcome regarding the hot seals? I also have a new to me No. 0, also greased, also stripped down by me and rebuilt after completely degreasing. I was running the vertical head on max speed tonight checking out for faults and it quickly became quite hot. I'm using 90 weight diff oil as it's the closest I could get to the specified oil in the manual without buying a 20l drum.

Pete

Hello Pete,

Since acquiring my Schaublin mill, I have only used the No.O a few times, and only in the horizontal mode for sawing. (The little Hercus can accommodate a half inch larger diameter saw than the 13 giving it one useful advantage over the Swiss mill)

As a result of being lazy and having no pressing need to deal with the seals, I've done nothing. I do still need to deal with the problem.

Running the Hercus for a period of say, five minutes in the lowest of the normal speeds, results in excessive heat in the vertical head. There could be something else at play other than the seals.

I've been mucking around with a pair of high speed drive pulleys on my 9"ARL. At high speeds, the bearing become very hot. Bearing preload appears to be the cause.

I have set the preload in accordance with recommendations given in Peter Hercus's Textbook of Turning. A spring balance is used to determine the correct preload.

The spring balance that I have could well be better suited for use as a fishing accessory than as a precision measuring device. I need to check the preload again on the mill spindles.

I use Mobil DTE Heavy Medium ISO68 oil to lubricate my taper bearings. I'm not sure how that compares with your gear oil. I imagine the DTE is a thinner oil.

Run the head with the bearing caps removed and see if the bearings become hot. Oil will everywhere but you will determine whether the seals are the problem or not.

Bob.

My pulley was greased with a high temp light weight grease, normally used for the vibration shaft bearings on a 2 tonne vibrating roller. What will I notice if it isn't coping?
Larry