Thread: Hercus Model 0

nice so your making chips now eh

Hello MG,

Sounds like you are nearly there. I meant to ask this question after your previous post when you said the rewinder was able to convert the mill motor wiring from star to delta.

Does your mill have a factory fitted coolant pump in the base and if so, did you consider having the pump motor rewired so that it too could run off the VSD?

Regards Bob.

Hello Bob,

I opened the access plate in my base cabinet and found a void with goo stabilized wood shavings and nothing else. The wiring diagram I have says "if fitted" and there is a mark up over that part of the ladder as though it is not there. So no coolant for me yet. The hole in the splash tray has a domed plain plug closing it which is another clue I have no coolant.

The VSD I got is capable of doing the main motor only, not two different motors. The current draw will go from 1.1A to 1.1 x 1.73 = 1.9 amps in my case and the power and torque will remain close to original even though it is 240V 3 phase from 240V single phase. You need to be careful with mixing drives and motors because drives are designed to do either

multiples of identical motors at the same time with a single drive

or

a single motor per drive (and if they have to talk, you need a PLC)

It is costly when you get it wrong as well. On a coolant pump, I would probably look at 240V single phase replacement and compare costs.

I saw the pictures of your vice it looks good.

regards

MG

Hello MG,

If I had spent a bit more time thinking about how a vfd could run two motors, one of which may not always be running simultaneously with the other, I would have realized it wasn't going to work. It's a shame, because the pump is a nice bit of gear. What's a bigger shame is not having three phase power connected when I had the supply cable to the house and the meter relocated a decade ago.

You fortunately acquired the dividing head and tailstock when you purchased your mill. I didn't but was lucky enough to be able to purchase the main body casting of the dividing head from Hercus a couple of years ago when they were getting rid of their mill spare parts. I also picked up the 3 division plates. Nothing else. No spindle, no worm and wormwheel, no cast iron mounting bracket, nothing. Luckily, Fiora Machinery in Perth have the head and tailstock attached to a display No.0 in their showroom and another bloke had a head that I photographed and measured. Steve Durden came to my rescue on numerous occassions with much needed advice.

Making the bits and pieces I needed took a considerable amount of time. The bracket shown in the attached links started off as a large chunk of 4E cast iron that I purchased from Bohler Uddeholm who obligingly, partially cut through the bar to make my life a bit easier. When you have some leisure time, pop your dividing head apart and see what's inside.

I've nearly bowled over the tailstock and if you are interested I can post some photos.

Regards Bob.

Hello Bob,

I am impressed and that is top class machining and yes, I would like to see the tailstock. Also if you have time, I would be interested in the hole patterns on the dividing plates as I have only one not three. It should be a straight forward job to make the other two. I will get the camera out and forward some of the clock photos to show you some of my work.

In regard to the coolant pump, you may be able to modify it as a capacitor start and therefore single phase. From what I have been told, a refrigerator motor is an example of this. The mod itself is relatively easy and apparently robust but not suited to a main motor or a drive/feed motor. Given this is effectively a non critical motor (it doesn't matter if it pulses or varies in speed a bit) a cap start may be a good thing to investigate.

One job I want to do is make a collet adapter for the dividing head when I get to taking off the little chuck. Ditto for a better way to hold the cutter in the vertical head. On the vertical head, I have done some sketches for a quill feed on the head like a late Centec. It won't be a big drama and I reckon that the heating problems will be cured along the way. I will have to get the old mechanical designers hat out for that one.

Have you ever heard of a slotting head out there that we could get to and measure ??

best regards

Michael

Hello Michael,

My first indroduction to using a lathe was in 1965 at high school. I had less than no idea. I remember resorting to using a file to remove the tit on the bar end, left as a result of not being able to set the tool at center height. That was back in the days when teachers were allowed to give you a clip under the ear and guess whose ear got clipped for the fancy filework. I fooled around with a Myford ML7 at WAIT (now Curtin University) in the early 80's while there as a student and then bought a model A 9" Hercus about 6 years ago.

I have attached some images of the dividing head tailstock which is my current project. You might recognize some of the features coming to light in the photos. On a little mill with a little 6" rotary table, some of the setups can become a challenge. You and Nev will surely find out.

You might need to guide me through the coolant pump conversion to capacitor start, single phase in a bit more detail when you have the time. Using the pump hasn't been high on the agenda because a large percentage of what I have machined on the mill has been cast iron. I use a big ShopVac to suck up the swarf.

I will photograph the division plates on the weekend and attach them to a private email. The reduced photos posted here would not be of much use.

Funny that you should mention the slotting head. Another project on the simmer. Amongst the old mill parts I obtained from Hercus, was a casting that mounts on the mill in the same manner as the vertical head. It turns out that the first version of the head was not offset and this casting housed the spindle. I was going to try and use this casting as part of a slotting head based on the drawings contained within the mill owners manual. I have drawn a section through this casting with my intended spindle shown as a basis for discussion with Steve Durden regarding bearing preload. The casting accommodates larger tapered roller bearings than those found in the offset head.

I will attach some photos of the casting and drawing in another post.

You need to provide a bit more information on your plans for a quill mounted spindle. I should hope this incorporates a fine worm feed!

All the best
Bob.

Hello Michael,

Following is the information regarding the Hercus dividing plates as promised.

I imagine that you have plate No. 1 which was supplied as standard.

Dividing plate No.2 has 16, 20, 31, 41 and 47 holes on side 1 and 18, 25, 37, 43 and 49 holes on side 2.

Plate No.3 has 20, 35, 51,57 and 63 holes on side 1 and 32, 36, 53, 59 and 61 on side 2.

All plates have the holes drilled on the same pitch circle diameter spacings
The diameters are 1 11/16, 1 31/32, 2 ¼, 2 17/32 and 2 13/16 inches.

The starting point for all holes is 30 degrees above the horizontal counterbored fixing hole locations left of the vertical centerline.

I hope this information proves helpful. I have photographed the plates. If you need the photos, let me know. Because of their size, I would more than likely need to send them in a couple of emails.

I finished off the work on the body section of the tailstock this morning. I have attached a couple of shots for your and Nev’s interest. When I bored the hole for the spindle, I took one finishing cut with the boring bar on power feed in reverse i.e from the chuck out.. As often happens, the spring of the bar cut the hole .001”oversize, the hole should have been .750”. The “precision” ground 4140 bar I intended using for the spindle turns out to be .748” in diameter and the pinch bolt on the tailstock body won’t clamp the spindle without me having to resort to over tightening the bolt. I will have to turn down a larger piece of 4140 to suit. Funny how often the final “finishing” cut can lead to the beginning again!!

Still, nearly there.

Regards Bob.

Hello Bob,
Thanks for taking the time to send the information on the divisions. It will be very helpful. The tailstock looks great.

The VSD is a real interesting project. I had expected the VSD would be added to the existing circuit but it almost replaces it completely. The unit I have has an inbuilt thermal overload, better low voltage IO for soft stop / start as well as soft reverse. When I read the instructions a few more times I will get on to my electrical engineering buddies and get them to design the new circuit to get the best from the unit.

Did you make the QCTP sitting on your lathe ? It looks like a nice unit. Did you make it to a plan ?

regards
Michael

Mad Hercus nuts,
You have probably already seen it but on fleabay there is a Hercus power hacksaw for sale in WA for $120, may be of interest. Seems a good price but it could also be a boat anchor.
regards
mgtoolmaker

Hello Michael,

I could think of less awkward boat anchors. That hacksaw has been out out Bills' Machinery for a number of years. It is a good example of how not to weld a collection of broken castings.

Regards Bob.

Hello Michael,

The toolpost is based loosely on a model made by Hardinge. Could not be much simpler. I've attached a few photos which should illustrate it's workings.

Regards Bob.

Originally Posted by Anorak Bob

Hello Michael,

The toolpost is based loosely on a model made by Hardinge. Could not be much simpler. I've attached a few photos which should illustrate it's workings.

Regards Bob.

wow im really impressed was that made on a Hercus model O? got any pic's of it in use?

man if i had a mill and a lathe i would give that a try thanks for showing

Hello Patrick,

The toolpost was made using the Model O, along with a lathe and Douglas shaper. Here are some shots of it attached to the lathes. The toolpost was made to fit the green ARL which is fitted with an extended cross slide. This slide sits about 4mm higher than the standard cross slide which is why the tool block is raised up on the dark grey lathe.

Regards Bob.

Hello Bob (and other Hercus owners),

I finally got around to taking some photos of my current project which is a clock. I am making some of it at home and some on machines that others own (gear cutting). The plates of the clock are 3mm thick and they are about A4 in size. I am working on the pinions and arbors at the moment. I have included a photo of my lathe covered in brass swarf - no it is not a Hercus, it is a Herless approx 15 years old. My Hercus mill is being rewired at the moment and will soon be ready to be covered in precision swarf. The 4 way toolpost is 75 x 75mm for reference, is that similar to your QCTP ?

Hope you enjoy the photos

mgtoolmaker