Thread: New Lathe Part 2

This picture from the CY lathe manual has arrows pointing to what I assume is a feed stop system. Having looked thru the manual, one of the cam shaped blocks on the shaft is called an"Automatic Stop Block" in the main features drawing, but no other mention is made of this in the instructions.

Picture from Manual.jpg

Does anyone else have a lathe with this feature and is there anything besides the obvious to learn about it. The main reason I ask is the fact that there are 4 stop blocks on the shaft. I am wondering why.

As I have mentioned before, this shaft was broken off long before I bought the lathe and came into my possession thru shear luck and my desire to acquire metal for machining. I got it out of the scrap bin.

I have had another go at freeing up the components today. An end cap has been used by me to make something for the Nuttall. I knocked off one of the mounts today, and polished up some of the shaft at that (tailstock) end.

I think I just figured out the 4 blocks. The shaft rotates to 4 positions for different stop block locations. Its great how much you learn from this forum. There is a ring next to the lefthand mount with 4 numbers spaced around the circumference.

I will have to drill/mill out the grub screws holding all the rest of the bits as I cannot get them to move at all and I have not managed to get the grub screws to budge one iota. Way back when ideas for penetrating solutions were being discussed, I tried oil of wintergreen and acetone/atf mix for weeks with daily applications. They are still oily from this. Did not help. In the mill it will go. The grub screws are not hard. The shaft is too long for my press at about 1400mm.

I think it should be simple to make up a steel block to fit to the broken off tang of the mounts. They both broke across the row of mounting holes so locating them back on the lathe will be an easy exercise.

Dean

Dean, Grazianos have something similar, but different enough in detail to not be much help - if I understand your description. Sounds like you have it under control, but I will mention one thing. Two of my four stops were busted or missing. I suspect people try to use them for threading, which will break 'em every time. They only work for feeds. Start with that assumption anyway, until proven otherwise.

Originally Posted by Bryan

Dean, Grazianos have something similar, but different enough in detail to not be much help - if I understand your description. Sounds like you have it under control, but I will mention one thing. Two of my four stops were busted or missing. I suspect people try to use them for threading, which will break 'em every time. They only work for feeds. Start with that assumption anyway, until proven otherwise.

I simply assumed they were for feeds, rather than threading which fact has got me wondering about people who think othewise. It did not even cross my mind to consider threading and I am by no means an expert.

My understanding is that the two are completely different and use diffferent mechanisms. What happens inside the apron on this lathe I don't know at this stage and I have no intention of finding out thru necessity!

If I manage to get it fixed and working I will show more detail, unless someone has a great desire to know sooner. I would prefer to have it worked out so I can pretend I know what I am talking about. Luckily these lathes are not very common, so there are not many people who can contradict me. Imagine if it was a Hercus!

Cheers

Dean

Originally Posted by Oldneweng

I simply assumed they were for feeds, rather than threading which fact has got me wondering about people who think othewise.

It's just a hypothesis. Assuming it does its job of stopping the feed, how else could you break it - with the hand wheel?

Hi Dean,
I'd take a stab in the dark and say the CY is at least based on a Mori Seiki lathe. The apron is Identical to the Antrac's (except the one pictured about is flipped left to right).
My stops run on a raised section of casting on the base. They push the pin up which knocks the feed handle back down and out. The feed handle has a nasty habit of dropping out anyway some times. I need to find a heavier spring for the ball detent and see if that fixes it. Your assumptions are correct, the stops only work for the feed, and they are not all that consistent, maybe .5mm.

Ew

Originally Posted by Bryan

It's just a hypothesis. Assuming it does its job of stopping the feed, how else could you break it - with the hand wheel?

I can't actually picture how they could be broken as mine are very low profile. Someone must have done something to yours.

Dean

Originally Posted by Ueee

Hi Dean,
I'd take a stab in the dark and say the CY is at least based on a Mori Seiki lathe. The apron is Identical to the Antrac's (except the one pictured about is flipped left to right).
My stops run on a raised section of casting on the base. They push the pin up which knocks the feed handle back down and out. The feed handle has a nasty habit of dropping out anyway some times. I need to find a heavier spring for the ball detent and see if that fixes it. Your assumptions are correct, the stops only work for the feed, and they are not all that consistent, maybe .5mm.

Ew

My lathe is also flipped left to right. Either option was available.

You say that your stops run on a cast surface instead of a shaft like mine?

I used the feed quite a lot when making the skates and had no problems. It will be interesting to see how accurate the stops are as my impression is that this lathe does not have much wear for its age. Everything feels tight and positive, well compared to the Nuttall anyway.(insert big grin)

Dean

That's a very valuable addition to any lathe mate Mazak lathes always had the 4 position stop bar so as the saddle feed could be used at multiple points

IE use a Morse Taper attachment on the saddle for drilling look at this http://www.lathes.co.uk/mazak/

Set it up correctly and the drill can nest over behind the chuck look at piccies at the bottom of the page

Bruce

Originally Posted by Oldneweng

My lathe is also flipped left to right. Either option was available.

You say that your stops run on a cast surface instead of a shaft like mine?

I used the feed quite a lot when making the skates and had no problems. It will be interesting to see how accurate the stops are as my impression is that this lathe does not have much wear for its age. Everything feels tight and positive, well compared to the Nuttall anyway.(insert big grin)

Dean

Yes it might feel like It is solid and repeatable but it depends on the force and depth of the cut that's why my De Valliere 140 has the spring loaded force clutch in the saddle (adjustable on the end of the saddle) so you could dial in the repeatability, and separate stops for lead screw thread cutting.

Originally Posted by Aussie Bruce

Yes it might feel like It is solid and repeatable but it depends on the force and depth of the cut that's why my De Valliere 140 has the spring loaded force clutch in the saddle (adjustable on the end of the saddle) so you could dial in the repeatability, and separate stops for lead screw thread cutting.

The reference to the Nuttall left a very generous allowance for variables. (Even bigger grin).

Dean

I think the best thing to do for this type of stop is to make a bed stop, let the knockout throw out the feed just short and then hand feed to the bed stop. I often also use the graduations on the saddle handwheel to manually cut out the feed at the right spot, but this is a bit more risky.

Ew

Originally Posted by Ueee

I think the best thing to do for this type of stop is to make a bed stop, let the knockout throw out the feed just short and then hand feed to the bed stop. I often also use the graduations on the saddle handwheel to manually cut out the feed at the right spot, but this is a bit more risky.

Ew

There is also a multi stop device that clamps to the bed. I will look at this next. One thing at a time. I would think that it is more accurate. It is difficult when the manual makes no mention of these features. That is when the forum. becomes so helpful.

Dean

This is just a normal carriage stop with a rotating barrel and 4 separate stop adjustments. At the moment it has a flathead grub screw which does not grip very well. It does have a decent brass pin in there as well. I had to pull it apart to get rotation. A lttle bit of rust under the head end. A tap with the soft hammer and it popped out. Needs a good clean up and back together. I am going to get one of the adjustable locking bolts/levers for it as they have proved to be fantastic on the mill.

Dean

I have finally disassembled the feed stop shaft. It took a lot of work.

Feed Stop Shaft Pressing.jpg

The final 3 parts(red arrows) were stubborn. I had to resort to the above method using an 8 tonne jack. It finally gave with a huge cracking noise.

Feed Stop Shaft Parts.jpg

These are all the bits with the shaft at the back. I haven't cleaned anything except for the shaft yet. The brackets are both showing the top surface. At the back on both is a small length left, machined flat for mounting. I will set this up on a flat surface and take measurements for height, and for the distance from the bore to the bolt holes. The centre holes must be for a locating pin. It might be best to use these for the measurement.

I will then mill the top face flat, back to the rib and make a block to bolt on to this surface which is stepped so it fills the section missing. The ends will be machined flat as well.

Dean