Saddle stop for the 918 lathe

[Gerhard Olivier]

I have an idea for the saddle stop that would give me
1 )   Quick set up
2 )   No loss of any dimention / function
3 )   Can be used to as a left or right hand stop?
4 )   IS THRE ANY THING I DIDNT THINK ABOUT??????????

Il post thw bas and wait for some feedback / warnings before commiting to the design.

Some 25 mm MS


Drilled 8.5mm to 35mm and 5 mm all the way and tapped 10m to 15mm


Then cross drilled at 12mm





And placed in position to allow me to check that it is all practical


The idea is the make 2 grub screws with knurled knob so the 12mm bar can be removed completely if necc, but by moving the bar to the right a bit stops etc. can be added  or removed as necc.

Also if a multi position stop is needed it could simply be slid onto the bar and the bar locked in place again.

But can anybody see any problems with this idea????


Gerhard

[bogstandard]

Gerhard,

I looked at making one like that for my machine. Unfortunately I couldn't fit one because of the position of the operating shafts on my machine. I was looking to actually use the design for having an auto half nut setup when thread cutting. It would allow higher speed to be used when single point cutting.

The only problem I can see is that because of the length, and the associated flexing, you won't be able to use it as a precision saddle stop.

The saddle stop should be as close to the bed face as possible.

Have a look at this one, it might give you another idea of the way to go.

http://www.hemingwaykits.com/acatalog/Multi_Position_Saddle_Stop___Myford_7_Series.html


Bogs

[John Hill]

In addition to Bogs' comments the first thing I thought was that it would be a nuisance when cleaning under the machine...  otherwise, does it do the job as you expected? 

It does have a certain elegance of functional design and although using the chip pan may introduce some flex into the set up it does avoid mutulatiing the machine proper.

[chuck foster]

i thought the first thing bogs would have said was GET THE CHUCK KEY OUT OF THE CHUCK   

other wise things look good 

chuck

[Gerhard Olivier]

Oops no good leaving ammo in the gun- my lathe wont start with chuck gaurd open and cant close is key still in.  ut not a good idea -ta Chuck

John the chip pan is attached to 42mm kitchen worktop and I plan to bolt through both this should make some differance

Bogs have you anay idea how much precision would be lost?  I have tried to think of a way to test but cant think of any exept build it and cut a couple of lenghts and measure them.  I made a base that fits to the lathe bed but the v beds dont allow a positive grip it feels weak and if I can feel some movement then it cant be accurate??

Gerhard

[bogstandard]

Gerhard,

Your problem lies in the fact that you are stopping the saddle a great distance from the actual running face and using a flexible bar.

I have done a C-o-C to show what I mean. Unless you used something like a 25mm bar or larger, the flex could be substantial because of the moment forces imparted by turning the handwheel.

This is what I was on about, and when I get the time, I will knock one up for my lathe.

http://www.hemingwaykits.com/acatalog/info_HK_1840.html

This also gives a saddle clamp as well as an infinitely variable stop.


Bogs

[usn ret]

The idea of saddle stops is a great idea, I did a search on that other site at http://bbs.homeshopmachinist.net for carriage stops & saddle stops. There are some very good ideas and different applications posted there. W/pics!!!
Cliff

[Gerhard Olivier]

Thanks Cliff

There is a lot of good stuff in that link - I like the use of the dial indicator

Bogs to try to get as close to the lathe bed as poss I tried one of these


But the edge of the lathe bed on the front bottom is not deep enough ( see left part of the COC)

The ones in the link Cliff sent are all deep enough that the clamp on the bottom of the lathe bed oposes the peak of the v in the bed and makes the whole thing stable. Right part of COC

Have had some more ideas to improve the other design but just need to run some tests - will update as soon as I have something solid.
Gerhard

[bogstandard]

Gerhard,

The one on my lathe is very similar to that, and very easy to make. See C-o-C.


Bogs

[Gerhard Olivier]

Ok this took a while as I had to make a mock-up and test first but it seems to work fine.

The idea was to use the bar at the bottom to hold the saddle stop ora dial indicator.  To compensate for the flex in the bar I had to make a stop that fits between the saddle and the gear box.

The T-piece has a 12mm x1mm pitch thread all the way trough and I have made a series of threaded bars that give a range of stop points- by screwing one in the left side and one in the right side.  The whole thing  can be swung out of the way for prep work and when you need the lenght setting it can just be swung back in position.

I want to make a holder for the dial indicator as well,  and some simple stops for the non-critical stuff.

[arnoldb]

Good going Gerhard 
  Arnold