Carriage stop project off to a rough start

[mikey]

Glad it worked out, Jeff.

 

[Janderso]

If I build another it
will have TWO large clamps to hold it in place.

Good advice. This is a stout part and thinking about the clamping system, I'll make it as robust as I can

 

[mikey]

You will find that the accuracy of the angles of your stop are critical to its function as a stop. The more accurate they are, the better the surface contact will be between the stop and the geometry of the way. The better the surface contact, the less clamping force needed to lock it down. The plate used underneath to lock the stop to the way should be milled flat and the ledge that spaces it apart from the body of the stop should be high enough to deal with any bow in the plate when the locking bolt is tightened. If you get all of this right, a single bolt is enough to lock any carriage stop ... but two is better.

 

[rwm]

I was surprised at how much clamping force was required to actually stop the carriage.

 

[Winegrower]

I hope nobody is trying to use these clamps to stop a carriage under power feed?

The Takisawa has a nice feature where you can set up a trip point and stop the power feed...then move the carriage by hand a tenth of inch or so to contact the stop point. I made a similar stop for the cross slide that's very helpful while threading.

 

[Dabbler]

A good friend of mine rebuilt a Colchester lathe made in England, and it was exactly 50 degrees (per side) It makes it very hard to make parts that fit the veeway, as an end mill makes a 45 degree angle on each side.

 

[Janderso]

You will find that the accuracy of the angles of your stop are critical to its function as a stop. The more accurate they are, the better the surface contact will be between the stop and the geometry of the way. The better the surface contact, the less clamping force needed to lock it down. The plate used underneath to lock the stop to the way should be milled flat and the ledge that spaces it apart from the body of the stop should be high enough to deal with any bow in the plate when the locking bolt is tightened. If you get all of this right, a single bolt is enough to lock any carriage stop ... but two is better.

I’ll be making the bottom plate soon.
I have some ideas on how to get a solid fit.
I used my new kiln today to heat treat this A2 part. I was able to maintain a good soak at 1,700 degrees for over an hour, then I put it on a brick in the shade outside with a temperature in the mid 50’s. A file just skated off.
Then I spent some time with the Brown and Sharpe Micromaster
This piece is done.

 

[rwm]

That looks great! I am wondering why you hardened it? Won't it be prone to fracture and also possibly mark up the lathe ways?

 

[Dabbler]

@rwm if it is 4140, it will significantly strengthen by hardening, leading to less chance of a problem. Hard metal will accept swarf less readily and so will be less prone to scoring the ways.

 

[akjeff]

I hope nobody is trying to use these clamps to stop a carriage under power feed?

The Takisawa has a nice feature where you can set up a trip point and stop the power feed...then move the carriage by hand a tenth of inch or so to contact the stop point. I made a similar stop for the cross slide that's very helpful while threading.

Depends on the lathe. My Summit has an adjustable clutch type kick out on the carriage, and when its hits the desired resistance( like hitting the carriage stop ) it disengages the power feed. Doesn't work with the half nut engaged, of course, but works for the power feed.