Get a haircut.

What are your rules from experience with using a carriage stop-?
Spacial awareness:
I would like to make a "Carriage" stop that could sense pressure(Adjustable but accurate) to switch off the lathe, or disconnect the feed to prevent a crash if the topslide or crosslide were moved in such a way during the operation to cause a crash,.. to prevent a crash.

Hi Chris

I haven't got any clever ideas for turning the machine off to prevent a crash, although I have used lathes that had a microswitch arranged to cut the power if the carriage reached the headstock ( Smallpiece Cromwell S800).

But I do use carriage stops all the time, and so far have not had any disasters, I attach a picture of a simple adjustable carriage stop I made when I had an ML7-R , the stop rod is locked by GHT Thomas's pet split clamp arrangement which will slip if it all goes wrong. I made two of these, one for a friends S7 who being quite new to the hobby was worried about a jam up and damaging the fibre feed gears. The stop rod in the one shown is 5/16" diameter , but for my friends the rod was made 3/8" diameter and drilled to take a smaller rod ( 9/32" from memory) so that this rod could telescope into the larger rod, It was cross pinned with a brass shear pin, again from memory 3/32", so in case of a disaster the shear pin would break allowing the stop to telescope and prevent damage. The size of sacrificial shear pin was entirely empirical, we started with 1/16" which sheared too easily and 3/32" seemed about right. My friend tells me it has been tested twiceand has worked!

I have not got a photo of the shear pin one, but attach one of the version on my machine, it required careful positioning to avoid the back gear lever. Obviously this is for a non gearbox machine, but the shear pin principle can be adapted to many other stop designs. Hope this gives a few ideas.

Dave

I left it so you can observe what is being done, think about it and maybe learn something, rather than just being told something. As nobody seems to have picked it up, look carefully at the 6.30 minute mark. She has a long slender job in the chuck, then puts a fixed steady on the far end of the job and adjusts the steady jaws up to a nice neat fit on the job. Then she puts a dial indicator on the half inch of bar sticking out past the steady and rotates the job. "Look at that — no runout".

Think about it. What is she measuring with that dial indicator? Right next to the end of the job held in place by the jaws of the fixed steady.

Answer: Absolutely nothing. The fixed steady is holding the job in one position. It is impossible for the job to do anything except show zero runout. That's what the fixed steady is for.

She should have checked the end of the job for runout BEFORE she put the steady on it. If the end of the job was running out of true, she should have got it running true and THEN put the steady on it. In fact, with a flimsy job like that, she should have set the fixed steady jaws in postition on the job right up next to the chuck, then slid the steady along to the far end and used it to set the far end running as true as the chuck end.

The way she did it, that end of the long thin job could be 10 thou or even 100 thou out of true, if the bar was say bent like a banana, or held crooked in the chuck. Then you put the fixed steady on the stationary far end of the job and that end is still 100 thou out of alignment with the axis of the lathe. But when you put a dial indicator on it like she did, it will read zero runout, as the long slender job flexes with each rotation and but the steady holds the end in one position.

A surprising slip up for a good operator like Blondie. But a common, common mistake on American videos. YouTube is full of Harley Davidson "mechanics" making the same error when truing a set of flywheels. They place the dial indicator right up next to the bearings the crankshaft is running on and pat themselves on the back for finding "no runout". But if they were to move the dial indicator three inches along to the far end of the cranks mainshaft, they would get a correct reading, and probably find many thousandths of runout.

Rule No 1 on using a dial indicator: Think very carefully about exactly what you are measuring. Blondie did not do that at minute 6.30.

And here's a YoutTube Harley guru making the same mistake. putting the dial indcator right next to the locating bearing. See the 10.02 minute mark.

As I said in my post, my stop was made specifically for the purpose of putting the graduation lines on a set of resettable dials I was making for the Myford. It is designed NOT to move under impact so that the 100 small impacts as I put the 100 marks on each of the four dials I made will not result in the lines gradually getting longer as the stop moves.

If you want a less solid stop, its just a matter of replacing the threaded rod and nuts wilth a piece of plain bar and putting a grub screw or clamp handle like Stevie's or Dave Wooton's examples.

But my point was not how to make a stop. It was how the information could be grasped in 2.5 seconds in a couple pics and a paragraph of text, vs 25 minutes of video, to cover HALF the job.

FWIW here are the gradaution lines, below, on one of my dials the stop was used to cut. I went around the circumfrence once with the stop set for the short marks, missing out every fifth mark. Then advanced the top slide by the 30 thou to make the intermediate length marks at the un-numbered "5" points. Then advanced the topslide by another 30 thou to go around a third time and do the 10 long marks at the numbered "10" points.

Much quicker and easier to keep track of than the traditional method of varying the length of lines every fifth line, then going back to the default short setting then back to the longer after another five lines and so forth. I had the job done in a matter of minutes for each dial. This method also means you are using the lathe bed and carriage to "plane" the marks on the dial, not some dicky little shopmade graduating tool that always has slack between the body and the plunger, which is exaggerated by the lenth of the toolholding bar and results in inconsistent depths of cut. This way, the cuts are as consistent as your lathe's main bed and carriage.

As far as the safety factor of not crashing into a carriage stop under power, goes, the Drummond M Type has that beat. A leadscrew dog clutch with an actuating bar running the lenght of the bed, with an adjustable trip that can be set to disengage leadscrew at any point. Brilliant on long jobs. Set it up, set your cut going on a long job an walk away confident the feed will stop at the set point. Lovely! The ML7 was a step backwards.

My next job is to make one for the ML7 because I got so used to it with the Drummond I consider it essential. Handy too for disengaging the change gears quickly so you can use the leadscrew handwheel, which if you don't have a QC gearbox is a right PITA. I will do this by making an  ML10-style dog clutch consisting of a sliding sleeve over the existing leadscrew. with a couple of driving pins and slots. Then add the bed-length "knock bar" and actuating trip that gets knocked by the advancing apron at the set point.

Edited By Hopper on 20/02/2022 10:28:20

Hear hear. And I hope Stevie did not think I was having a go at him. He did say he "loves criticism" so I was merely obliging, whilst admittedly indulging a pet peeve of my own.

I am sure there must be videos and other information online about "How to Make a Video Presentation" etc. It's a well established trade in TV land and like all trades there are simple tricks and techniques that can be learned to move towards professional quality work. Just like Blondie and Joe Pie etc do for machining, some TV videographer types must be sharing their tips out there somewhere. All I know about it is from being a print journalist and photographer/designer. Same principles but different medium. But it's obvious in which direction my biases lie.

And here's mine for a WM250:

I made that a couple of days after getting the machine. It's 1" aluminium bar, with a notch to fit over the bed, a pinned clamp plate operated by the lever, and a sliding rod clamped by the brass knob. 7 years use suggests that steel would be better as the aluminium has spread. The rod adjustment was a waste of time, because there's no sensible way of adjusting accurately, and adding/removing shims is not going to happen. It was intended to be easy to make from stock I had, and to never need a tool in use which is always a requirement for me. It means I use it most times I turn on the lathe.

I might modify some of the micrometer adjustment designs for my machine later.

I agree. Although I would argue that Internet videos are consistently bad with a few good ones tossed in.

I'm American and I have to say that this forum is very good. Forums dominated by my fellow Americans can be brutal. Also – and I'm guilty of this at times – they too often don't read everything…Not reading previous posts and even not fully reading the original post. It's aggravating. It seems obvious to me that people who reply *here* have thoroughly read previous posts, the original post, and make well informed replies instead of a quick "well that's dumb, just do X!"

I hope the members who shy away from posting here would develop a little thicker skin and reconsider. Although I did spot the error in the Blondihacks video I appreciate everything Hopper has said….I hope Steve does too.

Sorry for the distraction.

Mike

Hi, I did notice he was measuring the run out while it was being held by the steady, but I see this has been explained already and yes you need to have the end running true before you set the steady onto the work.

Regards Nick.

Good news, there's much to like in Steve's video, and I didn't see anything unsafe! I particularly like his slow Yorkshire presentation and the absence of camera wobble and other common production faults.

Many improvements possible though and Hopper's list of basic story telling tips from a media professional are spot on. By applying them, I think the whole Carriage Stop story and design could be done and dusted comprehensively in under 20 minutes.

I did wonder which audience Steve is aiming at? The title 'Myford Adjustable Carriage Stop' strongly suggests a practical project for Myford owners advanced enough to know what a carriage stop is. However, the video's content often veers into 'explore the workshop' and 'basic introduction' territory. All interesting, but not mixed together! An improvement would be to edit out irrelevant stuff like the stickers and unfocussed comments like 'lot of letters printed on it', and 'we're not in a hurry, well I'm not…' A script would tighten up the commentary. I prefer to talk to a bullet list: they keep me on topic and allow ad-libbing. Scripts make me sound wooden.

There are a few mildly unfriendly items that might confuse beginners:

• Using random scrap is generally a bad idea because not all metals machine well. In fact many alloys are horrible. Giving newbies the idea that scrap will cut OK on a lathe is unhelpful. I'd make the Carriage Stop out of free-cutting mild-steel. Instead, Steve goes for a work-hardening Stainless that becomes "red hot" and mentions two other difficult metals – Titanium and Phosphor Bronze. The project is based on metal he happens to have rather than metal selected to do the job. Working with awkward materials is a video in it's own right.
• When turning stainless (with an interrupted cut!), Steve says he doesn't know what the correct speed should be. The video would be better if details like that, and the unfinished plan, were sorted out before filming started.
• The implication that a DRO Tailstock is necessary is misleading. Nice to have maybe though I've never felt the need.
• Flipping the hex bar in the 3-jaw chuck at about 12:45 causes an avoidable mismatch where the cuts meet. Not the end of the world, but misses the chance to discuss whether or not it matters, and what to do if it does! Being lazy, I'd have dodged the interrupted cut and chuck flipping error by not rounding the hex bar off at all.

Certainly not rubbish!

Dave