Installing a Trav A Dial on a Vintage South Bend Lathe

[@charleswelch249]

You explained the whole thing very well. Now I want one for my South Bend lathe.

[@MyLilMule]

They seem to sell for a pretty high price. I got this one with a bunch of other stuff, so the cost was very minimal. If you find one for the right price, go for it!

[@tomwhite1823]

I just mounted one on my lathe a few months ago. They work great. I also have them on my mill. Great job on the install and explanation.

[@MyLilMule]

Glad you enjoyed it!

[@roberttrescott2741]

When you touched the bracket top with your finger while the mill was spinning within inches, I cringed and couldn't finish watching the video. I have unconditional respect for sharp and fast spinning objects! Be safe.

[@MyLilMule]

Perhaps from the camera's perspective this seemed unsafe, but rest assured, since I make my living using my hands, I never take unnecessary risks. There was plenty of clearance between my hands and the spindle. The risk was less than walking down a flight of stairs.

[@TamahaganeSteel]

Great video. Looking forward to more southbend restoration though!

[@MyLilMule]

It might be a while for more SBL content. The lathe bed is at the grinders as I type this and it's going to be one of those "fit it in between important customers" jobs. Which I was 100% fine with. I'm hoping sometime in January.

[@outsidescrewball]

Enjoyed…great discussion/install, I have 2 on my Clausing lathe, the crosslide install is great for backlash error check

[@MyLilMule]

Thanks, Chuck! I watched your video on them a couple times to try and understand what I wanted to do here. And thanks again for the installation PDF, that helped out a lot. I only have the one, it came to me in a sort of seagull deal. 😉 One I couldn't pass up.

[@LetsRogerThat]

What an awesome tool. I’ve thought about the levelling issue. Presuming the lathe is level, you could take a digital level, put it on trav a dial in X and Y directions and theoretically your trav a dial would be perfectly aligned. Thanks for the great video my friend. Gilles

[@MyLilMule]

Thanks, Gilles! I don't believe it is about leveling, really, it's more about being aligned properly. I tried to convey, in a reasonably concise way, what I ascertained by studying the installation material and the patent. If the wheel is in perfect horizontal alignment and the tilt at the right angle, it can be extremely accurate and repeatable. It's a rather ingenious device, considering it was developed in the 60s. DROs made them obsolete, which is what I should be doing, but this one came to me almost at 0 cost, and it's cool AF. 😂😉

[@LetsRogerThat]

@ it sure is awesome. Can’t wait to see if you master its use. Its more fun than a dro 😊

[@ypaulbrown]

Love all you do

[@MyLilMule]

Thank you!

[@terrycannon570]

Greg I made and installed a cross slide DRO for my Clausing 100 lathe and another one for my BP Clone mill. Both are attached with some very good and very cheap magnets that I got from Amazon. I've managed some awesome tolerances and repeatability with them. I wanted to use the magnets to avoid drilling holes in the machines. I'm an insane purist when it comes to working on these old beauties.

[@MyLilMule]

I'm a bit of a purist myself, and I don't like drilling holes unnecessarily. I like your approach to the cross slide. I haven't considered putting a DRO on this machine, not for any particular reason, but figuring out how to get the cross slide scale mounted and not lose too much tail stock clearance or being able to use a follow rest, has been a head scratcher for me. The Travadial came to me with some other stuff, so it was practically a 0 cost addition. Plus it's cool. LOL!

[@terrycannon570]

@@MyLilMule I agree. the DRO has its own set of problems. Not so much on the z axis on the mill but it does get in the way of the tailstock at times on the lathe. I will eventually get around to making improvements on the mounting of the magnetic bracket but for now I used what I had. On these older machines finding a flat spot big enough for a mag base dial indicator is at the least difficult. if I had a Trava dial I would use it too. They are the purist form of a DRO. From what I have heard they are hard to find and expensive when you do find one. As Harold Waters says KO-KO. Thanks for bringing us along.

[@MyLilMule]

@@terrycannon570 Flat spots. What's a flat spot? LOL! I am working on adding a DRO to my K&T 2HL. NO FLAT SPOTS is an understatement on that machine. 😂

[@ypaulbrown]

Wonderful explanation, now you are making me want a Travadial….thanks…Paul…by the way, you can polish that plastic clear cover with tooth paste and an old tee shirt…and it will not get cavities either❤

[@MyLilMule]

Great idea!

[@ypaulbrown]

Such a beautiful 13 inch SB 1942…just like mine, March 1942 tool room, with taper attachment…cheers, Paul in Orlando….

[@MyLilMule]

I'm jealous of the taper attachment! But my 1960 13" will have one!

[@junkmannoparts9696]

Good video the dail mount looks good . If you have a 12'' calipers or even 6'' wip up a mount to hold them in your tool post and read off the chuck . or make a 4'' block . well just an idea hope it helps . JM

[@MyLilMule]

I've been bouncing a few ideas around in my head. This one sounds like it could help. Thanks!

[@Regal4555]

Take a drink every time he says Trav-a-dial!

[@MyLilMule]

That would be about 40 drinks! 🍻

[@honeycuttracing]

😂

[@shootgp]

I got lost at the end... I don't understand why gauge blocks of any sort would be needed for calibration or verifying the readout. If you get one full inch of movement with the dial indicator, and the travadial reads precisely one inch of movement, then I'd assume you'd be good to go. What am I missing? 😊

[@MyLilMule]

I am sure I did a really poor job of trying to explain something I know little about. It is not about the distance travelled, it is about the consistency of the travel in relation to the readout. And repeatability. I'm basing a lot of the "why's" off of the documentation I was able to scrounge up on these gizmos.

[@shootgp]

​@@MyLilMuleYou explained fine, I'm just dumb. Interesting device, I decided to try and build my own as an experiment. I modeled the gears in Fusion last night and sent the resin printer to work. Kinda wondering how bad I can make this... lol

[@rozinant1237]

Just curious?, why this route, and not a DRO?

[@MyLilMule]

The primary reason is because I wanted to, simply. But it also helped that I acquired this with a group of other things, so the cost was practically nil. And it was fun to get it working!

[@jerrypeal653]

Nice

[@MyLilMule]

Thanks

[@melgross]

I’m not certain that the radius changes with angle. It depends on how it’s tilted and measured. If you look at your illustration, if, the curve of the radius equals the diameter and the tilt is from the center of the thickness of the disk, the the radius is the same, no matter what the angle as long as it doesn’t run off the edge of the disk. If the curve of the radius is smaller than the diameter and the tilt is from some random place, then all bets are off.

[@MyLilMule]

Radius absolutely changes with angle. The pivot point is a line through the top of the disc (sphere section). Think about the earth. The earth revolves around an axis through the north and south poles. The length of the latitude lines get shorter the further away from the equator you go. This is exactly the same kind of geometry. The axis doesn't change, but the ground distance traveled definitely changes. It's why when we launch rockets that are intended to escape earth's gravity, we launch them from places closest to the equator, because they are traveling at greater ground speeds.

[@buckwheat7673]

Nice find.

[@MyLilMule]

I agree! It makes things a lot easier.

[@ThePottingShedWorkshop]

Wow, $30 for four offcuts of foam! I think I would have tried experimenting with my own cheaper concoction first!

[@MyLilMule]

I actually tried finding some material as a substitute, but I would have spent almost as much on it, the adhesive, etc. than I did on this, and all I had to do was click "Buy It Now" 😂. I much prefer to make things like this. I would have actually preferred felt, but I didn't have any felt that was thin enough, or the right "elasticity" for it. Thanks for watching!

[@EdgePrecision]

Do you have any standards for your micrometers. Say a 0-6" or even better a 0-12" set. In the past I have used them to do this. You will have to set up something on your lathe bed to do this. Possibly a dial indicator with a mag base and some V blocks. Make a fixture to mount in your chuck to hold the standards. To describe this fixture. Take a rod and drill it, bore it to fit your standards diameter closely. Then take it to your mill and mill a slot from the side to intersect the bottom of that hole such that the standard will have a good flat surface to contact on. Now put it back in your lathe running true. Now you can set up a mag base with an indicator to contact the standards mounted in the fixture. By mounting different standards you can check the calibration of the travel dial. You could so the same with gauge blocks buy orienting one of the chuck jaws horizontal in a low gear so you can set the block on the jaw. Now set up a dial indicator on your cross slide on a mag base such that you could zero it on the chuck's face but still contact a gauge block setting against that face and on the horizontal jaw. Then you could put different length blocks and comparing them to the travel dial. Those are a few ways I have done this. Depending on what I have had on hand. The other way is just to physically cut a part and measure it.

[@MyLilMule]

I think I am starting to get the idea! I do have some micrometer standards I might be able to use for this. Thanks for the description of the tool. I'm going to give this a try.

[@Rustinox]

Very nice find. Once you get used to it, you will wonder how you did things all this time without having one.

[@MyLilMule]

My thoughts exactly

[@mikeycoop66]

More question than answer, could you use a micrometer standard to achieve the desire length? Probably not as accurate as a gauge block setup but it is something that you have in the shop most likely. It is also very close, if not exact to the measurement it is designed for. Either way I am sure you will figure out the conundrum.

[@MyLilMule]

I might be able to use something like that to build what I think they expect to use, but not sure it would be much of a help. They seem to expect you to go back and forth repeatedly between the two points to check for cumulative error as well.

[@stevewilliams2498]

Am I missing something ? Or are you ? Isn't the reason the wheel is crowned purely to eliminate the error caused by tilt ? The rotating radius is constant regardless of tilt within the width of the wheel. As long as your amount of tilt isn't moving the pivot centre above or below the top or bottom of the wheel it is constant. Your diagram wasn't representing tilt but was showing vertical movement which represents line contact on the wheel. Reality you have a vertical face contact not a line.

[@MyLilMule]

Maybe a combination of both of us missing something. The two screws on the bottom of the mount are used to affect the tilt of the machinasin. Tilting the crowned wheel will most definitely change the velocity the wheel moves over the same given distance since it changes the radius of the curve around the pivot point. The radius is most definitely NOT constant. This is not my assumption, this is coming from the installation instructions I have been able to locate. "The calibration of the Trav-A-Dial is accomplished by changing its tilt relative to the running surface. To do this, the angle between the bottom of the Trav-A-Dial and the top of the M-5 base is changed by the position of the tilt adjustment screw threaded through the base. Raising the screw decreases the angle. Each full turn of the tilt adjustment screw will change the calibration by about .0050 inches over 6 inches of travel." This is also backed up by the original Travadial patents.

[@jm.workshop.q8]

👌🏻👌🏻👌🏻

[@MyLilMule]

👍🏻

[@junkmannoparts9696]

Hi greg you probably already know about these 0-600mm Readout Scale，Digital Linear Scale，LCD Readout Remote Linear Scale，DRO Linear Scale Digital Readout Kit，for Milling Machines Lathes… $68.00 on amizon

[@badjuju6563]

Was going to leave the same comment....its still an ugly bracket

[@junkmannoparts9696]

Well maybe he likes the vintage look or he was just unaware they exist

[@MyLilMule]

Not really a fan of those. If I was going to do that, I'd rather just install a DRO. Not against a DRO, but I paid less for this than the $68 cheap thing on Amazon.

[@jeffo881]

It's the maths.

[@MyLilMule]

And they never lie. ;)