What are your thoughts on Trav-a-dials?

[oscer]

Hi folks, I am thinking of making my lathe a little more user friendly. I really am not all that excited about DROs because of the cost and the presence of the scale on the cross slide. I have never used a lathe equipped with a Trav-a-dial and would appreciate hearing any opinions of those of you who have. Thanks oscer.

[SteveM]

The trav-a-dial is typically used on the carriage to measure left/right. I haven't seen one on a cross slide, but that doesn't mean you can't do it. You'd have to have the room to mount it and a surface against which the wheel can ride.

Steve

[JackF]

Oscer,

I operated a Graziano Sag 20 with a trav-a-dial and it worked quite well. As Steve mentioned, this one was mounted on the saddle to measure left to right. To measure cross slide we used a 1" or 2" mag based dial indicator along with the scale on the cross slide. We rarely exceeded the limits of the 1" indicator when turning or 2" when facing. The only problems was when the Trav-a-dial got loose or when the surface the wheel traveled got dirty and the dial skipped, which happened twice in the 2 years I worked there, so it pays to keep an eye on the dial to make sure it is moving at a consistent rate while it is traveling.

Jack.

[oscer]

Thanks for weighing in fellas, I wasn't planning on using one on the cross slide, only on the Z axis. It may have sounded like the cross slide was part of the plan because I mentioned my objection to the presence of a scale there.

The problem with a scale on my cross slide is ;there are oil ports right where the scale should be mounted and the saddle has a raised casting about 5/8" away from the cross slide. I may be able to plumb a small st ell under the scale to get around it but I'm not sure. The Trav-a-dial may be the best way to go. The Lathe is a Clausing Colechester Dominion. from the early 60s.

[BadDog]

I'm not crazy about the Trav-a-dial systems, but my close friend and mentor has one on his Mori and wouldn't have anything else. It does have it's benefits, mainly the analog function which makes it so easy to track and use. But if not maintained/cleaned properly they can give error readings, and folks want almost as much for them as a 2 axis DRO. And I love my Newall DRO, but again, approaching with digital isn't nearly as natural and intuitive as watching an analog gauge, particularly if approaching a bore bottom or step or pull-out thread end. My answer is to use the DRO for places it works best, and use a dial indicator with Mighty-Mag base for places I want analog.

[GK1918]

I too have been thinking of a trav a dial an alternate for a DRO. As far as a real DRO for my
needs, thats about $1000 +. So I search around for trav a dial so I need three and they are
no deal either. Maybe I will machine one. I do a share of bolt hole circles and the big problem
is old eyeballs compounded by 200 graduation dials. Love and marriage is the same as
old eyes and backlash.

[shootnride]

Oscer,
I have a Trava Dial on my lathe because it came with it. I kind of like it, but if tolerances are critical, I find that I can not really trust it to repeat. I have spent several hours tinkering with it, following Trava Dial's instructions, and still find that some times it can be off as much as .002 between repetitive motions. It may be just because it's old, I don't know. I've noticed on eBay that they still command a pretty steep price and typically you're buying old equipment, so............

Just my two cents

Ted

[oscer]

Thanks fellas, all good points. I like the idea of touching off a face or shoulder and setting a size that may b a lot farther than even a 2" dial indicator. I also like analog. I think if I could hold .002" I would be satisfied, for some parts, that is close enough, for something that really needs to be tight I'd just have to stay back and set up with dial indicator as I do now.
If only I wasn't so cheap I'd call up DRO pros and maybe just install single axis,seems like a big waste to do that though, so I would spend a lot of time trying to work around the old lathe design issue that I mentioned above.

[ctwo]

How come there's no dial on the big wheel? I've been thinking about making one. Wouldn't that be nearly as accurate as the other dials? I know it's usually a rack and pinion drive with a lot of slop, but can't that be taken up as usual?

[BadDog]

My longitudinal feed (big wheel) has a dial, but driving a pinion on a rack it's nowhere near as accurate as a good quality screw even in the best condition. Factor in some dust, dirt, chips, rust, and general accumulation of stuff in rack teeth and all bets are off. A screw is constantly self cleaning to some extent due to shear wiper effect on the thrust surfaces, the rack action is more about packing stuff in.

[ctwo]

That makes sense. I do recall seeing a dial on the end of the lead screw on a few 3-in-1 machines, where that is the only drive for the carriage.

[BadDog]

And that's driving by lead screw, not by rack.