QTR 115 Yuasa 8in Rotary Table

Please Note: I am a beginning machinist and I do not pretend to know everything. Please always operate machinery in a safe manner and if you don't know, find a reliable source. DO NOT COPY ME. I make a lot of mistakes. I provide these videos for entertainment only.

[@Dogfather66227]

Regarding the backlash in the worm gear set on the rotary table and the locking features, it is standard practice to lock the table at each incremental move when not cutting an arc or circle. As a practical matter machinists are taught to lock every machine axis that is not intended to be in motion, linear or rotary. Further, we always approach an incremental stop on the rotary table from the same “direction” so as to eliminate the effects of the backlash before locking. When milling circular features it is extremely important to consider the direction that the tool and table are rotating. Cutter force should be pushing against the direction of table travel (or you can unexpectedly learn how much backlash you really have in those gears). BTW I like your new rotary table a lot but realistically I'd probably be OK with the old one. Interesting video. Thank you for posting.

[@DudleyToolwright]

Thanks for the great tips. If you happen to watch my fixture making video, a couple ago, you would watch the table violently move back and forth while I was trying to cut a curve. I ended up having to have both breaks 3/4 on the whole time I was rotating the table and cutting. It took a fair amount of force to rotate the table and it was frankly exhausting. The backlash is about 0.100 inches. This seems a bit excessive. The Yuasa has zero when purely going by feel.

[@Dogfather66227]

@@DudleyToolwright In post #229 I thought that your difficulty with the rotary table had more to do with climb milling versus conventional than a shortfall in the machinery. As you experienced, climb milling allows the cutter to basically pull the table around until the slack in the gearing was taken up whereas conventional milling won’t. Yuasa may help with rigidity and accuracy but technique is also a factor. 229 is good video. It’s worthwhile to see outcomes that aren’t always as expected.

[@melgross]

Hiawatha is a good tool. For the money, the Shars is worth it. I’ve got an 8” Phase 1. It’s about in between the Shars and the Yuasa. I ended taking it apart, measuring some of the hating surfaces and doing a tiny amount of scraping, and that brought it in. I hate scraping, by the way. Sometimes you can adjust how tightly the gears mesh. I can’t speak for every manufacturer, but the Phase 1 has adjustments for that. A couple of screws on the outside.

[@DudleyToolwright]

Thanks for the tips. I was going to take the Shars rotary table apart at some point in the near future. I'll see if anything can be done. I am curious about the gear quality. Shars has been perfectly fine for other tools.

[@hilltopmachineworks2131]

Nice RT there.

[@DudleyToolwright]

Thanks! Your channel has so many interesting videos!

[@hilltopmachineworks2131]

Well thank you Robert. 🙏@@DudleyToolwright

[@AWDJRforYouTube]

My 8" Vertex [circa 2018] is very tight quality much like the like the Yuasa, i'd say they are both the same mfgr.

[@DudleyToolwright]

That is definitely possible. I hear nothing but good things about Vertex.

[@garysgarage101]

Now I’m going to have to measure out my 8” Vertex. It’s hit and miss with Shars, but I wouldn’t be ok with that much backlash. Always exciting to get a new tool. Great review.

[@DudleyToolwright]

I almost got a Vertex myself. They are also made in Taiwan and of very nice quality.

[@kevinedwards9365]

It be interesting to see how the vertex compared to the yuasa .I think it's around 400.00

[@Jasonschmidtschannel]

Isnt there a tiny grub screw 90 degrees to the lock down that you can adjust the back lash . I can adjust mine till there is no lash at all 👍

[@DudleyToolwright]

I will definitely look into that. Thanks for the tip!!

[@johnnyciantar]

@@DudleyToolwright When you adjust the backlash, you'll find you get greater resistance rotating the table, perhaps similar to your new table, there's a trade-off, the greater the resistance will give you less backlash versus easier and smoother to rotate with some manageable backlash. Would be great if you do a follow up video because I think your old table will be greatly improved and for the money you paid, you got a bargain. There's also a thrust bearing you can adjust underneath the table, easy to get to by standing up the table so it rotates vertically, this will help to minimise the up and down movement when you apply the brake levers. I enjoyed your video btw.

[@Pete-xe3il]

One would think both your tables came with some kind of certificate of accuracy like my Vertex did. If so, then what do those say versus what the actual test measurements are? And just how parallel are the tables to your surface plate in all 4 quadrants? Then what's the run out numbers on the Morse Taper? Tests have to check all the features and 3 dimensional alignments before you can be sure of anything. Despite the so called certificates numbers my Vertex was "supposedly" tested at, the Morse Taper run out, table flatness and table parallelism to it's base didn't match what my test numbers were. So to me, it's worm and wheel accuracy that I can't really check well enough are also highly suspect. Guarantees to a few 10ths don't mean anything when I start seeing up to twice or a bit more than what those test numbers were written down as. Fwiw, maybe 3-5 years ago, there was a thread on the Model Engineer magazines forums about serious issues with a Yuasa R/T' and the worm wheel being damaged when used while rotary milling. Some suspect that there worm wheels may have started out as a sintered blank and then machined and finish ground. If the poster was being up front and honest? Yuasa apparently said after being sent pictures of the damage that they weren't to be used for rotary milling. Why would you buy one for then? I've no idea how much any of it was true or not, or if Yuasa got the company in Taiwan to start using non sintered wheel blanks or not. If it were me, these tables are all pretty simple. I think I'd pull them both apart and compare the internals since that's where the real accuracy and justification for the large price difference starts.

[@DudleyToolwright]

You make some very good points and the Shars tools rotary table did come with accuracy claims, but I don't remember if it came with a test sheet. For that matter I don't remember it coming with a manual either, but I might just be forgetting.