Shiny New Yuasa Rotay Table Arrived Early

[lazlo]

The points are:[*]All thread, providing it is of adequate quality and fit is as strong as a normal rolled studs for this application which is pure tensile.

You apparently haven't seen the Chinese all thread we have here in the 'States It's made out of a really weak alloy of steel (or pot metal), and the threads are terrible fit and finish. It's truly a recourse of last resort.

Go read Caroll Smiths Nuts, Bolts, Fastners and Plumbing handbook

Yep, I have Smith's Nuts, Bolts, Fasteners and Plumbing Handbook, and Engineer to Win. Great books, but doesn't really apply here: it doesn't take a lot of torque to hold a workpiece onto a rotab, and the Chinese Cheese allthread handles that adequately.

But as far as the Chinese allthread being straight, or fitting the matching bolts, that's another story

Like you said earlier, the quality all thread from your local industrial supplier is the same price as the cheap Chinese stuff, and the threads are of much higher quality.

I got the MSC Free Overnight shipping upgrade, so hopefully I should have it tomorrow -- I'll post some pictures of what the Made In USA all thread looks like compared to the Chicom stuff.

[ckelloug]

My biggest concern was nasty soft allthread having the threads bugger up after 1 or more uses. Hardened studs are a lot better in this respect. Derekm has posted lost of interesting bolt and screw engineering stuff that I didn't know but realisticly, cheap althread will work fine for the 8 clampings I need to achive on the rotab for this project. If my dad was involved, he'd manage to twist the end of the cheap allthread off even though he put the nut on with a 6 inch crescent wrench. I agree that lightly built machines aren't friends with giant clamps but I'm on a 1963 bridgeport mill with an already buggered table so I'm not worried in the slightest.

My local folks quoted me lazlo's 7/16 teco stud set at $67.00. I had seen the price on teco's website as $153 (maybe I read the wrong one) and got heartburn.

At any rate, the clamps just have to hold. The 1/8 MT3 collet I was going to use to hold a dowel pin in the center of the table turned out unavailable (6 month lead time) through america's tool crib system. So, I just got finished making an MT3 taper with a 1/8 dowl pin precision drilled into the middle of it to go into the rotab mt3 taper. I actually made 2, one in S7 tool steel and 1 in T6 aluminum.

Amazingly enough, I got the taper right on the first try on the tool steel one but then had the hole drill in at a stupid angle despite center drilling the piece and drilling using the mt3 tailstock to hold the taper and the headstock to hold tools. Then, after getting the hole almost corrected, I managed to break off a 1/8 boring bar in the hole rendering the part useless for this application. The taper on the aluminum version took longer to get right but the hole is drilled correctly. As a bonus today, my local tool supply tossed in a B&S MT3 15/16 drill billed at the cost price of a 5/16 tap ($3.00) for use as a taper template. The lady said that this stupid drill had been on the shelf since 1988 and she was tired of counting it on yearly inventory and she was happy to see it go to a good home.

Now that the metaprojects are done, I guess tomorrow it's time to do the project.

[oldtiffie]

1/8" MT3 collets

Cameron.

I thought I'd seen those 1/8" MT3 collets - in stock:

http://littlemachineshop.com/products/product_view.php?ProductID=1605&category=874479994

[dp]

Cameron.

I thought I'd seen those 1/8" MT3 collets - in stock:
http://littlemachineshop.com/product...gory=874479994

Thanks for that link, Tiffie - I didn't know those were available. The complete set will suit me fine.

[ckelloug]

Thanks tiffie. I noticed that littlemachineshop had them as did the mdmetrics catalog and some vendor in Euclid Ohio that trades solely in bizarro collets (but gets this item from mdmetrics). It's interesting that there are none of these collets made in the USA despite the fact thate the original machines to use them (SB9 headstocks I think) were made here. The only collets of this type made now are imports (primarily used in an HSM environment) and in my primary supplier's case, they're on the slow boat from china.

I would have ordered them and been done but if at all possible, I need the project done tomorrow and getting the collets monday or tuesday from a new supplier is incompatible with finishing the project tomorrow so I didn't bother.

It seems like somebody would make MT3 tapers with dowel pins sticking out of them for use as rotary table centers and that this product would be widely available but I didn't see any in the half dozen large catalogs I have.

--Cameron

[lazlo]

Cameron, are you just trying to locate the center of the rotab? For that, you can just use a Bake co-axial indicator to touch off the center hole. I show that in my photo sequence on the servo plate build thread.

[derekm]

My biggest concern was nasty soft allthread having the threads bugger up after 1 or more uses. Hardened studs are a lot better in this respect. Derekm has posted lost of interesting bolt and screw engineering stuff that I didn't know but realisticly, cheap althread will work fine for the 8 clampings I need to achive on the rotab for this project. If my dad was involved, he'd manage to twist the end of the cheap allthread off even though he put the nut on with a 6 inch crescent wrench. I agree that lightly built machines aren't friends with giant clamps but I'm on a 1963 bridgeport mill with an already buggered table so I'm not worried in the slightest.

My local folks quoted me lazlo's 7/16 teco stud set at $67.00. I had seen the price on teco's website as $153 (maybe I read the wrong one) and got heartburn.

At any rate, the clamps just have to hold. The 1/8 MT3 collet I was going to use to hold a dowel pin in the center of the table turned out unavailable (6 month lead time) through america's tool crib system. So, I just got finished making an MT3 taper with a 1/8 dowl pin precision drilled into the middle of it to go into the rotab mt3 taper. I actually made 2, one in S7 tool steel and 1 in T6 aluminum.

Amazingly enough, I got the taper right on the first try on the tool steel one but then had the hole drill in at a stupid angle despite center drilling the piece and drilling using the mt3 tailstock to hold the taper and the headstock to hold tools. Then, after getting the hole almost corrected, I managed to break off a 1/8 boring bar in the hole rendering the part useless for this application. The taper on the aluminum version took longer to get right but the hole is drilled correctly. As a bonus today, my local tool supply tossed in a B&S MT3 15/16 drill billed at the cost price of a 5/16 tap ($3.00) for use as a taper template. The lady said that this stupid drill had been on the shelf since 1988 and she was tired of counting it on yearly inventory and she was happy to see it go to a good home.

Now that the metaprojects are done, I guess tomorrow it's time to do the project.

Introduce your father to a torque wrench.
There is a correct tightening torque for each size bolt and grade
your 7/16ths at grade 4.6 is around 8-12 ft lbs
and at 8.8 is around 20-30 ft lbs

[derekm]

...Yep, I have Smith's Nuts, Bolts, Fasteners and Plumbing Handbook, and Engineer to Win. Great books, but doesn't really apply here: it doesn't take a lot of torque to hold a workpiece onto a rotab, and the Chinese Cheese allthread handles that adequately....

My point and Mr Smith's is that there is only one way to tighten anything and that is properly. And there is only one way to select a fastner and that is using sound engineering principles.

If you read Mr Smiths treatise in detail you will see he is for using the correct size and grade fastener and then tightening them fully. If you strip the book of advice that relates only to his application you will see that the principles he talks about are just as relavent to selection of mild steel all thread for fastening Rotabs as selecting con rod bolts for a racing car.

[John Stevenson]

Having purchased a truly quality piece of machine accessory that will last a lifetime and more I couldn't imagine using all thread for studding, the grade 8 variety possibly as a minimum......it wasn't all about the strength of the proper studs, it's a question of fit, look and pride of workmanship.......

So if it's not about the strength that is most important but fit, look and pride I think you have your priorities wrong.

A stud is a tool.

It's there to do one thing and one thing only, hold onto to whatever it needs to hold on to.
Most times it's only temporary, there to hold a part for an operation then either put away or resetup.

If it was permanent or for display then looks will come into it but as a temporary tool, use should be the prime reason.

My CVA lathe is of 1950 vintage with the rounded castings and I much prefer the looks of the later squarer machines so should I weld a few lumps of angle iron to the headstock and mix up the odd pound of Bondo to get it to look like I would prefer, note prefer not need.

.

[lazlo]

Hi John,

So if it's not about the strength that is most important but fit, look and pride I think you have your priorities wrong.

A stud is a tool.

It's there to do one thing and one thing only, hold onto to whatever it needs to hold on to.

You're a pro machinist, and you feed your family with your shop.

My shop time is my hobby, so I completely strip, clean and repaint most of my machines, because I like them to look nice. So no, I don't like to d!ck with bent, stripped Chinese all thread, although I did in that picture of my rotab fixture that Cameron is talking about.

But somehow Derek has turned this conversation about Cameron's rotab into a tutorial about the correct torque for a Grade 8 bolt, when several of us were just pointing out that Chinese all thread is really lousy, usually bent, made from very weak alloy, and has wonky, drunken threads that are very prone to strip.

As Derek pointed out, and I confirmed with MSC, you can get quality Class 2A fit threaded rod for the same price we pay for all thread at Home Depot or Lowes. And no, I don't care about the tensile strength, or the amount of torque it takes to preload the thread

[hardtail]

So if it's not about the strength that is most important but fit, look and pride I think you have your priorities wrong.

A stud is a tool.

It's there to do one thing and one thing only, hold onto to whatever it needs to hold on to.
Most times it's only temporary, there to hold a part for an operation then either put away or resetup.

If it was permanent or for display then looks will come into it but as a temporary tool, use should be the prime reason.

My CVA lathe is of 1950 vintage with the rounded castings and I much prefer the looks of the later squarer machines so should I weld a few lumps of angle iron to the headstock and mix up the odd pound of Bondo to get it to look like I would prefer, note prefer not need.

.

I seem to keep getting ahead of myself and assuming the basics and extending the courtesy that fellow bb members aren't morons, apparently not always extended back......blush, I know you are aware of this John but the type shows the hole, of course function is the most important and the others are secondary but I think also important.......

My disdain for the poor quality all thread is clear, I wouldn't consider it for anything less than an unusual setup on a rush job and then I'd be thinking thrice, alas the importance of having a well stocked tool crib.

Seeing all thread on a brand new Yuasa is worse looking to me than seeing the proper studs on a POS India rotab...........all thread maybe questionably fine for short vertical clamping but poor for side torsional forces, as the vertical gets comprimised the torsional starts to come into play.......