Rotary table, non std gearing

[neksmerj]

There is a small rotary table for sale at the moment. In the text it says

please Note! the gearing on this Table is non standard so requires indexing plates , or re-gearing

What does this mean, would it be hard to fix?

ROTARY TABLE 130mm/5" horizonal / vertical 56-1 ratio | eBay (http://cgi.ebay.com.au/ROTARY-TABLE-130mm-5-horizonal-vertical-56-1-ratio-/110676496209?pt=AU_Toys_Hobbies_Model_Kits&hash=item19c4d54f51)

Ken

[Dave J]

That guys things always go for high prices:?
I wouldn't be worth modifying, though it can be used as is for simple dividing.

It's the same as the one I am looking at from H&F's, it's 94 to 1.

Dave

[neksmerj]

Dave,

The item started off at 99 cents, and the current price is where it is, because of the bidders.

I still want to know about what non standard gearing means.

Ken

[Dave J]

I know it's the bidders, (unless there is something going on) But everyone seems to bid his gear up for some reason.
Non standard gearing is something that is hard to divide into smaller numbers easily and there are no plates around for them unless they are custom made.

Dave

[neksmerj]

Thanks Dave.

Are you suggesting I leave well alone, or would it be a bargain for around $100?

I reckon I could knock up some plates.

Edit: Oops, the price has suddenly jumped, maybe I should have kept my big mouth shut

Ken

[Dave J]

Thats what I mean about his prices, I know he has a shop and goes to trade fairs but he must have a big customer following. I have watched some of his gear through last year and it has always gone above what I would pay, and some gear I could buy elsewhere for less than the final price.
For a first table I would stick to something with common gearing, I even see guys getting stuck and asking questions about dividing numbers on those, without throwing in the hassle of odd numbers.
I think it was Merv on another site, that had a program he created to make it easier. I could track it down when your ready.

Dave

[pipeclay]

Ken were you planing on making a template for the dividing plates,or some other means of indexing for the holes.

[neksmerj]

Pipeclay,

I would probably use Autocad, make a dxf file, and have the dividing plates laser cut.

To be honest, I hadn't given it much thought.

Why do you ask?

Ken

[neksmerj]

It's gone. The winning bid was $153.75. Anyone here buy it?

Ken

[pipeclay]

Just curious Ken,fair bit of work in making them on a manual machine,took me about 24 hrs to make 4 hercus plates.
Dont think the laser would be any good on the Holes,how accurate would they be.

[neksmerj]

Hi Pipeclay,

You are probably right, perhaps get the holes CNC'ed to a dxf file.

I'll worry about it if and when the time ever comes.

Ken

[Dave J]

Something you should look into before buying an odd gearing table. You will probably find out it's not worth the trouble/ time and money, unless like Pipe Clay you can make it your self. You can buy them for the 6-8 inch tables for around $100-$150 a set.
One way of doing it would be with a DRO with the "Holes in a circle" function. You centre the plate, type in how many holes you want and what PCD and away you go. You only have to push a button for a particular number and move the dials until you zero it for each hole.
This function was great when I was making the sub plate for my rotary table to fit all 3 chucks and the mounting holes.

Dave

[neksmerj]

Hi Dave,

Your last comments sound interesting. For this dummy, do you have a sketch of your proposal.

"DRO with the Holes in a circle function".???

Ken

[pipeclay]

Basically Ken its working off X Y co ordinates.
Can be done manually as well with use of dialindictor/s.

[Dave J]

You need a digital readout on your mill to do it, and you program in the amount of holes etc.
You can down load the manual from this ebay listing to read the instructions on how to use this function.
SINO 3-axis digital readout (complete DRO kit) | eBay (http://cgi.ebay.com.au/SINO-3-axis-digital-readout-complete-DRO-kit-/220660747717?pt=LH_DefaultDomain_15&hash=item336067cdc5)

Dave

[Stustoys]

Ken,
Its looks like this
http://www.woodworkforums.com/f65/rotary-table-questons-133374/index6.html#post1298745
You can do it by hand, your new book will explain I think.
Stuart

[neksmerj]

ST,

My godfather, you blokes don't miss a trick. Yes I have "the new book" A Complete Guide to Milling, and every second day, I plough through another section. I have to pop into hospital every second day for a top up and oil change. Reading a book with one hand is a challenge. Trying to open a pack of sandwiches tightly wrapped in cling wrap, is a real challenge.

But that's another story.

Stu, you are just about due for a visitor, I'll PM you first to make arrangements. In about a week.

Ken

[Dave J]

For things like this the DRO does it so easy without working out all the maths. Some just think of a DRO as a measuring device but with all the added features it's a lot more.

Dave

[Anorak Bob]

Ken,

Save up your play money and buy one of these.

YouTube - Haas Horiz & Vertical Servo Rotary Table, 8 Inch Dia., #53A-150.wmv

BT

[Stustoys]

Ken,

Oops, wrong book. The PCD maths is in his Dividing book(number 37). Although there is plenty on dividing heads and indexing heads in the book you have.

I'll start clearing a path the the VSD.

For those Harold Halls books a question. Milling a complete course page 70, Dividing page 65. There is a picture of the bearing block being carefully slit. What's the point of the center piece? Why go to the trouble of two vertical cuts and then two fiddly horizontal cuts. One vertical and one full length horizontal slit would do the same job.

Stuart

[Stustoys]

Your's BT? :p

[festy_]

I was watching that rotary table on ebay with the idea of doing a similar conversion - non-standard gearing wouldn't make any difference after the driver was tuned and calibrated.
Once the price started going up, I decided I'd be better off building one myself though.