Usefulness of cross slide rotary tables?

>>>etpm@whidbey.com wrote:
>>>
>>>>Greetings All,
>>>>I have and use a Troyke 12 inch cross slide rotary table (R/T). Before
>>>>the advent of widespread CNC milling machines these tools were
>>>>practically indispensible to mold makers and machinists making complex
>>>>parts with radii blending into straight or curved surfaces. I also
>>>>have a 4 inch rotary table. This little table is perfect for some of
>>>>the small one off parts I make but if they get too complex I either
>>>>make 'em on the CNC or use the giant Troyke. Seeing the need for a
>>>>smaller cross slide R/T I designed and have started making a cross
>>>>slide to fit the little 4 inch R/T. It's 6 inches square because I
>>>>wanted a little more room for clamps. It occurred to me last night
>>>>that this cross slide might also be something that model makers would
>>>>like. Unlike the small cross slides available that I have seen my
>>>>design is compact and low profile. It is also square with equal travel
>>>>in both axes. Pretty much a copy of the Troyke but on a much smaller
>>>>(and lighter!) scale. I'm posting this message in this newsgroup
>>>>because it seems to me that the UK has many more people interested in
>>>>model engineering than here in the US. And I'm wondering if there
>>>>would be much of a market in the UK for plans, a kit, or a finished
>>>>product. Any ideas anybody?
>>>>Cheers,
>>>>Eric R Snow
>>>
>>> Have you seen the one that was published in Home Shop Machinist a year
>>>or two back?
>>>
>>> I was pretty interested in programming the CNC mill at work to cut a
>>>base for the R/T portion, and it turned into a nightmare really fast,
>>>when the dimensions started adding up wrong.
>>>
>>> The reply from the editor was not promising either.
>>>
>>> It still looked like a decent project, just not one that could be done
>>>relying upon the dimensions given as being accurate.
>>>
>>> The PITA part of the equation is that the really small mills don't
>>>have the headroom for the stacked pile o bits, while the ones that do
>>>have the room, want a little larger R/T and slides.
>>>
>>> Hell, I'd be pretty interested in a decent, low profile, smooth
>>>turning rotary table, suitable for my Centec or on the slide of my
>>>Myford. The small, nice ones that I have seen go by were huge money, and
>>>the small affordable ones were not worth buying for being so rough.
>>>
>>> Best of luck getting this going. An article written and submitted to
>>>one of the Model Engineering magazines would very likely rouse some
>>>interest in kits, if one were to go that way.
>>>
>>> Cheers
>>> Trevor Jones
>>>

>>
>> Greetings Trevor,
>> Thanks for the reply. One of the reasons I'm making the cross slide
>> is because I want as low a profile as possible. With the small table
>> on a Bridgeport it doesn't make that much difference. But the low
>> profile also has the advantage of being more rigid. Nevertheless it
>> still will use up about 1 1/2 inches of spindle to table clearance. I
>> guess what I'll do is finish the thing and if I like it correct my
>> drawings and post them to the dropbox. If people like them I'll
>> consider writing an article.
>> The cross slide would need to be adapted to an existing R/T. I have
>> seen plans for low profile ones. The little 4 incher I have is a
>> Taiwanese one that I bought considering it a semi-finished kit. It
>> wasn't real accurate when I got it but I went through the whole thing
>> and now it's a fine tool.
>> Cheers,
>> Eric

>
> Well that right there is a pretty good subject for a written article.
>
> Some of the asian import R/T's I have looked at in person were, well,
>nasty.
>
> If you can massage one into a decent running rotary table with only a
>little work, then that in it's own right is an accomplishment.
>
> I have a Myford lathe, an Aamco shaper, and a Centec 2A mill.
>
> The Centec is REALLY challenged for height, really needing a riser to
>do anything much larger than small model stuff with small cutters.
>
> It has about the same work envelope as a Sherline mill, except it has
>several hundred pounds of cast iron in it, rather than 15 pounds of
>aluminum.
>
> Got any sketches? I'd be interested in seeing the design.
>
> Cheers
> Trevor Jones
>