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QSIMDO
08-19-2008, 05:46 PM
This might even be a common thing to do...dunno, so I ask.

I have a 15" Bridgeport rotary table which I really don't use that often and is getting just too unwieldy to handle ( it got heavier, I swear!) but thankfully I have an 8" Phase ll as well.

I've been thinking of getting what I can for the massive beast and then somehow adapting, say, maybe a 12" face plate to the Phase ll when I need a bit more capacity.

Is this readily accomplished or do I need more oxygen?

lenord
08-19-2008, 05:57 PM
QSIMDO,

Why not ? As long as the new table top does not interfere with the handle, and it is thick/strong enough, you should be able to readily do that.
I cut large wheel and worm gears, up to 15.5" OD, on a 10" table all the time. I do check that the face of the blank is still flat to the table surface, and it seems to work just fine.

I've also read that other machinists put a blank disc on top of a new rotary table as a matter of course.

I know where to get large diameter Al. plate rounds at a reasonable price too.

FWIW
Lenord

ammcoman2
08-19-2008, 06:23 PM
Yep, I have a 9" diameter 1" thick Al plate ( with T-slots) that fits on my 6" RT. 'Twerks like a charm. The ratio you propose is the same.

Geoff

lane
08-19-2008, 06:30 PM
I made a 14 inch steel top for my 10 inch Walter table . Thought I might need it but have never used it since made.Cut 4 tee slots and a bunch of 1/2' taped holes to tie things down with.

Reed
08-22-2008, 02:13 AM
I have a Phase II with a turned down SB 11.75" faceplate as an aux table.

http://i237.photobucket.com/albums/ff3/rstreifthau/in-use-front.jpg

http://i237.photobucket.com/albums/ff3/rstreifthau/RotaryAuxTable-mounted.jpg

- Reed
Raleigh, NC


This might even be a common thing to do...dunno, so I ask.

I have a 15" Bridgeport rotary table which I really don't use that often and is getting just too unwieldy to handle ( it got heavier, I swear!) but thankfully I have an 8" Phase ll as well.

I've been thinking of getting what I can for the massive beast and then somehow adapting, say, maybe a 12" face plate to the Phase ll when I need a bit more capacity.

Is this readily accomplished or do I need more oxygen?

rantbot
08-22-2008, 08:33 AM
When I acquired my 12" Troyke it had a square aluminum plate attached to the top - plain, no t-slots. The previous user had drilled and tapped whatever mounting holes he needed for any particular job directly into the plate. I imagine his plan had been to simply replace the plate entirely when it got too ugly with old and unused holes.

Mcgyver
08-22-2008, 02:33 PM
if one didn't have an RT the strategy might be great to minimize the outlay and maximize the utility....but because you have it already I'll take the opposing view. That's a quality RT and its going to be a hassle replacing with an equally quality smaller one, and perhaps cost money if you can't find the smaller one used (of comparable quality). Except when lifting, more RT is better, so why not instead look for ways to assist with the lifting; a small jib crane, die cart, etc? As the years go by all of them, RT's of any size, dividing heads etc are just going keep gaining pounds so imo downgrading equipment isn't the way to go

granted 15 is big, but i wouldn't want to give up my 12 for say an 8....although as i told my son the other day after lifting it, if i ever injure myself in here that'll be how

QSIMDO
08-22-2008, 08:51 PM
Sorry I haven't been able to post back before this...thanks to all for your views!
Reed, that's just what I had in mind, but the pictures also made me think of another question.

How much cumulative error is a stack of layers like that going to cause?
Seems like it's necessary and desirable to tram the head to the table.

Mcgyver, I really would like to keep it and cranes and such are a viable solution, but then I think of all the tooling I still need to get and how much the 15" would bring in......tough call.

Roy Andrews
08-22-2008, 11:46 PM
i have a 16" troyke and have thought a few times about going smaller. then one day when lifting my indexing head i decided to build a crane. i made a block that slips on to the back of my over arms (Kearney Trecker 205/s12) and made a jib using square tube and an atv winch. i have a few attachments that i rarely ever used because they where a pain to mount. now its so easy i don't hesitate to change.

BobWarfield
08-23-2008, 12:18 AM
Like Mcgyver's crane idea, but perhaps simpler:

http://www.thewarfields.com/cnccookbook/img/OthersProjects/MillViseSwingArm1.jpg

http://www.thewarfields.com/cnccookbook/img/OthersProjects/MillViseSwingArm2.jpg

I've always liked the idea of a simple swingarm, perhaps like this one, or perhaps with a hook of some kind, attached to the mill column. Next to the column and out of the way would be a table or shelf that the swing arm can reach with your heavy vises, rotabs, and anything else too painful to just pickup and move. Rather than lifting, you're just sliding and letting the swingarm do most of the work.

Best,

BW

noah katz
08-23-2008, 02:21 PM
I used a cast iron 45-lb weight plate, machined flat of course.

17 1/2" dia on my 10" RT works fine.

Chipslinger
08-23-2008, 03:58 PM
Bob I was thinking the same thing, though as usual, you did it beautifully.


Ps, to heck with slideing, lower the table and swing it out of the way.

Reed
08-23-2008, 05:23 PM
I assume it is a given for stacking errors. :-) However, the size of the errors are up to you.

To build this I milled 4 blocks (each RT T slot position) that I screwed into position with 2 screws each block. These were bedded with JB weld epoxy as the back of the plate is a cast finish (and not much gain to mill it). A center pilot was also machined in place on the faceplate threads as shown in the pic below.

http://i237.photobucket.com/albums/ff3/rstreifthau/bottom2.jpg

Then it was fixtured on the lathe faceplate. The blocks were faced down. Then the aux table refixtured and the aux table's face was skimmed.

Machine it to a tenth and you have a tenth error, machine it to a thou and then you have a thou error. <grin> Up to you, eh?

I also mounted a lathe chuck on a plate in the same idea as the aux plate. Just take the care to make these adapters with parallel faces.

I mount it with a t-nuts and socket head cap screws.

Enjoy the day, - Reed

[QUOTE=QSIMDO]Sorry I haven't been able to post back before this...thanks to all for your views!
Reed, that's just what I had in mind, but the pictures also made me think of another question.

How much cumulative error is a stack of layers like that going to cause?
Seems like it's necessary and desirable to tram the head to the table.

QSIMDO
08-23-2008, 07:10 PM
sez Reed;
"Machine it to a tenth and you have a tenth error, machine it to a thou and then you have a thou error. <grin> Up to you, eh?"

Oh, no pressure there, ha?
You've cursed this project for sure! :)
Thanks again for the input. The piccies are great.

Now I've gotta run down to Katz' gym and do some measuring!