Help with Palmgren rotary table?

Sounds like a 40:1 worm , which is a standard ratio - mine's 90:1 which makes each turn 4°. Do you have index plates with it ? I can't remember the calculation offhand , but with the plates you can divide a circle into however many segments you want - think "gearcuttung" , where the degrees don't really matter but the number of teeth does .

========== Try asking Palmgren.

see

or 800.621.6145 773.265.5740 (fax) snipped-for-privacy@palmgren.com

-- Unka George (George McDuffee) .............................. The past is a foreign country; they do things differently there. L. P. Hartley (1895-1972), British author. The Go-Between, Prologue (1953).

That sounds like a non-standard rotary table. If one turn turns the table 18 degrees, than the rotary table has a 20:1 gear ratio. Not what I would expect. 40:1 is what I would expect.

The MSC catalog has Palmgren rotary tables listed, but they are all

40:1 gear ratios. Would you mind checking one more time what the gear ratio is? I just find it hard to believe that your rotary table has a 20:1 gear ratio.

Dan

Dan,

I just went down and double checked. Twenty revolutions of the crank gives one revolution of the table. Perhaps it was a compromise in cranking speed; the table has no way to decouple the worm gear and shift the table by hand. It is a horizontal only table similar in appearance to the No. 86 made in the fifties. The age is unknown- it was a Cabin Fever purchase.

Kevin Gallimore

--Palmgren is known for making crap. Think of it as a boat anchor and get something better for precision movement.

Thanks for looking. I am not sure why they would have used 20:1 gearing.

Dan

To make N divisions on the table you turn the crank 20/N times

table crank

2 10 3 20/3 =3D 6 full + 66.7/100 4 5 5 4 6 20/6 =3D 3 full + 33.3/100 8 20/8 =3D 2 full + 50/100 and so on.

To mill a hexagon, like a bolt head, you'd start at zero and cut a flat. Turn the crank twice plus 33.3 marks and mill the second flat. Turn two full revs and stop at 66.6 for the third. Next turn two full revs and advance to zero (=3D100) for the fourth, etc.

I wrote a spreadsheet that lists all the full and partial turns for up to N =3D 100 for my 40:1 table.

jsw

SNIP

Hey Kevin,

Not real sure what their return policy is, but you could always take it back next week!!

Brian Lawson, Bothwell, Ontario.

ps...are you going??

Good idea. I'll make one up and post it on the door of the cabinet that holds the table.

Thanks,

Kevin

At this point I have gotten my money's worth out of it. Just couldn't figure out why it was made the way it was.

If the creek doesn't rise and there is no threat of snow (we got 30-odd inches in a single snowfall last week). I will be there with my two beautiful girls.

How about yourself?

Kevin

Palmgren is certainly cheap and cheerful. It will serve, however, until I find a Troyke at a small multiple of the price I paid.

Kevin