Author Topic: Homemade Rotary Table  (Read 13747 times)

Offline Robert Hornby

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Homemade Rotary Table
« on: April 12, 2013, 08:00:35 AM »
I was thinking about how I was going to make the expansion link for my marine engine as they have curved slots. Not having a rotary table I would have to improvise (I do that a lot) and considered drilling a curved row of holes and filing out. However I enjoy a challenge was determined to machine them somehow.
Whilst rummaging through a box of stuff searching for a pair of toolmakers clamps that I knew I had but hadn’t used for quite some years prior to a house move I came across a worm reduction gearbox (which I had forgotten about) that I bought at a car boot sale about 20 years ago with the intention of fitting it to a BBQ for a rotary spit. The spit never materialised but in an Einstein moment realised it would make the perfect basis for a rotary table.
It is a 30:1 ratio with a hollow output shaft of 16mm, I know of the brand (SITI) as I used them when working as a maintenance manager at a cable making plant and the quality is very good.
So searching the base materials bin I found a piece of mild steel 12mm thick x  120mm x 100mm and some 75 x 75 angle, I have plenty of stainless steel and aluminium so I didn’t have to buy anything.

Gearbox with plate and shaft

Machining feet

Finished , The hand wheel has 12 marks around so with the 30:1 box reduction each mark is 1 degree
Age and treachery will always overcome youth and skill

Bogstandard

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Re: Homemade Rotary Table
« Reply #1 on: April 12, 2013, 10:19:00 AM »
Robert,

A spot on job that cost you nothing other than a little time, what more could you want?


John


Offline tel

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Re: Homemade Rotary Table
« Reply #2 on: April 12, 2013, 11:24:32 AM »
Agreed! Very excellent and a tool that should last a lifetime.
The older I get, the better I was.
Lacerta es reptiles quisnam mos non exsisto accuso nusquam

Offline steamer

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Re: Homemade Rotary Table
« Reply #3 on: April 12, 2013, 11:39:16 AM »
Cool!

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Online Jo

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Re: Homemade Rotary Table
« Reply #4 on: April 12, 2013, 11:41:51 AM »
Often it is these simple little homemade tools that prove to be the best   :ThumbsUp:.

Jo
Enjoyment is more important than achievement.

Offline Lew Hartswick

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Re: Homemade Rotary Table
« Reply #5 on: April 12, 2013, 02:57:56 PM »
Often it is these simple little homemade tools that prove to be the best   :ThumbsUp:.

Jo
I believe the reason for that is the "homemade tool" was designed and built for a particular task and it
fits that perfectly, while the generic tool is designed and built for a wide range of tasks and hence is
not "optimum" for ANY specific one.  :-)
  Do you get the impression I don't believe in "multi-use" machines?   :-)
   ...lew...

Offline black85vette

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Re: Homemade Rotary Table
« Reply #6 on: April 12, 2013, 04:45:41 PM »
Very nice job of improvising.   I love it when I can work with what I have on hand.  :ThumbsUp:

Arbalest

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Re: Homemade Rotary Table
« Reply #7 on: April 12, 2013, 10:33:58 PM »
Nice idea, I would never have thought of that!

Offline Meldonmech

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Re: Homemade Rotary Table
« Reply #8 on: April 15, 2013, 07:04:01 AM »

Great innovation well done

Offline Robert Hornby

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Re: Homemade Rotary Table
« Reply #9 on: April 29, 2013, 08:13:59 AM »
Finally I utilised the rotary table (family visits and other stuff kept me out of the workshop for a week or so). I slot milled the reversing links and all went quite well. There was some shaking of the table even though I was only taking 0.05mm cuts with a 3mm cutter. I think the cutter is not as sharp as it could be and the material is stainless steel, so maybe that is all I can expect, but it got the job done. I have the slot mill in the drill chuck as I was only making light cuts, I do not think it is a factor in the shaking.:whoohoo:
Age and treachery will always overcome youth and skill

Offline steamer

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Re: Homemade Rotary Table
« Reply #10 on: April 29, 2013, 04:54:02 PM »
Hi John,

I'm very glad your table is working well!....It is very satisfying to use a tool you have made in your shop.   Nothing really compares!


I would like to offer a bit of advice on your pictured set up using the drill chuck to hold an end mill.
Drill chucks, in the norm, are designed to grab the fairly soft shank of a HSS drill bit.    That is how they get their holding power...they bite in.

If you've spun a drill in a chuck before you have seen the shank of the drill get scored...which just shows that the shanks are somewhat soft.

Now....End mills on the other hand are quite hard.    When an end mill is held in a drill chuck, the amount of grip available is very limited.  Generally what happens is the end mill is pulled from the chuck, or, more catastrophically, the chuck and or it's arbor are pulled from the machine!.....Either way, there is usually damaged parts and sometimes operators.

One might ask what is the deal with carbide drills then?....they make drill chucks with diamond impregnated jaws for those...but they really aren't meant for end mill applications as in general, an end mill pulls down on the spindle during a cut, while the drill pushes up.

So what I'm getting on about, is you should really use a collet or end mill holder for an end mill, and keep the drill chuck for drills.

Hope you take that advise as intended, to be helpful.

And again, Great job on the rotary table, and I'm glad it's all working out for you there! :praise2:

Kind Regards,

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Bearcar1

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Re: Homemade Rotary Table
« Reply #11 on: April 29, 2013, 08:05:56 PM »
Excellent! Nicely done Robert, a bit of ingenuity and some pieces from the drops drawer and BINGO  :pinkelephant:


BC1
Jim

Offline Robert Hornby

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Re: Homemade Rotary Table
« Reply #12 on: April 29, 2013, 11:57:26 PM »
Thanks Dave, some good information there. I do use the correct holder for almost all of my milling but if I need to locate a small cutter centrally into a hole of the same size I put a dummy shaft into the chuck, align it and then replace with the slot drill. My morse taper on the drill chuck is held firm via a draw bar so it cannot come loose but I take your concern re the hardened shaft of the cutter.
Robert
Age and treachery will always overcome youth and skill

Offline Ian S C

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Re: Homemade Rotary Table
« Reply #13 on: June 05, 2013, 03:49:59 PM »
Robert, how is your chuck held on the MT, a lot of them are just held by a Jacobs taper,  Some, as in hand drills, with 3/8"UNF or some thing similar, some times if it's a reversing drill, with a left hand screw inside, so the chuck does not unscrew.
    My first attempt at using an end mill was with a chuck, I still use the tap wrench I was making--- chunk out of the side and all, nearly finished, and the chuck fell out, bother.
                                                  Ian S C

 

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