Author Topic: "F" for fail, making new tooling...  (Read 7535 times)

Offline John Hill

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"F" for fail, making new tooling...
« on: March 20, 2011, 02:39:48 AM »
First step,  saw off a chunk of mongrelium..

IMGP9169 by aardvark_akubra, on Flickr


Put it in the lathe and didnt forget the first step which was to drill and tap the end to 12mm..


DSCN0309 by aardvark_akubra, on Flickr

Quite a bit of swarf later and I had a very rough looking stub of taper and some 1 1/2" 8TPI thread..

DSCN0314 by aardvark_akubra, on Flickr

It took ages to get a smooth finish to the taper but eventually it fitted to the rotary table allowing me to mount a threaded face plate on the rotary table and drill it to mount a chuck.


IMGP9168 by aardvark_akubra, on Flickr

I made another threaded taper, this one MT3 and it fitted the chuck to the lathe.  Turned the end of a piece of scrap and needless to say the needle barely wavered when I tested it, as one would have expected...

IMGP9172 by aardvark_akubra, on Flickr

Then the chuck was spun off the thread and moved over to the dividing head....... run out was not so good.....

IMGP9173 by aardvark_akubra, on Flickr


The crunch test, mounting the chuck on the rotary table...... the run out is no laughing matter...

IMGP9174 by aardvark_akubra, on Flickr



I need to find some better steel and have another try after figuring out more accurate sequences to the machining.
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Offline picclock

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Re: "F" for fail, making new tooling...
« Reply #1 on: March 20, 2011, 03:58:00 AM »
Would purchase of an MT2 to MT3 adapter resolve the issue ?  By using this the threaded part is unchanged, and it is likely this that is causing the error. (and you get another bit of useful kit  :headbang:)

Best Regards

picclock
Engaged in the art of turning large pieces of useful material into ever smaller pieces of (s)crap. (Ferndown, Dorset)

Offline Bogstandard

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Re: "F" for fail, making new tooling...
« Reply #2 on: March 20, 2011, 04:08:24 AM »
John,

It isn't just a matter of the thread. You require plain registers to keep everything aligned.

The thread can be almost anywhere and anything, it is the face that the base of the plate hits that keeps it perfectly upright, and the upright register attempts to keep runout to a minimum.

Have a look at this piece in this topic, it is what you are attempting to make, notice the bottom part of the threaded part, two registers, one horizontal, one vertical. Ones matching them should also be on the removable plate.

http://madmodder.net/index.php?topic=422.0



John


If you don't try it, you will never know if you can do it.

Location - Crewe, Cheshire

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Offline John Hill

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Re: "F" for fail, making new tooling...
« Reply #3 on: March 20, 2011, 04:19:19 AM »
Thanks guys,  I am sure you are right John in that the register is what is missing,  I have one on the lathe adapter but not on the rotary table. 

Obviously thats where I should begin.. :scratch:
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Offline Bogstandard

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Re: "F" for fail, making new tooling...
« Reply #4 on: March 20, 2011, 04:57:52 AM »
I know it can be difficult for you where you live John.

But like everything else, I would like to make everything myself, but most times, with something like this, I would always go the route of buying part machined backplates, as they already have the correct registers machined into them. In fact, for me to make one, although easy enough to do, it would be twice as expensive to purchase the material plus the time spent making than buying a commercial one.

In fact, I will be purchasing a couple of spare backplates soon, when I next prepare an order. It will be handy having them in stock, just in case I come up with a new idea for some new tooling I want to make. I already do that with blank 2 & 3 MT's and R8 arbors.

To me, it isn't worth not having them in stock if you are into making bits for your machines.


John
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Offline John Hill

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Re: "F" for fail, making new tooling...
« Reply #5 on: March 20, 2011, 05:26:57 AM »
I know what you mean about the cost effectivness of this little project John  but I am actually trying to learn new skills.  Tomorrow I will go down to one of the small engineering firms in this town and see if I can get some suitable steel of at least 45mm diameter to make another adapter or two.

We can get most things here but it takes a while and with Christchurch still in a state of disarray some things take longer than usual.  There are no limits much on what bits and pieces we can import so thats always an option though it varies a bit as our dollar staggers from one low to the next.

The Little Machine Shop has the chuck adapter plates for US$30 but I have not see any MT2 to 1 1/2 x 8tpi adapters out there.

Fortunately the engineering firms in this town are rather small(ish) and I find them quite approachable and a great resource for small bits of material and advice.  They can be quite interesting to visit too as happened last week when  (as we walked through the shop to his back yard) I remarked on them working on a traction engine, "Oh yes,  we are doing three right now".

What I did notice though is that the size of the shop and the amount of machinery appeared extensive compared to the number of people around. ::)
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Offline JimM

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Re: "F" for fail, making new tooling...
« Reply #6 on: March 30, 2011, 03:18:53 AM »

The Little Machine Shop has the chuck adapter plates for US$30 but I have not see any MT2 to 1 1/2 x 8tpi adapters out there.


Hi John

Not sure what postage cost etc will be to NZ but Chronos stock them, second up from the bottom of the page

http://www.chronos.ltd.uk/acatalog/Vertex_Rotary_Tables_and_Accessories.html

HTH

Jim
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Offline Bogstandard

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Re: "F" for fail, making new tooling...
« Reply #7 on: March 30, 2011, 03:41:25 AM »
Jim & John,

I used those adaptors for a fair while on my RT, but found them rather limiting if you want to hold longish items.

I now use an adaptor plate, which not only is a little more rigid, but by having the hole right thru it, allows longer (but still rather thin) items to be held.

http://www.chronos.ltd.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww.chronos.ltd.uk%2facatalog%2fnew_engineering.html&WD=adaptor%20chuck%20plate&PN=3--Rotary-Table-Adaptor-with-Myford-Thread.html%23a112185#a112185


John
If you don't try it, you will never know if you can do it.

Location - Crewe, Cheshire

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Offline John Hill

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Re: "F" for fail, making new tooling...
« Reply #8 on: March 30, 2011, 04:17:29 AM »
John, Jim,  I persevered and got a satisfactory result.

Not having any steel of adequate diameter I instead turned up collars to fit on my adapters (two) that I could carefully turn to get good register fit with the chuck mounting plate. The collar was especially useful when making the one for the lathe as I was able to put the collar in place on the adapter with a dab of Loctite then loosly tighten  the draw bar the result being the taper fully home with the collar bearing against the face of the MT5 to MT3 sleeve.  I did the rotary table one another way in that I put the adapter in place, then the collar with a dab of Loctite and spun the plate on.  In each case the collar was a light press fit on the adapter.

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