Author Topic: Quick Change Tool Post for Raglan 5inch Lathe  (Read 11787 times)

Offline Meldonmech

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Quick Change Tool Post for Raglan 5inch Lathe
« on: May 11, 2015, 04:06:33 PM »
Hi Guys
  When I bought this lathe it came  with a non adjustable single tool post. Reading posts from members re,which size to purchase for their lathes, I decided to make a few sketches and make my own. To ensure it would fit my lathe, I made a prototype out of timber, to prove the design. The wooden model worked well providing positive locking.
                         I had a steel ground block, which has sat on a shelf in the workshop for years, and suddenly realized it would make the ideal  body for the tool post. The tool holders will be cast aluminium.
 
                                                            Cheers David

Offline vtsteam

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #1 on: May 11, 2015, 07:29:28 PM »
Looking forward to this one David!  :thumbup: :thumbup: :thumbup: :coffee:
I love it when a Plan B comes together!
Steve
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Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #2 on: May 12, 2015, 02:29:01 AM »
 
The steel block block was marked out, and the dovetails cut on the milling machine.  They were roughed out using an end mill, and finished with a 60 degree angle cutter. The flat bottomed hole was then drilled and bored in the lathe. As the block had been previously ground, aluminium protection strips were fitted to  the vice jaws.

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #3 on: May 12, 2015, 02:32:31 AM »

   The block was then drilled, and reamed for the locking plungers.

                                                Cheers David

Offline vtsteam

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #4 on: May 12, 2015, 08:31:34 PM »
Very nice job you're doing!  :coffee:
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #5 on: May 13, 2015, 05:44:38 AM »

  Steve, thanks for you comments.
 Next came the locking cam, which aims to lock the tool holder in position, in an angular handle movement of 45 degrees. The basic turning was done in the four jaw chuck, then set over to machine the cam. Finally, the height had to be machined, to provide a close running fit in the tool post. The chuck was first changed to a 3jaw.  A hard wood mandrel was turned with a slight taper to fit the bore of the cam, and a fixed steady used at the other end. Light cuts were taken to carefully machine the bottom to size.

                                                                         Cheers David

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #6 on: May 14, 2015, 01:57:05 AM »
 
   The tool holder patterns were made using timber. Because  the patterns were so simple I tried open sand casting.  The moulding was much easier, and the castings satisfactory.

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #7 on: May 14, 2015, 02:17:41 AM »
 
The castings were machined to size on the milling machine using a fly cutter.  They were then marked out for the next operations
One of the machined blocks was set up in the mill to cut the dovetail. A slot was first cut using an end mill, then finished with an angle cutter. When angles had been formed two pieces of ground silver steel were inserted one either side to check measurements. The dovetails must be a tight sliding fit with the tool post.

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #8 on: May 17, 2015, 09:23:56 AM »
 
 The slot for the tool was milled, and the tool holding down screw holes, drilled and tapped. Note I made the front two holes close together to enable short tools to be held. A

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #9 on: May 17, 2015, 09:38:39 AM »
 
 After one holder was satisfactorily completed, a small batch were made.

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #10 on: May 17, 2015, 09:51:19 AM »

 The remaining parts were straight forward machining ball handles etc. the tool holders were assembled, and tool post set up. A trial was completed, and I was pleased with the results.

                                                              Cheers David

Offline vtsteam

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #11 on: May 17, 2015, 10:30:04 AM »
Hey I like your mill table clamping blocks!!! :thumbup:

And David, really satisfying to see all those toolholders and the finished post! Great job! :bow: :bow:  :clap: :clap: :beer:

I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline NormanV

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #12 on: May 17, 2015, 11:11:32 AM »
I have a Dickson QCTP, the tool holders are silly prices. It had never occurred to me that cast aluminium would be ok for tool holders. I will be looking at it more carefully now. I could cast long sticks to make the machining quicker and then cut them off to size.

Offline awemawson

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #13 on: May 17, 2015, 12:28:05 PM »
Saturate your molten aluminium with copper Norman to make it significantly harder.
Andrew Mawson
East Sussex

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #14 on: May 18, 2015, 02:09:44 AM »
 
 Norman, you are quite right, on my last batch I made a new pattern and cast a block of six. After machining the block to size, dovetailed the block then sawed the tool holders into six.
                           
          This is definitely the way to go.
                                                                         Cheers David


                                                             

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #15 on: May 18, 2015, 02:36:45 AM »
 
 Andrew, I cast a couple of tool holders from a recent scrap melt which consisted of aluminium carpet thresholds which were surprisingly hard, and some old hard drive cases which contained some tiny copper coils. The resultant casting was so hard it blunted my HSS fly cutter and I had to use a carbide tool. The casting was also quite brittle. I dropped one tool holder I had finished and rather than a burr which I half expected, it had chipped the edge. The finish on this hard material looked almost polished, and was very reflective.
                                        What form was the copper you applied to your melt, for instance was it filings? I think my melt may have contained too much copper. The percentage required is quite small.

                                                        Cheers David

                             
                                         

Offline vtsteam

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #16 on: May 18, 2015, 10:02:58 AM »
About 4% by weight copper would put it in line with the major copper-containing high strength non-tempered aluminum sand casting alloys. Increase in hardness seems to be from about 45 to about 60 Brinell.

I might try that today as the day's experiment......  :dremel:

(looks like it needs 6% silicon -- so a combination of piston and 6061 extrusion scrap I have here...)

Edit: here's the aluminum trial: http://madmodder.net/index.php/topic,10705.0.html
« Last Edit: May 19, 2015, 08:34:02 AM by vtsteam »
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline vtsteam

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #17 on: May 18, 2015, 04:23:33 PM »
Aluminum tool holders can certainly work. Here are some QCTP Norman style holders I made 9 years ago for the Gingery lathe. The regular 1/4" lathe tool holder held up well, but the deeper one that I used to hold a cutoff tool broke -- you can see the crack. Next to them is a raw casting. Pretty clear to me now both aluminum tool holders could have been made about 1/8" or more thicker on the bottom, and I doubt I'd have had the breakage problem.



I later made 8 tool holders from steel -- featured in a thread here. But I still use the aluminum holder -- they're all interchangeable.
I love it when a Plan B comes together!
Steve
www.sredmond.com

Offline krv3000

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #18 on: May 18, 2015, 05:45:30 PM »
good post

Offline Zadig

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #19 on: May 19, 2015, 02:14:02 AM »
Great post, very interesting to watch develop.

Offline Meldonmech

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Re: Quick Change Tool Post for Raglan 5inch Lathe
« Reply #20 on: May 19, 2015, 11:26:44 AM »

     Thanks Guys for all your interest and comments.

                                                                             Cheers David