Gallery, Projects and General > Project Logs
Making a 5MT Myford adapter
bogstandard:
Tim,
Now you can realise why my hand was starting to hurt.
Not only did I grind towards the head, I also came back again at the same speed, and still got a few sparks coming off even though the setting hadn't been touched.
Some people must be able to do it faster, but with the setup I have, I have found that is what gives me an acceptable to superb finish.
Something else to remember, this is sometimes the only way you can machine hardened or some very hard materials.
So what you do is make the part a tiny bit oversize, harden it, and then grind out the distortion caused by the heating process.
I just hope the lads who are making their own toolpost grinders realise that it isn't for doing quickie 'chop' jobs.
Bogs
spuddevans:
--- Quote from: bogstandard on October 17, 2009, 07:48:08 AM ---Now you can realise why my hand was starting to hurt.
--- End quote ---
No kidding !!
--- Quote ---I just hope the lads who are making their own toolpost grinders realise that it isn't for doing quickie 'chop' jobs.
--- End quote ---
I dont know if they are, but I sure am taking note for when I make one. :thumbup:
Tim
Darren:
--- Quote from: spuddevans on October 17, 2009, 12:35:45 PM ---
I dont know if they are, but I sure am taking note for when I make one. :thumbup:
Tim
--- End quote ---
Me too, when I tried grinding on the lathe with an air die grinder I know know I was trying to cut too deep too fast .... Thanks again John for the info . :thumbup:
sbwhart:
--- Quote from: spuddevans on October 17, 2009, 12:35:45 PM ---
--- Quote from: bogstandard on October 17, 2009, 07:48:08 AM ---Now you can realise why my hand was starting to hurt.
--- End quote ---
No kidding !!
--- Quote ---I just hope the lads who are making their own toolpost grinders realise that it isn't for doing quickie 'chop' jobs.
--- End quote ---
I dont know if they are, but I sure am taking note for when I make one. :thumbup:
I spent a good deal of time when I was an apprentice the tool room grinding. The practice was for the turners to leave +0.010" to 0.015" on the finished size as an alowance for the grinders to grind to size after the tool had been heat treated.
Stew
Tim
--- End quote ---
bogstandard:
So now that the adapter is solidly fixed into the spindle nose, I can now concentrate on finishing off the nose end. Making it so that a Myford fitting can screw onto it.
The first job was to get the back face made that the chuck or fitting will run up to. This face needs to be very well finished, as it is this which straightens the chuck up to it's final running position.
I measured three different backplate fittings and noses that I have in my possession, and they all came up with the same basic figure, 0.12mm (0.005") clearance for fitting on the spigot.
Whether that is intentional, I don't know, as it looks a little excessive to me, so I decided to go with 0.05mm (0.002") clearance instead.
And that is what I turned the spigot to. A nice, smooth sliding fit.
I went thru single point screwcutting only a few topics ago, so I have no need to repeat it all again, but I will just show the setup I have. Topslide set to 27.5 degs (half of thread profile angle) and everything exactly as before. This time I will be cutting 12TPI.
If you look at where the leadscrew is, you can see just how little movement I have towards the headstock. If the original leadscrew guard was on there, I wouldn't have been able to do this job.
On the forwards planning to do this job, I had no experience of using this machine to cut imperial threads, so I had purchased a cheap die to bring the threads down to the correct size. But flush with the success I had with the first thread I cut, I decided to bite the bullet and not use the die, but the machine to cut the thread to finished size.
I don't think I could have got a better fitting thread by using the die. It was spot on.
Confidence now super boosted. I have no further worries about single point cutting of imperial threads.
I now need to check out the metric side of things.
I will eventually be making an ER32 collet fitting to go onto this stub nose. So I drilled down as far as I could with a 9/16" drill. This will allow me to hold something like a 150mm (6") length of rod in the collet chuck.
The old and the new.
Raw material costs, less than a squid.
Amount learned about screwcutting on my machine, priceless.
So that is another tuit out of the way.
I might do another one, maybe two, before I start back on the Halo build.
Bogs
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