Author Topic: Raglan mill help  (Read 3099 times)

Online Florian Eberhard

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Re: Raglan mill help
« Reply #15 on: February 11, 2019, 09:39:54 PM »
Hi Terry

To me it looks as if the long screw would still be in pretty good shape - maybe just a wrong impression? But I would check that out before looking for a new screw.
The front one defenitely needs to be replaced.
Now, maybe you could adapt the acme screws (Spare parts...) from another (chinese) milling machine - for example the BF20 Design for your machine?

The Reason why i would think about htat is that - although the chinese acme screws also will not be the most accurate ones - they are most likely more accurate than a standard precision acme screw. (Which are allowed to have 0.3mm deviation per 100mm length in european "standard precision)
This is quite a lot for a milling machine - expect if you are going to use a DRO - then it won't matter. But otherwise you won't get too happy with a standard screw.

Another benefit would be that you will also get a spare nut which fits to the leadscrew...

Cheers Florian

Offline steamer

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Re: Raglan mill help
« Reply #16 on: February 11, 2019, 10:06:49 PM »
Florian
True that, but with a dro, its less important.   Some screw stock on this side is better than others.
Dave
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Offline steamer

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Re: Raglan mill help
« Reply #17 on: February 11, 2019, 10:12:53 PM »
 Terry    if your lathe will cut that acme.  Just do it.   8)
Dave
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Offline scc

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Re: Raglan mill help
« Reply #18 on: February 12, 2019, 09:16:30 PM »
First practice on some scrap bar and a cutter ground by eye :ShakeHead:    Necessary before I spend money on taps.    I need to set up a carraige stop to make it easier to pick up the start point for every cut, and obviously grind a tool correctly.

I am not entirely convinced that I am dealing with an acme thread :thinking: Looking at an unworn end the thread flanks look parallel..a square thread? Surely an acme won't wear that way.   Unfortunately I do not  possess a good enough camera to show it. Would a square thread have been used?  More advice needed,

Offline steamer

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Re: Raglan mill help
« Reply #19 on: February 12, 2019, 09:28:38 PM »
First practice on some scrap bar and a cutter ground by eye :ShakeHead:    Necessary before I spend money on taps.    I need to set up a carraige stop to make it easier to pick up the start point for every cut, and obviously grind a tool correctly.

I am not entirely convinced that I am dealing with an acme thread :thinking: Looking at an unworn end the thread flanks look parallel..a square thread? Surely an acme won't wear that way.   Unfortunately I do not  possess a good enough camera to show it. Would a square thread have been used?  More advice needed,

A square thread is a possibility, but square threads are thread milled in general.   For the replacement, I would go with an Acme.    If your convinced that you want to turn your new screws, I would get the tap, and tap a small piece to make a gauge...    then you can cut it to fit nicely.   

Dave
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Damned ijjit!

Offline scc

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Re: Raglan mill help
« Reply #20 on: February 12, 2019, 10:02:02 PM »
Thanks Dave,      I think that's the way to proceed.

Terry

Offline Steamer5

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Re: Raglan mill help
« Reply #21 on: February 13, 2019, 11:39:15 AM »
Hi Terry,
Looking good!
I spoke to my Dad last night about his mill. He cant remember what was done to it prior to him purchasing....given he's pushing 92 & he's had the mill he thinks 20 odd years not surprising really! The guy that did the refurbish is still around but lives 450 km's away, I'm sure he could help out.

I'll give Dad a call & ask if he can work out if the thread is square or Acme, & just to make sure I've got it right you are looking at the X & Z axis threads?? I'm off on holiday latter today......I'm at work ( Oooooooo he used THAT word    :Mad: :cussing:) & its a bit after midnight here...but will endeavor to get you the info ASAP!

Cheers Kerrin
Get excited and make something!

Offline scc

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Re: Raglan mill help
« Reply #22 on: February 13, 2019, 05:34:51 PM »
Cheers Kerin but I am going for the acme whatever.
Have a great holiday and give my best wishes to your dad.

Terry

Offline Steamer5

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Re: Raglan mill help
« Reply #23 on: February 14, 2019, 04:30:51 AM »
Hi Terry,
 That’s fine, when I told him that you had built a 4” traction engine on yours & that he would have to up his game, he thought you were very keen! Will pass on your wishes.
Look forward to how you get on with the refurbishment

Cheers Kerrin
Get excited and make something!

Offline scc

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Re: Raglan mill help
« Reply #24 on: February 16, 2019, 08:43:01 PM »
Thanks all for comments.     Taps arrived today so I had better get started. The original nuts do not look very well made, nothing looks concentric.  I made up a plug to approx root diameter, stuck it in the nut and set it up in the four jaw. I then bored the nut out to 0.75"
The next move is to bore and thread some round bar and loctite into the nut.
A few questions.......what grade of loctite?
                              What clearance is needed for the loctite?
                              Is a 12.5mm tapping drill ok or do I need to go bigger?


Advice obviously required and appreciated                             Terry

Offline steamer

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Re: Raglan mill help
« Reply #25 on: February 16, 2019, 08:46:13 PM »
High Strength Cylindrical retaining


Loctite 648    0.002" clearance...and work fast to get it in there.

Love is a wonderful thing....but 648 is forever....or a torch...which ever comes first


Dave
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Damned ijjit!

Offline steamer

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Re: Raglan mill help
« Reply #26 on: February 16, 2019, 08:48:37 PM »
And ....I found this...It's for the Clausing...which is my mill...and is what I'll be doing...probably in the not so distant future....

I attached it for reference.....


What your doing looks great!   Keep going!

Dave

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Damned ijjit!

Offline steamer

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Re: Raglan mill help
« Reply #27 on: February 16, 2019, 08:55:24 PM »
3/4-10 right?

"Mister M'Andrew, don't you think steam spoils romance at sea?"
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Offline steamer

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Re: Raglan mill help
« Reply #28 on: February 16, 2019, 08:57:03 PM »
Let me get my Machinery Handbook....hang on

Dave

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Offline scc

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Re: Raglan mill help
« Reply #29 on: February 16, 2019, 09:01:31 PM »
Dave, mine is 5/8 x 8