Model Boat Mayhem

Please login or register.

Login with username, password and session length.
Pages: [1]   Go Down

Author Topic: Milling steel on the Proxxon  (Read 1180 times)

Southern Sailor

  • Southern Sailor
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 196
  • Location: Cape Town, South Africa
Milling steel on the Proxxon
« on: August 11, 2022, 01:17:04 pm »

I am making a spacer to fit a new quick change tool post to my Optimum D300 mini lathe.  I am using 6mm flat steel plate.  I cut it out with a hacksaw, drilled a 10mm dia. hole (my largest capability) and then had to square and clean up the edges and enlarge the hole to 17.95mm dia. I am busy shaping a boring bar to enlarge the hole, but this article is about squaring and cleaning the sides. I have a Proxxon BFW 40/E milling machine mounted on a Proxxon KT150 compound table. The book of words say this milling machine can mill steel, so I thought I would give it a go. The first pass with a 6mm end cutter went well (conventional milling) but on the second, the cutter snatched and almost gave me a heart attack.  I'm not sure what was damaged (I can't see anything wrong and the spindle still measures perpendicular to the table - within 30 thou which is what it was before), but I realize I was climb milling and the depth of cut was too large, at least for steel. I re-planned the passes and finished the side without further mishap.


Two conclusions I have come to and if there is any advice, it would be appreciated.


Firstly the Proxxon BFW40/E can mill steel if you're careful about it.


Secondly, it seems that the final pass of any milling operation will be climb milling - I can't see any alternative.  I attach a sketch showing the three passes that I finally used, the secret being in my opinion to make the amount of material to be removed on the final pass as small as possible.


Cheers
Brian







Logged

Southern Sailor

  • Southern Sailor
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 196
  • Location: Cape Town, South Africa
Re: Milling steel on the Proxxon
« Reply #1 on: August 11, 2022, 01:26:16 pm »

It seems the pics did not attach. Now, hopefully, attached.
Logged

Southern Sailor

  • Southern Sailor
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 196
  • Location: Cape Town, South Africa
Re: Milling steel on the Proxxon
« Reply #2 on: August 22, 2022, 11:06:48 am »

I must be doing something right, - or very stupid - 'cause there ain't no responses. Unusual for this Forum. I was hoping for some advice/comment on my method and perhaps milling steel on the Proxxon. Keeping a low profile! Brian
Logged

Capt Podge

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,443
Re: Milling steel on the Proxxon
« Reply #3 on: August 22, 2022, 01:03:30 pm »

Well Brian, I would imagine if you'd done something stupid you would most probably have suffered a serious injury at best, so I guess all is well with what you have achieved thus far.
I'm no expert on milling though...  %)


Ray.
Logged

Southern Sailor

  • Southern Sailor
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 196
  • Location: Cape Town, South Africa
Re: Milling steel on the Proxxon
« Reply #4 on: August 22, 2022, 07:43:21 pm »

I guess you're right Ray. Cracking on regardless. I'll be milling the contact surfaces of the Stuart Twin Oscillator next, so trusting they will turn out OK.  :police:   


Brian
Logged

Capt Podge

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,443
Re: Milling steel on the Proxxon
« Reply #5 on: August 22, 2022, 07:51:40 pm »

Ok Brian, looking forward to seeing how things go.
I'm definitely not a model engineer though so try to explain things in layman's terms please  :-)


Ray.
Logged

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,449
  • Location: North of Watford, South of Hadrians wall
Re: Milling steel on the Proxxon
« Reply #6 on: August 23, 2022, 08:53:04 am »

Climb milling is not to be recommended on toy workshop machinery, it's a rigidity or lack of thing. Used in industry in the past on big and heavy machines with finely adjusted slides and leadscrews to eliminate backlash. CNC controlled machinery now use ballscrews but the smaller ones are still a problem. For the unknowing, climb milling is when the material is travelling in the same direction as the cutter, so instead of the material being forced against the cutter, it has a tendency too be dragged through.


  Scary, wear lots of padding, eye protection AND a tin hat. Another for the wise, NEVER use a milling cutter in a drill chuck.


  Regards  Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

Southern Sailor

  • Southern Sailor
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 196
  • Location: Cape Town, South Africa
Re: Milling steel on the Proxxon
« Reply #7 on: August 23, 2022, 01:23:33 pm »

Hi Ian, thanks for responding.  I understand about climb milling, but in the example I was working with, I can only see that the final cut will always be climb milling.  That was my problem which I overcame as shown in the sketch that I posted.  How does one get past that problem? Your advice would be appreciated.


Brian
Logged

Circlip

  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 4,449
  • Location: North of Watford, South of Hadrians wall
Re: Milling steel on the Proxxon
« Reply #8 on: August 23, 2022, 10:19:47 pm »

Final cut will be climb milling if that's how you set it to be. What's difficult to wind the cutter off and always go back to the first end and reapply the cut?


  Regards  Ian.
Logged
You might not like what I say, but that doesn't mean I'm wrong.
 
What I said is not what you  think you heard.

Southern Sailor

  • Southern Sailor
  • Full Mayhemer
  • *****
  • Offline Offline
  • Posts: 196
  • Location: Cape Town, South Africa
Re: Milling steel on the Proxxon
« Reply #9 on: August 25, 2022, 07:43:26 am »

I understand that, but it seems to me that when you reach the final cut at that "level" you will effectively have a climb milling situation.  I have tried to reduce the effect of that (see my sketch) by making the final cut as narrow as possible and reducing the angle of contact of the flutes.  It seemed to work.
Thanks Ian and regards
Brian
Logged
Pages: [1]   Go Up
 

Page created in 0.105 seconds with 22 queries.