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Aug 20, 2010, 08:25 PM
Micro-Heli-Concepts
jasonjetski's Avatar
Thread OP
Hi Guys,
Well Iam very slowly getting this Z axis made.
It has taken a lot longer than I first thought,But maybe in the next week,I will be able to test it.
2 concerns so far are the flex at the upright plate just behind the motor bell and the heat that the spindle might generate.
With this machine mod,I will mainly be cutting thin delrin up to about 3.2mm for about 15 minutes at a time.
I will be keeping a close eye on these 2 things. If needed,I will remake the spindle mount out of ally.
Regards Jason
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Aug 21, 2010, 12:04 PM
Inciting Riots
village_idiot's Avatar
For Delrin is the spindle speed going to be too high? In acrylic I found that anything over about 1000 rpm and I start to get melting, I haven't done enough work with Delrin to know the speed limit yet. This is even worse if I have a 4 flute mill, the 2 flute mills seem to do a much better job in the plastics.

Also of note since you are using thing material, with a regular mill are you seeing any problems where the mill pulls the material up away from the base? I get that with regular up spiral mills and am slowly buying down spiral mills for me plastic work but they are kind of expensive so it is a slow process.
Aug 21, 2010, 12:25 PM
Micro-Heli-Concepts
jasonjetski's Avatar
Thread OP
Quote:
Originally Posted by village_idiot
For Delrin is the spindle speed going to be too high? In acrylic I found that anything over about 1000 rpm and I start to get melting, I haven't done enough work with Delrin to know the speed limit yet. This is even worse if I have a 4 flute mill, the 2 flute mills seem to do a much better job in the plastics.

Also of note since you are using thing material, with a regular mill are you seeing any problems where the mill pulls the material up away from the base? I get that with regular up spiral mills and am slowly buying down spiral mills for me plastic work but they are kind of expensive so it is a slow process.
Hi,
I now cut the delrin in one pass at about 150mm minute with a spindle speed of around 11000 RPM. Maybe slightly higher.
If I use a sharp bit,I have no problems with melting. The bits I use on delrin are the proxxon 1mm bits. http://www.mytoolstore.com.au/produc...-end-mill.html They seam to work the best that I have tested on delrin.
This is my old machine cutting some very small rocker arms for a UFO#8
Walkera UFO#8 Rocker arms (4 min 32 sec)
You can see how I use cap head screws to hold the material down. When I first started to cut delrin,I had the bolts spaced about 100mm apart and the centre of the material would lift sometimes.
Regards Jason
Aug 21, 2010, 01:58 PM
Registered User
Acrylic is usually harder to machine than delrin, at least for me. My CAM software suggests a feed rate, and spindle rpm for many materials. They left off delrin, and acrylic. Its usually a much faster feed rate than my machine can handle. The spindle rpm is usually in range, between my two spindles.
My machine runs almost constantly when I'm in the shop. I had second thoughts on buying it, thinking I might not have enough projects. Now its clear I need a second bigger one.
Aug 21, 2010, 04:37 PM
Micro-Heli-Concepts
jasonjetski's Avatar
Thread OP
Quote:
Originally Posted by Roto Rob
Acrylic is usually harder to machine than delrin, at least for me. My CAM software suggests a feed rate, and spindle rpm for many materials. They left off delrin, and acrylic. Its usually a much faster feed rate than my machine can handle. The spindle rpm is usually in range, between my two spindles.
My machine runs almost constantly when I'm in the shop. I had second thoughts on buying it, thinking I might not have enough projects. Now its clear I need a second bigger one.
Hi Rob,
I tend to get a lot of chatter marks when I machine acrylic as you can see on the edges of my spindle mount. When I cut it,I only cut 1mm deep each pass.
Delrin is beautifull to cut.Does your CAM software have "Acetal" listed.
My CAM software is Cut2D and it doesn't give me feeds or speed for materials,but it does have them pre-set for the tools.But I always change them anyway,Just looking for that perfect cut.
A larger machine would be great. I guess small parts and large parts can be made on a large machine.
Maybe I will try a gantry for my next one.
Last night I decided to wire up the spindle motor and see if it spins up.
Wow,It works great. Keep in mind,it is only free revving,but sounds a bit like a turbine now I don't have a dial gauge here,but I sat a metal pin in the collet and spun it up. I could not feel any runout.
There is always plenty of things to be made with these machines. As Iam learning a bit more from using the machine.I find more and more I can make. I have had a couple of cases at work where I cant get a part supplied,so I tell my boss I will just make the part after hours at home.He says it cant be done because it is too hard and I just tell him "Somebody made the original"
But now my boss has learned I can make name plates and small signs with it,so he now wants me to make heaps of them for every door at his house.
Regards Jason
Aug 21, 2010, 07:53 PM
Registered User
My software is BobCad, it only has metals for the feed, and speed. It has user defined materials if I want to save settings for future use. I usually just type in a reasonable feed in the tool selection screen. In Mach3 I adjust the feed until the cutter and machine sounds happy. I think I get best results in acrylic with my high rpm spindle (20,000rpm). I have been working on getting the best feed, and depth for the projects I repeat. I'm getting the fastest good results from cutting fairly fast, leaving a little bottom and side allowance, and a slower final cut. In my carbon sheets I cut with one slower pass.
Big machines might not be ideal for small parts. I think I will keep the small one.
Aug 22, 2010, 09:39 PM
I hate propellors
emufingers's Avatar
Quote:
Originally Posted by jasonjetski
Hi Rob,
I tend to get a lot of chatter marks when I machine acrylic as you can see on the edges of my spindle mount. When I cut it,I only cut 1mm deep each pass.
Acetal can be a real pig to cut. Try using a two flute down spiral bit or a special plastics bit. The fewer flute you have, the lower the heat generated so you can run a two flute fast than a 4 flute. When routing Acetal and the like I have found that placing a piece of sticky tape over the areas where there are edges rediuce bot chipping and the effect you describe. Should work with a mill too.
Aug 22, 2010, 11:47 PM
Inciting Riots
village_idiot's Avatar
The don spiral are a little hard to find. Bam Carbide seems to have the best prices but only go down to 1/8 inch (on 1/4 shank) and they do not have ball nose down spiral bits. That said their 1/8 and 1/4 have done a bunch of work on my mill and produce really nice results on both Delrin and acrylic, I really need to bite the bullet and get a 1/2 down spiral for larger removals and better surface on larger pieces.
Sep 11, 2010, 05:10 PM
Micro-Heli-Concepts
jasonjetski's Avatar
Thread OP
Hi Guys,
Well,I now have my little machine back together with the slanted axis.
It has not done too much work yet as time is limited,but It has given me the results I wanted for the slanted landing gear.
Regards Jason
Sep 11, 2010, 08:42 PM
Inciting Riots
village_idiot's Avatar
How long will it be before you put a stepper on that column?
Sep 11, 2010, 09:09 PM
Micro-Heli-Concepts
jasonjetski's Avatar
Thread OP
Quote:
Originally Posted by village_idiot
How long will it be before you put a stepper on that column?
Hi,
Do you mean so I can adjust the angle with a push of a button?
At the moment,It takes me about 5 minutes to adjust the angle.
It would be nice to have it controlled by Mach3 though.
Regards Jason
Sep 11, 2010, 09:39 PM
Inciting Riots
village_idiot's Avatar
I was thinking more to have the software control it.
May 15, 2016, 03:43 PM
Registered User

how best to set up the MF70 with standard travel and 4th axis


hey all

I have just purchased the MF70 CNC Ready mill from Axminster Tools, It comes along with 3 Stepper Motors already fitted but has no control unit or software included. I intend to use this brilliant little machine to make a prototype turbine engine and therefore require a 4th axis too, how do you suggest i go about the following:
  • Controlling The Mill (Off the Shelf Control Unit?)
  • Integrating a 4th Axis
  • Best CAD/CAM Software for use with These components?
  • How much will all these cost?

Regards Mike
Jun 30, 2016, 03:26 AM
Registered User

Proxxon MF70 shaft convertion


hello,
Someone can help me for replacement a right spindle ER11 and bearings for MF 70 new ?
I have a dubt for a ER11 with arbor 10mm or 12mm, and what type of bearings buy..
Oct 26, 2016, 06:10 PM
Registered User
Hi all and thx good infos...

i convert my machine to cnc and i want start play it.. but i dont have any infos but i want learn ...how make solidcam settings for mf70 and my card use soft usbcnc pls help i select machine type which?


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