[amyers]

Good method if you have cnc, I remember seeing it done this way a long time ago.
https://www.youtube.com/watch?v=7vxjCEwsQK4

putting the tool in the lathe holding the pulley and manually broaching that way is another common method.
am

[phomann]

Hi am,

Thanks for that. It seems a more solid setup than I used.

I considered using my lathe but I couldn't think of a way to lock the spindle.

Cheers,

Peter

[Alan XR8]

Well done Peter. Looks great.


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[Neptunes]

Nice work Peter it's like the way they use to do the railway wheels at the old foundry in Sydney just on a smaller scale.


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[phomann]

Thanks for the kind works.

Over the weekend I modified the motor mount to fit the new motor. Luckily the bolt hole pattern is the same as the existing motor so I can use the existing motor mount plate.
The mounting holes on the new motor are 8.5mm, clearly designed for M8 bolts. The Motor plate mounting hols are tapped for M6 bolts. I thought about drilling and tapping them for M8s but I think I'll go with M6 bolts and a washer. If this does not turn out, I can enlarge the holes at a later date.

The main task is to enlarge the hole in the plate to accommodate the 83mm diameter mounting boss on the new motor. There are a number of ways to do it but the goal is to ensure that the new boss is concentric with the old one so that the bolt holes line up when fitted.

The approach I took was to make a fixture that had a boss in it that would hit the existing hole in the motor mount. That way I know it's concentric and everything is lined up. Then mill it from there.

[phomann]

I turned to my favourite fixture material, 12mm Corian plate. It's precise and machines easily.
IOnce I dug out a suitable pice I mounted it onto my Taig Mill with a couple of clamps and 123 blocks. The blocks were necessary so that I could fasten the motor mount plate to the fixture from below.

The images below show the machining of the fixture. The locating boss is 2mm high.

Attachment 298252 Attachment 298254


Testing the motor mount plate to the fixture
Attachment 298256


Motor mount plate bolted to the fixture ready for machining.
Attachment 298258

Cheers,

Peter

[phomann]

The mounting boss on the new motor is 83mm diameter, 2.5mm proud. The motor plate is about 92mm wide from memory, As the boss is only 2.5mm proud I decided to make the new recess only 3mm deep rather than cutting completely through the plate as the existing hole does.

It all went well although I didn't take an image of the finished mounting plate.

Attachment 298262 Attachment 298264

Now that the motor plate and pulley modifications are done, all I need to do now is wait for the motor to arrive and hope it all fits.

Cheers,

Peter

[phomann]

Well the motor turned up yesterday.
As I suspected the key slot in the pulley was too narrow. It is 3/16" (4.7625mm) rather than the required 5mm. A small square file fixed that.
Attachment 297238



The motor mounted to the plate without issue and mounting the motor with the 6mm bolts seems fine.

Attachment 298268 Attachment 298270

The keen observer will notice that the belt is not horizontal. I'll need to turn down the motor mount posts to get it all level. I could fit the motor pulley lower on the shaft but I'd prefer not to do that.

Cheers,

Peter

[phomann]

Prior to this motor, the total running time of the spindle has been about 30s. I ran the original motor and controller when I first converted the axes over to CNC. It lasted the 30s and gave up the ghost. I received a new motor and controller and never got it to work after countless hours of trying on and off over the last 12 months or more. Mind you the documentation was almost non-existent.

So getting this new motor installed has given me a boost to get this conversion project finished.

On installed I had to give it a run, so I wired the motor up the controller, configured it and pressed the run button on the controller. Ran it up to its max speed of 6000rpm before running it at a more respectable speed.

Attachment 298280


After running the spindle at around 2500-3000rpm the spindle and lower bearing housing were very warm. When I converted the spindle over to belt drive I replaced the spindle bearings with new ones from VXB. I guess I need to watch the temperature for a while.

Cheers,

Peter

[phomann]

I finally got around to reducing the height of the motor mount standoffs. They needed to be lowered by 3mm. Now the belt is horizontal.
I think quite a bit of the generated head was because of the pulleys being out of alignment.



Cheers,

Peter

[Fastest1]

Peter, IMO and I mentioned it to Scott was the pulleys need to be closest to the upper bearings. Not to put the tach wheel on the bottom. During 1 of my next mods my intent is to move that sensor and its ring.

How is moving the pulley farther away from the bearing any different than too much stick out on the other end? Personally I would like the pulleys between the sets of bearings. Just my thoughts. Not knocking his product at all. Everything can be improved or made more specific to your own needs.

[phomann]

Yes, having the spindle pulley closer to the bearing makes sense.

As to the motor pulley, it overhangs the shaft by 3/8"-1/2"and I didn't want to make the overhang worse. Turning down the supports seemed like the easy solution.
Cheers,

Peter

[phomann]

As an aside, I reduced the lengths of the motor standoffs on my 7x14 CNC lathe. It too is in the process of being converted (I never seems to get these conversions finished)

I used the built in wizards to do the facing operation. I then decided that now that I had the lathe set up and running Ineeded to make something more substantial to test the lahe. So I decided to make a chess pawn as I wanted to use a new program I came across called Ezilathe.
Ezilathe - Tools for the CNC lathe

It's quite an intuative program an easy to use. Once I'd drawn the pawn in Draftsight to get the dxf file, I loaded it into Ezilathe and produced the Gcode.
The pawn piece is 80mm x 36mm. The plunge feedrate is a bit slow, but it was my first attempt.

The first video shows part of the roughing process.
https://youtu.be/bdMDnEHW-2Y


The 2nd video show the final profile cuts. You can see where the backside of the profile tool catches and cuts at one point in the profile cut.

https://youtu.be/TaklyKCMBw4



Now, back to the mill.

Cheers,

Peter

[Fastest1]

(I never seems to get these conversions finished) You are NOT alone!

Congrats on the lathe. Having said that, on video 2 I almost fell asleep waiting for the initial tool contact ;-)

[phomann]

Yeah, the plunge rate as set far too slow

Live and learn.

[phomann]

Well, I've decided that I need to remake the mill stand. The current one is too high and too narrow.
http://www.cnczone.com/forums/bencht...ml#post1215151

I'm going to use it for my lathe, so it won't be wasted.

The new stand will be based on the one that Zach designed. I particularly like the deep V in the tray with it's full width slot.
http://www.cnczone.com/forums/bencht...g-forum-2.html

I don't plan on a full enclosure though. I also want to make some progress on a power drawbar as well in the short term.

Cheers,

Peter

[zamazz]

Credit where it's due, I borrowed the design from one of the rf45 builds. The tray on mine is quite poorly welded and if I were to do it again I'd take the flat section out of the bottom of the vee and just make a single bend in the middle. Then I'd weld two triangles to the sides. Less welding and no flat area for chips to sit. Actually, I may remake that section now that I have a tig machine, just for aesthetic reasons.

Your parts look great! Keep up the excellent work.

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[phomann]

Thanks for the tip, it makes sense.

I think I can work out the size/height of you base from the image that contains it and your G0704 stand.

Cheers,

Peter

[deuce217]

Thats something that never gets old. Watching a CNC machine. Great work. Once I am done with my 2 year build on the 0704. This looks like a fun one.

[LeeWay]

Actually a flat spot is not a bad thing to have in a tray. If you use a wash down pump, the chips will still wash away. If you are working around the inside and drop a tool or screw, bolt etc, it doesn't go into the drip basket 100% of the time. You have a good chance that it stays in the tray.
Your tray looks great I think.