PDA

View Full Version : So what can I do with this ... 5-Axis.



Jonathan
23-11-2011, 02:48 PM
Albeit only momentarily, I made a new spindle mount to set my machine up for 5-axis:

4962
4963
4964
4965

But I cant think of anything to make with it :lol:

Clearly I need to drop the bed down (which is fine, it's adjustible) to get enough clearance.
I can also mount both rotary tables and the spindle on the Z-axis to get the spindle rotating in XYZBC configuration. May need some reinforcement. The reason I made my Z-axis have 400mm of travel is to allow sufficient clearance for future 5-axis machining with that set-up.

Unfortunately there's quite a lot of backlash in the rotary tables, which is difficult to eliminate, so it's probably only going to be useful for woods and plastics. Ideally I should make a BC mount for the spindle using harmonic drives (too expensive), or double worm wheels preloaded (generally annoying), or timing belts (struggling to find info on how much they will stretch). But is it really worth it?

luke11cnc
23-11-2011, 07:03 PM
around ball in a square block??

a bust of Santa

a set of wind turbine blades ??

the list goes on

James

wiatroda
23-11-2011, 11:47 PM
Albeit only momentarily, I made a new spindle mount to set my machine up for 5-axis:


But I cant think of anything to make with it :lol:

:rofl::rofl::rofl::rofl::rofl::rofl: good one Jonathan

Quite recently I've made one wind turbine blade (580x120mm)


4966


Rough with end mill + finish with ball-end
I think it could be faster with 4th or 5th axis when I could do finish cut with an end mill

Jonathan
24-11-2011, 12:09 AM
Ahh nice one!
Perhaps the photo is deceiving me, but it looks like you have set the airfoil at the same angle along the whole length of the blade? It should be twisted ... look at the oncoming wind and the speed of each point, radially, on the blade as vectors and the angle between those vectors plus the angle of attack is the angle you set each cross section at. I also offsetted the leading edge to obtain a taper, so the chord at the end of the blade is centered about the root. This was my first attempt before I made the CNC router, so done on the mill in 4 operations, plywood:

4967

4968

4969

Then I did an MDF mould about the same length as yours and made them with fiberglass...which you've already seen. It's so much better, try it!

http://www.mycncuk.com/forums/showthread.php/3324-Making-small-GRP-Wind-turbine-blades

1.5m blades coming soon...

4 axis would make it faster as you could use the side or, with 5 axis, the end of an endmill for the finishing pass. But I'm not sure it's really worth it? Would look good though!
Since I'm going to make moulds for the blades, not the actual blade, the surface is concave so I would still have to use a ball-nose cutter. 4/5 axis allows the cutter to be kept at a constant angle to the surface, which should allow it to cut faster as it avoids using the centre of the ball nose cutter.

wiatroda
24-11-2011, 12:36 AM
Ahh nice one!
Perhaps the photo is deceiving me, but it looks like you have set the airfoil at the same angle along the whole length of the blade? It should be twisted ...
It's barely visible, but it is twisted. Some time ago I was messing with 3d software and first thing that came to my mind was to make wind turbine blade. I left memory stick in a workshop with file, but as far as I remember there is 5 degr angle at the tip and 10degr at the root. Blade was designed to fit 120x45mm 650mm long leftover timber from Wickes I had.
I may someday consider to make the proper ones and raise some wind turbine:whistling:,but those damn stupid permissions- can spoil whole fun of hobby engineering:sad:.
I'd like to make them fiberglass ones, but wooden ones sanded, dyed and high gloss lacquered- pure beauty- I could keep then in livingroom and enjoy their stunning look

luke11cnc
24-11-2011, 02:26 PM
Would this rotary table be any good ??

http://www.axminster.co.uk/axminster-axminster-150mm-rotary-table-prod22377/

or should I go smaller ??

James

wiatroda
25-11-2011, 07:35 PM
Would this rotary table be any good ??
http://www.axminster.co.uk/axminster-axminster-150mm-rotary-table-prod22377/
James
Difficult to say until you try
I have HV6 from WARCO and it looks like for me Jonathan have the same one :), /or all them can be generic ones with different names. Anyway I don't complain about mine so far. I just come back from the garage after exercising dividing plates, (46 tooth timing pulleys- 1 full turn and 22 holes@23 holes dividing plate, enough to make my hand sore :whistling:

Jonathan
25-11-2011, 07:57 PM
Difficult to say until you try
I have HV6 from WARCO and it looks like for me Jonathan have the same one :), /or all them can be generic ones with different names.

The Axminster one looks exactly like the one Chip got with a different label. The giveaway is it seems the vertex ones have thin fine lines for the markings and a bigger dial with vernier scale whereas the others have thicker more wobbly lines...the HV6 on the warco site (http://www.warco.co.uk/rotary--compound-tables/124-horizontal--vertical-rotary-tables.html) says SOBA on it, and also has 4 slots whereas the vast majority of vertex have 3 slots.
Whether it matters or not depends on what you're using it for.


Anyway I don't complain about mine so far. I just come back from the garage after exercising dividing plates, (46 tooth timing pulleys- 1 full turn and 22 holes@23 holes dividing plate, enough to make my hand sore :whistling:

That's why I almost immediately after getting mine put a stepper motor on it. Gets tedious fast doing pulleys manually. I did one 16T that way...

http://www.youtube.com/user/Jonblissett#p/u/8/lVuBEEceWJ4

wiatroda
25-11-2011, 09:09 PM
That's why I, almost immediately after getting mine, put a stepper motor on it. Gets tedious fast doing pulleys manually. I did one 16T that way...

Agree, stepper would greatly ease and speed up a job.
It's not cranking itself , but pulling back handle to unlock is painful as the spring is really strong- too strong.
My rotary has 4 slots and fits nicely to four mounting holes in a chuck
How about programming rotary table- looks like hand written G-code for me.
What about making some macro with some loop working until machine cut desired amount of tooth???? some no. of tooth variable in a macro??

luke11cnc
25-11-2011, 09:21 PM
Have you decided what your going to make with your 5-axis yet Jonathan

James and Luke

luke11cnc
14-12-2011, 10:46 AM
what about this Jonathan

http://www.youtube.com/watch?v=1gmTPlNE-mU&feature=related

James

Jonathan
14-12-2011, 03:24 PM
It's not cranking itself , but pulling back handle to unlock is painful as the spring is really strong- too strong.

I didn't use a dividing plate, never really seen the point when the rotary table has a scale which just move to the right angle.


What about making some macro with some loop working until machine cut desired amount of tooth???? some no. of tooth variable in a macro??

If you use EMC you can do it in just a few lines of code as, unlike mach3, it supports loops. I just wrote a quick program to write the code for pulleys:

http://www.mycncuk.com/forums/showthread.php/3051-Some-Gcode-generating-programs

The main reason I did that program was for milling XL pulleys using just a normal endmill, but you can use it with a form tool too.

Jonathan
14-12-2011, 03:27 PM
Double post, deleted.

black5f
15-12-2011, 10:28 PM
Ooooo! Nice! A nice spinner, Two more blades, a collective pitch head, free electricity? How about a Turners cube? In one go with an under cut tool like a dovetale. Or something on the same lines? Should keep you busy for a bit ;-)
Tom