5-axis (BC/AC) head construction

[valio]

Looking for not expensive way to construct 5-axis head.
So need photos and drawing materials with internal kinematic
plans to consider some real examples of commercial 5-axis
heads like a TRI-TEACH, (not sure that Doughty Drive), etc.

Please!

If some own such compact (not heavy-duty heads),
do a couple shots and sent it to me ..

Thanks a lot.

[metalworkz]

Hello Valio,
I have been watching your thread here and don't see any responses so far. I am also working on a design to make a 5th axis head for my next CNC build. I started with a basic rectangular shape for the head but would really like to do something more like the Tri-Tech design with a more streamlined appearance.
Maybe it will be good to start with the simple shape and then try to improve on it after it is done and I have a working prototype? Have you done anything with your design or started build it yet? If I get started on mine I will post pictures and details as I go with the build. Here is a snip of what I have drawn so far:



Regards,

[metalworkz]

Wow,
I'm surprised there isn't more people interested in the construction and use of a 5th axis B/C head. I have seen a couple of 5th axis builds here on the zone but no in depth 5th axis B/C head ideas. Maybe the lack of reasonably priced 5th axis software does not help.

[FPV_GTp]

Originally Posted by metalworkz Wow, I'm surprised there isn't more people interested in the construction and use of a 5th axis B/C head. I have seen a couple of 5th axis builds here on the zone but no in depth 5th axis B/C head ideas. Maybe the lack of reasonably priced 5th axis software does not help.

have a look at this build http://www.cnczone.com/forums/showthread.php?t=98554

cheers

[louieatienza]

Originally Posted by metalworkz Wow, I'm surprised there isn't more people interested in the construction and use of a 5th axis B/C head. I have seen a couple of 5th axis builds here on the zone but no in depth 5th axis B/C head ideas. Maybe the lack of reasonably priced 5th axis software does not help.

There is... we just keep it under wraps!

Reasonably priced is a relative thing. If it's your livelihood, you'd factor in the return on your investment; also some software vendors provide financing, but most likely mainly to corporate or business accounts. If it's just your hobby, well then you need deep pockets!

[metalworkz]

Originally Posted by louieatienza There is... we just keep it under wraps! Reasonably priced is a relative thing. If it's your livelihood, you'd factor in the return on your investment; also some software vendors provide financing, but most likely mainly to corporate or business accounts. If it's just your hobby, well then you need deep pockets!

Hello Louie,
I am looking to make the 5th axis for my next hobby CNC machine, so it would help to have deep pockets but that is not so in my case. If I had deep pockets I would simply purchase something available like say one of the Doughty B/C heads. I will just have to design and build my own along with the CNC router/mill in about a 48" x 48" size. I had other ideas regarding the design of the machine itself to perhaps enable a smaller footprint machine to do larger work but have not decided which way I will go with it. I have the bulk of a small B/C head designed from scratch so I will just need to start cutting the parts and see if it all works out. I will probably see about getting the B/C parts drawn in inventor so I can better see how it will work.
I have kept my intentions to build the 5th axis mostly to myself also but I figured there isn't a better place to network these ideas and see what the rest of you are doing along these lines. Thanks for replying to the thread, and I hope some more people will respond with their ideas and advice.

Regards,

[louieatienza]

Hey Wes...

I have a few drawings of ideas for a B/C head. I would like to contain either my steppers or servos within the unit itself, so it's not sticking out in the way, and use timing belts for gear reduction/turning each axis. Only thing is, I'd have to make the gantry tall to accomodate everything, as well as keep the Z stiff enough with the longer length...

[metalworkz]

Hi Louie,
That is the way I have mine designed so far also(motors enclosed inside the head and belt driven) It will required a tall Z as you have mentioned, but the tall Z will also allow machining of taller items. I wonder if the location of the motors can be changed to reduce the height some for the Z axis? The placement of the motors in my current design is more of an inline design and the location of the motors may be modifiable to reduce the vertical height? I would have to look into the interference fit for all the parts to make sure it will not inhibit the angular travel of the head. I think for my first 5th axis I may just use my original design and make changes after the prototype is done. I would rather have a good functioning head at that point but am willing to make some changes to better the design while being able to actually test it. I was thinking of a .25" thick aluminum construction but a .125" 6061 AL will probably be thick enough and I can add some gussets if needed to beef it up.

[Master of nun]

Hi Guy's

I'll share the head I've been working on.

Although still not completed and tested, it's well underway.

Louie, You'll be happy to see the steppers contained within the unit, 50:1 harmonic drives are used for reduction. Using these drives makes packaging very straight forward, Prurchased secondhand off ebay for around US$90 for the pair. (the internal bearing of the drive is not shown in the photos)
I've spent about a weeks labour putting it together and now only needs shortening of the two axis to make it more compact.

130mm aluminium solid bar was used.
THK crossroller bearings cost nearly Au$500 ea.
350 oz-in steppers housed within and may need some form of cooling fan attached to the housing, although the housing will work as a great heatsink.

Hope this gets the creative juices flowing for you!

I haven't attached photos before so here go's

Liam.


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I've since changed the way it is assemble since this photo was taken to the above but it does show the second rotation that isn't shown in the above
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[metalworkz]

Hi Liam,
Wow, that is a very impressive 5th axis! I will not be attempting anything that large now, and will have to keep mine as light as possible. Your machine must be a bit more industrial strength and size than what I had planned for mine. Thanks for posting your pictures and info, and please do keep us updated on your progress.

[Master of nun]

No worries and thanks for the compliments.

obviously this concept could be downsized for a smaller machine.
Also to minimize Z height my 4th axis stepper resides within 150x150RHS Z axis column.

I may be bias but i think the harmonic drives are the way to go if had for the right price.

happy building

Heres a link to the build thread for some background info
http://www.cnczone.com/forums/showth...ybrid&t=101936

[louieatienza]

Wow Liam that's radical! You building a VMC?! Excellent work...

I'm not too familiar with the harmonic drives but that may b e the way to go if I can score some cheap enough...