SMW Shop / My NEW Hobby

[Del Monte]

Love it!

I'm just starting to get into using HSM toolpaths in Mastercam X7. I bet they're a huge advantage on a hobby level machine

[BigSki]

Originally Posted by rob_b

CAD software is Inventor | 3D CAD Software | Autodesk It's really nice. Part, fixture, programming and verification all in one file with complete associativity when changes are made.

This is what I'm learning in school right now, It's powerful software for sure. The associative updates is a nice feature but it still causes me headaches as I still try to make all of my projects 'resolved' links.

[rob_b]

Just learning the software or 10 years in its always a struggle to keep all the references happy. You will learn what methods are bulletproofish and what to never ever do again.

[rob_b]

Kinda sucks having to do your day job for your hobby
Starting with the cross slide ball nut (X AXIS). Wanted a 5/8" but only the room for a 3/8" without an extreme chopping of the cast iron. Another must have on this machine is pre-loaded balls nuts. While Mach3 will electronically account for backlash the goal here is to just mechanically eliminate it. Seems to me that any diametrical positioning error in the cutting tool will result in twice the actual error so this should help minimize it. The design is based/expanded upon pictures posted in a thread on CNCZONE, a website I highly recommend checking out.

Won't get deep into the design but it should allow the balls in the two nuts to ride on opposite sides of the screws ball track. The tension will also be applied and adjustable using the wavy springs and adjustment collar. The green shoulder bolt will be custom as well to lock down the ball race yet still allow the brackets/nuts to float relative to each other axially accounting for pitch irregularities while constraining radial movement between the two. If they work I might have to upgrade the mill!

bla bla bla... pictures








Just fits

[Crawling Calvin]

Wow nicely done! I have ballscrews that have ballnuts with ~.0004" backlash so for me that is more than accurate enough! That being said mechanical backlash can be a huge issue when your doing climb cutting and it is not good for tools.

I admire your diligence to detail on the machines. Did you ever cut oil slots in your mill saddle to allow direct "one shot oiling" like on a Bridgeport? I did that on my Hi Torque Mill and it works very nicely since I can inject a little oil and it is held in the pocket and keeps everything nicely sliding with no problems

[wings_of_fire]

Originally Posted by rob_b

Seems to me that any diametrical positioning error in the cutting tool will result in twice the actual error so this should help minimize it.

What ever you are doing it is superb

Example:-
The diametrical position of the tool if shifts 10 microns on one side from the machines theorotical z axis centre line then when the tool rotates, the same error will multiply after 180 degree of rotation. So then, tool error will be 20 microns just spinning. Then add to this 20 microns, the ball screw error which will give us the final error value.

[rob_b]

Originally Posted by Crawling Calvin

Wow nicely done! I have ballscrews that have ballnuts with ~.0004" backlash so for me that is more than accurate enough! That being said mechanical backlash can be a huge issue when your doing climb cutting and it is not good for tools.

I admire your diligence to detail on the machines. Did you ever cut oil slots in your mill saddle to allow direct "one shot oiling" like on a Bridgeport? I did that on my Hi Torque Mill and it works very nicely since I can inject a little oil and it is held in the pocket and keeps everything nicely sliding with no problems

What brand screws and nuts are you running? Everything I have found in my price range is rated .005"-.008". I used oversized balls in the mill but still ended up with .003" or so of lash in each axis. I wish that I would have done a one-shot, manually oiling it every time gets old. The lathe will have one.

Originally Posted by wings_of_fire

What ever you are doing it is superb

Thanks

[Crawling Calvin]

Originally Posted by rob_b

What brand screws and nuts are you running? Everything I have found in my price range is rated .005"-.008". I used oversized balls in the mill but still ended up with .003" or so of lash in each axis. I wish that I would have done a one-shot, manually oiling it every time gets old. The lathe will have one.




Thanks

Oh wow really! I took the time to cnc my friends (now mine) Hi Torque mill from scratch strictly because it was that much more accurate using these screws vs the ones on the market.

Ballscrews I emailed the place and the guy said they had about .0004" backlash. I will get a photo up later of the part I made in stainless sheet with the screws. I was stunned

Do note if you get the screws in their hardened state they are REALLY hard to cut! I never annealed mine since I was worried about bending them so I machined them hard on a HAAS SL-10 lathe and it did decently its just the inserts didn't enjoy interrupted cutting through hardened steel. past the outside skin it was relatively soft inside the screw.

[rob_b]

Cool site Too bad they don't have 10mm screws.

[wings_of_fire]

There are some more nice websites...

Roton Products, Inc. Quality Lead Screws and Nuts for Power Transmission

Acme Lead Screw from Nordex Inc.

Haydon Kerk Linear Actuators, Lead Screws, and Linear Rails

Ball Screws & Lead Screws

[Crawling Calvin]

Not sure if you have read this or not but its pretty informative

Machine Tools: Lathe CNC Home

The guy who runs the site does some sweet conversion stuff so read up. Could help

[rob_b]

Good stuff guys!

Re-wiring day on the mill tomorrow, adding a cnc'ed 4th axis into the mix as well.

[wings_of_fire]

Seems like the rotary table already had a flat machined on it when you bought it. What brand and what model is the rotary table? looks good to me.

Nice to have a collet chuck.

[rob_b]

It was converted from a manual as well. http://www.use-enco.com/CGI/INSRIT?P...PMPXNO=4841009 You only have to make one permanent mod which is cut the end of the input shaft off to mount the coupling. Lol, no turning back now.

I bought the 5c chuck when I turned the ends of my ball screws for the mill. http://littlemachineshop.com/product...ProductID=3047

Lots of adapting going on but the rotary and lathe are completely interchangeable as far as chucks go.

[wings_of_fire]

Thanks for the links.

For the adapter plate, what makes it cocentric to the rotary table axis? Is there a shaft from the adapter plate that enters the rotary tables centre bore?

[rob_b]

This is going to get interesting! I'm thinking a custom set of drivers is in order.




Video...
http://static.photobucket.com/player...psb4ea3e2a.mp4


Sorry for the crude links, posting via my phone...

[Almighty Malach]

Pretty cool shit dude.

[rob_b]

Keeps me out of the bars...

[C*H*U*D]

Slick! I'd love to get a 4th axis some day. Did you make the plate that attaches the 5C collet chuck to the rotary table?

[rob_b]

Originally Posted by wings_of_fire

Thanks for the links.

For the adapter plate, what makes it cocentric to the rotary table axis? Is there a shaft from the adapter plate that enters the rotary tables centre bore?

Originally Posted by C*H*U*D

Slick! I'd love to get a 4th axis some day. Did you make the plate that attaches the 5C collet chuck to the rotary table?

Yes and Yes. Plus an adapter from LittleMachineShop.com. The small ring with the tapped holes allows for me to make a different sized adapter to match the pilot size of any chuck up to 6" and skip the LMS adapter completely. Some day I might re-do it all to reduce the stack height but it seems to function fine as it stands. It was all originally designed around the 3" chuck from my first lathe.