If you lift your separator to sit on top of the barrel and put a piece of plastic around it, you will get much more room for dust, and can see when it is getting full. The Thiens sure work great don't hey!

 

What is a good multipass depth for mdf with a 6.4mm and 3mm bit?

 

In mdf with the right feed you should be able to do half depth passes IMO

 

Well, that's not telling much, is it?

Nigel, look here for the information you want: http://www.amanatool.com/2008catalog/cnc_router_bit_feed_info.pdf and another one here http://staff.cua.edu/mckibbin/Resources/FeedRateCalc.pdf

 

You're welcome! Found also a video of LMT Onsrud (they sell a lot of good bits) in which they explain the principles and refer to their catalog, in which they have tables printed. Get that catalog!

 

I'm just reading a very comprehensive piece of work about the issue here http://www.cnccookbook.com/CCCNCMillFeedsSpeeds.htm. There seems to be a lot to speeds and feeds as it appears to be called. I think we should add this link to the Helpful tool sections. Although I'm sure the guy behind it did a lot of work on his g-wizard calculator, but paying $ 79 a year for a subscription to that software is a bit too much asked. The Cookbook is very informative though.

The link is added to Helpful Tools!

The CNC USB controller software also has a build in calculator that can be used. Not as comprehensive as the g-wizard, but still very useful and a good starting point.

 

According to the CNC USB Controller software a 0.25" 2 flute with a cutting speed of 250 feet/min, 12000RPM, 0.013" chip load will give a feed rate of 312 in/min. The 3mm bit gives a feed rate of 156 in/min. And I think this is with (as David already indicated) half the bit diameter (or a full bit radius if you prefer) in mind.

Remember: these are just a starting point from which you'll have to fine tune the feed rate. Listen to the sound of the tool and observe your machine to adjust accordingly. If it doesn't sound or look good, stop and find out what the problem is. Too slow is not good, too fast neither. It has to be about right (not exact, although preferred) for the best results.

Hope this helps a bit (no pun intended).

 

Hey everyone,
I've been working on making some garolite plates (originally recommended by kram for the OX) to offer to the fine folks on here wanting to build the machine. I made a few modifications, including a recess for the steppers so spacers are unnecessary (increases the rigidity of the plates as well with them being flush mounted). I also removed unnecessary holes on the front gantry plate to retain as much strength as possible (compatible only with 2060 z axis). Also, if anyone is wondering why they are orange ish is because the same stuff in black is much more expensive. I went with this color to keep the cost down and painted my set black very easily. Check them out here:http://clockwerkmech.weebly.com/ox-cnc--garolite-plates.html

 

Very nice work with those plates Sly

Tweakie.

 

Thanks Tweakie

 

Very nice work @SlyClockWerkz!

That will be a great lower cost alternative to the aluminum plates being offered.

 

Thanks! These were my thoughts as well. They also perform admirably in everything ive used them for from plywood all the way to aluminum.
made by the ox, for the ox

 

Very nice ...

I see you take custom orders as well. This could come in handy for those wanting to tweak the design for their first build.

 

Yes, website is a work in progress, but im planning on trying out some custom orders (depending on the scale of the job of course) if people want something special

 

Yippie! Just received a bunch of router bits I can test. After all, what good is a Buffalo without teeth? Some ball noses, v grooves, roughing and finishers and an engraving bit. Let's go outside and play!

 

I have finally finished the mechanical assembly of my system. You can see the videos of the first couple of movement tests here-- I have an eager assistant helping me out in the first video . I still have to get the Mach3 software set up and hook up the computer to the machine. But I'm getting there!



First Test of CNC Router (X & Z Axis Only)




Second Test of CNC Router (All Axis and Router Spindle Attached)

I noticed the Z-axis is wobbling a bit. When I checked into it, it turns out the lock-ring has slipped and the lower bearing is just hanging. I need to get that re-seated and tightened back up.

 

A question for whoever can answer it. It's about speeds and feeds.

Material MDF
Bit: 1/4" Upcut Spiral 4 flute carbide
Chip load between 0.006" and 0.008" per flute.
RPM of Router 18,000

Feed rate (according to Onsrud formula) should be RPM (18,000) x #flutes (4) x chip load (0.006") = 18,000 x 4 x 0.006" = Feed rate of 432 ipm at cutting depth of 1 x Diameter. This would be a feed rate of (432 imp x 25.4mm)= 10,973 mm/min. To me, that seems to be extremely fast and I'm afraid the Buffalo will fall apart at that speed or the bit will fly thru the wall (and maybe me!). Even at half that speed I doubt nothing will break.

Does this speed "looks" normal to the "experienced" machinists here? Or do I have it all wrong in the calculations?

 

And out of that question another one popped up; how fast can you go with the nema 23 steppers on an OX? Max feed rate for this setup?

 

Unfortunately this is where compromise has to come into the equation.

The ideal speeds and feeds assume a rigid, industrial type of machine (no disrespect intended here) rather than our hobby type machines.

When working with wood / MDF it may pay to reduce the spindle speed (and in my case changing to single flute cutters) as the feed rate has to be kept high enough to avoid burning / overheating the work / cutter whilst still keeping within the available torque envelope of the axis stepper motors controlling the motion.

Bit of a balancing act really but some trial and error will soon show the best settings for any particular design of machine.


Hope this helps.


Tweakie.

 

Hmm, all the steppers I've ever heard sound like they're singing when they get going. Is that what you mean?

 

"Unfortunately this is where compromise has to come into the equation."
You have a formula for compromise? LOL

"The ideal speeds and feeds assume a rigid, industrial type of machine (no disrespect intended here) rather than our hobby type machines."
That's what I also thought, those speeds just seem to fast for the OX.

"When working with wood / MDF it may pay to reduce the spindle speed (and in my case changing to single flute cutters) as the feed rate has to be kept high enough to avoid burning / overheating the work / cutter whilst still keeping within the available torque envelope of the axis stepper motors controlling the motion."
Is there a way to work out the torque on the steppers, so the maximum possible feed speed can be calculated?

"Bit of a balancing act really but some trial and error will soon show the best settings for any particular design of machine."
The trial part is ok with me, but the error part I like to keep to the minimum since getting new quality cutters is a nightmare here in Thailand. Everything has to come from abroad (time and money factor!).


"Hope this helps."
Yep, to become more aware of all factors involved but not in getting closer to the answers. LOL

Maybe you can share the feeds and speeds you are using with the OX on various materials? At least we can have an idea where to start.

 

Is it possible to get V-Slot rails of a length about 3300mm (approx 10-1/2 feet) ?

 

No, this is not a model of the new high rise buildings in Beijing but a bunch of V-slot connectors for the X axis. They go in there to connect them together and will contribute to a stiffer X axis (that's the plan!).

 

Please also make a video that shows us how it works .

Did you design the connectors yourself?