BT30 Spindle Capabilities

[Chips Everywhere]

This is what I have so far for a 3/8 EM.

Here is the 1.1 gauge length tool holder:



Here is the 1.75 gauge length and 1.25 below holder:


1.75 gauge length assembly:

 

[DavidScott]

You won't be able to push the tool as hard with the longer gage length. How hard you can push it depends a lot on draw bar retention. There is a big difference between 500 lbs and 900 lbs.

 

[LOTT]

With a 1.1 side lock you should snap off a 3/8 end mill before the pull stud goes, so it's less expensive to push past failure. At least that's been my experience with standard BT30's.

The same may or may not be true with a 1.75 gage length but I haven't seen it happen, if someone else want to try it and report back....

 

[Chips Everywhere]

Guess I'm making a riser and going with a shorter holder. I'm not trying to run any pull stud experiments at this time on a new machine.

 

[david n]

Guess I'm making a riser and going with a shorter holder. I'm not trying to run any pull stud experiments at this time on a new machine.

That would be my course of action also.............................

 

[gkoenig]

Why are you pushing it?

BT30 machines do not make their time in roughing! They make their time in acc/dec and fast tool changes. The road to hell is paved with the intention to make a BT30 machine remove material like a CAT40 mill, with busted pull studs and spindles as filler material.

Take a breath, open up your CAM, and take a zen hour of process refinement - set your clearance heights to their minimums, tune your cut entrance/exits to be as small as possible, hit your retracts from a cut literally as soon as the cut edges get 0.005" from the finish material, viciously exterminate all wasted motion, pauses, or stops. Take every non-engagement feed move, and set it to the machine's max cut feed.

 

[eaglemike]

Several good suggestions above about using roughers. Reduced cutting force, fast feed, and much better chip control. The last can be important at times. Zero Divide on here sells some software that is quite useful for calculating cutter loads, a really nice tool for a 30 taper machine. I went from all 40 tapers to all 30 tapers for my parts, have never regretted at all. Lower electrical use, reduced cutter cost, and reduced cycle time. Advanced tool paths were very useful in the transition.
Good luck!

 

[Orange Vise]

BT30 machines do not make their time in roughing! They make their time in acc/dec and fast tool changes.

+1

Also make sure your process doesn't get bottlenecked by chip buildup. No reason to push a machine to its absolute limit if the choke point is a guy scooping chips with a plastic shovel.

 

[Pete Deal]

Haven't tried those end mills from Mari-Tool yet. I typically use the Destiny Diamondback. Yes it's a little loud but I've done 10,000 parts with one of them, removing a ton of material per part.
The next time we get that job I'll put the Mari-Tool to the test.

I think the Maritool 1/2” rougher in my older machine is 5-6 years old. Got it when I bought the machine. It too has done 10k or so parts. As someone else once said on here- “they last till you run them into the vise”.

 

[Finegrain]

+1

Also make sure your process doesn't get bottlenecked by chip buildup. No reason to push a machine to its absolute limit if the choke point is a guy scooping chips with a plastic shovel.

To that end, be aware that the chips made by a serrated rougher like the Maritool EM I referenced are VERY compact in the chip pan, more so than those from a segmented cutter like Destiny Diamondback, and way, way more so than from a standard straight EM.

That's generally good IME, but those thick stubby little chips can be difficult to scoop, and can block up the drain holes in the chip pan screen.

Regards.

Mike

 

[Chips Everywhere]

Why are you pushing it?

BT30 machines do not make their time in roughing! They make their time in acc/dec and fast tool changes. The road to hell is paved with the intention to make a BT30 machine remove material like a CAT40 mill, with busted pull studs and spindles as filler material.

Take a breath, open up your CAM, and take a zen hour of process refinement - set your clearance heights to their minimums, tune your cut entrance/exits to be as small as possible, hit your retracts from a cut literally as soon as the cut edges get 0.005" from the finish material, viciously exterminate all wasted motion, pauses, or stops. Take every non-engagement feed move, and set it to the machine's max cut feed.

I'm not trying to push it, quite the opposite. I don't have any experience with BT30 machines, so I wanted to know if my cutting parameters and set up was adequate for what I am trying to do. Turns out, no, so I am starting to lean towards making a riser and using a 3/8 tool with a 1.1" gauge end mill holder. I also don't want to run my roughing tool slower than it can go because I have a decent amount of material to remove. I will start slow and work my way up to a comfortable feed.

Thank you for your feed back on process refinement, I will do my best to eliminate most of the waste.

On a side note, what are you guys setting your Z plunge feeds to? after the tool rapids to the top of the part and its about to switch to the plunge feed so the end mill travels to the its bottom height, on an outside contour. I hope this makes sense.

 

[Chips Everywhere]

Ask the techs.... My Feelers were specced to a Z travel of 400 but I got another 25mm out of the travel (thus extending the Z nearer to the table) with no issues. You have to check the nut can travel that amount on the ballscrew and the guarding doesn't concertina/bottom out, but usually you can get more out of a machine....

Thanks for this suggestion, this may give me the extra reach I need so I don't have to make a riser for my pallets. I assume the tech would just change a parameter on the control if there is more travel to be had, as long as no parts on the machine collide?

 

[BT Fabrication]

I'm not trying to push it, quite the opposite. I don't have any experience with BT30 machines, so I wanted to know if my cutting parameters and set up was adequate for what I am trying to do. Turns out, no, so I am starting to lean towards making a riser and using a 3/8 tool with a 1.1" gauge end mill holder. I also don't want to run my roughing tool slower than it can go because I have a decent amount of material to remove. I will start slow and work my way up to a comfortable feed.

Thank you for your feed back on process refinement, I will do my best to eliminate most of the waste.

On a side note, what are you guys setting your Z plunge feeds to? after the tool rapids to the top of the part and its about to switch to the plunge feed so the end mill travels to the its bottom height, on an outside contour. I hope this makes sense.

Z feeds depend on the tool and the material.

anywhere from 40-50% of regular cut speed.

 

[gkoenig]

On a side note, what are you guys setting your Z plunge feeds to? after the tool rapids to the top of the part and its about to switch to the plunge feed so the end mill travels to the its bottom height, on an outside contour. I hope this makes sense.

At first? I feed from the clearance plane because I’m a giant sissy.

Once everything is proven out though, I rapid to 0.01” above the cut plane and use the option to round corners on linking moves. If I’m feeding into a corner, I’ll use a tangent entry and minimize it. Entering against a wall, I’ll arc in, but minimize the arc length (but not the radius- I want that at about the tool radius).

 

[crossthread82]

Thanks for this suggestion, this may give me the extra reach I need so I don't have to make a riser for my pallets. I assume the tech would just change a parameter on the control if there is more travel to be had, as long as no parts on the machine collide?

Generally speaking with newer machines you have less freedom to do things like that, not saying its impossible but YMMV.

BT30 machine can hog if setup appropriately, you can't treat it like a 40 taper machine. Dynamic toolpaths combined with a very free cutting 3/8 endmill and they can really move some aluminum. If you use a lower rake endmill that reduces the stress on the drawbar which is the weak link in a 30 taper machine. The AX-FPS from fraisa is one of the most free cutting tools on the market right now but its pricey, I like the GWS alumigators b/c they can helix at 45*.

Short holder, free cutting tool, 3/8 diameter and you won't have any issues and you'll be able to run it balls to the wall and the tool and machine will all be comfortable.

 

[Matt@RFR]

On a side note, what are you guys setting your Z plunge feeds to? after the tool rapids to the top of the part and its about to switch to the plunge feed so the end mill travels to the its bottom height, on an outside contour. I hope this makes sense.

Rapid! You've got your hand on the rapid override during setup anyway, I find it safer this way than having a feed move there. Plus it's faster.

On that topic, get rid of all your clearance plane moves at the end of a tool. Let it go straight to the tool change versus Z.25 or whatever.

 

[empower]

Generally speaking with newer machines you have less freedom to do things like that, not saying its impossible but YMMV.

BT30 machine can hog if setup appropriately, you can't treat it like a 40 taper machine. Dynamic toolpaths combined with a very free cutting 3/8 endmill and they can really move some aluminum. If you use a lower rake endmill that reduces the stress on the drawbar which is the weak link in a 30 taper machine. The AX-FPS from fraisa is one of the most free cutting tools on the market right now but its pricey, I like the GWS alumigators b/c they can helix at 45*.

Short holder, free cutting tool, 3/8 diameter and you won't have any issues and you'll be able to run it balls to the wall and the tool and machine will all be comfortable.

@BROTHERFRANK demo'd a 12mm Fraisa AX-FPS for me about 2 weeks ago. absolute fucking nuts - 100CI MRR on a 30 taper. i didnt believe it until i saw with my eyes.

 

[DavidScott]

I'm not trying to push it, quite the opposite. I don't have any experience with BT30 machines, so I wanted to know if my cutting parameters and set up was adequate for what I am trying to do. Turns out, no, so I am starting to lean towards making a riser and using a 3/8 tool with a 1.1" gauge end mill holder. I also don't want to run my roughing tool slower than it can go because I have a decent amount of material to remove. I will start slow and work my way up to a comfortable feed.

Thank you for your feed back on process refinement, I will do my best to eliminate most of the waste.

On a side note, what are you guys setting your Z plunge feeds to? after the tool rapids to the top of the part and its about to switch to the plunge feed so the end mill travels to the its bottom height, on an outside contour. I hope this makes sense.

If the tool isn't cutting then it's a rapid move, or high feed if that is faster. Don't be scared of a 1/2" tool in a stubby side lock holder, my general purpose rougher is just that. By the way, the " 30 taper pull studs are weak" comes from mistakes that overpower the drawbar pulling the holder out of the taper a bit so the holder rolls around in the taper putting a side load on the pull stud, which is what breaks most of them. Knowing how much drawbar tension your machine has is very important to know how hard you can push the tool, and how important tool projection from the spindle gauge line is. The more the tool is designed to lift the chips, and part, the more careful you need to be.

 

[cosmos_275]

I use 3/8 roughers in 1.75 side locks. Reaching stuff this helps but also for coolant. Super short and coolant might have a hard time getting where it needs to be. I don't push mine all that hard so the length doesn't affect anything. I have used 1/2 rougher but switched back to 3/8. Depends on the job. If I had a huge job that would pay for repairs, I might push the envelope, but being my only milling spindle I haven't felt the need

 

[Chips Everywhere]

+1

Also make sure your process doesn't get bottlenecked by chip buildup. No reason to push a machine to its absolute limit if the choke point is a guy scooping chips with a plastic shovel.

If the DT2 auger system is like the one on my VF2SS, then I will be scooping chips out with a shovel. It gets overwhelmed easily.