metalmadness
Hot Rolled
- Joined
- Nov 25, 2015
What was the quote out of curiosity?
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Damaged BT30 spindle. grrr
- Thread starter Houndogforever
- Start date
- Replies 146
- Views 17,936
What was the quote out of curiosity?
Pete Deal
Titanium
- Joined
- Apr 10, 2007
- Location
- Morgantown, WV
What’s the in place grinding cost?
Since the Brother spindles aren’t cartridge spindles I think in place grinding would be best. Not sure how they’d do it outside the machine without talking all the bearings off.
Since the Brother spindles aren’t cartridge spindles I think in place grinding would be best. Not sure how they’d do it outside the machine without talking all the bearings off.
machinistrrt
Stainless
- Joined
- Aug 15, 2008
- Location
- near Cleveland
I'd contact Sopko's, though there may be others; in fairness, they're relatively nearby me.
plastikdreams
Diamond
- Joined
- May 31, 2011
- Location
- upstate nj
Enough about the spindle...let's hear about the crash!!
Wsurfer
Cast Iron
- Joined
- Apr 1, 2013
- Location
- Austin Texas
+1,
I'm also curious to know what would happen if the pull stud didn't break. Somethings gotta give. Not knowing much about machine building, what would be the best/worst case scenario?. I would think an end mill would break before the pull stud, but IDK. I've done light radial HSM cuts on my Brother with a ..625 necked" x 3" long end mill in aluminum, but I run pretty conservative. How much is too much ?.
On larger machines the servos or the spindle will alarm out at overload. A CT50 pullstud isn't much smaller than a BT30 toolholder.
Seems to me like 30 taper machines are built for ultra fast speeds, especially WRT rotating mass for acceleration. Seems like broken pullstuds and replacing a low cost spindle have been the best solution to what is going to give out in a 30 taper crash.
On the other end of the spectrum a 50 taper machine can tear vises off your table and not care. 10HP servos on every axis and 30HP at 5000 RPM can make a big mess. Your average 10K RPM 50 taper spindle takes 200 amps of 240V 3 phase to take it from zero to 10K RPM in 1/10th of a second. One 50 taper spindle start is probably more juice than a Speedio uses all day.
DavidScott
Diamond
- Joined
- Jul 11, 2012
- Location
- Washington
Most 30 taper pull studs are breaking when the tool holder is getting pulled out of the spindle some and rolling around putting a side load on the pull stud. If you creep up on too much cutter pull you will get fretting and many sonic clues that things aren't happy. It generally takes a catastrophic crash to break things.
Tonytn36
Diamond
- Joined
- Dec 23, 2007
- Location
- Southeastern US
Make sure the ball retainer isn't cracked if it broke the pull stud. It has been my experience that that can happen depending on the crash type. We have a spare spindle in stock and just swap it out. Takes less than an hour after you have done the first one. Usually the balance is good enough to run while waiting on the loaner balancer to come in.
MachineAmateur
Plastic
- Joined
- Jan 11, 2021
There is a lot of archived talk about side loads being dangerous with BT30 (likely in combination of pulling forces with angled flutes?). I have liked the performance of 1½ 90degree 4-insert shell mill on metal removal tasks for steel, but i have wondered if that is dangerous as its capabilities are much more than the machine can deliver. It projects about 2 times as much lever arm as say, 3/8" end mill would and has no mercy if it crashes.
Attached generic steel cutting path with 8mm depth of cut and 4mm steps adaptive load. This will take about 50% spindle power 2000mm/min feeds based on the machine display. I have no idea if this is stupid or not? Changing this toolpath to small end mill with 0.8mm steps increases cutting time from 6 minutes to 12 (6000mm feed). Not getting paid though so want to avoid expensive mistakes.
Bigtoy302
Cast Iron
- Joined
- Jul 31, 2011
- Location
- Eugene, OR
Grinding a Speedio spindle is not recommended. You will have to pull the spindle and shim it back to spec due to how the tool changer/drawbar works. This is what I was told by Peter when I messed mine up. Good time to upgrade to dual contact. That's what I did.
Mari does have his own version of the high strength pullstuds but I get the real JM ones from Yamazen. PS every broken pullstud in a brother has been a Mari.
Mari does have his own version of the high strength pullstuds but I get the real JM ones from Yamazen. PS every broken pullstud in a brother has been a Mari.
Pete Deal
Titanium
- Joined
- Apr 10, 2007
- Location
- Morgantown, WV
Yours or have you done a national investigation? Did this happen when you were over-torqueing your pull studs and ruined your spindle?
Bigtoy302
Cast Iron
- Joined
- Jul 31, 2011
- Location
- Eugene, OR
Just talked with other Brother owners about it. We all talk to each other on IG lol.
I haven't broke one but I run JM's in all roughing stuff and Nodicor for standard. I do have one Mari pullstud on my Mari slitting saw arbor.
Just ruined the taper by over torqueing.
BROTHERFRANK
Stainless
- Joined
- Dec 20, 2013
- Location
- SoCal
Grinding a spindle on the machine is not recommended but doable. A light cleanup will not alter the z relationship enough to throw anything off. Not doable on Dual Contact unless you plan on not running as a dual contact after. What Peter was referring to I think is when someone changes out the bearings. Then you will need to check the stack up and most likely need a new lower spacer ring and grind it to achieve the proper bearing preload. New spindles come with a custom ground bottom ring that ensures proper preload.
Houndogforever
Hot Rolled
- Joined
- Oct 20, 2015
- Location
- Boring
Back from family weekend away.
Part was crooked on one end, so it ends up being a parallelogram. My 1/2" 5 flute that is used to rough the periphery in .020 radial cuts rounded a corner expecting less than. 020 to be there. Ended up being about .100. 360ipm. Bang, drop overload and swear a bunch.
Dude sets up on a angle plate and says he tests it for runout at 12" from gage line. Blue spot the gage for full contact.
Home Page
We shall see how things go. He comes on Wednesday.
Part was crooked on one end, so it ends up being a parallelogram. My 1/2" 5 flute that is used to rough the periphery in .020 radial cuts rounded a corner expecting less than. 020 to be there. Ended up being about .100. 360ipm. Bang, drop overload and swear a bunch.
Dude sets up on a angle plate and says he tests it for runout at 12" from gage line. Blue spot the gage for full contact.
Home Page
We shall see how things go. He comes on Wednesday.
plastikdreams
Diamond
- Joined
- May 31, 2011
- Location
- upstate nj
Wait...80 thou extra broke a pull stud...
Finegrain
Diamond
- Joined
- Sep 6, 2007
- Location
- Seattle, Washington
Material? If Al, that sounds weird. I cut Al @ .175" radial x 1.25" axial @ 288 IPM/16k RPM regularly, in my S700X1. If steel, OK, that's 36 in^3/min assuming 1" axial, which would be a big bite for BT30.
Regards.
Mike
Houndogforever
Hot Rolled
- Joined
- Oct 20, 2015
- Location
- Boring
I believe it lifted the part from the vise when it hit and things just ended.
Looking at the edge of the material, it looked like it was attempting to take a 1/4" radial cut which is why I assumed it moved in the vise.
After that I went on vacation. Back tomorrow to see what's up.
Material is P20 mold steel. About HRc26-30
plastikdreams
Diamond
- Joined
- May 31, 2011
- Location
- upstate nj
Once it lifts, it's all over
wheelieking71
Diamond
- Joined
- Jan 2, 2013
- Location
- Gilbert, AZ
This is important shit.
If a DC spindle taper is ground, they would HAVE to grind the face. Or a DC tool will pull up tight on the face with zero taper contact.
I can't see how a DC spindle could easily be ground "in the field" properly.
I mean, with spindle orientation, I guess it could. But I bet you would be money ahead to just buy a new spindle.
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