Pre-Drill Holes for a BETTER way to tab off Machined Parts!

[@CJ-ty8sv]

Good Video. On the topic, drilling is almost always a faster and more economical way to remove material than milling, so if it were me, I would (if the job allows for it) make tabs much smaller and have more of them (i..e. more drilled hole) and also would remove as much of the slot as I could with series of drilled partial and full depth holes. If done correctly, you could get away with just a single pass or two with the mill to clean up the rest of the material and make better use of the mill (i.e. deeper and / or full depth cuts). Although it might not be ultimately any faster (especially since CAD/CAM time will likely increase), it does often result in better tool life and since drills are almost always cheaper to replace than mills, cheaper overall tool cost in the long run.

[@angrydragonslayer]

I agree but would like to add that, assuming we got the toolchanger space for the drill, we'll drill and then run an HFM ramp at as fast as the endmill wants to go (upwards of 4m/min at the standard haas 8100 or 25m/min in my personal machine if i got a larger drill than endmill)

[@CrashingCarbide]

Hey you made the video! Thanks again for the advice. I’ve been using it for quite a while now and have gotten excellent results in a variety of materials.

[@iimuch3760]

Love that you haven’t forgotten about the desktop folks.

[@PowerSports]

Excellent video! Much better narration and camerawork than usual.

[@copperlemon1]

On the subject of drilling, have you ever checked out exchangeable tip spade drills? I work in a shop that does short and single run parts, so solid carbide twist drills and indexable insert drills usually aren't an economical choice. The spade drills are a nice intermediate; being less expensive, but still being faster and yielding better hole quality than HSS twist drills. Having cutter materials and geometries suited for nearly anything while still using the same body is quite nice. Feeding at the recommended rates can be pretty aggressive, so they might not be a good fit for some smaller machines though.

[@kevink6420]

We run ingersol gold twists with 1000psi tsc and they are awesome. We actually have better luck with the 180 deg tips and I like them better as a programmer as I can use them to do small , deep pockets with a pretty flat bottom. The only kicker is that the 180 def doesn’t locate well on top of existing holes, it does its own centering on flat surfaces though, saving a spot drill operation. Im a journeyman toolmaker, use them mostly in a2,d2, mild, and 4140. Try flat bottom tips instead of the spade. We use them for through holes routinely as well. Rarely switch to a spade now.

[@JebJulian]

Great video. Tabs sound like they're trying to kill my hand made CNC. Will keep this technique in mind.

[@johnmarkel8160]

Hit them with a dead blow

[@DavidCook42]

Interesting video ! It totally makes sense for tool life. Most of the things I need to make on my lol CNC router require full slotting like this. (I'm so close to getting my wife to give me the GO signal for a Tormach Mx ) These tips are great because it is totally out of the box thinking. The simulation makes sense. the load reduction on the tool for tabbing makes sense. This will totally help me out. In my case I cannot really drill since I am limited to high spindle RPM, but I can still take my 1-flute 1/8" and helix ramp it into making holes before I run it into the crazy slots. Thank you !!!

[@maxrcaustralia8720]

Excellent Idea for tool life

[@pcsmachineworks]

I have been doing this with some parts I routinely make in 304 and 316 stainless, I've found that drilling out the corners to a larger size than the endmill helps significantly when slotting out deeper parts. I try to drill corners less than 90 degrees at double the endmill diameter. For instance, there is one part I make from 1" mill plate that I profile out with a 1/2" endmill, the corners are drilled to 1" diameter to let the chips flush as the mill ramps in. This has allowed me to hit surface finish specs and the part is complete minus deburring. Prior to the oversized holes i would have to setup a final pass operation because chips where recutting and damaging the finish.

[@pmdeutsch]

Simple but intriguing concept. I'd like to see if you could actually beat your cycle time by using a smaller endmill and trochoidal/peel milling at full depth (say, a 3/16" endmill starting from 1/4" drilled holes). Another thought is trying those new solid high-feed endmills. They should be able to handle the small step downs pretty easily and feed significantly faster.

[@Stasiek_Zabojca]

This really is situational. You have to evaluate if that extra time you spent on drilling will really benefit you. Will that extra time increase tool life enough to return "wasted" time? Especially in production runs, where tool cost is only fraction of all the costs of making things, where time is majority of it.

[@pmdeutsch]

Cycle time isn't everything... I'd rather have a stable process without broken tools or time down replacing tools than save a few minutes. Ramping down/slotting will always kill your endmills faster than any other kind of cut so eliminating as much of these strategies as you can is a good idea (esp with a drill which has a higher MRR than any other tool in a mill)

[@Stasiek_Zabojca]

@@pmdeutsch As I said, you have to check it for individual parts. Maybe in reality it isn't really that bad and won't have that much impact on end mill life.

[@TrueMachine2]

Good idea! Nice Job!!

[@YCM30cnc]

😎😎👍👍…. You’re delivering Gold over there…. Used to the snow yet?

[@manicrally1839]

KZbin demo titanium chunk. Lol. Oh you guys :P

[@brucec954]

Seems like a good idea. However, I have found with my Tormach Jacobs chucks & 770 mill that it doesn't like drilling much over a 1/4" dia hole and the tool likes to pull out or even come off the mounting taper (even though whacked it with a dead blow hammer to make sure seated) Anyone else have these problems?

[@kevink6420]

You’re dealing with 1.5 spindle hp I believe in that machine. What kind of material? Coolant or not? Edit, yeah get a new toolholder. I thought you were using a tapershank drill. If you’re pulling out at the holder either your chuck has a screwed up mount or your holder is messed up.

[@pcsmachineworks]

I used to have a similar situation, granted it was a much much larger machine. I have a horizontal boring mill that would spin mt6 chucks off of 50 taper tool holders. Cleanliness is the first rule, any oil residue and you'll have problems. Clean everything with acetone at the very least.. Secondly, I now put chucks on with a mild heat shrink. Chuck goes in oven set to 200 degrees and arbor goes in freezer. Hour later Quick slam them together and wack the end of the chuck with a dead blow to really seat it in. 200 degrees is well below any tampering temperatures of even the worst grades of steel and won't harm the chuck. A set of the proper wedges and a propane torch will still get things back apart if need be.

[@krolfson]

I also have had that happen with my 770M. I had to whack it several times so it wouldn’t come off.

[@SecondClassCitizen]

He may have answered this, and this question is coming from someone who doesn't even do machinist work. But why would you want to tab something like that?

[@mikefundy1815]

I would like to see use some toollox 44!

[@MKxpl]

i feel like you could have made three parts out of that stock

[@khotsokeyho5525]

Wish I had and know how to use cnc machines.

[@deemstyle]

Where's Johnny 5?

[@giuliobuccini208]

Is not the best idea to use a vise to clamp raw material to be "tabbed". Anyway, it is an interesting video.

[@bmbunch8825]

Should just slot mill the entire thing. No need to drill all those holes.

[@rickyracer8717]

Agreed! I machine a lot of acrylic and aluminium sheet. I have the material toe clamped at 20mm above the bed, supports in strategic places, and use the ramp feature in F360 to slot mill the entire part until it falls out the bottom onto the machine bed. Quicker, way less post processing and cleanup, and way few tool marks...

[@Sicktrickintuner]

@grimsoknives lol