I am finishing setting up my Journeyman and onto drilling holes into my spoilboard. I have two sizes: 3/4" for the dogs and 3/8" for the screw inserts.
The problem is when I create the gcode from F360, it says that the manufacturing operation will take 12 minutes to complete; however, in 1F, it says 3.5 hrs.
Looking at the feed/revolution in F360 it says 0.00537037 in for a 1/4" flat end-mill and 0.00296296 in for a 1/8" flat end-mill.
This seems excessively long to me, but has anyone else done this that could share their experience?
The feed rate is 290ipm already. Correct my understanding, but isnt the vertical step down determined by a 2 degee ramp ona flat end mill? Are there other bits better suited for this purpose?
Both my Amana and my SpeTools bits are about the same speed. In fact, i think the Amana is slower.
I see a lot of people out there with wateboards that have inserts and dog holes. Are they all done by drills instead of by a CNC?
The hope was to gain accuracy by using the 1F so that the wasteboard and the base board (where the inserts go) are in alignment. Then, all i have to do is mill out another wasteboard and it all works without issue. Am i dreaming here?
I know in Vectric the “preferred” way to do holes is to use a profile cut with a spiral ramp (using an upcut end mill of course). This gets you a hole in a single motion in place of a pecking motion which takes forever. I know nothing about F360 and the options to drill a hole, but thought the methods may be of help.
Hmmmm…maybe i should look at V-Carve and see how it behaves. Perhaps it is the gcode that F360 generates where the problem lies. Good idea!
I am using a spiral bore operation in F360 with a flat end mill and the ramp is 2 degrees (as per the bit manufacturers). I am not doing a peck operation since these holes are more than double the diameter of the bit.
I am half crocked to throw in a drill bit, put the router on the lowest speed and see how it goes. Then, clean up the holes with an end mill.
I just wanted to try to do things the “CNC way”, but hole drilling seems to be problematic.
You said your IPM is 290ipm. I assume that is horizontal. What’s your vertical IPM? That’s what governs you hole boring.
Also, Look in the tab with the ramp settings. How high are you starting above the hole? Spiraling down at a slow IPM vertical will take forever when doing lots of holes.
If your heights tab is set for the stock top and you have already flattened it, that’s an even farther, slow spiral until the bit gets to the start of cutting the hole.
Slow vertical moves multiplied by a large number of holes takes a lot of time. Finding the minimum vertical above the bore will take hours off a new wasteboard run.
Yeah, sorry about that, I was going off of memory of the feed rates. That was horizontal. The vertical plunge rates are 1/4" = 96.66 IPM and the 1/8" is 53.33 IPM on the SpeTools bits and on the Amana 46102-K (which is a plunge bit) is only 30 IPM.
F360 also has a Ramp Feedrate, which are currently the same as the plunge rates.
I have not flattened my wasteboard, in fact, this is actually the mount board (table top equivalent). The wasteboard is on top of this, which is another set of holes that need to be drilled.
So then 3.5 hours is not unreasonable to do a wasteboard with 175 holes at 18mm depth?
Did a quick check on my quarter panel wasteboard. To do 36 screw holes is a 00:01:01 in fusion 360*. When I go to the passes tab and click on ”use ramp angle” It grows to 00:02:49…which is nearly three times as long.
I can see the CAM blue cutting lines go from a nice spiral to a nearly complete cylinder of blue because the gap between each turn is tiny.
Consider boring a few holes without ramping. I use an IR thermometer to see how hot my bits get. If you have one check the temperature rise with and without ramp on a couple of holes. From my experience across a bunch of different cut types, I get a 2-4 degree rise when I have the feeds n speeds as well as the cut geometry (ie, ramp / no ramp) correct. When i am too conservative on feeds n speeds or off in geometry, I get a 5-10 degree rise in bit over the stock temperature.
*I cite fusion cut times because different configs on the 1F lead to different times on the same file. For instance, lots of complicated 3 d cuts would take 10x what F360 reportd. I upped my jerk rate, and cut times dropped by about a third. Still way more than what F360 reports but not the seemingly unreasonable time growth from before
Hahaha…You’re going to laugh…here is what I ended up doing.
I took a plain ol router 1/4" straight 2 flute bit from a set of bits I had for years lying around from Harbor Freight. I figured if I am going to break one, might as well try on a cheap one first.
I first ran a straight plunge the full depth at 13.24 IPM. I noticed a bit of a smell on some of the holes, so I changed over to a 0.125 peck depth (so, 6 pecks per hole) and was able to drill out 5 holes in about 1 minute.
I don’t have a IR thermometer, but I did touch the bit after the 5th hole and it seem slightly warm, but not hot.
All this trying to be careful with the specs from the Amana and SpeTools and the cheap ol Harbor Freight bits worked wonders. I didn’t even have to ramp down or use a spiral bit. Go figure.
Then, clean up the holes with an end mill.