New Build 1000x600x200mm (newbie)

[routercnc]

I tighten belts by making sure I can just about twist (by hand) the bit of belt run furthest from any pulley by about 90 degrees. I know this is also subjective but it should get you somewhere close

[Noplace]

Hey again, yesterday I was finally able to test cutting aluminum after getting the t-slot table and fixing it in the frame. I need as much guidance and advise as you could provide me since I had several issues.

I was spraying the bit with WD40 as well as having the mist coolant system spraying water and air ( but the water/oil valve was off so only air ) and I did that to get the chips to clear since I was milling a hole, however it was far from ideal and although had chips flying in direction of air still had plenty not moving out of the hole, I did a slight adjustment to direction and angle of nozzle and helped a bit but I didn't want to just keep doing that.

second issue was that the chips that flu were flying onto my long axis rail and a bit on the ballscrew which was behind it, wasnt an issue now but it will definetly be one, I held on purchasing dust covers because the supplier i found asked for a high price, appreciate if anyone can point me to low cost solution on this part

third issue is that the piece was a bit hot to touch, so I guess I failed of having the heat transferred to chips instead of the part/stock, appreciate if anyone can guide me on proper oil/water/air combo for lubricating and cooling during milling aluminium.

spindle was around 7500RPM feed rate 150mm/sec (taking it real slow to be cautious) however I read somewhere that aluminium needs a bit higher feed rate so to not stick, but not sure about that, your help here is again appreciated.

cutting tool was 4flute 8mm HSS, test was milling a circle with 23mm radius and 20mm depth, my stock was just a scrap and it needed facing on all sides like no body's business, but this was just a test and wasn't worried about it being a bit tilted and not reach all the way through ( you can figure by the photo and the small cylinder piece left at the center)

I still am not sure how parallel my spindle is to my table and how much error is there when I move it length/side wise but it seems decent enough for now as I'm way below the level of making precise parts. will definitely be asking for tips on this as well but I also know that due to quality of parts and my labor it wont go beyond a certain level of accuracy and precision.




here are some photos, am sure you will laugh when looking at the back side photo but I will try to make it tidier hehe, also am a bit sad about having to put the vise horizontally as opposed to the standard way but thats because I opted for bigger/lengthier t-slot table for mounting large wood stock as opposed to having a a smaller t-slot table but horizontal slots instead of vertical. it is bothering to turn the vise but it's a small issue no big deal.

[Clive S]

It looks like you have done a profile cut to make the hole A pocket would have been better to have the hole cleared.
You don't say how many flutes the cutter has etc.

[Noplace]

It looks like you have done a profile cut to make the hole A pocket would have been better to have the hole cleared.
You don't say how many flutes the cutter has etc.

Sorry updated the original post, it was a 4 flute cutter. I just used an online g-code generator to generate cutting a hole, it goes down 3mm depth at a time and makes it a circle path. I'm already using hsmexpress so I'll do the toolpath on that next time and see.

[Clive S]

Sorry updated the original post, it was a 4 flute cutter. I just used an online g-code generator to generate cutting a hole, it goes down 3mm depth at a time and makes it a circle path. I'm already using hsmexpress so I'll do the toolpath on that next time and see.

Try a two flute cutter at about 14K with a pocket tool path

[JAZZCNC]

Hi Khalid,

Nice to see it working. 4 flute cutters are no good for aluminium because has you found out you can't remove chips fast enough so they get re-cut chips causeing cutter heating of material and tool. Your very lucky you didn't go into melt down and Gum up the cutter with those feeds/speeds.

My standard setup is to use 3 flute Carbide Ripping cutters for roughing leaving 0.35mm wall material cutting approx 40-50% Dia DOC and feed rate between 900 -1600mm/min. Spindle speed 14000-24000rpm all depending on material grade and how big a hurry I'm in.

I Finish with a Full depth pass using single flute HSS to remove the 0.35mm material. Any where between 9000-12000rpm and feedrate 600-900mm/min.

When cutting Aluminium there is NO one cutter or feedrate/DOC etc suits all and each grade of material cuts different, infact the same grade can differ from batch to batch. Lower grades also have hard and soft spots which can catch you out if cutting parameters are close to max'd out.

So for this reason you'll find your constantly tweaking with settings to suit your machine and material being used at the time.
In all cases you need at least blown air cooling to clear chips and ideally you want some form of coolant, mist, odourless mist or flood all work good.

Another tip is don't use cutters any wider than 8mm if slot cutting at any depth has the cutting forces increase hugely and stress the spindle/machine. Wide cutters are good for shallow surfacing or deep edge milling with lower step over. Just avoid deep slot milling with them.

[Noplace]

new issue with auto tool height, any insight is highly appreciated

I’m using C35 http://cnc4pc.com/Tech_Docs/C35R1_2_user_manual.pdf to control my machine and everything works great, trying to setup auto tool height but there is a problem with the wiring. I tried wiring port 15 and ground pin as the two points for my tool height accessory and there is nothing wrong with it until I hook the thing to the tool/spindle. the issue is that my spindle is grounded to the backpanel of all electronics and that in turn goes back to the earth wire in the electrical socket. never had an issue until the auto tool height wires touch each other while also hooked to the endmill/spindle, when they touch suddenly the unit gives an error and stops working until I re connect to the PC and restart mach3.

so in short, if the C35 port 15, ground port and my ground point all connect Mach3 will pop an error that the motion controller is disconnected.
I also saw very tiny sparks when I made the plate touch the spindle and the wire with hook.

have I made a grave error by putting my VFD in the electronics enclosure which in turn made the spindle ground connect to it and in turn made my whole machine the ground point?