Speeds, Feeds, and Strategies for Bench Top Mills

Great thread. Following with interest.

About your tool change you could command a x and y position after you command the z to go up, but before doing the tool change. Basically adding some lines like this (had this saved in a file, did not write this now. I'm not that skilled :) )

In the header:

double ToolChangeX = 10; //Tool change X position (all in machine coordinates)
double ToolChangeY = 2.5; //Tool change Y position
double ToolChangeZ = -.01; //Tool change Z position


Down in the macro file:

double XOriginalPos = exec.GetXmachpos(); // Get the current machine coordinates
double YOriginalPos = exec.GetYmachpos(); // Get the current machine coordinates
double ZOriginalPos = exec.GetZpos(); // Get the current machine coordinates

exec.Code ("G53 G00 Z" + ToolChangeZ); //Moves to tool change position
while (exec.IsMoving ()){}
exec.Wait (200);
exec.Code ("G53 G00 X" + ToolChangeX+ " Y" + ToolChangeY); //Moves to tool change position
while (exec.IsMoving ()){}
exec.Wait (200);

Quote:

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Originally Posted by metalmayhem

I can sort of relate to your frustration . I decided the other day to fire up my 3d printer after probably 2 yrs of no use . I have some 7x7x1.5 " control boxes to make . the first 2 came out warped but are useable I suppose . Getting prints to stick has been the bulk of my problem plus bad programs , and I'm days into it .
It's been so long since I've used it that I completely lost all my previous saved settings and it's like learning all over again . I've started so many worthless programs so far that it's ridiculous . I wish I knew everything about everything but I don't and this printing stuff is killing me

Today I fired it up to get it warm and within minutes I started to smell smoke . I know that smell and I knew it wasn't going to be good . I looked up and smoke was pouring out of the controller . It turns out I cooked the motherboard portion for the heat bed . The really stupid thing about it is there is a mosfet mod to prevent this issue from happening and I have it but never installed it . Afterwards I figured I had nothing to lose so I inserted the mosfet mod and sure enough I could see the temp working up towards the 60 degrees that it's set to , then it kept going to 65 70 80 and eventually up to 140 . Needless to say I've got a new mother board on the way for this turd

If I had the material on hand I could have machined a bunch of aluminum boxes in a fraction of the time I've spent with this . I think I remember why the printer was left on the side to be forgotten , except now I'm at the point of being in the pissed off determination mode

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Sometimes she goes, sometimes she doesn't. Lessons from the machine shop and The Trailer Park Boys. Over the years, I've learned to take a break when things aren't going well. I used to just get frustrated and break a bunch of extra stuff.

https://www.youtube.com/watch?v=3SpihGKmYgY

Quote:

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Originally Posted by Buoyen

Great thread. Following with interest.

About your tool change you could command a x and y position after you command the z to go up, but before doing the tool change. Basically adding some lines like this (had this saved in a file, did not write this now. I'm not that skilled :) )

In the header:

double ToolChangeX = 10; //Tool change X position (all in machine coordinates)
double ToolChangeY = 2.5; //Tool change Y position
double ToolChangeZ = -.01; //Tool change Z position


Down in the macro file:

double XOriginalPos = exec.GetXmachpos(); // Get the current machine coordinates
double YOriginalPos = exec.GetYmachpos(); // Get the current machine coordinates
double ZOriginalPos = exec.GetZpos(); // Get the current machine coordinates

exec.Code ("G53 G00 Z" + ToolChangeZ); //Moves to tool change position
while (exec.IsMoving ()){}
exec.Wait (200);
exec.Code ("G53 G00 X" + ToolChangeX+ " Y" + ToolChangeY); //Moves to tool change position
while (exec.IsMoving ()){}
exec.Wait (200);

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So I took loads of programming 20 years ago, but until now I've had little use for that knowledge and I am pretty useless at it now.

My m6 macro was actually given to me, and since it's been working great, I've been afraid to tinker with it. Fusion outputs a tool change position, so it works fine while machining. I generally use Park 1 for tool changes when I input them via MDI. I did not do that last night. It would be nice to have it handled in the m6 macro though, as it would certainly eliminate the type of crash I had last night.

Quote:

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Originally Posted by CL_MotoTech

Sometimes she goes, sometimes she doesn't. Lessons from the machine shop and The Trailer Park Boys. Over the years, I've learned to take a break when things aren't going well. I used to just get frustrated and break a bunch of extra stuff.
]

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lol yup , sometimes it's not worth trying to ride out the Sh#^ wind

Quote:

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Originally Posted by metalmayhem

lol yup , sometimes it's not worth trying to ride out the Sh#^ wind

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haha, my man!

I've almost gone down the 3d printer road a few times and I keep talking myself out of it. Aluminum and end mills might be more expensive, but I can usually create something that's totally useable on the first or second try. With a 3d printer I feel like I'd just be making stuff to mock things up and would end up machining it anyways. I always kind of thought a larger format printer would be cool for mould making, but from what I have read, I'd be better off with a router and a bunch of foam.

A friend of mine has a Mark Forge X3, he prints all sorts of brake ducts and other bits for his race car. That's pretty cool, but if I was dropping that kind of cash I'd buy a Mini Mill or maybe a used Brother VMC.

Rapid prototyping as I've seen them refereed to , I think not
I see it as a novelty item . A guy can design a one off that doesn't need to be tough , fire up the printer then walk away . At least thats the way it's supposed to work lol . I like it for making electrical stand offs and stuff like that .

Here's the damage and the new probe. Insane service from itpstyli. Not sure how to format their name...

Anyways, I ordered Wednesday and got the new probes Friday. I've always used them for probes, extremely affordable and excellent quality!

https://i.imgur.com/mHz34Mu.jpg

https://i.imgur.com/AOqqFA5.jpg

Drew makes an awesome probe for the price, but that ruby sure shines compared to the stock probe. I'm sure performance will be equal. The large tip diameters will help me out in certain scenarios.

Realistically, I need to dial my probe game in a bit. There are few fundamental mistakes I am making. I guess it helps that I am aware of them and can half arse them away in process.

Oh, and probably the best update. I ordered some 5 flute carbide end mills. Let's see how the old 0704 deals! F&Ss incoming! Hopefully I have the new mills Monday! I plan to shred on some stainless, I'm really looking forward to this. After years of aluminum it's fun to test these waters out. I need to clear my customer orders (daily type stuff) before I can get back to the fun though. I'll post some of my day to day machining work in the mean time. It's boring (heh) stuff, but it paid for my machine many times over. So I suppose it's worth a couple of photos.

Here is something I've always liked doing. Especially cutting aluminum. I use an end mill with a radius. Say .062". Set D.O.C. to .04"
Run max spindle speed and max feed that the machine will run. It's just a form of high feed milling.

For the core of my business I do shock work, especially so for vintage twin shock motorcycles. It's a semi long story, but I mostly fell into it.

The shocks generally have a rubber bushing, I touch probe the existing hole, then machine them to fit some spherical bearings. The pockets come out perfect, I machine them .002" over. The bearings go in by hand, with a slight interference fit. The snap ring slot tends to leave a slight burr, I clean that up with an exacto knife. The aluminum on these shocks is quite gummy, so it took some playing to get it right. I use a three flute bull nose end mill, but run rather slow as my fixture for the shocks isn't incredibly sturdy. Even still, it's about a 1 minute process to do the machining. I am going to add a slight chamfer to the opening soon, the ATC makes it easy. With manual tool changes I always avoided extra tools, but I'm working on rewriting a lot of my old programs around the improved system.

https://i.imgur.com/ZMPZxl3.jpeg

https://i.imgur.com/ZKtNljA.jpeg

Also, I haven't received the new end mills and chamfer mills. Today or tomorrow says the tracking. I am going to knock out as many shock orders as I can in the mean time. That said, looking at my CAM on the stainless fitting I should be able to get run times down to like 11 minutes per part with the new mills. I'm very excited. Hopefully my fixture is up to the challenge.

interesting market . Niche markets are tough to find these days but once a guy gets into one then it can get pretty good , and it often opens many other doors . Years ago I worked next to a shop that bought vintage jap bikes , rebuilt them and exported them to Japan . They ate up vintage bikes like America does with muscle cars . If I recall right they were all 350cc and under that they'd redo because Japan had a motor size limit

You should be able to haul with the 5 flutes , they'll be beefy and sturdy

A few more parts for customers.

These eyes come to me and I just bore them, slot them, then send them back. The spherical bearing adaptation is all mine though.

https://i.imgur.com/gI3ptqk.jpg

I got the 5 flute carbide today. I expect more fun stuff tomorrow.

I however have more customer shocks to work on. So I'll probably push them through before I setup for the stainless project again. Once i get through through these orders I'll be back to the fun stuff!

I make these bushings to adapt the 15mm ID bearings to 14mm mounts. I also do a 12mm and 10mm version of this. The 14mm one is a spot tricky on account of the .4mm wall thickness. These probably could be made faster on a lathe, but I don't own one... It's about 3 minutes per part. I'm sure I could push the machine a bit harder, but since I run 5 pieces per cycle and the tool changer does all the hard work, I just let it run. The interesting part is finding parts in the machine. Sometimes they get washed into the chip tray, sometimes they stay right on the table. There's nothing like an easter egg hunt in a pile of chips...

https://i.imgur.com/R3i1zsX.jpeg

I am back to fighting some odd gremlins, the machine has been really good so I can't complain too much.

The X-axis limit switch has started tripping randomly. When it trips, if I remove it from the axis it will deactivate. The switch also seems hyper sensitive, and it switches when not anywhere near the targets. I also changed the switch out by soldering a new switch on the cable, and the issue happened again. I was using $3 "Omron" proximity switches and while they have been pretty good for the price, but I decided to get something a bit nicer just to try and troubleshoot something that could be caused by these knockoff switches (despite years of good service from them).

So I have ordered and installed one of these Autonics switches. They are the same size as the Omron switches so I didn't have to modify my brackets or anything. Nice! I am going to give it a run and see if the issues return. If so, I will be replacing the lead next. Then after that? I'm hoping the issue goes away. It could be an EMI issue, I don't know. It's odd that the switch deactivates the second the switch leaves the machine. Bending and working the lead made no difference, I could not make it activate by doing that.

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

Onto the second issue. I am intermittently stalling my X axis again. I've loosened the gibs, the machine is getting a nice coat of way oil, I've lowered max velocity down to as low as 90ipm (I usually run it at 160ipm). Nothing has fixed it, the X just jams up. Sometimes I can run for four hours with no issue, other times it happens five times in 20 minutes. My guess is that the DB-9 plug is burning up again. Likely I will need to replace the controller side DB9 plug as well.

How accurate are those proximity sensors? I looked at the specs for a few and they were rated at 10% of the sensing distance. That's a pretty big variation.

X stall: Maybe there's a chip on your ball screw or in the nut? I had that happen once. Bad drive, bad motor, bad connection? I'm using the GX16 connectors on my machine. They are rated for 5A.

I measured the sensors a while back and forget what I found, but they've been pretty good. Getting the target right was the trick. Of course the new sensor I bought came with documentation that tell me how it should all work, including target size and distance from the sensor. I use one sensor per axis. The periodic failure of the sensors is probably the bigger deal, which is why I went to the more expensive name brand units this time around. It would be nice to not have to solder up new sensors every 3-6 months.

The ball nut could be dirty. I haven't greased them in probably a year or more. I am going to start with the DB9 plug first. I tried to find specs on DB9 amperage, I think I saw 5A as well, but the pins sure are small. If the plug looks clean, then I'll starting digging deeper. The X ball nut and screw is protected quite well, if I were to have contamination issues I'd expect it to be on Y. Even with decent way covers generally chips get through to that area. The drive is new as I blew up my last MX3660 a few months back, the motor is old. I suppose I could check the bearings on the motor. Some coolant almost certainly gets there occasional even with my motor cover. I should probably make a second cover for that motor.

Anybody know what size/model the AC bearing for X is with ArizonaVideo's kit?

I was working on the mill tonight and realized the exterior AC bearing is running without the seal. I am not sure when it departed... Either way I need to order a pair of those AC bearings and rebuild that end of the X ball screw.

I flushed the AC bearing with WD40 and was able to run it 200ipm. No stalls even if I leaned heavily on it, in fact I was unable to make it lose steps even at 200ipm. I'm hoping my random stall is just debris in the open bearing. The stall was rarely during cutting, usually during rapid before a tool change. The direction the table moves before tool change would load this AC bearing. Fingers crossed this is it.

I also removed the stepper cover for X. The stepper was covered in chips. So despite being covered plenty of chips are getting in the there, and where there are chips, there is coolant. I WD40'd up the bearings on the stepper. It's hard to to say if it made any difference, but I guess I feel better about it. I reworked the existing stepper cover so it fits tighter and is more secure, and I am going to bend up a new larger cover that will cover the existing cover/stepper. Hopefully with two covers the stepper will be high and dry even as the coolant rages on.

The mill has been humming along pretty nicely. I think that bearing issue has solved my random stalling for good. I am testing a new Y chip cover and will make an aluminum version of it soon as it seems to be a success. It covers the ways and the stepper at times. I'll grab some photos soon. I also am going to finish up my drawings on the new chip tray and chip evacuation system. I am going to put an auger in the chip tray and run it with my battery drill occasionally to pull chips out of the tray and then catch them in a bucket. Should be an improvement over the poorly thought out chip tray I have currenlty.

Additionally, I rode down to Precision Matthews yesterday. I had been looking at their lathes for a long time, but they are all sold out exception of some broken crate lathes. So I looked a few over. I decided to buy a PM-1127VF-LB Lathe that has some minor damage. The cross slide is broken, the chip guard is slightly bent. It only cost $1500 and it has the DRO's. That lathe retails for $3800. It looks perfectly fine asides from these minor issues, so I'm hoping it's not twisted up. The plan is to convert it to CNC, but I'll probably use it manually for a while.

I got the lathe picked up and am working on getting it on a bench.

It appears the cross slide isn't broken at all. One T bolt (not sure the proper name) is missing and the other was loose. So the cross slide was flopping all around. The handle however is broken off the quick change tool post and the rear guarding is a bit bent. Otherwise I can't find any damage asides from a few aesthetic things.

https://i.imgur.com/dToMQA9.jpg