-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
What size metric tap do you need?
Already got it and cleaned out the lead screw mounting block.
Thanks though
Steve
2 Likes
I have done everything to physically eliminate the backlash. ( The backlash problem is not actually backlash but slop in the way the lead screw mounts and the way the machine was designed. I have not been able to find a procedure for this so I did what logically seemed right and eliminated a very scarey loosening of the drive gear.) Currently, the Z axis is right on. However the X axis is about .020" off and the y is about ,005" off. I tried using a dial gauge to directly measure it and didnāt really get a reliable answer so I am working from a part I cut. There was a total of .040" difference in the X and .010" on the Y and I believe the backlash is actually half the error because it occurs in both directions. At least I think that is right. I have been using climb milling. I think it may be a more accurate cut if I use conventional milling. Not sure why that is but that is what I read and it may be worth a try. Rather than attempt to modify the mill I think it would be best to simply add the backlash in the EMC2 program and let the program add a correction.
Anyway, the mill is up and running and there are new end mills in the purple box. 1/2", 1/4" and 1/8" carbide end mills. I forgot to look at the collets to check the sizes but Iām sure there is a 1/4" and a 1/2" colletā¦ I think there is also a 5/8" collet. I have also donated a mechanical edge finder that fits in the 5/8".
Anyone who like to try their hand at milling, feel free. I have had success with 6061 Aluminum milling with the 1/2" at 2000 RPM ( or all the way up to 2200), 15 - 17 IPM ( I ramp it in at 15 and straight cut at 17) , depth per pass of .0625. Takes a bit of time but it works so Iām pretty happy. Also, the 1/4" bit 2000 RPM at 5 - 7.2 IPM depth of cut .0625. When I use a step over, I do 50%.
These are hopefully conservative numbers but Iām thinking this is not a production machine but a good training tool and really, the cuts Iām getting are darned impressive.
I do not plan to take the Emco down again anytime soon so other than work on the accuracy in the EMC2 program and develop feed, speed and depth for the 1/8" end mill, thatās all Iām planning to do. Well I suppose I will have a āHOW TO USEā session and try to allow as many people as possible to give it a try.
2 Likes
I was up there last night, and no 1/8" collet. I was going to use the 1/16" ball-end endmill instead in the 1/16" inch collet when I found out that the 1/16" mill is 1/8" shank. So, as far as I can tell, no way to do holes smaller than 1/4". There is a 1/4" ball-end mill in there, and Iām thinking I may use it to dimple where I need a smaller hole, and then drill it later. Any idea on when the collet set will come in (or be ordered, if it hasnāt gotten that far?)
I talked to Bryan on Monday via e-mail and he mentioned he was leaving town on Tuesday and wanted to order tools before he left. I assume he did that and several collets will be on here in a week or so. He mentioned that the CNC router uses the same collets but if you borrow one from there be SURE to clean it and definitely RETURN it. I am hoping to keep the two separate but if you just canāt wait, it is an option.
I havenāt ordered it het, Iām waiting on someone to tell me what size vise is needed.
OOPSā¦ SOrry Bryanā¦ I thought I had sent you an e-mail. The issue is clearance in the mill. The vices I see are tall by virtue of the rotating baseā¦ so I would actually use a 1755 4" without the base for most applications. https://littlemachineshop.com/products/product_category.php?category=1963256912
Dang it, you replied productively. I was gonna say, āAbout yay big.ā
Terrific! Thanks Bryan!
Ok Update. Thanks Bryan for the mill vice. It looks awesome and I cut the slot guides so they will fit on the Emco. Being Austrian, the slots are a little small for the standard t-nuts that comes with most kits and the guides were a little oversized out of the box.
A problem I have encountered that I need to mention. I could show you details but the bottom line is that the axis lead screws have a toothed gear on the end for the drive belt. This screws on to the lead screw and holds the bearing block against the mounting point and if it unscrews we get backlash. They use a set (grub) screw as a ājam nutā . I cleaned everything off and I saw that they had used something like Locktite to hold everything together. I didnāt want to over tighten the gear on the lead screw but that allowed for up to .008" of backlash. I retightened them as much as I dared and used blue locktite. If for some reason the manage to work loose Iāll have to use Red locktite.
I will be adding some changes to allow for a touch off plate to set the tool height. I have found a procedure and I will be adding this soon. I already prepared the hardware and I can read the Probe signal so all I need is the software change. This can be really useful since the tools will be at different heights every time we use them or break them. (It happens).
Anyway, it is up and running and the tests Iāve done are pretty nice for a small mill.
1 Like
Quick Update
Good news bad news. Got the Z touch off radio buttons installed in the EMC program. I also configured the hardware for Z axis touch.
Bad news, for some unexplained reason, the probe pin stopped working. I traced it back to the computer and I think it may be the Parallel board. I picked up a ānewā Parallel board and if that doesnāt work I still have one other option to solve this problem.
So good news is that we are still on track and the Emco is still working.
3 Likes
OOPS! Replaced the Parallel card in the computer and that seems to have solved the problem. I did not upgrade the driver as I really donāt know anything about Linux so Iām just going to keep my fingers crossed and hope it continues to work. It was working perfectly and I finished installing and configuring the software to include an X and Y axis Zero set radio button. It is just a convenient way to set both X and Y axis current location to zero. I also added the Z Axis Touch Off radio button and tested it several times. Iām Pretty happy with it but I think there is an occasional issue that Iām guessing is related to debounce. The short search Iāve done makes me think I guessed correctly. I have a probe pad ordered and it should arrive in a few days.
The OOPS part is this. I realized when I got home that someone might look at that radio button and think it is automatic and all you need to do is click it and it will touch the top of the workpiece. Nopeā¦ right now, if you activate it with a bit over a workpiece, it will drive the tool into the workpiece and only stop when it finally stalls damaging both the bit and workpiece. So for the moment, DONāT USE THE Z TOUCH OFF Button! I will disable it later but only just realize it is a potential issue. Otherwise, the Emco is working.
- strong text
**
2 Likes
I have been struggling with a very strange issue. Pin 15 of the parallel port appears to be driven by the computer. It should be an input but something happened that fried the new Parallel board I had just installed. I re-installed an old one which might also have its pin fried but everything else works. I cannot drive the pin high and it is definitely an issue coming from the computer. This is only an issue because I need one more output for the touch off sensor. I think I have figured out a way to free one of the other inputs but I will have to do a little rewiring, I checked the travel on the X and Y axis and I am still having very good results. .001" error in an 1" of travel.
I installed software for an Imperial Mill for inch dimensions. The original CNC mill software is still there but it is configured for Millimeters.( I have not installed the touch off button on the Metric software in case anyone was wondering about that. It is on my āto doā list). The reason was for measurements. The Metric software will accept and correctly translate Imperial movements except when G-Code is typed in manually, it still translates it as metric. So G0 X1 moves 1 mm instead of 1 Inch even when Iām viewing in Inches. Very annoying when you are attempting to determine backlash and movement in inches. All our dial indicators are imperial. Iāll transfer the information to the Metric software later. (Metric is a passing fad.)
A new and annoying issue has developed. For some reason, when I launch the Imperial software for the first time, it gives an error. Then it will work without complaint anytime afterwards until I restart the computer. This will probably take a Linux savvy person to solve. Honestly, I just canāt be bothered by this particular problem. Seems dumb!
Anyway, the suffering continues, seemingly without end, but thatās why I get paid the big bucksā¦ right?
2 Likes
That made me giggle. 
Youāre doing awesome work, in my opinion.
OOPS! I did it again. Sorry if I messed anyone up. I was working on the Emco today and made a pretty significant wiring change. I was working with the Imperial Mill program and have that correctly configured for the changes, but I didnāt change the Metric Mill program. I suspect it will refuse to run tonight because the home switches have been reassigned. I had put the changes off until later because I will have to transfer some numbers and I need to convert them from Inches to Millimeters.
On the plus side, I was able to free up two inputs and have tested one for the Z Touch Off. I am altering a touch off pad to work with the program and I believe this will save a lot of time and trouble.
I will reconfigure the Metric program tomorrow and I THINK, that will be it for any changes to the operation of the mill. At least I PLAN to leave it alone. There might still be some cleanup but it can be done at any time. So, progress has been made and the next and last piece of the puzzle will be to set up FeatureCAM with a profile for the Emco.
1 Like
Ok, Everything is working. I have reconfigured the Metric mill program, Added the Z axis touch off and so for the moment, I think I am finished with the physical part of the mill. Still to be done (in addition to reloading the ball bearings in the lead screw nuts and making a clear plastic door) is finding out why the display goes blank. It is powered by an Arduino and I suspect that it halts but I must admit I am not absolutely sure. Without apologizing, this IS a Frankenstein of a mill. I can only speculate it is a swinging ground or low voltage and while it is inconvenient, it is not essential to the operation. The safety of the Estop and the air control still work so I am not going to worry about that for now.
I will be happy to show anyone who wants to start using it how to operate the mill and use the Z axis touch off. Iād like to put together a formal operating class. Thereās not a lot to using the mill but the web site does say it requires training and there are a couple of gotchaās that should be mentionedā¦ and a few things that I believe should be ignored when they happen. Knowing which is which is a good thing.
So Iāll still be looking at it but I will also be looking at a few neglected projects I have on my plate.
I plan to start looking at FeatureCAM and see if it makes sense to set up a profile for the Emco.
1 Like
Need some input. I have installed a touch sensor in the Emco. It works perfectly. However, it has caused an unexpected problem. I had to wire the Home switches in Series to free up an input so all the Homes are connected together. I have noticed some noise in the X axis causing it to fail to home occasionally. So when āHome Allā is executed the Z axis homes first, then the X axis. When the X axis fails, the home process stops but the mill will not operate until all Axis have been homed. If the X axis home switch is still tripped it creates a situation that I cannot solve. Attempting to Home All a second time causes the Z axis to lower. The computer cannot differentiate between the switches so the Z axis will continue to lower until it hits something. It is easy to manually home the remaining axis but there is potential for stalling out the Z axis. So I could return it to the original wiring and remove the touch sensor or leave it as is and just let everyone know how to handle a failed to home situation. At some future date, we could install an additional parallel port and I believe that will allow more inputs for the system. I donāt have a clue how to do that in a Linux system so that is out of my hands. Any thoughts?
Thank you for all the hard work! I wish I had something to add. I would like to get some time on the machine to really grasp all the work youve put into it
1 Like
OK, The EMCO is down! It broke the X drive belt so I am in the process of tracking one down. It is not marked in a way the local rep can knows what it is, so I will take it over to see if they can find a match. This may take awhile. Anyway, while Iām at it and the EMCO is down anyway, Iām also looking at repacking the ball screw nuts. I ordered some ball bearings that should work. I can already tell, this is going to be hilarious in a very sick and mean way. I will be leaving town for a bit so it will probably be down all this week. Sorry, Iām sure it will be back up next week.
1 Like