Micro Router 2nd Hand

[Chucky5516]

Hi Guys,

Hope everyone and their families are well and safe from this dreaded pandemic. Just a quick one really, I am trying to get to grips with tool offsets. I get the concept, but do I have to set the tool offset EVERY time I make a new cut\project? This is what I have been doing, but I'm sure it's wrong as it seems quite time consuming having to set up the same cutters for every project.
Secondly, is there a way of getting a touch probe calibrated with VR Milling and the Denford Micro Router? If so, which one is best and how?

Thanks in advance for your help,

John

PS The device driver failing seems to have just vanished as quickly as it came. Part of me thinks it was down to the laptop becoming too hot, because where it used to be was in direct sunlight. As soon as I moved it and the weather got a little cooler it seemed to stop. However this is just a theory, with no scientific evidence behind it. I now have a new z axis micro\limit switch, just need to build up the courage to change it, as I still occasionally have the problem reoccurring of the z axis not homing properly.

[TDIPower]

Hi, funny I just watched a video which made me think of you, are you still looking at vacuum pumps? it turns out that these compressors are also vacuum pumps. Looking at the specs for the level of vacuum from the denford ones this would do the job as its stated output pressure equals the vacuum used.
https://www.amazon.co.uk/Compressor-Hai ... r=8-3&th=1

Here is a video about how they function https://www.youtube.com/watch?v=eEF-owkyI-o

And the confirmation that they are both vacuum and compressors in one https://www.nitto-kohki.eu/en/operating ... pumps.html

Anyway onto your other issue, tool offsets.

Provided you can always install the tool to the same depth in the collet then No, you don't need to do it every time, you can make an L shaped 'depth tool' so you sit the cutter on the lower part of the L and then use it to push the tool into the collet until the upper part touched a known point on the router housing. OR you can buy collars to go onto the shank of cutters so you always inset to that point. so you have to always mount the cutter in the collet to the same depth.

I believe you need to set tool 1 1st and then every tool after that and record them in the tool library can be set against that. Then I'm not 100% but you may need to set the Z zero for the job with tool one and then swap to which ever as required. I have never done it as tools get swapped between machines at work and often get broken or need replacing as they are used in the hand routers too. we always just lower to the material and set with the thickness of a bit of paper. If we are doing a load of work say in 18mm MDF then once it's done we can keep swapping out the job and not worry about the Z as it will be the same. however for some other materials they can vary from job to job so we need to set Z up for each bit. We try to avoid kids projects needing tool changes just to make life easier and speed up the process.

There is a section in the Help in Vr milling on the process, Click: Help > VR CNC Milling > CNC theory > Configuring Z tool length offsets.

Pete

[Chucky5516]

Hi,

Me again. I'm still having issues with the Z axis. It often doesn't home correctly as previously mentioned, but even after setting tool\work offsets correctly it will sometimes cut too deep\too shallow? Is this all linked to the faulty micro switch?

I have bought a replacement micro switch, but it isn't 'screw' terminals as on the original which has now been discontinued, but is 'quick connectors' meaning I would have to cut and strip back the wires before crimping on some connectors, which not being knowledgeable about electrics I have been putting off. It has now reached a point where I need to bite the bullet, as only today a small engraving bit got broke by it: 1. Ploughing into the timber even after setting everything correctly, and then, 2. When emergency stopping and homing the machine to stop this deep cut, it didn't home correctly and instead dragged the bit across the wood, breaking the bit in the process, when it should have just homed correctly.

I suppose the reason I am writing this is because, do you think all these issues are linked to the faulty micro switch or is there something else going on too? I shouldn't be having to set the tool offsets EVERY single time I do a job, because I made a jig as you recommended to set the correct depth in the collet with each tool every time, so the tool offsets shouldn't change, only the work ones. Even before this I was setting the tool offsets for every single job individually, every single time, and I still had these issues of inconsistency with depth of cut\homing correctly. Yet no matter how thorough I am, the machine can be sporadic about it's depth of cut, which tells me something is off on the Z axis, as other than this there are no other issues.

I'm a novice so just need some advice on what to do, as the set up of job, and inconsistency of the machine is costing material, mental health, and time, and now router bits\end-mills. It's making a pleasurable hobby, extremely frustrating, and the annoying thing is I feel it isn't anything major! It's just I don't have the knowledge to confidently diagnose the issue. Help, any help at all, would be greatly appreciated, as the amount of people doing help videos\blogs for Denford or VR Milling problems (apart from here) is minuscule.

As an aside, is there any way of connecting\wiring a tool such as this, or is there one out there and compatible, not necessarily this one just showing an example, to a Denford machine, without having to change to Mach 3? https://ooznest.co.uk/product/ooznest-xyz-touch-probe/
Or are there any other alternatives?

Thanks in advance for your reply, as always its much appreciated. Hope you and your family are safe and well in these strange times!!

All the best.

[TDIPower]

The micro switches are only used when you power the machine and have to home it, if they go faulty you find the machine will continue to try and travel even when it hits its travel limit.
You are correct you can't get the screw switches anymore, but once you have converted from the ring terminals to the spade type it will be easier to replace when they fail in the future. (dust ingress is the problem i believe)

I wonder if your machine is 'loosing steps' what this means is the travel is binding up due to dust normally in the lead screw nuts, so when the stepper tries to drive it only gets a set number of pulses to move 1mm, now if due to to much resistance it didn't move on one of those steps it will loose position. you can normally hear it when it is traveling a sort of stutter in its normal sound.

Z axis is a bit of a pig to clean out so I will explain how to do the front on one the X axis as its easy to get to, you will then be able to do that one and get a better idea of how to do the others.

with the machine homed open the door
look at the lead screw right in front of you
where it enters the 'gantry' there is a triangular 'nut' held in place with 3 allen screws.
Put a dab of tipex so you can see it lines up when re fitting.
Undo the 3 allen screws and wind the nut out of the gantry, it will travel along the lead screw as you turn it.
This is just a plastic nut, a spring to keep pressure on a red bit of plastic (keeps the nut tight on the lead screw). This is probably full of dust and crap.
it needs cleaning out.
Once done wind it back in to the gantry and refit the allen screws.

That's the easy one... good luck with the others!!!!

Once you have done that lube all the lead screws and bars with silicone lube let it dry then traverse so you can get the areas you missed.

Now you know where all the dust gets you will make sure you keep it clean, you don't really want to have to fully strip on of these, it took me ages to work it all out

Pete

[TDIPower]

Zero tool,

I would get
a feeler gauge https://www.screwfix.com/p/hilka-pro-cr ... auge/4406r
a 9v battery,
3 bits of wire
a 12v bulb or 12v led
some crocodile clips.

now wire as follows

Make up the 3 wires with a croc clip on each end. wires A, B, C,

wire A, one clip on the cutter, other end to battery +
wire B, one clip to battery - other clip to one side of bulb
wire C, one clip to other side of bulb, other side to which ever thickness feeler gauge you have selected to use say 0.5mm

Now when you touch the feeler gauge to the cutter the light will come on.

when you come to zero the machine you can step the the cutter in 0.01mm steps until the light comes on and you know you cutter is 0.5mm away from the job and you can account for that in offsets.

You can do much better jobs of what i have described, I kept it as simple as I could as you had already said you are a bit worried about swapping the microswitch.

Pete

[Chucky5516]

The micro switches are only used when you power the machine and have to home it, if they go faulty you find the machine will continue to try and travel even when it hits its travel limit.

I'm not having this issue. Sometimes when I home the machine, the machine moves up to home on the z axis, but doesn't complete, it just goes half way up, and the bolt doesn't even touch the switch. Yet on the computer it is showing as Z 0. This can happen even after the machines cycle\jogging was started from the 'correct' home position.
Other times when you hit home, the machine starts micro stepping downwards and I have to stop the machine, do the secret home button thing, and jog it into the correct position before trying again.
Other times you hit the home button and it just barely moves, before 'homing', but again the bolt hasn't contacted with the switch??
Then sometimes it works correctly. It all just seems a bit random. Almost as if the machine isn't getting a consistent signal.

I'll change the switch today and give it a clean, but if you can think of anything else to try or it could be then that would be great. If what you are saying about the micro switches

and if they go faulty you find the machine will continue to try and travel even when it hits its travel limit.

then the micro switch doesn't sound like it is the correct problem, as this has never happened.

[TDIPower]

It sounds like a bit of both, faulty switch and dirty/binding drive

If the machine does a proper home and then lowers Z down for machining but misses steps on the return due to the weight of the router and binding lead screw then it won't return to the true zero point, the control will have sent the correct number of step pulses BUT its not been able to move on some of them because it's stuck or binding hence it stops short on the return.

the issues with the the motor creeping either towards or away from the zero point when homing is faulty zero switch. the way it works is the unit travels until it hits the switch, it stops then creeps away waiting for the switch to change state (either open or close) at that point it knows it's home. So if the switch is stuck internally either open or closed it will do this as soon as you hit home.

Pete

[Chucky5516]

Thank you. I undid the triangular thread on the Z axis today, and as predicted it was pretty filthy. I cleaned the Y and X axis a while ago and I checked those today and they were still clean. So it must take a while to build up all that muck that was on the spring and plastic cap today.
I am having trouble finding a replacement switch with the right size, mounting holes, and most importantly connectors. A lot of the 'quick connectors' have huge\large connector points underneath which, given where the Z axis switch is, prove to be in the way unless bent 90 degrees, which as I found today can cause weakening of the connector and breakage. Do you have any suggestions of what would be a good fit for the Z axis micro switch? If you do great, if not I'll carry on looking myself.

[TDIPower]

the original screw connection and no longer made, they have all swapped on to 'spade' terminals. I had one in it's packet on my desk when lock down started and for the life of me i cant find it! I'm 99% this is the unit. We had one fail at work on a machine when a kid was doing his GCSE so I ended up bringing the material home and machining it on mine! We ordered in a few spares, as we don't want to be in that situation again.

https://cpc.farnell.com/multicomp-pro/m ... o%20switch

One option you could have is to solder extensions to the switch tabs so you done need to bend them and then put a connector between the extension and the machine loom.


Pete

[Suggy]

Im waiting foe there to turn up

https://www.ebay.co.uk/itm/V3-Microswit ... 2749.l2649

[Chucky5516]

Hi Everyone,

Quick update and another cry for help. I have changed the micro switch on the Z axis and it seems to have done the job, so thank you for your help with that previous issue.

The ONLY problem I am now having with the machine is this 'device driver call failed' error and the connection dropping out. I then turn the machine off for 20 seconds, turn it back on, reset the software (VR Milling Ver 5) and then try again, only for it to play up again.
Sometimes the machine will work for several hours before it starts doing this, sometimes it starts as soon as the machine is on. There seems no routine to it. It happens WITHOUT the spindle running, it happens sometimes WITH the spindle running. I have tried plugging the USB direct from the card to the computer, this hasn't worked. I've adjusted the 'power save' settings on the laptop I'm using to stop any power drop outs or the USB ports disabling.

The problem I have is I'm very inexperienced in electronics, and understand the basics of CNC eg; drawing and executing a project, and also know my way around a computer, but I'm not experienced in electronics eg; regulators, grounding, earthing, wiring etc etc etc

I've read it could be a number of things. From electrical\static interference, right through to the regulator over heating. This is becoming a massive issue for me, and incredibly disruptive as I use the machine for work (woodworking). The shame is, apart from this one issue, the machine is in excellent condition, both cosmetically and as far as I can tell functionally too. It's a cracking machine in good condition compared to some I see advertised second hand. If I could just get this diagnosed and sorted I'd have an excellent little machine, an ideal size for my needs.

Does anyone know what else I could try? How I could go about trying to diagnose it more specifically? Anyone I could get in to fix it\diagnose the problem? Is an electrician suitable or would they not have a clue? Would Denford help? I know it's a second hand machine but I purchased the licence for the software directly through them?

I feel it's only a small issue, but it's diagnosing it and getting to the bottom of what is causing it. I hope it's not a deal breaker, but I need to get it sorted asap. ANY help would be much appreciated. Thank you so much in advance.

[TDIPower]

Hi, I just typed up a long response then realised i had put it all done in my previous posts.

Denford are a company, pay em and they would sort it, but it's megga money for control boards. They do come on here and from looking at the post about this problem that was linked they have gone through all the possibilities in there.

A general electrician would be clueless, for this kind of thing you need someone who is experienced in electronics, has a kind heart and time who is willing to work out the issue. This might be the reason why the machine was sold on.

The only thing I can think is that if you have tried
New cable
Different USB port,
Different computer
when you get the error are you getting the USB disconnect sound from the PC.
If so then it would go back to a possible powersupply issue and you need to know what you are doing with a meter and or an oscilloscope for that.

Where are you?

[Chucky5516]

Sorry for the (very) late response to your post, I have been very busy recently and had a period of illness.

I am based in North Herefordshire (about 40 miles from Birmingham\26 miles from Worcester).

I have used the CNC a fair few times recently and only had the problem once. However, I have been getting in the habit of disconnecting\turning the machine when not in use, between jobs or when setting up new work pieces\cutters. I don't know if there is an over heating problem my thinking is this would allow it to cool down a bit, instead of leaving it constantly running. The cooler weather may also have helped?? I did a job that took over 50 minutes to machine the other day, with no issues at all, so I'm really not sure what the issue is. I wish I could find out and sort it, as it is the one thing that is stopping me having confidence in the machine.
When I am machining a job, instead of leaving the machine to do it's thing while I work on other stuff, I constantly feel I have to watch it as I don't trust it\have confidence that it won't cut out.
I really need to get to the bottom of it, and any help would be great. Could trying a new laptop help? I have changed all the power settings as recommended and don't have other issues with the laptop but I'm just clutching at straws as it's the only laptop\computer I have used with the machine?
It is such a shame as the machine is in such good nick cosmetically and functionally, apart from THIS ONE issue!!! It's frustrating, and although it hasn't done it recently, I'm not convinced the problem has just vanished. What would be my next step regarding this, and could it be an element overheating on the board, and could that element be replaced easily??

Thanks again, hope you and your families are well.

John

[Chucky5516]

PS When I get the error message I don't thing I get the disconnect 'sound' from the computer. I'm not 100% on that, but pretty sure.

[Steve]

Try running a shorter USB cable say 1M or less, If you can get one with ferrite suppressors this would help.

I would also ensure that you make sure the power settings on the PC are not allowing the USB port to shutdown for power saving.

Device driver call fail occurs when the USB communication handshaking does not occur. electrical noise and static can be a cause. Running a vacuum to clean the machine causes static discharges created by the dust travelling down the hose also noise generated by spindle motor brushes can cause this but you have stated it happens regardless of the spindle running or not.

[Chucky5516]

Where would I get a USB cable with ferrite suppressors? My issue with a cable less than 1 metre is because I am going direct into the board inside the 'black box' with my USB cable, by the time the cable has travelled through the black box and out you would then be left with hardly any slack to fit to the laptop. (unless my laptop can float in mid air!!!) When I originally bought the machine, the USB connection coming out of the black box was only sticking out about 3-5 cm, so there was no way of connecting it to the laptop without an extension of some kind or the laptop levitating!
I will google the ferrite suppressors and I have checked the power saving for the USB ports on the PC and altered accordingly.
As a side note, if it wasn't any of these things, cable\static etc, is there anything more serious it could be? Could it be caused by a component on the control board over heating?
I read somewhere on here, something about the 'regulator' over heating and causing the board to drop out momentarily causing disconnection and this error, also about a possible momentary drop in voltage causing the same issue?
I've looked for answers on here, but apart from cable, power settings, static etc, the rest I don't know enough about to understand properly. It would be handy to have it explained in layman's terms if you know what I mean!
Apologies if anything I say is moronic, but I am quite tech savvy when it comes to computing, and understand the basic principles of CNC and what the components are and how they interact, but am not electronically or mechanically knowledgeable at all.
Thank you for your patience and help with this. The way this is going, one day we will be able to co-author a book or thesis on "device driver call failed" and the pit falls of your first CNC!!!

[Chucky5516]

https://www.amazon.co.uk/product-review ... ll_reviews

Would this cable be ok? It says it protects from 'electrical noise', most people in the reviews seem to be using it for radio transmitter work or for audio uses, would it be suitable for this? The cable I'm using at the moment is my 10 year old printer cable!!!

[TDIPower]

Hi, hope you on the better side of ill!! The cable indicated looks like the sort of thing you could try.
Static caused by extraction is an issue, we have the metal cased 'henry' work shop heppa vacs on our routers in work, we have seen it arc between the lower and upper body over the runner seal which is about 1.5". I added earth bonding between the lower and upper cases to stop this. This is why proper extraction tubes are metal with only short runs of flexible.
Couldn't hurt to try another PC on it, you could even try running it from RS232 if you have a PC with an RS232 port (not likely on a laptop) they are on pretty much all proper PCs, the connector might not be on the rear case but you can get a cable to go from the mother board to a rear panel connector.
Some of our machines run RS232 and some USB and I can't say I have seen a difference in performance of the routers/mill.

You are a bit of a distance away. Had you been a closer it would have been an excuse for a run out on the bike to have a look.

Just thinking a few things you could check (clutching at straws),

Pop the tops off you mains plugs and make sure all the terminals are nice and tight (obviously can't if moulded plugs) old leads/plugs can work loose on the screws. That includes extension leads,

Steve is a man who would know more than me on these machines.

Pete

[Chucky5516]

Thank you so much for your kind reply. I'll try all these things and get back to you. I have done the power settings on the PC. That was my first port of call. It's just frustrating because it's such a nice machine in great condition, and is working really well. If I could iron this out, it would be perfect. It's frustrating because it's one of those things that could be a number of issues and eliminating them all is tedious. Just when you think you have cracked it, BAM! it comes back!!! I don't think\hope it's not a 'major' problem that would be hugely expensive\difficult\time consuming to fix, just something annoyingly finicky.
Thanks for your concern too. I'm definitely on the 'other side' of ill now, but for 2 weeks I wasn't great. It wasn't Covid as got tested, but just a really nasty chesty\achy cold\man flu, which as I'm sure your aware is the worst type of cold\flu.
Hope you are well. Stay safe, and thanks again for all the advice.

[Martin]

Have you checked the power saving settings on the computer?

https://www.denfordata.com/bb/viewtopic.php?f=9&t=3365