Denford Software & Machines

Its ok I know the machine you have. You can use a vacuum cleaner, if the bed you get has the ball valve and a big rubber thing to stick in the vac you will need to take those off and bung up the hole in the metal plate on the bed (easy to do I had to). That rubber bit and valve use standard fittings so you can then just get adapters to fit the valve on your machine.

The thing with that is the vac is noisy, what you can do is if you use a vac for extraction on the machine T off it so some vacuum goes to the bed some to extraction.

The best option is to pick up a vacuum pump, a lot less noise and use a lot less power. I'm in the garage tomorrow and can take a pic of the pump motor I have (can find the specs), it is the same as fitted to the generation after your machine, I picked up one on ebay for £20-30 second hand.

Pete

Have now bought the vacuum table as was only £25, ex display model, and as they are discontinued it is hard to know when they will come up again so at that price it seemed a no brainer.
I would be really interested on advice for a suitable, affordable, vacuum pump and more info on how to connect it to my machine. Is it true you can use 6mm MDF on top of the vacuum table as 'insurance' and it is still strong enough to hold work pieces because of the porous nature of MDF?

Thank you so much for all your help, you have been immensely helpful, and are making this first foray into CNC much more enjoyable, and a lot less frustrating.

I've tried the 6mm MDF it does work but I still prefer to use doublesided tape to hold on the sacrificial bed.
It all depends on what you are going to be machining, softwoods, MDF, modeling foam etc provided they are flat on the base ok on the 6mm and some double tape.
If you need to do anything in hard wood or aluminium you need to be fixing a bed to the side rails, double sided tape and screws if possible. Rigidity is key on the harder stuff.
For rapid prototyping in 50mm thick model foam I have reground new drill bits either flat or ball nose so i could cut at the full 50mm depth on roughing cuts.

Good price on the bed I think I paid about £40 for mine. The valve and vacuum point are mounted in a small metal plate (it's just a nut on the inside), this is just hot glued to the MDF frame. You just need to get the plate off, remove the valve and glue it back in place. The hole, I fitted a plastic bung with a little sealant. (it's the same as on the ones that came with the machines).
Check the pipe from the bed of the machine to the valve on the side is clear, drop the vacuum bed over the top of the hole in the bed, pretty much anywhere, hook up what ever you finally get to use a pump (the denford one is about as loud as a fridge motor) and turn on. place your work on top, square it up and then press down (just make sure the bed will seal on the vacuum sections) I have a strip of acrylic 60mm wide I place between the inside edge of the X frame and the Job as I know the distance to the cutter center from the frame is 60mm at full travel.

I knew I had forgotten to do something in the garage yesterday, Ill go in tomorrow and get the specs on the pump, I've been teaching myself to Tig aluminium so I can crack on rebuilding my Landrover.

A quick tip, once you have zeroed the job, load up your code and click on the inspection (i) letter i in a circle (along the bottom bar), this will do a check on the travels to make sure the machine can do the travel need from your zero point. Nothing worse than on a 20,000 line code getting an hour into it that 'travel exceeds limit line 12,123' popping up and the machine stopping all because you were 0.02mm over on the travel at that point!

Pete

Some pics of the bed and the pump. If you look up the specs and try and get something along the same lines. The white plastic section on the pump houses a foam filter.

Thanks for your help so far. I tried looking for that vacuum pump on eBay, but most are based in America. The price of them is reasonable, but then they want $150 of shipping and import tax, making the price ridiculously inflated. I don't know a lot about vacuum pumps, so not sure what alternatives would be suitable or not? Do you have any other suggestions?

Also, the light in the cabinet, the PVC cover strip on mine is very discoloured causing the light to be very dim. I would like to replace it, but don't know what I am looking for, what the technical name would be?? I have tried searching and found similar items, but as I am not 100% sure if the item I am looking at online is correct, I am reluctant to purchase. I just wondered if you knew what the replacement part would be called?

These might be stupid questions, but its nice to have a second, more experienced, opinion. It helps me to approach things more confidently, and sometimes validates my thinking.

Hope you are well and safe.

I don't know the cover but you could try using some toothpaste and water on a soft cloth or paper towel to polish it to see if the discolouration can be cleaned up. It's what I use to clean the rear plastic window in a convertible top and the plastic head lamp covers on my VW Passat. Cheap, quick to try and most people have toothpaste in the house.

it looks like on the diagram the Work light picks up from the 24v PSU on the machine, you could look at getting a replacement light LED or similar, mine has done the same and I intend to get a roll of the LEDs from eBay when i get round to it. Something like this stuff, you would pay about £10 for 5m on ebay.
https://www.led-lighthouse.co.uk/led-st ... rproof-24v

Or you could just remove the existing light and fit something like this with a mains feed to it
https://www.toolstation.com/sylvania-ls ... ube/p12109

On the vacuum front, you just need to find something that will pull around the 9in Hg,

I found 2 on Amazon, this is mains powered, it looks to have open driven pistons on each side of the motor, so it would want boxing in.
https://www.amazon.co.uk/dp/B07Q8RF9WL/ ... s9dHJ1ZQ==

Or this 12v one which would need a power supply
https://www.amazon.co.uk/120kpa-Negativ ... KPQG8NSEXB

As to how good they are or how long they would last.... But stay clear of oiled ones as when they pull vacuum the oil vaporises and coats everything!

Pete

New day, new problems!!!!!

I was using a borrowed laptop to run my VR Milling software from. I eventually bought the laptop from my friend and took the laptop back to factory settings, and reinstalled everything (as if it were brand new). I reinstalled my VR Milling software, and the device drivers.

Now, after turning the machine on and connecting to VR Milling, the machine randomly drops connection with the laptop, with the message "Device Driver Call Failed"
It does this at random times. You can home the machine, jog the machine, even start machining, but then it will drop connection at various points. Sometimes after 5 minutes, sometimes after 20 minutes, which is infuriating.

It never did this before I factory reset the laptop. I have changed the power saving settings on the laptop, including for the USB port as recommended by Denford, and it is still doing it. I am connecting to the machine via a USB extension cable, as the one coming out of the black box is way too short.
I am at a loss as what to do??? Why has this suddenly started happening? I am desperate, as I have a few jobs that need finishing asap.

Thank you in advance for your help.

John

You might want to try a different USB lead, IIRC it was someone else here on the BB that had USB comms issues occasionally and it turned out to be a duff lead.

there is also a post from denford about usb dropping out due to powersaving on computers they do say what setting to change. I had it happen to me 2hrs into some machining. I couldn't remember what it had said to change so went into the power setting and told it never to sleep or power save.


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


Pete

Hi Guys,

Thanks for your quick replies as always. Tried replacing the USB cable today, and still causing problems. Reinstalled the VR Milling software from scratch, and still dropping out. It's really strange, as it was working perfectly until yesterday???? I can't think what is different? Could it be over heating? Can I run the USB straight into the board rather than to the back of the machine? Seems to be worse when machining. I left it on for an hour just connected, not machining, and it didn't drop out, then when I started machining it cut out within minutes.

Really frustrating as have jobs to complete. Couldn't happen at a worse time.....Any help really, really, appreciated. Maybe one day I can buy you a few drinks!! You've earned them so far!

Just to add, it has sometimes dropped out when not machining too.

Searching for "Device Driver Call Failed" turns up this thread on the BB https://www.denfordata.com/bb/viewtopic.php?t=1650 which indicates it may be a hardware issue. As that specific error message got one match it would seem to be a Denford software error message rather than Windows.

The denford guys did a really good write up on their fault finding there.

In answer to your question Yes you can plug direct into the top board, open up the panel, you should see the main control card with 7 segment display, the USB plugs in there.

I'd do that as a 1st port of call.

Pete

Tried plugging direct into the board, and changed the cable, and it worked for a while, the longest it has since its been doing this, but then cut out with the same error again!!!
I notice when I leave the machine connected and homed but in idol mode it will stay connected, it only really drops out when cutting. I wonder if it's anything to do with the spindle???
I'm pulling my hair out because it was fine until 2 days ago, and I'm wracking my brain trying to think what's changed? I cleaned the machine cabinet (NOT the black box but the cabinet with the spindle in) out with a hoover and I'm wondering if I knocked anything?? The weather has been a bit warmer, could it be overheating somewhere??
I changed the power settings on the laptop....
I'm just at a loss right now. I have read through the threads you directed me to, and I've tried a few things on there, or don't understand the other things, like voltage losses and the causes etc

Which unit do you have as a spindle motor? I only have experience of the porter-cable units, you do need to keep an eye on the brushes as they do wear. It is easiest to take the motor out to check them. Also it can be worth either turning off or un plugging the spindle and running a job with no cutting. By turning the spindle off/unplugging you still run everything in the control cab. If it works fine then thats what you need to look at

Pete

I have the Kress spindle. I changed USB ports on the computer, and came home and finished running a long program I have been trying to complete, and it finished it with no drop out. I'm going to do some today and see how I get on too.
If I continue having problems that will be my next port of call, as it seems ok 99% of the time when not machining. I left it for over 2 hours on Saturday plugged in and it didn't drop out, so will move onto the spindle next if it continues.

Thanks again for the help and advice.

Just an update for anyone who comes across this thread and has the same problems.

I did two jobs today, one over an hour long, plus finished a long job the other night with no "device driver call fail" problems at all??? So far, so good. It hasn't dropped out once. This after it dropped out after around 20 mins at most of machining. So it's definite progress.

I'm trying to wrack my brains over what is different? I am going direct to the board now, so from the board straight to the computer. However, I did this before and it still dropped out, so I don't think it is that???

I am maybe using a different USB socket on the computer. So maybe one of the USB sockets on the computer is knackered or not drawing enough power???
Yesterday was cooler, but today was still warm so don't think it is heat. Plus the fan on the machine is pretty strong and it feels cool.

I'll have to keep an eye on it, but touch wood, whatever it is, hopefully it's gone, so far so good. I hope it doesn't come back, as it's pretty annoying. The machine drops connection with the computer, I have to turn the machine off and back on again, and reset VR Milling, and you can hear it reconnect to the computer with the sound the computer makes when you plug in a new device. So it's a momentary drop off, then connects as normal once reset. Very strange.

After saying all this, I'll probably have a nightmare of a day tomorrow now. Fingers crossed all stays ok. If it does, then its been bizarre. If I do continue having issues, you'll be the first to know!!!

Thanks for everyone's help.

I would check that the USB ports are not set to go into power saving mode as this could be the problem. Also static is another big issue so if you are running extraction the dust down the vacuum hose can cause a discharge that would earth through the USB. Compressors can also be a problem when they fire up causing large spikes on the mains. If there are any of these issues it would be worth looking into them.

I had forgotten about static from extraction. I have witnessed how bad static can be. We have 2 microrouters at work, both have metal bodied Numatic heppa equipped woodvac units (like metal versions of the Henry). We heard a ticking noise one lunch when the machine was running, 40mins or so into a job. Looked over and could see sparks arcing from the lower section (where the dust bag is and hose goes in) over the rubber seal to the upper section with the motor section which is earthed. That a distance of about 20mm! I must remember when we go back to get an earth bond added between the 2 sections

When I was setting up an extraction system in my home workshop I considered using 100mm drain pipe but remembered something about static and on research saw people had had to spiral wrap an earthed wire the full length of their systems. I did it in metal.

I've no idea on the duty cycle on things like the numatic type vacuums so for personal use at home tend run extraction on my microrouter for roughing but make it so when the machine is running I can open the door and clear out only as required on finishing passes.

Pete