New CNC Mill on the horizon

**fvfdrums** · 09-02-2015

Thanks Silyavski :) yep justification is key!

Whats the best kind of grease for the screws and bearings?

**Boyan Silyavski** · 09-02-2015

Hiwin Lubrication Guide, in short any grease or oil that has no solids like Mo and Graphite. That includes WD40 too. That would be any normal bearing automotive grease which says NLGI2

I used yesterday normal lithium grease that said NLGI2. I thought of making central oil system but at the end decided against it, too much hassle and extra cash to do it properly, when i could simply use the grease gun and forget about it.

Grease lubrication

Grease lubricationFor grease lubrication, we recommend greases in accordance with DIN 51825 of consistency class NLGI 2 as specified by DIN 51818.

For normal loads, standard greases with the designation " – K1K“ are sufficient.

For higher loads (P/C < 15), high-pressure lubricating greases are required: "– KP1K“The use of greases of other consistency classes is possible subject to the approval of the lubricant supplier.

NOTE Greases with solid particles such as graphite or MOS2 must not be used.The following information on lubricants serves to provide examples and is only intended as an aid to selection.

Oil lubrication

Lubricating oils offer the advantage of more even distribution and reach the contact surfaces moreeffectively. However, this also means that lubricating oils collect in the lower area of the product asa result of the force of gravity and thus more quickly cause soiling. For this reason, higherquantities of lubricant are required than with grease lubrication.

Oil lubrication is as a rule onlysuitable where a centralized lubrication system is used or for products equipped with a lubricationunit.Observe the lubrication system manufacturer's instructions.The following information on lubricants serves to provide examples and is only intended as an aidto selection. Other lubricants may be used after clarification of the specific application and thecentralized lubrication system used with the lubricant supplier.

**Lee Roberts** · 09-02-2015

Originally Posted by fvfdrums

Whats the best kind of grease for the screws and bearings?

Lithium 2 (grease) is what I always suggest, can get a tube for £3 here, can't remember size but it's on par with a tube of silicon sealant or decorators chalk, so quite large for the amount you'll use.

Oil don't last as long but grease clogs up, take your pic.

.Me

**fvfdrums** · 16-02-2015

So it looks like its time for some wiring!

I have spent a vast amount of time reading through the forums and over using the search facility (if there is such a thing).

Anyway I am drawing up a wiring diagram at the moment but there are a couple of things I could do with advise on.

I have decided to go with the CS Labs CSIMO -IPM as it seems to suit the machine perfectly as its running a single belt to drive both x axis screws. This also means I only need run a separate 24v DC supply for powering the unit and also the safety circuit.

So on to the safety Circuit it is....

I am confident I have the bases covered on isolating the mains supply to the drivers on fault or Estop however what is the best way to isolate the spindle? as I have been reading removing power from the inverter is not always a good thing? what are people doing to make the spindle safe in an estop senario? (chinese 3 kw spindle setup)

That then brings me on to drives, when I started the machine (many moons back) the drive and motors were ordered from china I was under the impression we were getting digital drives, having glanced over them at the time I did not really take any notice but it appears we have 3 of the DM860a drivers. Now given that this much effort has been put in I am thinking its worth switching these units out for the AM882 of the EM806 drives? Would this be a good move or a waste of time?

If a good move then I have 3 brand spanking new DM860 drives for sale if anyone is interested please PM me!

Thanks as ever for the on going support from an incredible knowledge base!

**Boyan Silyavski** · 16-02-2015

Originally Posted by fvfdrums

So on to the safety Circuit it is....

I am confident I have the bases covered on isolating the mains supply to the drivers on fault or Estop however what is the best way to isolate the spindle? as I have been reading removing power from the inverter is not always a good thing? what are people doing to make the spindle safe in an estop senario? (chinese 3 kw spindle setup)

When BOB is reset it stops giving On signal to VFD ON input so the VFD stops, hence VFD low voltage On is chained on the Estop line.

Originally Posted by fvfdrums

That then brings me on to drives, when I started the machine (many moons back) the drive and motors were ordered from china I was under the impression we were getting digital drives, having glanced over them at the time I did not really take any notice but it appears we have 3 of the DM860a drivers. Now given that this much effort has been put in I am thinking its worth switching these units out for the AM882 of the EM806 drives? Would this be a good move or a waste of time?

Waste of time, these are good DSP drives. Almost the same as the AM882.

**Boyan Silyavski** · 16-02-2015

However if you have the simplest 3kw inverter like the diagram below, care should be taken what voltage flows there. So if you board is 5v and the inverter is 24v or vice versa. Best would be that you have an Estop button with double switch circuit or you just use an enable output on Mach3 and a relay on your BOB.

**JAZZCNC** · 16-02-2015

Depends how Anal you want to get.!!! . . . Really with an emergency stop then power should be removed. Just removing the RUN signal isn't compleltely safe.

Killing power to the VFD isn't ideal but in a true emergency then it's what you want to happen. It can be done safely using timer relays to allow time for spindle to shut down safely before power is removed.
Is it really needed.? Well only you can answer this one.! . . . Me i'm happy to isolate the run signal using a relay, Which by the way the IP-M as built into the controller so can connect direct to the VFD.

Drives because you have them I'd stick with and they'll do the job ok but NO they are not good as the AM or EM which are much smoother refined drives. Just because they use a DSP doen't make them the same.!

**fvfdrums** · 16-02-2015

So in a nutshell - what benefits am I likely to notice between the DM and the AM/EMs? I know they have the stall detection is that as vital if I am only running one motor for the x axis? or have I missed the point...

I think the run signal works for now. I can see this panel taking as long as the bloody machine at this rate!

**fvfdrums** · 16-02-2015

Also,

just reading through the manual for the BoB it suggests if using a large contactor to switch off the power its an idea to have a diode and a noise suppression device? is this to prevent voltage spikes? and how would one go about adding these to the control panel?

**JAZZCNC** · 16-02-2015

In a nutshell you'd get smoother movement from the motors, esp at lower speeds. Also less motor heating as they handle current much better and the drives software seems much more refined.
These things I know for sure just from the limited experience of the DM's vs AM/EM which I've loads of experience with.
While I can't answer this 100% because my experience with DM was limited I'd take an educated guess and say you'd get slightly less speed/torque compared to EM as well.
This said I still wouldn't sell the DM if you have them as the difference in use will be minor but there is a difference. The stall detect isn't an issue at all for you so don't fret about this and you haven't missed any point.