CNC components

EMV-25CNC kit headplate

EMV-25VBB CNC Kit – The story

Over in the shop we are running a preorder for the CNC conversion kit. Here we would like to give you a bit of background on how it all came about and our design intent.

From day 1 of ordering the EMV-25VBB milling machines, the CNC conversion kit was always going to be an option we would offer. As the development reaches commercialisation and release, let us give you a bit of background on how we designed and thought the project through.

The first conversion our team did involved a Chester Machine tools Super lux. At the time, we were short of cash and also wanted to get the machine running asap. This was not a good combination as corners were cut, money was skimped with the end result…well much to be desired. Thanks to that machine one of us learnt to hand scrape for flatness and alignment as well and owns more metrology tools than we would need, a Biax powerscraper and a granite table.

The following learning outcomes have stayed with us as we designed the conversion kit for the EMV-25VBB:

Servos are so much better but Steppers can be good

Granted there is a cost to servos and there is also a learning curve regarding PID position control and parameter tuning. Thankfully Clearpath servos are here to save the day! Plenty of YouTube videos to prove why, including John Sanders’ special projects! Thankfully for those with a limited budget, the option of using steppers is not eliminated due to the servo motors we will ultimately inlcude are also Nema 23 frame sizes. The added bonus of the servo is that you can back drive it much easier than a stepper. Our protoype kit sports steppers, because that is what we had at the time

Don’t touch the castings!

Invariably the castings used on the machines we are aiming this kit to are not aged or stress relieved. In some cases they are not even ground well enough. On our Chester we found that even drilling lubrication points was a bad idea as the saddles would move killing the accuracy we hand scraped into them. So great effort has been expended to get a custom made ballnut and ballscrew mount to allow fitment of the X-axis screw. In fact we even use the same screws from the factory in most case. No more hunting around for a mate with a Bridgeport!

Backlash sucks!

Yes you read that right, no too ways about it. Yeah you can use the CNC controllers backlash compensation function but why not just eliminate it from the getgo? We came to this conclusion about 3 months after we put the first machine together. Kept chasing repeatability, squared off circles and steps in all directions. So ditch the silly ideas of springs between the nuts, shims etc and go with quality precision manufactured ballscrews and bearings throughout.

Hence our kit is based on C5 accuracy ground and preloaded ballscrews. They are so good they can be backdriven!

Wish I had kept the handles

Why code a a hole drilling program if you only want to do a quick job? Not going to eliminate the quill too right? So yeah, jogging with a keyboard is impractical and for the one quick hole you want to make using that drill you cannot really be bothered to touch off…Lets keep the handles on. Oh but wait, what happens when the handles are spinning with the motors? Best make them the safety kind.

Material choice

In order to eliminate backlash and lost motion, we have made the ballnut mounts out of steel. As you may already know the coupling between the casting and the nut occurs through a boss and it is held in place with a single screw. Using steel we know that the parts will last a long time with no loss of rigidity.

What machines will this fit on?

The kit came about with some help from Aaron Powter of Youtube fame. He designed his kits to fit the Titan machine tools, available in Australia. His kit fits the AMAT25LV, the Optimum BF20, HBM BF25 and other machines too. The biggest difference between the EMV-25VBB and the other mills is the end of the table. Ours takes a small flange that does not cover the ends of the T-Slot area, while the others have a larger plate. To keep all of your covered we have designed both variants.

How do we get this kit?

Getting the numbers up is critical in being able to make this viable. Unlike the other kits available, we have put great effort to ensure it is as plug and play as possible, this has built in the complexity of needing special ballnuts and holders. So, we are asking that our customers head on over to the shop area and preorder their kits. This commitment keeps you keen and us on track. Think of it like crowdfunding.

Head on over now to see the rest of the photos!

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Quick change and repeatable Z tooling for MT3 and R8 spindles?

Industrial and hobby machinists alike all have the same pet hate when it comes to changing tools whether using a Bridgeport knee mill or a bench top CNC mill:

“It takes too long!”

Lets explore this topic and how Emvioeng.com will help small and large workshops alike become more efficient.

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Smoothstepper series: Lets send some pulses

Welcome to the third instalment of the Smoothstepper series of posts. In this post we discuss what you need to do to make the computer communicate with the Smoothstepper over Ethernet.

When you connect you Smoothstepper to you computer you will need to make a very important decision: Which IP range do you want to use?

This decision will be influenced on whether you want the computer you have running the CNC machine to easily access you home network. In home networks we usually expect the router to do all the work assigning the IP addresses to each computer using the DHCP (Dynamic Host Configuration Protocol). For those not familiar with the term IP address, it is the numeric address assigned to a node on a network. Home networks will usually use the form 192.168.0.xxx where xxx is a number from 0 to 254. Do be aware that some routers will issue addresses 192.168.1.xxx.

For a SmoothStepper to be able to talk to your computer you need to have the IP address of the Smoothstepper and the PC on the same range. This means that they need to have an IP address that only differs in the last of the 3 sets to digits. We have set ours as 192.168.0.50 for the Smoothstepper and our computer as 192.168.0.10

From the factory, every Smoothstepper is programmed with an IP address of 10.9.9.9 which means that you would need to set your computer to have an IP for example 10.9.9.8. This is easy enough however should you wish to plug an ethernet cable into the PC, it may not communicate with the home router.

I will let the Andy over a Warp9TD.com do most of the talking. The next two videos show two different methods which can be used to set up your Smoothstepper. Most people that have a computer dedicated to the CNC machine will be covered by following the first video. More advanced users should follow the second.

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Messy Cables

Smoothstepper series: Connect it up

Connect it up

In the first post of our series, we discussed some ways to mount your Smoothstepper in your control box. In this post we would like to share some thoughts on how to connect the boards electrically to you drives, switches, encoders and relays.

The most important connection to make is that between your computer and the Smoothstepper. Needless to say, we insist on using a good quality cable for this. All our Ethernet Smoothstepper bundles ship with CAT-6 Ethernet cables. If you have preferred the USB variant then it would be wise to buy a good quality cable and add a ferrite ring to it.

Thinking of the Smoothstepper 2.5 (USB version) or 3 (Ethernet) parallel ports in one (with benefits of course). So you have the options to go with three breakout boards (BOB) that then connect to stepper drives, switches or relays or an all in one solutions that incorporate the drives and the BOBs. The Smoothstepper is outfitted with 26 pin headers on it that will require suitable ribbon cables. We supply ribbon cables with the D25 port connector on the end as we have seen the boards mostly used with BOB’s anyway.

As you may already know, Ports 2 and 3 of the Smoothstepper can have pins 2 to 9 set as inputs or outputs in the plugin. When selecting a BOB, make sure you are getting what you want because usually on port 2, pins 2-9 are input only.

For port 1 only, there is no reason not to go with the generic and readily available and cheap 5 axis breakout board. These boards usually offers optical isolation to your Smoothstepper and sometimes comes with a relay built in. Cheap and cheerful!

In some forum discussions it has been noted that the Breakout board optocouplers may not be as quick at reacting to pulses as the Smoothstepper is to send them. This may be the case on some very cheap breakout boards. On the ones we stock, the reaction time of the worst one was 175ns (nano seconds). That means they are able to accomodate frequencies of up to 5MHz, with the Smoothstepper being able to transmit at up to 4MHz.

A number of other suppliers have expansion boards that link directly to the Smoothstepper with the our recommendations being:

  1. The PDMX-126  is a very capable board and offers a very neat solution for connecting you Smoothstepper up. This is a top notch board that is worth its money if you are willing to pay the price and import duties from the USA.
  2. Our favorite in terms of value is the unassuming C25 as developed and sold by CNC4PC . This board provides a good saftey barrier between the drives, switches and other peripherals and the Ethernet

 

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ESS with C25 and cheap BOB

Smoothstepper series: Mounting

As users of the Smoothstepper in our machine, we thought it would be good to share our findings and some tips.

First and foremost let’s debunk a myth that has been going round the various CNC communities saying that Smoothsteppers have bad support from the manufacturer. This is drummed on about on a number of fora/forums but it is not exactly the case. There has always been a forum on Warp9’s website to assist people and the designers of the board have actively been trying to keep up with the demands and needs of their customers. It is true however that some of the responses have been slow in the past, thankfully the organisation of the company has changed and they are now up to speed. The Smoothstepper is by a long shot the best value for money feature packed motion control board on the market and that is why here at Emvio use it.

So with that out of the way lets get to some tips

Have you seen the new Smoothstepper Configuration Utility? If not then head on over to Warp9TD.com to find out more on this amazing development!

ESS with C25 and cheap BOB
Relays and connector block on DIN rail

Mounting

Both the Ethernet and the USB Smoothsteppers share the same mounting hole pattern. The hole pattern and dimensions are both available in the user manuals. What if you just want to hold it done on a plate without drilling and tapping? As part of our series of tips, we will show you what we do on semipermanent installations!

Industrial cabinets have long used the DIN rail to mount all sorts of automation and safety component.

Luckily some lovely person has also made models for 3D  printing of brackets specifically to be used with the Smoothstepper.

Relays and connector block on DIN rail
ESS Smooth stepper DIN rail mounting clip
Ethernet Smooth Stepper Enclosure

The Gallery below details a quick method with which we have mounted the Smoothstepper in the first photograph of the post.

We are sure you will come up with your own methods of mounting. If you would like us to include photos in this section to show them off, we would love to hear from you.
Stay tuned for more tips!

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Emvio is now a SmoothStepper distributor

We use Mach 3 by Newfangled Solution LLC as the control software on our CNC machine tools. The flexibility and customisability of this package combined with the fact that it runs on Windows (XP, Vista, 7 and 8) makes for a very good solution despite the limitations imposed by being tied to a PC.

As time has progressed, the parallel port originally used for the control of the cnc machines through Mach3, has just about faded away. Software and hardware limitations have crept up on it and although the golden standard for many, including the Linux community, it now is not as common as it once was.

The SmoothStepper in action on our KRV2000

Thankfully vendors of solutions to the issue have emerged to ensure we are still able to use our beloved machines with newer operating systems and hardware.

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