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Member postings for David Jupp

Here is a list of all the postings David Jupp has made in our forums. Click on a thread name to jump to the thread.

Thread: battery problems
13/01/2018 11:14:40

I've had similar problems when batteries have seemed a 'sloppy fit' in the holder - it seems that not all brands of battery are exactly the same size.

Consider trying a different brand of battery.

Thread: End mills for alluminium
22/12/2017 16:27:31

Possibly even consider single flute cutters.


Thread: Single to 3 phase vfd
06/12/2017 09:38:30
Posted by David Jupp on 06/12/2017 07:24:40:

The screen is not really intended as the Earth - that should be a separate core.

Easiest way to connect the screen is to use proper 'EMC' glands to suit the diameter of the cable used.

That assumes the terminal box on the motor is metal - not one of those horrid plastic terminal boxes.

06/12/2017 07:24:40

The screen is not really intended as the Earth - that should be a separate core.

Easiest way to connect the screen is to use proper 'EMC' glands to suit the diameter of the cable used.

Thread: using an inverter to power a 3ph hoist
04/12/2017 11:29:28
Posted by Roger B on 04/12/2017 11:20:32:

The area I would look at is the brake. If it is entirely mechanical no problem. If it is spring apply electric release it should be ok but probably wouldn't allow for variable speed/ramping.

Many inverters will have a built in relay which can be used for things like operating the brake (check supply voltage for the brake). I know that some have built in functions specifically for use with braked motors - I've used them in a different application. When used in this way, a separate cable (or extra cores) is required for the supply to the brake unit.

Thread: Has anyone regretted migrating from MS Winows to Linux?
17/11/2017 12:32:43

Posted by Russell Eberhardt on 17/11/2017 10:58:30:

Posted by David Jupp on 17/11/2017 09:46:12:

I've looked at Linux a number of times - got very frustrated by how complex installing software can be (though for a lot of stuff it is fine). I have to use Windows for some of the software I use.

Linux Mint includes "Software Manager" giving you access to over 80,000 programs which can be installed just with a single click. I have Linux Mint dual booting with W10 on my laptop for the few programs which are not available for Linux. I use it for just Fusion 360 and for updating my GPS.


Perhaps I should qualify my comments - I did say " complex installing software CAN be..." the software managers in several Linux versions are arguable even easier than Windows, which is fine if what is covered by the manager is all that you need.

I've spent ages installing a Brother printer/scanner on a Linux laptop (Ubuntu actually) - this involved very close following of not very clear instructions on printer manufacturer's web site - all this done at the command line with little or no feedback on what was happening. I eventually got it to work. Getting DVDs to play on the same system was another long and drawn out process.

Don't even get me started about the software where the only instructions are mention of a few dependencies, or some gibberish about make files - with nothing to explain what this is all about.

There is some very capable engineering software that is produced for Linux - but when there isn't an rpm file or similar it can be a nightmare. I accept that a lot of that is down to whoever produces the software and (lack of) instructions.

One thing that is good about Windows is the software installation process - you buy the software, run the installer, and (the majority of the time) that's all you need to do. I know it does go wrong sometimes!

I'm not anti-Linux, it frustrates me that much of the Linux community wastes effort on creating multiple systems to tackle the same problem, yet (with notable exceptions) does very little to make Linux accessible to new users.

17/11/2017 09:46:12

I've looked at Linux a number of times - got very frustrated by how complex installing software can be (though for a lot of stuff it is fine). I have to use Windows for some of the software I use.

One thing I've come across recently which may be worth being aware of if you dual boot - Linux and Windows store CMOS time differently. Windows writes local time to CMOS, whereas Linux writes UTC to CMOS.

If you change OS (dual boot or swap system disk) it can take a while before system time gets corrected. Many modern licensing systems require contact with a remote server at software launch and will include a time check - if time is significantly out, the software will be disabled.

It is possible to configure Windows to write UTC to CMOS instead of local time - that might be worth looking into if you intend to swap OS.

Thread: Windows 10 printing problem
13/11/2017 17:33:59

Could be a failed or incomplete Windows update - have you checked the update history ?

What software are your PDFs printed from ?

13/11/2017 16:33:39

Check for latest driver package for Windows from the printer manufacturers web site.

Disconnect printer from computer, uninstall the printer, re-boot computer, run the manufacturer's set up program, following the instructions regarding when to connect the printer.

Thread: Setting up a website
05/11/2017 09:14:00

One option would be to use a Dynamic DNS service to point to your own system, then work just like you have done previously. Check first if you are going to run into bandwidth or monthly data allowance restrictions on your internet connection.

Thread: Simple Cad Drawing start-up.....
01/11/2017 19:53:29

Anything that will export STL files should be fine for 3D printing - that should include just about any 3D CAD package worth anything at all.

'Best' means many different things to different people. There is no single answer.

Some packages include tools that might give some guidance on suitability of a particular design to 3D print (though even that varies by printer technology & material).

'Small sum' is not very specific.

If it works for you, then by default it is 'good', no matter what others say or think...

Thread: Stepper motor driver
29/10/2017 08:39:53

I don't read the data sheet extract as suggesting pulse needed on DIR. It just says that the state of DIR input decides which direction the STEP pulse is treated as requiring. I can see how you could read it to think it's talking about pulses on DIR.

I've used a similar driver board, no need for pulses on DIR.

Thread: Upgrading a Denford Triac
08/10/2017 19:27:26

If budget is important, you might be able to re-use existing driver board & steppers by simply connecting a breakout board to drive from Mach3 (or similar) - that's what I did with my Novamill - OK you don't get microstepping, but it works fine.

Spindle drive - probably a 0-10V signal to either DC drive board or an inverter. With minimal messing about I adapted usied hardware in original Novamill cabinet to work from PWM output (would have been even easier if not for a fault on the DC drive board in my Novamill).

Lots of good info and help scattered around the denforddata site.

Thread: Denford Triac Mill
08/10/2017 19:21:36

Since I only had one easy change holder with my Novamill, I removed all the easy change stuff and instead substituted an ER collet chuck using the original manual drawbar.

05/10/2017 13:59:49

Triac and Novamill used a similar arrangement to lock holders in spindle when ATC was fitted. If you dig around the Denforddata site you'll probably find some drawings of the arrangement.

Thread: socket_head_cap_screw_iso_ISO_4762_M5_x_16_16S
04/10/2017 11:41:25

Processing power isn't really a problem for creating a one off part - but when you get many fasteners in an assembly, and if you then create a 2D drawing from that, you can end up with the drawing view taking many minutes to generate.

Not as much of an issue as it was a few years ago - but can still be a pain. That is why most downloadable CAD models have either no threads at all, or the simplified representation.

Thread: Denford Triac Mill
03/10/2017 13:49:57

There is heaps of information available on the Denforddata forum.

I have a Novamill (smaller brother to Triac) - I did a half way house conversion, kept the existing driver board/cabinet, but removed the processor board and linked to the parallel port of a computer running LinuxCNC (or Mach3).

Thread: socket_head_cap_screw_iso_ISO_4762_M5_x_16_16S
01/10/2017 21:04:40

That is typical of fasteners with 'cosmetic threads' - intended for use in CAD assemblies, not for 3D printing.

The cosmetic thread is simply a pattern of ridges - because that is much easier to model/render, but (at first glance) gives the impression of threads.

True helical threads put huge demands on processing capability and can really bog down the CAD system.

Thread: Myford help required please
17/09/2017 21:21:36

Lenze inverters are very good quality kit. Exact features available vary from model to model - I've used a couple of different models in projects, from the basic to those including positioning capability.

Thread: Tow bar wiring loom
05/09/2017 08:27:40

I fitted a tow bar on a Jag - made life easier by buying the vehicle specific wiring kit, not the cheaper generic kit.

Vehicle specific kits have connectors which allow you to simply plug in to existing wiring (at back of rear lamps, at parking sensor control box). No need to cut/splice anything.

Stripping off rear bumper (and the amount of other things I had to remove to get at that) makes it clear why this can be an expensive job.

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