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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: Help requested wiring VFD - Again!
25/09/2020 19:32:43

It looks like the VFD can read either a current or voltage input to control speed. You'll have to tell it which to use - presumably a parameter setting.


EDIT - looking again, that's a matter of wiring to the correct terminal and setting the parameter.

Edited By David Jupp on 25/09/2020 19:46:03

Edited By David Jupp on 25/09/2020 19:47:34

Thread: Machinability of Steels
27/08/2020 10:40:03

T condition equates to 850-1000 MPa Ultimate Tensile Strength. Based on one of the conversion tables I use, that's 25 - 32 Rockwell C.

Any of these strength/hardness conversions for steel are approximate, reality may vary from grade to grade.

Thread: My wife broke the internet
20/08/2020 08:26:55

If a phone is connected without DSL filter, it will seriously degrade the DSL signal.

The router doesn't need DSL filter.

Thread: ⅜" Whitworth wingnut
16/08/2020 18:57:38

Quick web search reveals several sources

one of which was this

Thread: Gas Analyser U/S
10/08/2020 18:59:25

Ian, capping or purging the cell not only extends life, it gives much faster response time if measuring low oxygen levels (for example ppm of oxygen in hydrocarbon gases).

These sensors are used for a very wide rage of analysis - there's nothing wrong with capping or purging the sensor when it isn't being used. Obviously NOT if it is being used to continuously monitor breathing air.

10/08/2020 17:08:26

Almost certainly the cell is exhausted. Typically an electrochemical cell, that is used up in presence of oxygen regardless of whether the device is turned on.

To extend life - some users cap the cell to keep air out, others nitrogen purge it after use.

Hardly mass market stuff, so won't be cheap. Is it an 'Analox' brand?

Thread: Quality small metric spanners
27/07/2020 18:44:13

I added a couple of Halfords Professional combination spanners to extend down to smaller sizes, I was pleasantly surprised by the quality - not sure how small they go...

Thread: Where can I get terminal posts?
16/07/2020 17:02:56

Not sure why you need 6 terminals - if it'll be a permanent change over, you only need 3.

When I did something similar I just added an extra ring terminal to each of the 3 posts.

Thread: Sourcing Belzona Fluid Metal Materials
07/07/2020 17:33:26

Contact their Harrogate head office

Thread: LED GLS bulbs
06/07/2020 12:55:24

Straightforward, but not cheap way to detect spikes, dips etc. - a power quality analyser.

I purchased a single phase Fluke analyser on the back of a customer project - it's very impressive and also easy to use. It automatically produces a time stamped log of spikes, dropouts, etc. plus frequency, harmonics. So if you note when (say) a switch was operated - check the log at that time for any disturbances.

You might be lucky and could borrow or rent such a device.

Thread: My new Sieg SX3.5DZP problem
30/06/2020 13:32:31

Lighting can also make a big difference to paint colour match. I used to own a red car that looked fine in daylight - under sodium street lamps a door and rear quarter showed as a completely different colour to rest of the car.

It an effect called metamerism. A match under daylight, may not be a match under fluorescent lamps, or LED for example.

You can only get a match under all lighting, if your paint uses the same pigments as the original (basically that will be if it comes from the same source).

That's on top of the effects Jason mentioned.

Also good red pigments are VERY expensive, so cheaper ones tends to get used. That means you ned lots of coats to build up good coverage of red (which Jason also mentioned). Red paints fade a lot for the same reason.

Thread: Convert PDF to DXF?
14/06/2020 16:31:37

When all is said and done, it may be as fast, and more reliable, to re-draw / re-model whatever the design is natively in your CAD system of choice.

Thread: A red face and a bottlejack
08/06/2020 15:03:55

Not sure if it was the same make - one I used years ago was released by pulling the handle back slightly from the slot in the 'rocker' - this allowed the handle to be depressed further than when pumping, allowing the oil to 'return to tank'.

It needed a significant push down on the ram if not actually carrying a load, the weight of the ram alone wasn't enough to force the fluid back round the circuit.

Thread: Modular 5C Collet Tray
05/06/2020 10:28:22

The 'bow tie' is a neat way to fix modules together - does it work well?

Thread: Machining Ceramic material
03/06/2020 11:34:47

There are ceramics available which can be machined with standard metalworking tools - another possible option.

Edited By David Jupp on 03/06/2020 11:35:31

Thread: Hydraulic Motor
26/05/2020 09:33:16

It should be relatively easy to get assistance for 'common & current' hydraulic motors. For old or very specialised items it may be more hit and miss.

I'm aware of one particular range of hydraulic motors where the (very old) design rights have been sold on and a small specialist supplies parts to a limited size, but critical market.

Thread: 3D CAD software - what do you use?
19/05/2020 18:15:54

Large monitors (in terms of pixel count) put a lot of extra demand on the graphics requirement.

So a '4K' monitor (or worse 2 or more of them) will hit the graphics capability hard.

A single screen of modest pixel count is more likely to cope tolerably with integrated graphics.

18/05/2020 17:28:21

Think about which 'bells and whistles' are important to YOU.

Most users don't need the high powered tools that some systems offer - but, if you do need some specific function that can be a very important factor in your choice.

For 'once in a while' cases, there are usually workarounds to not having a particular feature.

Extra buttons on the interface can slow the learning process.

Thread: Learning CAD with Alibre Atom3D
10/05/2020 14:33:45


Cut/Copy/Paste via mouse alone are restricted, not because of any particular desire to prevent Atom3D users having access, but simply because opening up that 'chunk' of user interface would also give access to a whole load of other things. It would require a total re-structuring of the user interface to be able to give some of the 'expected' tools in Atom3D. That won't happen short term just for Atom3D, but may happen in the longer term as part of a wider overhaul of the technology and structure of the user interface.

09/05/2020 19:30:48


1st or 3rd angle is inherited from the drawing template - except for if you don't use templates, then Jason's instructions hold.

ISO world = first angle, US = 3rd angle, unfortunately in UK we use both, so no template is likely to be 100% correct. You need to modify your template to avoid having to set it each time. In Atom3D you don't have all the editing options you might like.

Projection Cone - I have a custom symbol somewhere, unfortunately Aom3D doesn't support that nice trick.

Again if you modify the template, it only has to be done once...

Save modified templates with their own unique name to avoid them being overwritten if re-installing the software.

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