Member postings for Andrew Entwistle

This solder plug, trimmed to to leave vestigial ears for gripping to disconnect, sealed with adhesive lined heatshrink, topped up with hot-melt could hang off the flash unit (e.g. eBay item 254292037485). The rewireable socket (eBay item 161839908218) could be wired with flexible 2-core silicone sheathed cable.

Andrew

Edited By Andrew Entwistle on 01/09/2021 16:27:23

Bill, that looks ideal for the job Michael has in mind, I'm tempted to get one to keep in hand.

Andrew.

For a really compact connector you might be able to trim the C7 plug and encapsulate it in a potting box, also trimmed or 3D printed.

The dielectric strength between the cores at >2kV L-N suggests there is no problem isolating 230V, especially with the additional insulation of the outside sheath. Durability needs to be the same whether 110 or 230. I would have no qualms about using this cable at 230V for a home project, but for a more official application the correct rating would be required - even though I suspect it is just testing and screen printing that makes the difference.

Hi Michael, my preference is to use a rewireable IEC C14 plug and C13 socket (possibly moulded-on if a standard 13A plug to C13 socket lead is available). It is a shame that there is no similar connector pair for figure of 8 format (IEC C7/C8) that would be more compact and with just the 2-poles that you need.

Andrew.

You may be interested in this type of 12mm shank carbide insert boring bar to fit these boring heads, available in a variety of lengths. The TBGH Inserts are almost as sharp as CCGT types for aluminium/stainless.

Andrew.

Have you considered backup to NAS (e.g. Synology) which in turn is backed up to a cloud service such as onedrive, dropbox etc? This has worked well for me for the last decade or so

The latest smart EV wall chargers monitor the total power consumption of the house and scale back the car charging when necessary to keep within limits.

I can recommend this TS100 60W iron. I use one at work and at home. It requires an external <=24V DC power supply (I use a laptop type mains supply or intercept 24V DC from instruments that I am working on, or from a battery pack via XT60 connector). It is like a pen to handle, warmup to 400C takes only 12 seconds and it takes plug-in bits that contain a heating element and temperature sensor. I run it on open source firmware (programmed via a micro-USB socket) that allows customisation of timeouts etc. I see that the TS100 model has been superseded by the TS80 that uses a USB-C connection for power and interface. 

Edited By Andrew Entwistle on 19/07/2021 14:08:53

Edited By Andrew Entwistle on 19/07/2021 14:19:13

Steve Sparrow (steamplates.co.uk) will do a good job.

If you could go down to 1.2mm then would fibreglass PCB material do the job? Standard thicknesses are 0,4, 0.6, 0.8, 1.0, 1.2, 1.6, 2.0, 2.4. It can be ordered machined to the desired dxf profile (usually 0.4 mm minimum radius) from a PCB manufacturer (JLCPCB, PCBWay) for as little as £10 for 5 off 100 mm x 100 mm.

Andrew.

The balls locate in the groove near the bottom of the taper, as evidenced by the indentations! Surprisingly both flanks seem to be engaged by the balls.

Edited By Andrew Entwistle on 17/03/2021 18:26:24

The Coventry type system is also available for slightly less from engineeringsupplies.co.uk. I tried making an ER25 holder from 304 stainless, but although it was made accurately, it soon developed runout because of indentations in the taper from the locking balls. It would need to be hardened at least in that region to be successful.

Andrew.

Misumi used to be a comparable option, and still are for work, but since January they have slapped a charge of something like £15 on UK orders.

I think Dave is referring to a CCGT type uncoated small radius insert for aluminium and stainless. They work well for lighter cuts in harder materials.

Andrew.

I have succcessfully used paintstripper to remove powder coating completely, The modern formulation is not as potent as original Nitromors but if covered with clingfilm or foil etc and left for an hour or more still does the job in one or two applications.

Edited By Andrew Entwistle on 08/01/2021 15:21:23

Based on pixel measurements from 100mm OD can't be far off 73mm.

Hi Frank,

I got mine to work with a graphite piston in the honed bore of a glass test tube, but I'm sure other pairs will work if clearances are optimised. There needs to be practically no friction for the engine to work as there are only milliwatts of power available. If you look from 1:34 of this video I made about my Jan Ridders engine you can see how free the piston needs to be.

Testing a low temperature difference hot air engine

Andrew.

Hi Frank,

If you can get a high resolution photo then it can be corrected for lens distortion and perspective in a bitmap manipulation program such as Paintshop Pro:

Andrew.

Edited By Andrew Entwistle on 13/11/2020 11:54:08

+1 for clockmaker's dial wax. I use a magic sponge (melamine) to remove excess wax without damaging even plastic surfaces.