Member postings for Andrew Entwistle

I did flash the original Anet control board to Marlin 1.1.18 with no problem, I only changed to the MKS board to get 256k memory, since the Anet board has only 32k memory and did not have space for mesh bed levelling.

Hi Martin,

I forgot that it was too difficult to map the wiring of the Anet LCD ribbon cables to the MKS board, so I just bought a RepRapDiscount Full Graphic Smart Controller (about £12) which includes an SD card reader. In practice I alway use the printer connected to a Raspberry Pi running Octoprint, so don't need the SD support.

Andrew.

Step by step instructions for installing Marlin can be found here:

**LINK**

Hi Martin,

the most important feature that Marlin offers over bottom end printers is thermal protection (detection of sudden changes in temperature such as a temperature sensor falling out and causing a fire through thermal runaway). I don't think a generic board is possible because much of the customisation to a particular machine has to be specified in the configuration files before compilation. I bought an MKS GEN 1.4 board for about £20, plus four stepper driver boards and found installing Marlin very straightforward. This enabled me to add touch probe mesh bed levelling and silent stepper driving, as well as customising temperature ranges etc.

1. Download Marlin code zip file from GitHub,

2. Download and install the Arduino IDE

3. Edit the two Marlin configuration files (There may already be templates to suit your machine for config.h and config_adv.h in the Marlin release)

4. Plug the board into the PC and in the Arduino IDE press the upload button to compile and upload to the board.

Andrew.

A finely honed hobbyist FDM (squirting molten plastic) printer can achieve the ultimate surface finish of professional models, but that is never very good anyway for FDM printers of any class. For a finer finish UV resin printers are used. They are coming down in price e.g. Elegoo Mars £230 with build volume 120 x 68 x 155 mm, but they are messy and the choice of materials is smaller.

Hi Michael,

The 57T Meccano gear is 38DP, I am sure dropping the nozzle to 0.3 mm or 0.2 mm would yield the same quality for 40DP as Andrew's 10DP (at least in the areas where meshing occurs).

Andrew.

Hi Bill,

Experimentation is only really required to achieve higher accuracy, default settings will in most cases produce a useable part. As you suggest solvent vapour can be used to reduce/remove layer lines on ABS prints, but at the expense of softening sharp edged features. PLA printed with a shell of several outer layers and >20% infill density feels almost indestructible when there are no slight features. I have found that PLA wood filament printed at 0.1 mm layer height results in layer lines that are invisible a foot away - see this 13 cm high rendering of the Gayer Anderson Cat (a standard test of printing overhangs)..

Andrew.

Hi Bill,

All slicers have at least one parameter that can be used to tune the width of plastic deposited. The slicer starts with an assumption of filament diameter and motor steps/mm filament linear feed rate, but in reality the filament diameter varies slightly between varieties, as does the way it flows to produce a layer, as does the effective diameter of the filament due to resistance of the filament to compression by the drive gear(s). To achieve an exact width I print an open topped empty cube, with single wall thickness (turn off infill and top layers) and then adjust the 'extrusion multiplier' by trial and error until I achieve say 0.4mm wall thickness for 0.4mm nozzle diameter. Changing filament usually requires a different calibration.

Andrew.

Hi Martin,

Just google 1785004255

3D Printing for Model Engineers: A Practical Guide by Neil Wyatt

Andrew.

I should also mention that I have read my copy of Neil's book on 3D printing.

Andrew.

Hi Michael,

The secret is that I started 3D printing a few years ago by replacing the woodworking router on my ex-education Conect CNC machine with a homemade extruder. This gave flawless positional accuracy and allowed me to concentrate on optimising just the extruder. Although slow (600 mm/minute maximum traverse speed) the machine gave results that I have not been able to beat even using an expensive machine at work. The current machine is a £120 Anet A2 kit where the only original parts now left are the aluminium frame extrusions and the switch mode power supply. Even the extrusions have been machined, dowelled and clamped to improve rigidity. I am sure I in total have spent much more than the cost of a more turn-key Creality machine, but for me the fun was in the re-engineering.

Andrew.

Not bad considering I have not yet refined the extrusion multiplier since changing to a dual drive extruder that indents the filament more than the original one did. The slicer really does a remarkable job, Simplify3D in this case, but I am sure Cura would have worked just as well.

Andrew.

Hi,

I printed a couple of 4mm thick Meccano style 57T gears, modelled using the CAMBAM involute gear generator using a quite old 0.4mm nozzle. The first image is a scan of the gears, top face towards the scanner glass. The second image (inverted) shows the deviation from design profile, along with a 0.4mm circle for scale. Material is PLA, 0.1mm layer height.

Edited By Andrew Entwistle on 01/01/2020 14:30:53

Hi Alan,

Another data point; seven years ago I secured the 1/2" throw crank on my power hacksaw to the 5/8" diameter crankshaft (both MS) using 638 only, with no issues.

Andrew.

Hi Ian,

I made one about 6 years ago (you may have seen it on YouTube) and still get satisfaction from just walking past it in the cellar, but mostly from when I use it to move on a project that might stall if I had to cut the stock manually. It has cut a few 4" plus slices of aluminum and plenty of steel square section for quick change toolposts My mistake in building was TIG welding the hacksaw blade frame instead of silver soldering, making it harder to clean up and align, otherwise straightforward. I was eventually able to achieve the 0.25mm thick slices of mild steel that David Abbot demonstrates.

Andrew.

Edited By Andrew Entwistle on 12/09/2019 22:01:46

Exactly as you describe Neil, I haven't experimented with the 8 sub options, just observed super smooth top surface (for admittedly level planar surface) with the default ironing on setting.

Andrew.

Hi Neil,

Have you tried the ironing feature within the shell group of settings? I find it gives a stunning top surface finish.

Andrew.

When I looked again at the two photos I realised there were subtle differences everywhere, the Leyland and Barlow looks like a perfect match though.

I also live just down the road, in Stretford, and I work about 100yds from Trafford Rd in Trafford Park.

Andrew.

Geoff, the lathe has some features in common with the Brittania No. 14 from 1890-1900 - see **LINK**

Andrew.

Edited By Andrew Entwistle on 14/04/2018 22:31:16

Hi Mick,

I have had good success adding a Danfoss SC21F 21cc compressor (available new on eBay) beside an existing 2HP compressor. Two valves and IEC mains connectors allow easy switching between the original noisy but high throughput compressor or the silent one. With the fridge compressor the 50 litre receiver fills to 100 PSI in < 5 minutes. For my use with a blowgun and for occasionally clearing swarf at low flow rates it has worked fine for four years, with no obvious signs of oil in the output. There are a couple of photos in my album.

Andrew.

Edited By Andrew Entwistle on 12/12/2017 09:17:53