Member postings for Steve Skelton 1

The thing that causes the most damage to an LED is running temperature. You will find most of the good quality high power units have a heatsink on the LED itself.

I have been on an Osram training course on the use and installation of LED's and they were very adamant that keeping the LED cool is critical and when they get hot they cook themselves and the light output is vastly reduced before they fail. Very similar to CFL's in that respect.

When you install LEDs consider where they are going and how to keep a flow of cooling air around them, otherwise LED's are a false economy.

By the same token drivers should be matched to the LED's they are powering for obvious reasons.

Ooops Andrew - missed your post!!

Steve

Edited By Steve Skelton 1 on 05/07/2020 12:02:30

Neil, feel free to use whatever.

It would be great to learn from others. I would especially like to find out more about printing with PETG especially if it is easier to print the larger more complex shapes - I find I have to think carefully about the design and print orientation when using ABS to prevent delamination or warping/lifting from the bed.

Steve

TNE,

Thank you for your comments, reinforcing what I have been thinking.

I have just placed an order for 3D LAC spray.

Am totally in agreement with the bed levelling and height for the first layer - it almost has to be pushed onto the glass for good adhesion. Interesting what you say about auto bed levelling - you have just convinced me not to buy a kit for auto levelling. It is a bit of a pain to make sure bed is level, and it does change slightly over time but it is not a huge hassle to do it properly. Have you seen this You Tube video I watched it last night - a bit drawn out but overall quite interesting, I have not heard about the "mouse ears" before, I will try it next time.

https://www.youtube.com/watch?v=DQu0ThBS4MY

I have thought about heating in the enclosure but have not done it yet as all the control electronics are in the enclosure and I am worried it may cook it. I think further research is called for.

Cheers

Steve

Hi TNE,

That printer looks really great - printer envy!!

I agree with you on the ABS front, do you run 1.75mm filament? Tiertime ABS looks expensive, does it produce much in the way of fumes. Have you tried ABS-X?

I have run both but ABS-X is easier to print. I have had no problem with burn-up in the nozzle but do not keep ABS in the nozzle for any time and use a purge to keep it clean between runs.

Without changing the nozzle I think I am limited to 250 C.

Cheers

Steve

I had meant to reply much earlier but work got in the way and then after composing a reply and just before posting it Western Power Distribution decided it was the perfect time to disconnect the power in our area and everything (including my will to live) disappeared in a big beeeeeep.

So here we go again.

As I mentioned I have been using ABS as I need a high-temperature polymer with a glass transition temp above 90 degrees and as the Tg for PLA is 60-65 that ruled it out, ABS is over 100 degrees, so as ABS can also be solvent welded with plumbers pipe adhesive I find it a quite useful material.

The actual grade of material I use is ABS-X. I do not have any problems with bed adhesion and do not tend to use any adhesion promoters providing I run the glass bed at 110 degrees. If the item I am printing has a small footprint, or the potential to lift from the bed then I use Kaptan tape with an ABS slurry painted on it (just ABS filament dissolved in acetone). The print is then easily removed by taking the tape off the bed. I used to paint the slurry directly onto the glass bed but have destroyed a bed when trying to remove a print from it as it took a lump of glass with it from the bed on removal!! This happened twice so I don’t think it was not just a bad bit of glass.

Neil, you mentioned odour problems with ABS. I use ABS-X and do not have any problem at all despite running it in an office without any ventilation. And I, like you, have been put off nylon due to the need to keep it bone dry,

Steve F and IRT, thanks for the info regarding PETG – not something I have tried, although I think I now will. I understand it has good weathering performance.

Barrie, carbon fibre filled Protopasta HTPLA sounds fascinating and is something I think that I have to try. Although it is PLA does the post extrusion heat soak increase the Tg when the PLA turns into a crystalline structure on heat treatment?

Thanks everyone for your comments. Like most of you I also buy my filaments from 3DFilaPrint, they are very helpful and their delivery performance is excellent.

Thanks

Steve

Martin,

The enclosure is a Creality unit which I bought via Amazon as I needed it quickly. Quite expensive at £80 but had the approval of the Finance Director (SWMBO). It is large – photo shows the printer in the enclosure with a light inside to show detail.

BTW I now only use a glass bed.

Steve

I bought an Ender 3 Pro, primarily for myself to play with, about 6 months ago and suddenly found myself using it more for work purposes than anything else designing components on Atom 3D and slicing on Cura. It has paid for itself many times over.

As the components require good mechanical properties and long-term performance, I decided it has to be ABS as PLA has lower temperature performance and will, I am led to believe, eventually biodegrade under some environmental conditions.

As a result, I tend to use ABS-X for everything now as it is flexible and can be solvent welded. I run the bed at 110 deg C and the hot end at 250 deg C. The only snag I find is that I have to design and print everything so that if the component is subject to shear it is printed so the shear will be along the line of extrusion rather than normal to it.

ABS-X is a material, made in the Netherlands, that it is claimed, offers low warp, low odour and improved inter layer adhesion. I have found this to be the case compared to conventional ABS filament.

I have also bought an enclosure to improve the printing performance avoiding draughts and maintaining the unit at a constant (although quite high) temperature.

What are other people’s experiences of non PLA filaments in an engineering context? I would like to try other materials and think it would be quite useful for others on this forum to know of peoples experiences with recommendations and benefits or any shortcomings or problems that may occur.

Steve

We run an online business and historically (three or four years ago) had nothing but problems with Hermes so didn't use them. We tried using the eBay Packlink service on something we were selling privately - we chose Hermes thinking it must have changed - what a disaster they were supposed to pick-up but didn't. You cannot talk to anyone and all it caused was stress for my wife.

NEVER AGAIN.

Steve

Simon, a little more info would (NPI) help. What are you trying to achieve, what wood, what shape PVC - rigid or plasticised, the type of bond, application?

Steve

Neil, have had a look to find the cellulose pads but can't find them. Where do you source yours from? I tend to use wet kitchen roll pads for soldering irons.

Steve

I tend to use cardboard scraps just prior to printing to clean the nozzle surface. What I tend to do is to wind back the filament after each run so during preheat there is none hanging about in the nozzle.

Another thing is I use purge filament regularly (about 20mm of filament) to clean out the nozzle as it is highly stabilised and pushes out any partly decomposed filament.

I tend to only use ABS filaments as PLA, I am lead to believe, will degrade in damp environments over a period of time.

Steve

Barrie,

The link you attached makes for interesting reading. Coming from the plastics industry I am aware and have used corona treatment prior to printing or applying coatings to plastics. Flame treatment was always something that was hit or miss and potentially dangerous in the environments in which we used to work and therefore was not suitable.

I would take issue with the accuracy of the document since it clearly states " The material itself is not particularly high performance and will deform and melt at high temperatures and be easily attacked by solvents. This makes solvent welding, ultrasonic or infrared welding or induction heating a good method of bonding polyethylene (to itself)"

I am not aware of any commonly available solvents for polyethylene - hence why it is used for packaging acetone and other highly volatile solvents and is used for the storage of hydrofluoric acid.

Flame treatment is a method that works but requires a fairly high level of skill to reduce the surface tension of the PE yet not melt or deform the base material.

Steve

Hi do not want to put a downer on this but if you are trying to bond polyethylene you are going to be disappointed as there are, to my knowledge, no conventional adhesives that will bond to polyethylene with any degree of adhesion under normal conditions.

Your best bet is to find a way to mechanically fix the gear such that it is keyed in some way.

First I would check what material the pulley is made of. Plastics that are characterised as olefins are notoriously difficult to bond to. Other plastics can be bonded but it is important to find what the material is.

Steve

Hi Dave,

Sorry to disagree again, but the ability to test for a speculative one-off (but may repeat again) pandemic is not what I would consider to be a part of the NHS which struggles to fund the day-to-day operation of a national health operation.

Without wishing to start a political debate, the cost of preparing for a pandemic that could never be forecast with any probability is part of the management of the country. Disaster planning on this scale should be separately funded and not part of the NHS. If, however the NHS has been asked to provide this service and funded appropriately then I would agree with you. I believe the health service has been doing the best with what it had.

I would repeat again that I believe the death/cases ratio is not something we should be measuring based on the flawed data we have available and is certainly not a reflection on the effectiveness of the UK health service

Steve

Dave,

I disagree. In the early days tests, in the majority of the UK, were only carried out on hospital admissions and therefore those needing medical care. This was due to the inability of the UK to carry out large numbers of tests at the time – I am aware of people who were not tested, although they asked to be, and are very likely to have had the CV (they holidayed in Austria at the time of the outbreak there and were poorly at home with the expected symptoms) .

Other countries in Europe and Asia were testing far more people who were not hospitalised and therefore who were counted as cases but probably much milder who recovered. We were not doing that to any great extent. So it is not a like for like comparison.

Thus, it is not a reflection on the effectiveness of the UK health service. Other countries who were testing at a far higher rate than we were will then obviously have a much better death/cases ratio.

Steve

SOD how on earth can you justify the deaths per case column. The UK has no idea (as is probably the case with most nations) how many cases there have been or are occurring each day so this is totally irrelevant.

Steve

Neil, I work in a business that tests RCD's and RCBO's by the many thousands each year, both new and used, and regularly find units that will not set under power due to internal failure of the monitoring circuitry. They are not repairable and all that you can do is dump them. We have a failure rate of about one in a hundred that fail in this manner - worryingly we also find about 2% that do not trip under severe fault currents - that is why it is essential to regularly test them using the test button which injects a small fault current into the circuit. As mentioned we also test new units which also occasionally fail.

Steve

Good God S-O-D you are a negative person.

Whilst this pandemic is causing huge stress and uncertainty for most people, it is from events like this that people with drive and initiative will have their hands forced for them to do something different and start-up on their own. Whilst you are right some will not be successful there will be a huge number who will and cottage industries will start up all over the country - some may even become SME's.

That is how a number of my friends (and I) have done it and then wished we only had done it sooner.

Steve

That is why copper is used as an antifouling on boats (old sailing ships were copper-clad and hence the expression "Copper clad investment" and why an exposed copper wire along the ridge tile will prevent the growth of moss etc on tiles.

Steve

Hi Barnabas,

Yes you are right , it is the DC component that causes the problem. You can use a basic AC type RCD which will trip on a pure AC fault but if the DC component is too high it may not trip. I am not an expert on VFD systems but the same problem can occur with charging systems for electric car charging systems and solar power installations.

It is no consolation for you but the price of Type B RCD's will drop as the demand increases.

I imagine that most people do not fit Type B units - probably from a lack of understanding they fit AC types.

My advice would be to do exactly as the manufacturer recommends as they are the experts but I would have thought that it is only the supply to the VFD that needs the Type B RCD and not the rest of the house.

Steve