3D Printers

[Stub Mandrel]

On 15/10/2019 at 16:15, Thalestris24 said:

I was wondering about that - do you just select a file to print from the card and leave it to it? No advantage in printing from a PC?

Louise

 

Yes, and if I'm doing 8-hour prints it means I'm not likely to hibernate the PC by accident...

[Chriske]

4 hours ago, Jkulin said:

OK I have got to ask, what people think of this 2019 Prusa i3 3D Printer DIY Kit MK3 Heatbed MK8 Extruder,Large Structure Size

For £73.19 would it be a waste of time or worth trying?

I thought maybe they were just selling the bed but they have confirmed "Our printers just need to be assembled to be a complete printable."

 

What I do not understand is that this guy can get away using the name 'Prusa' selling that wooden rubbish.

[Jkulin]

1 minute ago, Chriske said:

What I do not understand is that this guy can get away using the name 'Prusa' selling that wooden rubbish.

Fleabays ignorance sometimes shines in the wrong direction🙄

[Stub Mandrel]

1 hour ago, Chriske said:

What I do not understand is that this guy can get away using the name 'Prusa' selling that wooden rubbish.

Prusa is an open source design.

[gian]

6 hours ago, Chriske said:

Someone suggested  Google : 3d printer fire.
Do the same and Google also : washing-machine fire, dish-washing machines fire, laundry dryer fire...etc...

I'm not saying ignore safety measures, let that be clear.

the difference is here: it is safe to assume there is a washermachine in every house. so yes, occasionally they burn, but is a very rare event considering the installed base. 

plus washermachines have to go through testings and certifications. on average, they are built very very well, i have opened/fixed a few and the amount of engineering behind a washermachine is enormous. literally decades of evolution and millions/billions units built. 

on the other side, there might be one 3d printer every 1,000 houses or probably less, still you can find several cases of 3d printers burning. 

plus, a 3d printer will have up to over a kg of fuel sitting in close vicinity: the filament. 

i am far from being paranoid about fires, but i am aware of the limitations of 3d printers, the amount of engineering in them (pretty low, expecially the homebuilt ones...)  and the quality of the components used so i will leave a washermachine running unattended, but i will not do that with my 3d printer just yet...

power supplies: yes i know most PSU are chinese built nowadays but there are huge differences in build quality, materials used, design. some are pretty good, some are just outright dangerous. plenty videos on YT of people taking apart chinese electronics and finding abysmal stuff. 

i have usually trusted them, until one PSU i fitted to a CNC router i built went in flames right in front of my eyes. amazingly, the PSU kept working until i switched everything off. 

a bad cap is enough to ruin your day, and chinese are not famous for using good quality caps and transformers, which are what stands between you and a fire or an electrocution in a switching power supply. 

All printers are protected by a firmware setting

i work in software industry, pretty big and expensive stuff. 
trusting my life on firmware? nnnope....

gmr 

 

[Thalestris24]

4 hours ago, Stub Mandrel said:

Yes, and if I'm doing 8-hour prints it means I'm not likely to hibernate the PC by accident...

Yeah, I think especially for the simple, straightforward printing I'll be doing, just using the sd card seems fine. I wouldn't leave my printer running unsupervised, though. Probably not overnight either, even though it's very quiet!

Louise

[PeterW]

genuine Pruse stuff starts at around £300, that sounds like a cheap clone and not worth getting. Prusa is based off opensource, but they’ve improved it and they deliver very good results. The only hot bit on the printer is the nozzle and that can really only melt a tiny bit of material, so I’m not too concerned about long runs. I’ve had print stops where the head stays hot with filament in and cases where the head thermocouple fails and the heater runs off and “the magic smoke expires”.  I’d make sure the printer is sat on a nicely non flammable surface and away from stuff that could be made to burn. Of course, everyone should make themselves happy with the choices they take, each printer will behave in its own random way (don’t you just love them!)

A professional FDM user was bemoaning the lack of sensorS on even the Pro FDM machines, compared to over 100 sensors on the latest metal laser sintering machines. there is certainly still some improvements that could be made.

Peter

[Gina]

If you're an electrical engineer there's one advantage of building your own printer - you can select reliable components and build in failsafe protection.  My first printer was a pretty pricey kit.  As an experienced engineer I found many things wrong with it.  Some I was able to fix but in the end decided to build my own.  I have never looked back.

[saac]

9 hours ago, gian said:

PLA mechanical qualities are too poor for prodicing parts that will see real world use. 

 

 

I'll disagree with you on that one gian. The brackets I have printed in PLA do indeed have the mechanical and aesthetic properties for their intended application (adjustable bed for K40 laser engraver). Likewise the PLA printed assembly to hold the beam combiner will also function without difficulty.  My Polemaster camera when not mounted for polar alignment functions as an electronic finder held in place by a PLA printed adaptor  and has functioned perfectly well over the past 2 years.   I certainly wouldn't look to use PLA for a third stage RB199 turbine blade nor a wing box on an Airbus, but neither would I use mild steel, aluminium or carbon composite . However, PLA certainly does have "real world " application.  In common with any other engineering/manufacturing project material selection is part of the design consideration - 3D printing is not exempt from that consideration. To say however that PLA is not suitable for real world applications perhaps calls for a broader definition of "real world"  - my uses to date are certainly real world and PLA has satisfied the design brief very well. 

 

Jim 

Edited October 21, 2019 by saac

[Gina]

I'm getting a feeling of déjà vu here -  I think I have already said that I've found PLA eminently suitable for a number of applications.  I've used it plenty in astro projects, for instance.

[saac]

25 minutes ago, Gina said:

I'm getting a feeling of déjà vu here -  I think I have already said that I've found PLA eminently suitable for a number of applications.  I've used it plenty in astro projects, for instance.

To be honest Gina I think the world of 3D printing and its wide range of filament materials opens up an aspect of engineering design to many whom it may otherwise never really have been a consideration.  We both come from engineering backgrounds so these considerations are well understood but I guess the assortment of filaments can be confusing to many.  Like any hobby/interest there abounds misconceptions and "urban legends" - the 1 cubic meter  pier foundation syndrome comes to mind   

With specific respect to PLA I think it is a good all rounder:  inexpensive, good printing performance , no toxic fumes emitted.  It is a good general purpose filament and where it does lack a particular property then other filaments can be chosen with printer capability also in mind. The Ender 3 and 5 models are PLA and ABS capable but at the moment, certainly  for my needs, I can't see a need to use ABS yet and certainly not without some form of enclosure and fume extraction.  Ill be printing PLA for some time to come before I start on my 3D printed cold fusion reactor  

 Jim 

Edited October 21, 2019 by saac

[PeterW]

People are starting to make rocket nozzles with 3D printing. The latest machines make material with better properties than wrought, but there are still concerns about the cost effective validation of parts that are hindering uptake. Some lower temperature turbine blades and blade repairs are being undertaken already. All users need to assess the properties they need and the risk and implications of failure. Many people are happy with cast material which can have many more internal defects....  the technology continues to rapidly evolve, so what wasn’t possible a few years back is now easy to achieve.... interesting times.

 

PEter

[saac]

16 minutes ago, PeterW said:

People are starting to make rocket nozzles with 3D printing. The latest machines make material with better properties than wrought, but there are still concerns about the cost effective validation of parts that are hindering uptake. Some lower temperature turbine blades and blade repairs are being undertaken already. All users need to assess the properties they need and the risk and implications of failure. Many people are happy with cast material which can have many more internal defects....  the technology continues to rapidly evolve, so what wasn’t possible a few years back is now easy to achieve.... interesting times.

 

PEter

Indeed Peter but not with PLA  

Just out of interest additive layer or even sintering technology would have to progress beyond imagination to meet the performance of Rolls Royce single crystal blade technology.  But as you say some very interesting things are happening in the world of industrial 3D printing particularly in aerospace where a range of components are now 3D printed (both metal and non metal) .  The method of manufacture, cold pressing, forging, casting, fabrication etc has always had an influence on the mechanical properties of material (advantageous and undesired) , it's an area of engineering science well known to design engineers. 3D printing is no different. 

JIm 

Edited October 21, 2019 by saac

[Stub Mandrel]

9 hours ago, Chriske said:

Someone suggested  Google : 3d printer fire.
Do the same and Google also : washing-machine fire, dish-washing machines fire, laundry dryer fire...etc...

I'm not saying ignore safety measures, let that be clear.

Google 'Tumble Drier Fire UK'... should keep you entertained for a few days!

[Stub Mandrel]

I had one nasty failure - the heater cartridge came loose, at height the increased wire tension led to it falling out. I discovered a VERY hot cartridge stirring a lump of semi-molten PLA.

[teoria_del_big_bang]

22 hours ago, Gina said:

rigid.ink was just about the very best but they are not selling filament any more. The Economy range from colorFabb in The Netherlands is a lot cheaper pro rata and very good.  You might have a problem accommodating their very large reels though.

Yes that was good filament, but was expensive. I did not know they were not selling it anymore 😞 

Steve

[saac]

1 hour ago, teoria_del_big_bang said:

Yes that was good filament, but was expensive. I did not know they were not selling it anymore 😞 

Steve

I certainly saw a lot of positive recommendations for as well Steve  but pricey compared to others. That said I'd be tempted to try an expensive brand against the likes of Creality own brand which has performed well for me so far . Christmas is coming so I'm drawing up a list now  - a reel of plastics , oh how days have changed  

Jim  

Edited October 21, 2019 by saac

[ejp1684]

Referring to an earlier post about Prusa i3 printers, I bought one from ebay about three years ago, and it's still going strong. I also use dirt cheap PLA, again from ebay, for about £10 or £12, and they have performed as well as a £33 one from rigid.ink. In my experience 3D printing is as much an art as a science; it took me many hours to work out all the settings to produce quality prints good enough for my purposes. And by that I mean successfully printing all the parts for the Lowspec spectrograph, including all the screw threads where necessary, which surprised me.

Eric.

[saac]

1 minute ago, ejp1684 said:

Referring to an earlier post about Prusa i3 printers, I bought one from ebay about three years ago, and it's still going strong. I also use dirt cheap PLA, again from ebay, for about £10 or £12, and they have performed as well as a £33 one from rigid.ink. In my experience 3D printing is as much an art as a science; it took me many hours to work out all the settings to produce quality prints good enough for my purposes. And by that I mean successfully printing all the parts for the Lowspec spectrograph, including all the screw threads where necessary, which surprised me.

Eric.

Eric, can I ask how has the Lowspec spectrograph performed for you, would you recommend it as a project?

Jim 

[ejp1684]

Hi Jim.

I posted about my experiences with Lowspec earlier in the year here. I've done quite a bit since (weather permitting!) and a couple of nights ago obtained some nice spectra in Cygnus. I've been using a 150pds so far but I now have a 200pds on order which I hope will give even better results.

In short, I would recommend it as a project. It took me quite a few hours to complete, especially filing down the moving parts which hold the grating so it rotates smoothly, but well worth it.

Eric.

[saac]

19 minutes ago, ejp1684 said:

Hi Jim.

I posted about my experiences with Lowspec earlier in the year here. I've done quite a bit since (weather permitting!) and a couple of nights ago obtained some nice spectra in Cygnus. I've been using a 150pds so far but I now have a 200pds on order which I hope will give even better results.

In short, I would recommend it as a project. It took me quite a few hours to complete, especially filing down the moving parts which hold the grating so it rotates smoothly, but well worth it.

Eric.

Thanks Eric I think I'll definitely try it out. I've played around with the Star Analyser and managed to produce a decent looking spectra of Vega using rspec. I stopped short of getting my head round correcting for instrument response but I've always wanted to go back and pick it up again. The Lowspec looks like a very neat little unit - thanks for the link to your write up, following that now. 

Jim 

[Thalestris24]

52 minutes ago, ejp1684 said:

Referring to an earlier post about Prusa i3 printers, I bought one from ebay about three years ago, and it's still going strong. I also use dirt cheap PLA, again from ebay, for about £10 or £12, and they have performed as well as a £33 one from rigid.ink. In my experience 3D printing is as much an art as a science; it took me many hours to work out all the settings to produce quality prints good enough for my purposes. And by that I mean successfully printing all the parts for the Lowspec spectrograph, including all the screw threads where necessary, which surprised me.

Eric.

Ooh that's what I'm doing! How have you found your Lowspec?

Louise

ps did you try the 1800 line grating?

Edited October 21, 2019 by Thalestris24

[ejp1684]

2 hours ago, Thalestris24 said:

Ooh that's what I'm doing! How have you found your Lowspec?

Louise

ps did you try the 1800 line grating?

I enjoyed making it and getting it up and running. Like all slit spectroscopes it takes a bit of practice to use it effectively, but once you do, it works well. I haven't yet bought a 1800 line grating, they are about £120 (I think), but I'll do it when the piggy bank is ready.

Eric.

[Thalestris24]

4 minutes ago, ejp1684 said:

I enjoyed making it and getting it up and running. Like all slit spectroscopes it takes a bit of practice to use it effectively, but once you do, it works well. I haven't yet bought a 1800 line grating, they are about £120 (I think), but I'll do it when the piggy bank is ready.

Eric.

Oh ok

Paul Gerlach has suggested the gh25-18v (on Thingiverse) which is listed at £108.75 + VAT which does seem pricey for one component but not so much really. On the other hand I might be better off with a fewer lines/mm grating since I don't get great seeing here at the best of times and my aperture will be limited to 115mm. Also, the list prices for the lenses seem rather high for what they are - I'll have a look around for alternatives. As you say, half the fun is in building it, of course, though it would be nice to get some half-decent results out of it

Cheers

Louise

[RolandKol]

OMG...
I just found Tenlog 3D Hands 2...

Very interested..... they do have even larger ones.... cheap... but... this is probably that  I want 
please, talk me AWAY from THIS Purchase....