Member postings for Colin LLoyd

The recent discussion in MEW regarding the problem of dew-point condensation in workshops and the effect of such on machine tools (to which I added my penny'worth) has prompted me to think of this from another angle. Rather than maintaining a workshop either above the current ambient dew-point temperature or reducing the workshop humidity to reduce the condensation problem - why not raise the temperature of susceptible machines themselves above the ambient workshop dew-point temperature. Lathes and Milling machines have large metal masses - which creates hysteresis problems when external temperatures change. A cold workshop-machine environment may not have condensation problems until warm air with higher humidity enters the workshop space. Small items will rapidly adapt to the new environment - but large machines will lag behind and provide condensation surfaces. Maintaining these machines just a few degrees above the workshop dew-point temperature would solve the condensation-onto-machine problem. Heating tapes are often used to stop items freezing - and I've found tapes that provide low Wattage outputs (12W per metre, 20W per metre). These outputs are similar to greenhouse heaters. An added advantage is that the machines themselves would act as "greenhouse heaters" in themselves providing heat to the workshop.

Has anybody had experience of using heating tapes in such a way - or am I just being a bit daft.

Please keep this forum thread informed about your experience with this machine - it's good points and any bad points. This is a new way of doing it and if it's as good as the video shows - I might get one.

I have always used the A4 sheet (or part of) paper method and had no problems with nozzle-to-print-bed distance. I just go to each of the X-Y corners and do a "Home"-Z operation with a sheet of A4 paper below the nozzle and adjust the bed adjustment screw at that corner until the Home-Z operation is such that I can easily but with slight resistance pull the paper out from under the nozzle. I then go to each corner in turn and repeat - before going to the centre of the bed for a check measurement. For large discrepancies (i.e. when setting up or after changing nozzles) you may need to go around again and repeat the procedure - but in general use this nozzle-print bed distance is just a check-before-printing exercise and might need just a tweat if you are fastidious. My placement of the 3D printer doesn't lend itself to Neil's "reflection" method - and I'm not sure my eyes are that good any more - especially if I've had a glass or two of wine the previous night.

Neil - I look forward to your experience with 0.2mm nozzles. I went up from the supplied 0.3mm brass nozzles to 0.4mm stainless steel - mainly for speed of printing (and steel for longevity). Most of my 3D printing is for robust functional items - so I don't need a delicate touch - just quickly created items.

Will the stepper motor/filament feed mechanism be strong enough to supply melted filament through such a narrow orifice? Also - can you get 0.2mm drills to clear out blocked nozzles?

Colin

Iain - there are, of course, 3D printers "Ready-2-Go" but at a price. I found that building mine I learnt a lot that served me when things went wrong. With an assembled unit - this learning phase is missing - but the assembled unit will still go wrong - and you generally have no idea why.

Neil and Rod - I just don't like things waggling around. I appreciate that there might not be a performance "hit" from not constraining the vertical screw and actually mine is able to waggle by about 1mm in its top location hole.

With regard to wiring - I've put all the "flying" leads from the extruder unit (Fan, Heater,Thermistor) onto inline miniature plugs and sockets with drone-type LiPo battery XT60 plugs/sockets to take the extra amperage for the Heater. The stepper motor already has a plug/socket attachment. This is so I can easily remove the entire unit for servicing, clearing blocked nozzles, etc. - so much easier to do away from the printer.

Mine was a kit from China - and I had no problems with mis-functioning items. As most of the items in the Factory 3D printer were almost certainly made in China - the power supply, the interface board, the stepper motors, the extrusion unit, etc. with only the frame probably being made by Factory 3D, it's not really on to criticise Chinese kits,

From the Factory 3D site photographs of the Prusa i3 Printer - the thing I don't like about it is the lack of top support for the z-axis screw thread movement - but I may be wrong - difficult to see from the photos. And the support and screw travel rods are only M5 - the Geeetech's are 7mm in diameter. And just a single vertical aluminium plate to hang everything off ? The Geeetech Prusa i3 (and similar clones) have a 3-dimensional box-like frame that provides great rigidity to the x,y,z movements. I wouldn't swap my Geeetech for the Factory 3D Prusa printer based on what I can see from the Factory 3D website.

Hi Dave,

Yes - I've exported (and used) Shipping containers to both west Africa (1987) and Siberia (1999) for use as fieldwork office/labs. In west Africa - they were unbearable hot when the temperatures reached 45 deg C in May. In Siberia - I sent out "Office" containers that had windows, normal doors, internal wall cladding and installed electrical wiring/sockets to an external mains socket for attachment to a generator. It's probably still out there.

Colin

Hi Howard - so what was the ramification of the "slab" mistake? Was the composite slab/sand/cement bounded by a solid wall of some sort - without this the outer sand/cement will tend to slip away allowing the outer slabs to tilt. I'm planning to concrete in concrete blocks - both around the slab perimeter and an inner pattern to support the inner edges of the slabs These inner areas to be filled with hardcore and sand - this should provide the stability of a concrete base with the ease and convenience of using slabs (I don't have easy access to the back garden for moving a concrete mixer and constituent loose ballast and sand).

On the power supply issue - I was planning to bury 30A armoured cable from the external house supply to the workshop 7m away - not because I need 30A but to provide more strength and minimise voltage loss down the cable - although this is only about 0.6 volts

Wow - thanks for all the replies. Perhaps I should have mentioned that I'm 70 years old - so I'm not looking for a shed that will last 25 years. Secondly, the change of integral garage to Office/Guest Room will use up a fair amount of my time and money - so a quick easy shed-workshop is required.

To Silly Old Duffer-Dave: Although the present garage-workshop is comforting, it has been put together over many years in an ad-hoc "bits here - bits there" process - so the idea of a workshop where I can fully plan where things go and make bespoke benches, cupboards, shelves etc as well as getting rid of accumulated waste (e.g. why have I kept 20-odd old metal 3-pin wall sockets?) - and no disrespect to Peak4-Bill but I thought his picture was actually my workshop. And It does make sense - you can't put modern cars into 1960's built garages and around here - the conversion adds 10% to the value of the house - because we have front drive space for 2 vehicles and a caravan.

Which brings me to workshop base construction: my paver drive frontage on hardcore and sand "whackered down" supports 2 SUV cars and a caravan without any problem - so anything along these lines (concrete slabs over compacted hardcore and sand inside a concrete block surround) seems adequate for my needs.

I expect to reinforce the inside of the shed with extra timber to improve stability, as well as specify extra thick flooring and insulate the timber sections behind extra plywood sheets.

Having said all that, I appreciate and was intrigued by the many solutions to the problem. Twenty years ago, I would have followed the build-it-yourself route - as I have on many previous occasions - but not this time. I need to get a shed up quick and easy, move everything into it, and start/finish the garage conversion - all before we start our many annual caravan trips around the UK in April.

Colin

The one who must be obeyed has said I need to convert our integral garage into a normal room. This is where all my workshop equipment is. So I am going to build a workshop in the back garden. Does anyone have recommendations for shed suppliers.

I've ruled out Metal sheds because of condensation problems and also concrete block construction - too long a wait for base to dry out and not very nice to look at.

So a wooden shed - 12ft (or14) x 8ft (or 10). Tongued and grooved - double doors - windows not necessary. Will make all benches, shelves, cupboards self standing. My machinery is not very heavy (Mini-lathe, similar Milling machine, CNC router/engraver, scroll saw, and all the gubbins that go with these + power tools etc. I expect to put down a heavy duty floor. (20mm

I'm not sure about the underlying base. Could do a concrete floor - again drying time a problem. Concrete slab base onto concrete blocks in the soil - or possibly these new plastic base units that interlock and you fill with pea shingle.

I've heard good things about Dunster House sheds, also BillyOh. The budget is about £1000 - but could go slightly higher if product is highly rated. Any suggestions, information or comments on my proposed design is welcome.

Yes - the pipe and elbows just doesn't seem to fit with the rest of the kit - but you are right. The ejector pin is for pushing out filament from the ejector nozzle when the filament breaks - seems to only occur with PLA (not ABS) - something to do with moisture making the PLA less stable. You then have to use the normal Filament advance or retract in your software to try and get the broken off filament bit out - you can only do this with the ejector heater on at filament melt temperature. If you are lucky the filament comes out leaving a clear nozzle tube for the new filament. Hasn't happened to me yet - usually some filament remains in the nozzle pipe. The ejector pin is then used to push the remaining filament out of the nozzle (still at ejector temperature) or at least sufficiently for the new filament to find its way down part of the nozzle tube. I warn you - this is the part of the whole 3D printing that has caused me endless trouble - always fixable but a pain in the butt. Generally I find myself taking the whole stepper motor/filament advance/fan/ejector block off the Y-axis support plate and taking it all apart - and then having to carefully drill out the filament from the support tube and the nozzle hole (you can buy 0.3 and 0.4mm drills). It's one of the reasons I now only print in ABS - the filament doesn't break off. For my prints, ABS is a better material than PLA anyway - as they are generally going to go outdoors in the elements where PLA will just melt away. Once you have got things going - or even before - I recommend you buy some steel 0.4mm nozzles - much better and longer lasting than the brass ones supplied.

Ah - so it's not just useful for novices. As an ex-scientist, I always want to observe, measure and record my actions. Not for me the "it feels right" approach - although I am starting to get that with experience. If I can duplicate settings from previous recorded observations - I'm more at home. I'm not denigrating those engineers who "fly by the seat of their pants" - it just isn't how I operate. And with CNC machines - there is little opportunity for a machining by feel approach - nearly everything has to be set up correctly beforehand - and digital appreciation of many of the factors in normal lathe and milling operations feeds directly into CNC operation.

Tachometers are quite useful if you happen to be a novice. They provide you with a visual guide to spindle speed and a link to the recommended operatingspeed based on material, object diameter and all the other factors that experienced machinists know off by heart. Eventually I won't need to use the tachometer - but at present, I find they provide me with a safety starting point on the lathe and milling machine. Rally drivers never look at their speedometers but novice drivers would be well advised to just glance at their speedometer before taking that sharp bend.

So next time I get a 3D printer - it will be in Aluminium

Colin

Neil - you teaser - you can't do that - we need to know what the modification is.

Colin

My 3D printer has a laser cut Acrylic frame. All the pieces are 8mm thick and they connect together very well generally with mortise & tenon joints- no sloppiness seen in any of the joints - in some cases a little too tight - and this is where Acrylic falls down a little bit - if you use force - the acrylic is easily broken. You also need to be careful with the retaining bolts - again over-tightening will crack the acrylic. But the bolts are there just to maintain position - not to provide frame strength. But apart from that, the acrylic frame is solid and stable and I've had no trouble with any of it.

Aluminium sound like it should be better - but I think this depends on how thick the Aluminium is and how that affects stiffness and stability. There is little chance of deforming Acrylic - it will just break. Thin aluminium may deform if something goes wrong and solving a printing problem because your frame is slightly bent may take some time to discover. If I could have a frame made from 8mm thick Aluminium - I would. If the Aluminium frame is only a few millimetres thick - I would prefer a well-made Acrylic frame.

Will do both of these - just need to apply same techniques as for small mill machines - don't try to do too much at once - the router/engraver motor is not built for strenuous loads - neither are the engraver bits and end-mills that you can use with these machines. But this can all be set up in the design and operating CNC software - then just leave the machine to get on with the work while you go and have a cup of tea. I've found it easier to work with steel than aluminium - latter tends to soften and clog both the path of the machine and the tool-bits. Coolant can help but difficult to apply to flat sheets without constant supervision. Wood is no problem and you can make some impressive 3D pictures in wood with these machines.

Colin

Posted by XD 351 on 02/01/2018 19:22:16:

Colin ,Joseph and Neil thanls for the reples !

Colin , i have just had a look at those engravers and for around $700 au they would do 99 % of what i will ever need which is mostly pc boards and plastic lables do you think they are capable enough to make brass name plates using a small 1.5 a- 2mm end mill?

With the router i was thinking more along the lines of being able to machine holes in plastic and alloy up to 2mm thick for plastic and 1 mm for alloy to make front panels for some projects and carving out recesses in timber engine mounting boards etc , i currently do all this on my mill so not something i'm dsperate for !

Ian.

Hi Ian, - yes they will easily do PC boards and brass name plates - not sure about the plastic lables - depends on how hard it is - the tool may tend to melt lesser plastics. Just to show the capability of these machines, see attached "dragon" engraved on mild steel plate and a scroll-saw picture with a name label in stainless steel made for a Danish friend's son (Bjorn). I went against my previous recommendation to start off simple with the "dragon" this was one of my first attempts. I'm currently trying to do copies of old-time engravings with interrupted horizontal lines defining the image - the problem I have is trying to get the G-code to just do a single line rather than the outline of the line - this is more a design problem rather than a CNC machine problem.

Colin

Hi Joe - don't worry - no fire and flames from me - everything is down to personal choice. I started to use Linux way back in 1999 with Corel One - it was even geekier and harder then. Having constantly gone down the Linux path since then except when employer dictats forced me to use Microsoft for work (even then I dual-booted works PCs so that I could use Linux), Mach3 was not really an option. And being new to CNC anyway, I didn't have any pre-conceived idea of how CNC software worked. Conceived and comfortable ideas also raised their head when Microsoft went from Tabbed menus to Ribbon menus in their Office Suite- how convoluted and unnecessary was that - something that doesn't really happen in Linux - if people don't like what they have been given - they either go back and install what they like or fork the application and create something else.

As well as providing everything I need completely free - with a small global user base (not including the 500 biggest SuperComputers, the Internet and Android phones all using Linux) - its not on the radar of malicious hackers and even if it were, it's an inherently safe OS and being open-source, any possible breaches are quicker to be spotted and fixed by the tens of thousands of Linux developers than can ever be achieved by Microsoft or Apple.

But as you say, it's not for everybody - and I respect that point of view - no-one else in my family use Linux. Not quite true as my wife was having so much trouble with Windows 10 that I installed Zorin Linux (one of the Windows 7 look-alike Linux distributions) on her Laptop and she seems to be happily oblivious to the fact it's not Windows 7 - just looks like it and without the security troubles.

Colin

Sorry Ian - missed the point about a combined unit. Unless you go for a high-end 3D printer I don't think this will work. The forces that the 3D printer motors and support encounter in printing means that they are probably not good enough to withstand those forces encountered when routing or engraving metal. The lateral speed at which the CNC router engraver works is also far beyond those speeds on budget 3D printers. Just examining the control boards of my 3D printer and my CNC router shows me that the electronics in the CNC router are that much more powerful than the Arduino -powered control board of the 3D Printer. That's not to say it cannot be done - but I would recommend you try and dual-use a CNC Router rather than from the 3D Printer end - even though the initial price is that much higher.

Colin