Show all posts by user
Re: TAP-XXX Nozzle Contact Sensor - 3 years ago
I have just received the sensors and hope to work on them early next week. The plan is to set up some dummy beds - 220 mm square in 2mm and 4mm aluminium on my Cartesian Printer. I will initially try them in the manner that you designed them for and then look for areas where the signal might be compromised. To do this I will take the signal straight from the piezo to one of my own conditioners sby leadinglights - Tech-Talk
Re: Vacuum hold-down for 3D build surface. - 3 years ago
The bed is heated and in regular use at 60ºC and works well at 110ºC but as this temperature is used for ABS and ABS has too much edge curl for a vacuum hold down there has been no need for the higher temperature. The bottom of the bed with milled grooves for the heater wire can be seen on (right-hand picture) and the assembled heater can be seen on . Sealing works well with just a very thin smby leadinglights - General
Re: Kapton tape heated bed - 3 years ago
QuoteOldBikerPete...................You shouldn't have a problem with the different expansion of your steel bed and aluminium plate as your magnetic fixing method will allow the two to slide against each other.......... True as long as the bed is fairly rigid and the friction between magnets and steel plate is not too high. Thin beds and differential expansion is a recipe for stick-slip behaviorby leadinglights - Mechanics
Re: Kapton tape heated bed - 3 years ago
To get to higher powers a solid-state relay would be used for DC and either a solid-state relay or an SCR with a zero-crossing driver for an AC circuit. I can't recommend any particular one but I am sure I have seen such recommendations on this forum in the past. Mikeby leadinglights - Mechanics
Re: Kapton tape heated bed - 3 years ago
As VDX says, even 300mm cube is a stretch. The reason that the RepRap movement took off was that at 200mm cube, or even better, at 150mm cube, simple construction and materials like float glass, could give astonishing accuracy and speed. this was sort of a magic size for the DIY world. One way a DIY maker could make a large 3D printer is to allow very undemanding tolerances which can be used toby leadinglights - Mechanics
Re: A new, smaller sand table mechanism: Arrakis - 3 years ago
Video please. Mikeby leadinglights - CoreXY Machines
Re: Making larger parts suitable for higher RPM's - 3 years ago
I am a little confused here (it may be because of the 1960s) but can you clarify whether you want to make a fan for a scale model motor, a pattern for a fan for a scale model or full-size motor, or a 3d printed fan? I am assuming that it is a pattern to sand cast a full-size fan that you want. Although I can't speak for all cases, from the designs I have created, I think that simply setting theby leadinglights - Let's design something! (I've got an idea ...)
Re: Kapton tape heated bed - 3 years ago
I won't say don't use a base as thin as 3mm as it may work satisfactorily for whatever your tolerances but generally 5mm thickness is a consensus minimum for a 300mm square bed. 6mm is better and cast aluminium tooling plate as recommended by DD is good. For smaller beds the options are much more open - even using 3mm float glass directly on a heater has worked. There is a potential pitfall whenby leadinglights - Mechanics
Re: Kapton tape heated bed - 3 years ago
The power consumed by a resistor is equal to the voltage squared divided by its resistance. The resistance is dependant on the material (copper) and is proportional to the length of the conductor (wire or foil) and also to 1 divided by the cross sectional area. For the 1mil (0.025mm) by 6mm wide this is 0.15 square mm and the resistance will be about 1.11 ohms so power will be 514W. If the copperby leadinglights - Mechanics
Re: Kapton tape heated bed - 3 years ago
There are too many variables to give an accurate answer but approximately 1.12 Ohms at 24V and will need about about 520 Watts - slightly less when hot. This is based on 1mil (0.025mm) thick rolled copper. My guess is that you are using copper foil of the type made for stained glass. Note that tape is not specified for esistance and comes in 1.25mil and 1.5mil. Mikeby leadinglights - Mechanics
Re: 
Get a PhD for doing RepRap Research - 3 years ago
Why didn't you offer these PhDs 55 years ago? O.K., I guess there were no 3D printers, no internet and I guess you probably weren't even born. Mikeby leadinglights - General
Re: Looking for small bore flexible air hose for print cooling - 3 years ago
Quotethe_digital_dentist You can't use teflon tubing of the type used for bowden tubes for extruders? Standard Bowden tube is the fallback position but it would be nice to get as much flexibility in the various wires, conduits, and pipes going to the effector/carriage as possible. In the case of the proposed cooling tube at 10 bar pressure, there will be an additional force straightening the tubeby leadinglights - Tech-Talk
Re: Looking for small bore flexible air hose for print cooling - 3 years ago
Thank you for the pointer to the McMaster-Carr website, like the Misumi and Accu websites it has many things for the mad scientist but often available if you are a registered business. As you point out though, if something can be found on their catalogues it can often be found elsewhere (eBay) at an inflated price. I will probably use a polyurethane tube as suggested by VDX although it is more rby leadinglights - Tech-Talk
Re: TAP-XXX Nozzle Contact Sensor - 3 years ago
I have ordered an AXE027 cable and will download the software and drivers. I will run some tests and report back with results. Mikeby leadinglights - Tech-Talk
Looking for small bore flexible air hose for print cooling - 3 years ago
I am hoping to pick the minds of somebody on this forum who may know where to get small diameter reinforced flexible tubing. What I need is something with a bore of about 2mm which is able to deliver air at a pressure of about 10 bar (1.0MPa, 145psi) while being both flexible and lightweight. The need for this is to deliver air for "near field" part cooling immediately after the nozzle on a 3D pby leadinglights - Tech-Talk
Re: TAP-XXX Nozzle Contact Sensor - 3 years ago
PM with address sent. I agree about automation having unpleasant surprises for the unwary. My own favorite aircraft was a Piper J3 "VP-YEM" without so much as a starter - the only electrics were the mag switches Mikeby leadinglights - Tech-Talk
Re: TAP-XXX Nozzle Contact Sensor - 3 years ago
A nice demonstration, but for my peace of mind that it is truly consistent, can you try the following. Get a map of the surface using at least a 5 by 5 grid and save the readings. Move the sensor to two other positions fairly far from, and not symmetrically the same as the first position Repeat the mapping of the surface for each new position. Compare the grids, subtracting each from the originby leadinglights - Tech-Talk
Re: Extruder Temperature Sensors - 3 years ago
Quoterq3 ........................................... Should I gold flash the silver heat block? It's immersion gold, takes 30 seconds. Pros, Cons? Looks cool, costs money, wastes resources, adds corrosion protection (not). While I don't know for sure if silver will tarnish in a hotend/plastic fume environment, I can offer the following supporting evidence:- My pure copper hotend bodies were insby leadinglights - Tech-Talk
Re: Extruder Temperature Sensors - 3 years ago
I did not realize that platinum RTD sensors were available at low cost and in small sizes. The last time I used a PT100 sensor it was fiercely expensive, quite bulky and needed a dedicated amplifier. For the time being I will stay with my thermocouples for the reasons stated earlier but hope to find a project where I can use a PT1000 sensor. In passing though, to go with your platinum sensor, sby leadinglights - Tech-Talk
Re: Extruder Temperature Sensors - 3 years ago
I tend to use thermocouples for hotends – this is not to disagree with your points, but I find the absolute accuracy is not too important as keeping the delivered temperature constant. From this point of view, does the temperature change with plastic flow and other causes such as unwanted nozzle cooling, limitations on the PDI control etc.. Resolution for thermocouples can be similar to thermistoby leadinglights - Tech-Talk
Re: Compact Belt Idler/Tensioner - 3 years ago
Regardless of the merits of the idea, there tends to be little discussion of this posting, or of many others because:- Most of the 275 hits (at this time) were from net indexing bots. Many of what remains were from people looking for stimulation who click on several items a minute in a daze of apathy. Some are from people who would contribute but are afraid of trolls and smart-arses disagreeingby leadinglights - Mechanics
Re: racial supremacy is allowed in reprap.org 2.0 - 3 years ago
For info, ayozek did try to get a discussion going on Reddit, but it was removed by the moderators in about 2 hours Mikeby leadinglights - Administration, Announcements, Policy
Re: racial supremacy is allowed in reprap.org 2.0 - 3 years ago
Now reported as you can neither justify your threats, or cite any reason for your definitely hateful and possibly racially motivated remarks. Mikeby leadinglights - Administration, Announcements, Policy
Re: racial supremacy is allowed in reprap.org 2.0 - 3 years ago
Please put links to Reddit and other any other forums where you discuss this. Links to the case in the EHCR would also be informative. I would be interested in knowing what part or words or alternatively what construction of meaning you put on VDK's posting as quoted below. QuoteVDK ... if you're intereted, how ressources can be badly dumped or wasted, then look for chinese "tofu-dreg" projectsby leadinglights - Administration, Announcements, Policy
Re: recycled plastics,metals and geopolymers, biopolymers for numerical machines (extended) - 3 years ago
Quoting from your earlier posting Quoteayozek ...............i do not reply nor play the game with racial supremacists, for them i only use exposing, shaming, rejection or violence if necessary. ............. Do you realize that threatening violence is actually illegal in most countries. Another point, quoting again from your last post, you use a term which could be construed as being intended tby leadinglights - General
Re: recycled plastics,metals and geopolymers, biopolymers for numerical machines (extended) - 3 years ago
I find it hard to find anything in the posting by VDX that appears to be what ayozek is complaining about - perhaps not capitalizing the word Chinese?? QuoteVDX ... if you're intereted, how ressources can be badly dumped or wasted, then look for chinese "tofu-dreg" projects Finding the conduct of a nation reprehensible does not equate with insulting the peoples of that nation as that conduct isby leadinglights - General
Re: Silver Heat Block - 3 years ago
The figures I get for volumetric heat capacity are from and I get J/g.K g/cm3 J/cm3.K Aluminium 0.900 2.7 2.4300 Silver 0.233 10.5 2.4465 Copper 0.386 8.9 3.4354 The thermal conductivity of Aluminium alloys is significantly worse than pure Aluminium, but compared with Copper alloys itby leadinglights - Tech-Talk
Re: Silver Heat Block - 3 years ago
I would be interested to see what your results are as I looked in some depth at various materials and geometries for hotends and came to the conclusion that the race is a lot closer than you might think. One starting assumption that I used is that having a high specific heat is a good thingas it acts a a heat store while the heater is trying to catch up. From this point of view, while Silver hasby leadinglights - Tech-Talk
Re: Metal ball joints source? - 3 years ago
The MP Jet joints you pointed at do seem far too small. I would suggest searching for "rose joint" or "Rod End" on Google. Alternatively you could also look at Igus ball joints which are either partly plastic or all plastic but out-perform most all metal ball joints. Another possible is to look at magnetic joints - use Haydn Huntley's joints Don't make your own magnetic joints unless you haveby leadinglights - Delta Machines
Re: Delta home issue - 3 years ago
I only used "G0 Z20" as an example so it would not crash into the bed. When you did "G0 Z0", did the effector go down to the bed or move at all? Were there any erro reports? Mikeby leadinglights - Delta Machines