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The 0.2mm will form the outside wall, where the infill would be 0.5mm.
Doing that would allow good tolerance on precision gears, which is still a problem on the current nozzle diameter that is in general use.
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Grogyan
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New Zealand RepRap User Group
You could, however the larger you make the box, there will be a noticeable droop or sag in the X and Y axes which will interfere with the Z.
by
Grogyan
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General
Thanks
My RepStrap in still in progress, but will do some videos of that when its built.
by
Grogyan
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General
Discussion here on a full embedded C version of the Arduino code
At the moment there is no true embedded C code for the Arduino, and currently needs someone to translate the entire code to embedded C.
I see this as a priority as we move forward into V2.0 Mendel, having a full true embedded C version of the code base would mean that people are not limited to the processor. Also embedded C is t
by
Grogyan
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RepRap Host
Just to clarify to anyone else reading this, You're referring to ATMEL AVR studio?
You don't need to buy an Arduino chip, you can use any chip you like, just that the RepRap design is designed for the Arduino board.
Well it isn't made clear on the site or wiki that the code for the RepRap is an Arduino derivative of embedded C, and i'm not sure who you could ask in the core group to break it do
by
Grogyan
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General
Don't use them, the motors/gearmotors don't have much torque to be of any use in a RepRap, except on the Tamiya Extruder. The brushes will also break sooner, plus all the EMI that will come out of it.
If you go with the Tamiya extruder, you'll get the dc motor with the universal gearbox anyway.
Just my personal opinion
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Grogyan
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Mechanics
The Arduino's and Sanguino already use the Atmel devices.
The Arduino environment is terrible, in my opinion, and on my next project that will have to use an Arduino board, it will be coded with C.
Th Arduino's are programmed in a C++ variant, as they are marketing their product for the beginner to intermediate level of builders, who may not understand all the workings of C or C++ but would lik
by
Grogyan
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General
As normal, they heat up the plastic normally, then turn on the screw
Except we will not be having the worm drive reciprocate as they are in injection moulding.
The system for a RepRap will also mean that the system will operate vertically instead of horizontally as in injecting moulding
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Grogyan
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General
When I was in Saeco Precision a few weeks ago, I looked at their automotive timing belts, and there is 2 big reasons why we can't use them.
1) They're big, I mean really big, and seeing as we're trying to reduce the size of the thing that isn't a good idea.
2) On a lot of vehicles, the timing belt is ribbed differently, either laterally (length ways) or V shaped, neither of which would have eno
by
Grogyan
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Mechanics
If its a 1206, you can easily use solder down a through hole 100nF cap instead, heck, i've broken an SMD cap, 0402, and replaced it with a through hole capacitor.
by
Grogyan
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Controllers
Hey Andrew,
If you're going to build your own V1.2 mobo, it is certainly possible, just use a 0.8 or 0.9mm drill bit, available from Jaycar, and use a piece of wire soldered from both sides of the board to get your vias ok.
Clearances can be a problem, though you could try using Press n Peel, available from Jaycar, a friend of mine managed to get own to 5mil track and space with that stuff, so p
by
Grogyan
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Controllers
I'm just referring to the extrude when the drive train isn't moving and not actually printing anything.
Could you measure it for me please, and let me know what the diameter is, and the size of nozzle that you used too?
Thanks
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Grogyan
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Mechanics
Righteo, some news, got word back from various cnc businesses, and here is a real problem without more of a solution.
In order to get a 0.3 or 0.2mm hole just right to get roughly the same extrude diameter out requires that a dent in the end of the object to be machined, in my case its looking like dome nuts.
Putting a dent in the end causes a real problem, as the finish afterwards would mean th
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Grogyan
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Mechanics
jpcw Wrote:
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> sam0737 Wrote:
> --------------------------------------------------
> -----
> > A hopper extruder that accepts plastic in
> granule
> > form! Not necessary in one part, could be
> > hopper/extruder that produce 3mm filament than
> > feed into the existing extruder.
> >
> > I thin
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Grogyan
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General
Yeah, I meant during the wipe procedure sequence, that's the best time to do it, real-time monitoring would be pointless.
Unfortunately, PTFE is all that we can use, that is both cheap enough with good thermal characteristics.
I think I mentioned before somewhere that ceramics aren't very easy to machine, but there are a couple, its more likely to printout a mould for the thermal barrier and fil
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Grogyan
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Mechanics
Here is a very rough sketch. My apologies to Vik for using his photo
The Sketch shows a possible 2 head changer, just changing the geometry of the head changer would allow a 3 or even a 4 head changer
I've shown the extruder raised up a bit to see a proposed geometry for an extruder to slot into
As for a Darwin head changer, I personally wouldn't even waste my time on something so simple an
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Grogyan
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General
Simple, the rotary head changer notes in memory where the heads are, and so no two heads will be more than 270 degrees out of alignment before having to reverse in the other direction to select the next nozzle.
Of course i'm suggesting a 4 nozzle head changer, but the principle is till the same for a 3 nozzle head changer or even a 2 nozzle head changer.
I'll do a sketch if I can to show what i
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Grogyan
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General
sam0737 Wrote:
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> Oh wait. What's grogyan suggesting is interesting
> - the optical mouse.
>
> The optical mouse that we use everyday now on
> unmarked table, or even glass for some model. The
> one that we though unachievable 10 years ago and
> requires a marking mat to use.
>
> Two issues I can think of:
> 1.
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Grogyan
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Mechanics
Mendel, as a Darwin Auto head changer would reduce the physical work area.
At least that is what i've observed in the videos.
The Mendel head changer would be a rotary one on one side, using a stepper and a solenoid to lock, unlock and rotate through various heads.
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Grogyan
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General
I keep finding AoI buggy beyond use, frequently.
I use Blender for all my mechanical designing. You can even setup animations to see how certain sections would work. It does however a high learnung curve, but once you grasp the basics and hotkeys, its a pleasure to work with.
by
Grogyan
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Plastic Extruder Working Group
How about an Auto head changer, able to change between 2 or 3 heads.
by
Grogyan
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General
Yup, a granule feeder is one of things that is on the todo list, along with,
multiple heads
Auto head changing
Supporting a head that extrudes a support material
Though even with the idea in my head for auto head changing, it can't support a granule feeder, its just going to be too big.
Though, i'd like to throw to you an idea, and maybe you could design a hopper extruder based on that.
Coach
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Grogyan
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Mechanics
True, so how about maybe using an optical mouse to read the rate at which the extruded material is coming out?
All i'm suggesting is knowing for sure that stuff is coming out and how fast, as this in turn determines how much filament needs to be pushed through.
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Grogyan
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Mechanics
I'm going with thermocouple on mine, as thermistors aren't really meant to be used at the temperatures that being used in the RepRap project.
There is a simple kit, which you can pretty much free form anyways on veroboard, from MakerBot.
I haven't got my machine up and running yet so its just an idea.
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Grogyan
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Mechanics
I remember reading a couple of those before, thanks, forgot about them.
I believe the problem lies with the fact that they are just assuming the rate stuff is being extruded, instead of measuring it, as there is a hell a lot of force being applied to the extruder to push plastic through.
I'm not sure yet of a way it can be measured reliably, but a work around for the bulging, is a simple one th
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Grogyan
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Mechanics
Well I quickly created a wall (more of a blob really, but I did get the rough shape of a wall) of fire cement, roughly 15mm thick.
Don't try this unless you're prepared to get seriously burnt, this is extremely dangerous
With a butane torch on one side and my finger of the other, and I barely felt it go above ambient.
This means that it should be an excellent adhesive for the thermal barrie
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Grogyan
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Mechanics
I'm curious now, which blogs you're referring to with mechanical failure of the PTFE?
The biggest problem with the setup, is the adhesive, while there is little (i'm guessing here) heat transfer through the plastic, its the adhesive used that will break, epoxy weakens at around 100 degrees I have noticed at work, as I often use heat to chip off epoxy to get to where I want to get to for repairin
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Grogyan
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Mechanics
I thought I might post here my experience with finding and ultimately doing my own extruder nozzle design.
The story goes, trying to get a hold of 16mm dia PTFE rod and make the thermal barrier turned out to be near nigh on impossible, and seeing as I wanted to have extruder nozzles that can be unscrewed and switched,and also Tim Carr and Vik Olliver are working on RepRap kits for us kiwis, I st
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Grogyan
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Mechanics
Have you checked out the datasheet?
The L298 does however require external diodes for shoot through protection.
One thing that will likely break an h-bridge, but I dunno about chipped ones, but if two lines go high at the same time, that WILL blow up the h-bridge, trust me on this, i've done it, and learn't, just don't do it.
The chip already has shoot through diodes so you shouldn't need to
by
Grogyan
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Controllers
