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Re: Where can you get PLA? - 14 years ago

Its new stock, might not be on the site, drop them an e-mail, I had some transparent Red from them. Tony.

by tofletcher - Plastic Extruder Working Group

Re: Where can you get PLA? - 14 years ago

BFB has PLA in three colours, Clear, red and blue

by tofletcher - Plastic Extruder Working Group

Re: Anyone know a UK supplier of PLA? - 14 years ago

BfB has PLA in clear, red and blue. Check out the web site for details

by tofletcher - General

Re: Skeinforge Powwow - 15 years ago

Enrique, I have Activate Comb and 'Use Intermediate Feedrate in Corners' as you said. In the case above if the first line of code after the M101 was a long segment then it would be printed at a very high speed. Looking through the file this intermediate feed rate is only associated with M103 and M101 and not with other "corners" in the printed thread. This being the case then the change in spe

by tofletcher - Skeinforge

Re: Skeinforge Powwow - 15 years ago

Hi Enrique, can you give me a little more detail on how the following works? Below is a section from a skienforge G_Code file. The first block down to the M103 is a normal thread running at 960mm/min After the M103 Extruder off I have set a travel speed of 2400mm/min 1)Is the first line after M103 an acceleration, set half way between the 960 and 2400? 2)All the code between M103 and M101 is thi

by tofletcher - Skeinforge

Re: Warping - 15 years ago

1)Yes, the heater is just a large washer with an element stuck to the top surface. The bottom surface of the washer is mounted approx. 1mm back from the tip so it runs very close to the extruded filament 2&3)Yes, the idea is to warm the surrounding material ahead of the nozzle, then keep it warm after the nozzle has gone past. Tony

by tofletcher - General

Re: Warping - 15 years ago

The major factor for warping is not important as in both mechanisms stress is trapped in the filament. I figure that if we keep the head over the plastic longer then it will give time for the stress to relieve or for the surrounding plastic to expand so when things cool there will be a lower levels of internal stress. Rather than going slowly I have fitted another heater. The new design is usin

by tofletcher - General

Re: A few questions from a new user - 15 years ago

Hi Sam, Have a look at bitsfrombytes.com, it may be what you are looking for;-) Tony

by tofletcher - United Kingdom RepRap User Group

Re: Warping - 15 years ago

Nophead, thanks for your thoughts, Considering shrinkage as change in volume with temperature. If you put down a fixed volume of plastic in the form of a long filament then surely it does not matter when it freezes the change in volume per unit length is the same. The fact it freezes quickly means it shrinks quickly. If it is stuck down then the warping effect should be the same. For the warping

by tofletcher - General

Re: Warping - 15 years ago

Thanks for the feedback guys, philwaud, the effect I tried to describe is well defined and used in many fluid systems to calculate pumping powers and losses. Where I think it gets interesting in this application is the extream viscosity of the plastic, the material is very viscous through to solid. As a viscous fluid flows through a pipe it clings to the pipe wall reducing its velocity, fluid i

by tofletcher - General

Warping - 15 years ago

Sorry for my absence from the forums, I have been flat out on the BfB web site trying to make sure all the questions get answered. I thought the following few notes might kick off a thread. We have a large print table on the Darwin and the RapMan, it was inevitable that people would want to print larger objects. Size amplifies the warping effect to a point where it can ruin the object. With thi

by tofletcher - General

Re: Polypropylene - 15 years ago

Sorry about the mix up Chris, the polycarbonate is in 3mm x 2m coils, again Ian at BfB supplied it. First test suggests this could be a good material for extrusion. High temperature but a nice clean filament. I did not try to print so I have no idea on how it bonds to itself. The filament is in a coil that fits into an A5 envelope so quite flexible. I only have the one length that will be run a

by tofletcher - Plastic Extruder Working Group

Re: Polypropylene - 15 years ago

Hi Chris, the PP and PCL both came from BfB, I am sure Ian still has both materials in stock. The PP is in 3mm filament x 100m coil. The material is very flexible and tough. As for getting it to bond with itself - have a look at the pictures I posted in this blog. You can just about see how the layers are melted together. The resulting mini mug is very tough, it will flex across the rim with a v

by tofletcher - Plastic Extruder Working Group

Re: Polypropylene - 15 years ago

Sorry for the slow response, all my spare time has been taken doing finishing touches to the firmware on the new V3 laser cut machine. Regarding the extruder, I will try and put a few notes together over the next few days and post on the builders blog. Tony

by tofletcher - Plastic Extruder Working Group

Re: Polypropylene - 15 years ago

Forrest, Only a couple of hours actual printing with PP. Maybe half a day including trying to get a set-up that worked. I had four materials arrive at the same time, PCL, PLA, PP and Polycarbonate. I quickly tried each through the machine and chose to go with PCL and PLA for initial development. Main reasons for this were temperature. Polycarbonate was too high period(but will extrude and does

by tofletcher - Plastic Extruder Working Group

Re: Polypropylene - 15 years ago

Hi Forrest, All the recent parts have been produced using a BfB extruder with the twin motors, the same one you commented on when I posted the video clip of the working machine. The extruder has remained more or less unchanged. I have changed the hot end a couple of times to get a more consistent filament. The final version has now been in use for many hours of printing being very reliable and g

by tofletcher - Plastic Extruder Working Group

Re: Polypropylene - 15 years ago

This is as far as I have got with PP. Printed on to a PP base with no raft, temperatures were up at 240DegC. Tony

by tofletcher - Plastic Extruder Working Group

Re: reprap wireless link - 15 years ago

I have a slightly different solution, Serial Bluetooth adaptor on the machine and pick it up with a PC, PDA or Mobile phone. I am using Bluetooth on an instrumentation project passing quite high data rates. The instrument reads 4 sensors then transmits the data over Bluetooth to PC or PDA. I can view the data in real time on both PC and PDA plus do basic set-ups. When the Reprap gets kicked out

by tofletcher - Controllers

Re: Binary Format G_Code Files - 15 years ago

There are undoubtedly many ways to dish up the steps to the micro, both Chris and Forrest have post processed the coordinates into byte sized chunks to make it easy to work with. Running the PIC24 with a text file doing all the number crunching detailed above, it just about managed, segmented circles were the only area where I had any real problem. Circles defined using I's and J's ran fine. If

by tofletcher - RepRap Host

Re: Binary Format G_Code Files - 15 years ago

Me too, I tried it on the PIC24 and could not get it to show real improvment. Tony

by tofletcher - RepRap Host

Re: Binary Format G_Code Files - 15 years ago

Enrique, I never considered that this Binary format would be the sort of thing that could be included in the skeinforge tool chain. The short application I used to generate the binary file was written in VB.net, it takes standard G_Code and spits out a packed binary version. I don't know if I will be able to port it over to python any time soon but if there is general interest in the idea I wil

by tofletcher - RepRap Host

Re: Binary Format G_Code Files - 15 years ago

Wow Forrest, you don't mince your words do you! I had to come back on this one, G_Code is the way forward. Millions of CNC machines run on the stuff, its the default machine language. However you want to package it the REPRAP is a lightweight CNC machine with a new tool. I did the notes on Binary format to help out with segment pausing on low end processors. If I understand you correctly you hav

by tofletcher - RepRap Host

Joystick Controller - 15 years ago

Joystick control: It looks more and more likely that the things will develop using removable media and also that at some point break its chains from the PC. I thought it might be useful if I outline one method of control used with my PIC24&32 electronics. A standard PC joystick is a very easy device to integrate to the micro controllers and it offers proportional control on all three axes.

by tofletcher - Controllers

Binary Format G_Code Files - 15 years ago

Binary files. In the past I have referred several times to my use of binary files with the PIC24. The original idea was to try and make the machine smoother by reducing segment pausing. Every time the print head stops to think where it has to go next you get a blob deposited on the object. Study some of the early printed items and you can clearly see this effect. Not to put to finer point on it:

by tofletcher - RepRap Host

Re: crazy idea - school program - 15 years ago

Sorry guys, I have just found this thread, It is entirely possible to run a machine without connection to a PC. As far as I can see a PC is still needed to prepare files but after that dump the G-Code onto portable media and go run off the parts. My machine runs exactly like this, there is a board with LCD screen and a joystick with buttons, with this you can pop in the SD card and scroll throu

by tofletcher - General

Re: SD Card > PIC24 > Route PCB - 16 years ago

...Now doing basic printing See builders blog

by tofletcher - General

Re: SD Card > PIC24 code - 16 years ago

I now have a PICkit-2 and can confirm it will programme the PIC24. The Explorer16 board even has a PICkit-2 header. Tony.

by tofletcher - Controllers

Re: SD Card > PIC24 code - 16 years ago

Erik, I took this text off the Microchip web site, by this you can use the PICKIT 2 on all chip families. Device support list: Microchip: PICkit 2 Development Programmer/Debugger Part Number: DV164121 The PICkit

by tofletcher - Controllers

Re: SD Card > PIC24 > Route PCB - 16 years ago

Hi Erik, Thanks for the comments, the whole design will be posted in full and the idea is to keep on developing it as far as it is practical. I deliberately dumped a description of the whole project into this forum to see if it was of interest to a wider audience. It contains a fair bit of info to digest and thought if people wanted it

by tofletcher - General

SD Card > PIC24 code - 16 years ago

PIC24 code the way forward? I have attached the main modules of the PIC 24 code. This interfaces an SD card to the PIC and utilizes the Microchip AN1045 File system library. It also includes code for the joystick interface and stepper controller. Throughout the project I have been somewhat single minded in my approach, I have only implemented code that was required to solve the particular issue

by tofletcher - Controllers