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Here's what I made, here's a photo, and here's a link to the [[page]] on RepRaps wiki!
Re: Latex 2-Part Molds - Help Needed! - 13 years ago
The liquid latex you are using is air drying. Its used for making moulds by painting on the object and gradually building it up in layers exposed to the air. The skin is then peeled off and you use it to cast the new part. Its used commonly to cast plaster of paris parts and garden ornaments. As its air drying, this is why it doesn't go hard in the bottle its supplied in and will not cure in a mby martinprice2004 - Casting and Moldmaking Working Group
Re: Why are filament spools so expensive compared to pellets? - 13 years ago
Going back to your original point as to why pellets are cheaper than filament it is simply economies of scale. Consider the steel industry. They make standard billets of steel, or pig iron bars. They can produce it cheaply because their process never has to change, it just runs and runs continously without changing. Its cut into managable sizes just for ease of transportation. They are not interby martinprice2004 - General
Re: lcd contact printing mask - 13 years ago
The argument of using an mpeg file to transmit a design is a little confused for the following reasons. 1) Data in any form can be encoded - transmitted - decoded securely, its done millions of times every day. Its also hacked now and again, this is a different argument. Choosing a video codec to transmit this type of data is like choosing a sock to carry water. 2) Most modern video codecs incby martinprice2004 - Polymer Working Group
Re: Water Jet Cutting - 13 years ago
Has anyone considered using a car fuel injection pump as these go to incredible pressures (1000 Bar /15000psi). They are easily available and could be driven from an electric motor. They do tend to use the fuel as internal lubricant / cooling and I'm not sure of the flow rate. What sort of pressures and flow rates are we looking for for cutting say a 1mm steel sheet?by martinprice2004 - RepLab Working Group
Re: What's about a really BIG reprap for mega-sized objects ... - 13 years ago
I dont think it would be too much trouble to increase the size of a reprap. After all there are large cartesian and delta robots used in industry. As the accuracy doesn't need to be so fine, you could get away with rack and pinion linear drives and servo motors. The problem as has been suggested would be with extruding. I think the expanding foam idea may be a little unpredictable. There has beby martinprice2004 - General
Re: Bed Serface - 13 years ago
From other posts PLA seems to be much easier to use than ABS as it shrinks less, so there is room to use a cold bed. I use only ABS filament for my parts. I had no joy with printing on perspex as supplied with my Makerbot...absolutely useless. I have had good success with kapton tape. I replace it regularly, but it can also be cleaned with acetone to prolong its life. This was OK on a cold bedby martinprice2004 - General
Re: Digital micrometer for positioning - 13 years ago
Yes If you are using stepper motors 3 times per second would be enough as you are only verifying position. We are confusing this with a closed loop system where the signal feedback is used to control the motor position in real time. This is how servo motors are controlled in CNC and you would need faster feedback for this. One use I could see for what you are proposing is to set the initial daby martinprice2004 - General
Re: Digital micrometer for positioning - 13 years ago
Digital Calipers are often used as linear encoders on machine tools see the following image. Linear encoder milling The data I think is sent 3 times per second from the port which may be sufficient. Here is another link to some info. Interfaceby martinprice2004 - General
Re: Powderbed Machine - 13 years ago
There is a thread about this machine in the Resin photopolymer section. The projectors are about £115 I think. It does look very nice Taking the industrial market as a lead, powder laser printers seem to be very popular, which leads me to believe that UV curing resins still have many issues. Probably resin cost / resin stability and machine running costs. I am following your machine wiki with inby martinprice2004 - Powder Printing and Selective Laser Sintering
Photo Reactive Resin - 13 years ago
I just came across this light curing resin used on surfboards, I wonder if any of you had tried this as possible raw material. The price seems quite cheap compared to other photo curing resins. Solarez I am wondering whether this stuff would cure when exposed specifically to light or, sets off a chain reaction like most fibreglass resins to cure the whole part.by martinprice2004 - Polymer Working Group
Re: Delta-Reprap/Technik - 13 years ago
Here is a copy of the Helium Frog Delta Robot Firmware. It might help you get started. Helium Frog Delta Firmwareby martinprice2004 - Neue Ideen - Archiv
Re: DIY Photopolymer machine - 13 years ago
It looks to me like the part is fixed to the top plate and is built upside down to how we do it in a reprap. The bottom bed is flooded with a thin layer of liquid polymer, hardened with the projector, the part lifts up (maybe away from the bottom surface to allow another layer of polymer to food under the part. When the part is finished it is hanging under the top plate. Im assuming the lower tby martinprice2004 - Polymer Working Group
PLA Powder - 13 years ago
I have been looking around for some powder for use for laser sintering. I was wondering if anyone had experimented with PLA powder. During my search I discovered that it is used in hand cleansers and make up products to provide an abrasive "scrub" to remove dirt. There are also other powders available such as a PLA wax mix that may be of interest to us reprappers. I thought that this might beby martinprice2004 - Powder Printing and Selective Laser Sintering
DIY Photopolymer machine - 13 years ago
I came across this article whilst on line. Does anyone have more details of this machine as the print quality looks very good. I wouldn't be too hard to rapid prototype the frame of this machine. DIY Photopolymer printerby martinprice2004 - Polymer Working Group
Re: On the Fly Powder Printing Bed - 13 years ago
This is a nice idea building the wall with a reprap. The "sinking/rising box" in normal powder sintering machines isn't the easiest thing to engineer at home and I imagine would make the a desktop machine quite large. With the current interest in multi head repraps this seems to be a realistic proposal. I have had a few thoughts of depositing powder in strips of about 5mm wide, a bit like a taby martinprice2004 - Powder Printing and Selective Laser Sintering
Re: MakerBot Clone Build Log - 13 years ago
I own a Makerbot and one of the flaws in the mechanical build is the plywood T slot fixings. When you tighten them up they tend to pull the nut through the material. In acrylic its even worse, overtighten and the parts crack in unexpected ways. The X Y carriage soon become very loose and the extruder cracks after a few months. There was a post here with a design using tie wraps, but I can't findby martinprice2004 - General New Machines Topics
3D Scanning versus 3D digitizing - 13 years ago
I have been following the 3D scanning with some interest and have had a look at the David scanner. There seems to be some discussion as to the resolution of such devices. there is also a fundamental issue with the output of such devices. One of my other hobbies is animation and most 3D scanned models are of very little use for the following reasons. The vertex count is often too high. The vertby martinprice2004 - 3D Scanners, Book Scanners, and Optics
Re: Why the moving platforms? - 13 years ago
There are countless configurations of CNC machine out there and they each have there advantages and disadvantages. I think that machine size to build area is one of the less important design considerations. If your machine was 300mm longer in one direction, it probably wouldn't put you off if it was a better machine. The Reprap is based on relatively inaccurate parts, so stacking the Z axis on tby martinprice2004 - Extruded Aluminum Frames
Re: Metal FDM thread - 13 years ago
Hot Forging Another possible method of joining wire to your part would be not to melt but to form interatomic bonding. I used to work for a spark plug company and the ground electrodes on sparking plugs are not welded on but projection heated and forced together. The process is similar to a blacksmith forging two pieces of metal together, heated until soft then hammered or pressed together. Theby martinprice2004 - General
Re: Simplifying equations - Help required - 13 years ago
It is unlikely the angles will change as my design is triangular, so the angles between the towers are 120 degrees. If you want to take a look at the design go to the link below and also a video on youtube of it working. I'm just tidying up the firmware, hence the drive to simplify the equations. Helium Frog Website There is also an excel spreadsheet which performs the calculations Excel docby martinprice2004 - General
Re: Simplifying equations - Help required - 13 years ago
0.5 is sin 30 in these equations I'm trying to do all the calculations in an arduino mega firmware, that way I can use off the shelf PC G Code software to drive the robot. Is there any stuff on the net how to calculate the curve fits for these equations?by martinprice2004 - General
Simplifying equations - Help required - 13 years ago
Its been years since I did any complex transformation of formulae. Could someone help. Is there a way to simplify the following formulas , preferably to remove some of the square or square roots? They are transforms for my delta robot. For non programmers pow(x,2) is x squared sqrt(x) is the square root of x 0.866025 is my approximation of Sin 60 if that helps. T1 = sqrt(pow(F,2) - pow(sqrt(pby martinprice2004 - General
Re: Metal FDM thread - 13 years ago
Another issue with using a welding arc for FDM is weld spatter. As the arc welds it spits and blows small amounts of metal everywhere. This way it is very difficult to deposit metal with any accuracy. Welders already use wire generally smaller than the reprap filament (around 0.6mm diameter) and the minimum weld width you can achieve with this is say 8mm wide on a good day. Unless you are fabricaby martinprice2004 - General
Re: Delta-Reprap/Technik - 14 years ago
Video of Helium Frog Delta Robot posted on Youtube Helium Frog Delta Robot - First Stepsby martinprice2004 - Neue Ideen - Archiv
Re: Helium Frog Delta Robot - 14 years ago
Uploaded video on Youtube Helium Frog Delta Robot - First Stepsby martinprice2004 - Delta Machines
Re: Helium Frog Delta Robot - 14 years ago
Just a quick post to let you know that The Helium Frog Delta Robot has made its first baby steps. The robot firmware has been written in basic form and it now accepts G1 and G92 codes only. This is enough to test out the delta algorithms. I have had the robot drawing a few square boxes and all seems OK. I'll try to post a video on Youtube in the next few days and get the models and firmware uploby martinprice2004 - Delta Machines
Re: Flexible Coupling - 14 years ago
Thanks for the information. I think the plastic tube (Maybe with a little collar in one end ) looks just the job.by martinprice2004 - Mechanics
Flexible Coupling - 14 years ago
I'm looking for a flexible coupling to go from a standard Nema stepper motor to a M8 threaded lead screw. Any suggestions for a cheap solution as purchased joints seem to be a little expensive. Have any of you had any success with flexible pipe etc.by martinprice2004 - Mechanics
Re: Design for low cost delta with 3 servos - 14 years ago
Soldering iron sounds quite heavy, but have you considered a diesel engine glow plug. They come in all shapes and sizes, but are generally around 5mm diameter and about 100mm long. They are very light and have a lying lead and connector attached. There are also glow plugs used for Radio control car engines which are very small and screw in. If I remember rightly they run on 1.5 volts. There mayby martinprice2004 - Delta Machines
Re: Polar Rep Rap - 14 years ago
Viktor I didn't understand your exact meaning. Are there any images of such a setup? Something like this may be nice. It keeps the motors and reduction gearboxes off the arms and has an extra linkage for stability. The inverse kinematic calculations shouldn't be too hard and it seems to leave a nice platform for the extruder.by martinprice2004 - Polar Machines, SCARA, Robot Arms