The original LOM machines were using butcher or wax paper plus the laser. Technically, you could probably use a Darwin Z table, a halogen lamp, and a modded Cricut to make a near-tabletop version.by SOI Sentinel - Reprappers
1) Maybe. I check all over the place, Mcmaster carr, fastenall, MSC direct, ebay, local hardware store. 2) those are 608 bearings, so those should work for the 2 608's 3) I think they still need to be fabricated. Ask Vik. 4) www.vxb.com Buy them in 100 ct quantities and share with someone. 5) See #1. Given that M4 and #8 are dimensionally identical for clearance holes, this should work. A lby SOI Sentinel - Mechanics
That explains a bit. Industrial block and rail and other designs align and have a single floating axis to get around this on most light duty machines. Metalworking is a whole different world, and yes, that's where dovetails, hand ground ways and gibs, and a whole lot of trial an error come in to get the accuracy and stiffness correctly. I just wish they had been able to use 608 bearings as thoby SOI Sentinel - Mechanics
I was thining about all the bearings required for the Mendel, and I was wondering why we're using roller bearings on a fairly low mass/low force machine instead of plastic linear bushings (Igus parts for instance). I've had the prices come out pretty competitive, and one bushing would replace three bearings plus much of the associated steel hardware. Some variants run on steel without issue (moby SOI Sentinel - Mechanics
Just an idea. Sometimes we want to extrude something that will be permanently bonded to another object. Now, we'd need a new "head" for this. First, we place the object on the build area. Then we scan the object (laser, touch sensor, camera, whatever). We'd need an STL generated from this point cloud. Then we design over top of it, effectively boolean subtracting the object from the final pby SOI Sentinel - RepRap Host
Maybe. 32" TV's routinely have something like 90W input per some power calculations I found online. So we're talking probably 20-40W directed at the screen.by SOI Sentinel - Plastic Extruder Working Group
Thanks to some work by a fellow reprapper that caught the eye of Hackaday and got nailed for it, we have an introduction to electrochemical machining. This is a way I hope will provide a support machine for our trickiest hardware. By using a three axis stepper board and a constant current and pump control "extruder board" we can do a stepper spindle controlled CNC lathe . Reprap plastic compby SOI Sentinel - Reprappers
That's what I was somewhat worried about. X-rays are annoying. Now, an X-Y stage in a bell jar isn't too implausible. DO NOT DO THIS, however the interior of a CRT screen is exactly this. High KV electron beam gun, lead shielding, but it uses magnetics to steer the beam. That, however, is a different RP system (electron beam used on a metal powder bed). Keeping a seal is difficult if you aby SOI Sentinel - Plastic Extruder Working Group
I've been doing a little research into some work at home on small quanity filament extrusion. I think a modified Gingery press would be best. While the base design (metal block, 2 cartridge heaters, die, and piston) is fine, it also requires significant machine shop hardware to get the piston drilled and reamed accurately. I was thinking that a design made out of a long steel pipe nipple wouldby SOI Sentinel - Mechanics
I was just poking around my old haunts from college a bit, and was reminded that you can get ABS with chopped glass fiber reinforcement. It's available in pellet form (although I haven't dug to find a non-chinese supplier yet). So we could get it converted to 3mm welding rod format. I wonder how it extrudes. We might pick up strength and lose some warping (or gain some! testing...), but Iby SOI Sentinel - Plastic Extruder Working Group
I've been debating between a lasercut repstrap and a Darwin. I'd go darwin if I can find someone with parts! I actually have someone locally who wants the first set of parts I print, too! (wisconsin area)by SOI Sentinel - Reprappers
Ok, the US node is available for printing from. Unfortunately, there's been some changes. Acrylic lost 4.5mm, gained 4mm Acrylic lost 8mm, gained 9mm MDF lost 8mm, gained 6mm (only) Gained Delrin in 3 and 5mm thicknesses I have verified free shipping on $100+ orders within the USA from the USA node, however. Orders less are not too bad ($11 for a triple extruder head order for instance). Righby SOI Sentinel - General
I do understand, and it appears that I brought the misunderstanding. With a single X-Z motor, what I meant for 2.5 D is that you cannot move more than 2 axes simultaneously in that configuration, especially since Z motions would not be orthogonal. Full 3D motion would be possible in the 3 motor system, but the varying velocity due to Z motion travel would be a challenge to code to provide lineaby SOI Sentinel - Mechanics
Here's the basic idea. Imagine that I actually drew these in CAD and didn't get over-detailed to the point where he didn't even get one parallelogram leg finished. If the motors move in parallel, we get X motion. If they move in opposite directions, we get Z motion. Now, as the object gets taller, the build area shrinks. You'd also have to account for increasing static torques as the forceby SOI Sentinel - Mechanics
I haven't seen much information on this lately, so are we (probably mostly nophead) still seeing bowing in large objects? I'm working on a conceptual RepRap design that is similar to the triangular frame on the new Reprap concept. However, it involves each side being made of two right angle triangles. Between the uprights in the center of the triangles we have the vertical lifts clamped. Theby SOI Sentinel - Mechanics
Sounds good. Added the extruder kit now, too. It's roughly the same cost for cutting time, materials, and shipping on that one. I wonder if it will make a good difference? Everything is about cut time, so rounding corners may reduce the overall distances that need to be moved, reducing cut times. However, square corners on some items may allow more shared borders, also reducing cut times.by SOI Sentinel - General
I just put up the Acrylic set with 3mm as blue tint, the rest as clear, MDF board. I'm asking $210 + $40 shipping ($250). US shipping only for the moment. Although I think this is shipping from NZ still given those shipping costs. I'm hoping to knock it down to $5 or $10 on June 5. Depends on what they do to change it.by SOI Sentinel - General
That is really weird. The US version is all Paypal. I upgraded to a Premier account so I could set up the store account.by SOI Sentinel - General
It's should be lower now (with the special Prime account). $240 ish?by SOI Sentinel - General
So, any color suggestions?by SOI Sentinel - General
Do it now, it's reverts to a more expensive version at midnight PDT Email I have Hi there Gerald, Thanks again for your interest in all of our hard work to deliver you the world's easiest making system. Ponoko - just upload your designs, choose materials, then click to make and sell them online. With all the support you need to get it just right. And with Value Prime you also get big cost saby SOI Sentinel - General
I bought a "founder" ponoko prime account before seeing the deal Vik has. Vik, Do these rates appear similar to what you have? For instance, the total cost of a RepRap V1.1 cut is slightly less than $200. I want to charge a 5% premium to cover the cost of the account in a store setup. This is material cost + $0.87/min cutting cost. Does this sound fair? We'd have to pre-set up materials andby SOI Sentinel - General
From comments elsewhere (gizmodo) it spins a plastic rod to heat and weld the parts together, and has had several generations. It's still an option (say, a lower temp material for welding parts together if you can't reprap the components directly in), but it sounds like the strength will be lacking. Ultrasonic welders are tricky beasts, and I note they usually have a titanium tip "horn".by SOI Sentinel - Plastic Extruder Working Group
the optical encoder would work fine, really. It would depend on build quality and how good you are at aligning optical elements as the size shrinks. Lower end steppers do not necessarily mean significantly lowered cost. As you approach your torque threshold, you start worrying about missing steps. Alternatively, you can go faster like nophead. Or drive a bigger head or larger feedstock witby SOI Sentinel - Controllers
I kinda like the idea of traditional chess pieces. We actually need a 4 to 5 head reprap to do that one. One black plastic, one white plastic, one support material (optional), one gripper, and one vertical grinder with vacuum and an "isolation wall" that drops down while operating. It would be quite... interesting when you go "pawn takes rook" and the head grinds the rook to scrap (for multicoby SOI Sentinel - General
Probably the ideal "consumer" head would be a Porter Cable or DeWalt laminate trimmer, as they have exposed metal construction and more power vs Dremel like machinery but still maintain the 10Krpm+ speed and are lighter than a standard router. Still too big for a RepRap/RepStrap though.by SOI Sentinel - General
A note for those of you looking at furnace cement and other refractories. The general rule of thumb with them is to use the lowest possible temperature rating you can. I'm not certain how the strength of the material varies, but the thermal conductivity goes down with reduced temperature rating. Higher temp refractories may last longer, but you need a thicker layer to insulate to the same degrby SOI Sentinel - Mechanics
A little time travelling brings back the original Z Corp binder ZB7 and powder z100: Binder: Powder: Plaster, sugar, a few other things. Shows what they evolved from. Also of use is this: Aparently this patent is someone trying to duplicate the Z Corp system with commodity equipment. Of special note is that the system they inspected used a large format, low resolution HP print head,by SOI Sentinel - Powder Printing and Selective Laser Sintering
They do, but the economics aren't there. Most are 1KB or 2KB. There's been up and down talk of building a pseudo SRAM 16MB module over on Sparkfun out of a CPLD and a SDRAM chip onto a DIP carrier, but there wasn't enough interest. The CPLD could have been reprogrammed to act as a SRAM module or a DPRAM module (we were doing camera interface discussion at the time). A SPI interface would notby SOI Sentinel - Controllers
As long as you work with an SD card instead of a USB stick for the mass storage option, I believe yes, you can do it all with a second Arduino without a problem.by SOI Sentinel - Controllers