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Discuss any sort of mechanical stuff here: positioning systems, gears, extruding methods, etc.
Re: Prusa i3 Mega - Heatbed and extruder question - 9 years ago
For that size heatbed the normal advice is to use a mains powered silicone heater. There are suppliers on Aliexpress that can make custom sizes and powers, although it's quite likely you can find an off-the-shelf heater for 400x400. You'll need an SSR to control the mains power from your control board. You could put together 4 smaller heaters, but it's probably a lot more straightforward to justby JamesK - Reprappers
Re: Ghosting or layer shift issue. - 9 years ago
Those sorts of artifacts seem to be quite common, and I'm not sure how to get rid of them. I usually see them on a corner near a hole. I guess the obvious thing to try is slowing the print speed way down, but I have a feeling that speed isn't the root cause in this case.by JamesK - Printing
Re: New technique for ABS adhesion! - 9 years ago
That's good to know - thanks for testing!by JamesK - General
Re: New technique for ABS adhesion! - 9 years ago
That sounds promising, depending on how conservative they are with the rating. The price is good though, so I've ordered a couple of sheets to try. I'm pretty sure that last time I tried to order from them they declined to ship to Canada, but it sure looks like they can do it. I wonder how much they are going to hit me for postage...by JamesK - General
Re: Invert Inductive Sensor for different hotends - 9 years ago
QuoteDaveOB I considered a mechanical switch that the nozzle could push, but if there is any filament hanging below the nozzle from the previous print, then that would affect the function. Good point, but if you only need to re-establish Z when you switch hotends it might not be too bad to clean off any excess plastic at the same time. QuoteThe problem is that both hot ends fit in the same extrby JamesK - General
Re: New technique for ABS adhesion! - 9 years ago
QuoteLoboCNC That's why I was wondering if it might be worth testing the McMaster PET/polyester adhesive backed film. If it works, the adhesive backing would be way more convenient than glue, and also, McMaster is pretty consistent with their sourcing. For sure it's worth trying. A lot will depend on the temperature characteristics of the adhesive. I see some of the 3M transfer tapes are ratedby JamesK - General
Re: Invert Inductive Sensor for different hotends - 9 years ago
That's a neat idea. A simple mechanical switch should work fine in that config.by JamesK - General
Re: New technique for ABS adhesion! - 9 years ago
I can't find anything about the manufacturer or the plastic used in the transparencies I bought - Apollo VCG7060. It seems to me that it's hard to say much that is meaningful about a lot of these plastics as most of the names used refer to generic families of chemicals.You'd need more specific information to compare one manufacturer's product to another. For example, polyester is a family of chemby JamesK - General
Re: New technique for ABS adhesion! - 9 years ago
Did a few more tests today. ABS adhered well enough to pull the transparency off the glass again, so on to another glue... Petg seems to work really well on this surface, and since it doesn't shrink much it's less inclined to rip the sheet off the glass. On the other hand, I couldn't get enough adhesion with nylon to stop it from curling away from the bed. I suspect nylon will need an extra treatby JamesK - General
Re: New technique for ABS adhesion! - 9 years ago
I was thinking the two part epoxies would be the glue of last resort It's a conundrum - I don't really want to put glass over the aluminum bed of the next printer because of the weight, cost of getting custom size glass, poor thermal conductivity, risk of breakage and the fact that it would otherwise be unnecessary, but at the same time I need to be able to replace the printing surface when it wby JamesK - General
Re: New technique for ABS adhesion! - 9 years ago
Finally got my hands on some transparencies, but sadly not the right glue. I'm working my way through the glues I have available to see if anything works. The first one definitely didn't, but held together long enough to do some experiments with pla. It seems quite promising: I had to increase bed and first layer temperatures a little over what I normally use, 70 bed/230 hotend compared to 6by JamesK - General
Re: strange clogs with PET - 9 years ago
If the extruder is slipping and grinding the filament you need more pressure on the idler. Can you give a link to the filament - I'd be interested to see what it is.by JamesK - Printing
Re: adhesion problem and poor printing quality - 9 years ago
If you're printing directly onto a pcb heatbed, or onto the heatbed with kapton tape, it is very unlikely to be flat enough for large prints. You can either try to increase the flatness by adding a sheet of glass (or other flat material) on top of the heatbed, or seeing as you have abl you could try the distortion compensation in newer versions of repetier firmware which is quite effective.by JamesK - Printing
Re: Too much adhesion to bed? - 9 years ago
Changing tape sounds like a good starting point, but even with the blue tape it's possible to get too much adhesion. I found the 'window' of good settings with pla on tape to be quite narrow,which is one of the reasons I switched to glue stick on glass. Are you heating the bed? If so, drop the bed temperature in 5 degree increments until you start losing adhesion, then go back up a couple of degby JamesK - Printing
Re: Z banding (Possibly extruder problem) - 9 years ago
Isn't that fascinating. The period looks too long to be the extruder I think. You could double check by calculating the length of extruded filament per turn of the hobbed bolt, but I can't imagine it's anything like you're seeing. Plus, extruder related issues tend to produce diagonal artifacts which change angle fairly dramatically as you change print parameters like extrusion width or layer heiby JamesK - Printing
Re: E-Step, Random Length extruded with same E-Step Value - 9 years ago
Can you post photos of your extruder setup? That would make it easier to suggest possible causes.by JamesK - General
Re: RAMPS's D8 dead. Question about reliability. - 9 years ago
No failures on my ramps yet, but I guess I'm only a bit over a year in.by JamesK - Reprappers
Re: My coreXY design is progressing to the build stage - 9 years ago
Looks great. Is that a snooker table your cat is sitting on?by JamesK - CoreXY Machines
Re: Spaghettification half way through print - 9 years ago
Quotess002d6252 If you look carefully at the picture you can see where the layers have suddenly shifted by about 10mm to the side. Craig Hi Craig, if you provide higher resolution photos it will be easier for people to spot that sort of thing. For the many possible causes of shifted layers, take a look atby JamesK - General
Re: High performance motor controllers - 9 years ago
Board looks great - congratulations on getting this far. Those are some serious connectors!by JamesK - General
Re: ABS print lifting - 9 years ago
That's a good bit of warp for sure. I can't answer the question as to why the top half came out the way it did. There's a whole load of physics going on as a 3d print is formed and you do get some pretty weird stuff happening from time to time. Nebbian's suggestions are good for improving that first layer adhesion. My feeling is that you should be able to get a workable print of that object. Iby JamesK - Printing
Re: Auto bed levelling - IR, inductive or nozzle probing - 9 years ago
Hi Mike, will you be adding a photo of the new design to the original piezo thread? I'm still hoping to implement this for my next printer so if the new approach seems to be working better than the original layout I'd be interested to see that. Peizo goes on the top of the beam so that it stretches when the bed is displaced downwards? I made up a very simple switch based probe from this threadby JamesK - General
Re: 1.75mm Excelvan Filament - 9 years ago
QuotePhytone So what are the good alternatives to Excelvan? I've been quite pleased with the Solutech filaments. They're not bargain basement prices but are pretty good value and have been good quality so far.by JamesK - General
Re: ABS print lifting - 9 years ago
QuoteTonyPagett Why would the first 10mm shrink but not the next 12mm? There is a definite line around the item as if it were printed in two parts. Below the line has shrunk to 4mm thick in places Above the line is perfect By the way, the print is a custom size project box with 2mm thick sides and face with a few added extras for perfboard support etc Sounds interesting, any chance of photos?by JamesK - Printing
Re: ABS print lifting - 9 years ago
QuoteWhat I don't understand is the fact that all was fine for about an hour then it all went wrong. The bed temp was still the same The layers close to the bed stay warm. As the print gets higher the layers cool to lower and lower temperatures and shrink more. The forces build up until something gives - either the bottom layer pulls away from the bed or the model splits. By using an enclosureby JamesK - Printing
Re: E3D takes unfair advantage over competition - 9 years ago
Classy response from Sanjay. I wish all companies were so well engaged and communicative.by JamesK - General
Re: My coreXY design is progressing to the build stage - 9 years ago
The makerspace sounds fantastic. It restores some of my faith in people that it works the way you describe - long may it continue! Your build is looking great. I hope to make a start on mine over the Christmas break, but I still have lots of design work to flesh out. Sadly the amount of time and energy I can find recently hasn't been up to a major project like the new printer, so progress has beby JamesK - CoreXY Machines
Re: My coreXY design is progressing to the build stage - 9 years ago
Looks like they have a pretty nice mill at the makerspace. How is the place funded? Is there some sort of training scheme/sign off for getting access to the machines?by JamesK - CoreXY Machines
Re: Extruder stepper not working - 9 years ago
Glad it's up and going - now the real fun starts! Welcome to the forumby JamesK - General
Re: Thermal Runaway with my E3D Chimera - 9 years ago
Try sliding the insulation back and measuring at the solid conductors. If it's 4.8 there the problem is likely a bad crimp connection (two out of three of mine have had bad crimps). If you have a crimp tool then the fix is obvious, if not, you can carefully use a pair of side cutters to improve the crimp.by JamesK - Printing