- User Since
- Aug 31 2016, 12:51 PM (98 w, 4 d)
Fri, Jul 20
@mcoronado nice! i really like the design!! Great job!
Tue, Jul 17
From Rory at E3D:
Mon, Jul 16
@karrad i modified one of the filament constraints to have an 1/8th inch inlet hole (3.18mm) and was able to remove some swollen filament no problem. The same filament jams in the standard constraint. Also i am printing with ninjaflex right now. I will let you know how the print looks tomorrow, but we might be able to just hit all the iinjection molded filament constraints with a 1/8th inch drill and prevent the filament jams.
@karrad i can contact E3D about this issue but we have seen this occur since we started using the aeros. Based on my investigation into this issue, it is happening entirely because the inner diameter of the heat break (~3.2mm) and heat sink (~3.2mm) is a larger diameter than the inner diameter of the injection molded filament constraint piece. This is a side affect of having a toolhead that can print both rigid and flexible materials. The inlet of the constraint peice is right at about 2.97mm diameter, while the outlet of the constraint peice is 3.35mm diameter (its conical). When the filament cools to the form of the heat break and heatsink it is then too large to pull out of the inlet hole of the filament constraint. So, if you heat the filament up and extrude a small amount (whatever was in the heatsink/heatbreak) you can then easily pull the filament out. This is why we are telling people to remove their filament at extrusion temp after a small amount of extrusion.
@logan ..i think it is possible that they were used for both purposes. ....regardless. If it is decided that this is actually an issue we can re open this ticket.
@EricNugent You are coorect that there is an upward force from the chain on the y bed plate, however the amount of upward force is very slim and i dont think you would see noticeable wear from this in the lifetime of the printers. Also the weight of the bed plate and heated bed etc applies a downward force so they do cancel each other out somewhat. The shims used were not to alleviate an issue with y cable chains, it was to level out the y axis due to issues with sheet metal. The minimum bend radius for the cable chain used is 28mm or a 56mm diameter. The chain is mounted in a gap that spans ~72mm so there is a lot of margin before we see forces from exceeding the bend radius of the chain. This chain is not really overkill for the job as generally you want at least 10% of the volume in the chain to be free space, otherwise you see a lot of broken wires like we saw in the foxglove chains. Also I do not think rotating the chain would help as it would increase the amount of torque on the y bed plate which will cause uneven wear on all 4 y bushings and increase the rotational slop of the y axis.
Fri, Jul 13
no worries! thanks!
Hey man the mounts i got are the wrong stl file
Thu, Jul 12
@nickp i have the datasheets for the motor and the motor/gearbox assembly, however the gearbox spec isnt on the pdf's. Andy gave me the gearbox spec via a link: https://www.linengineering.com/products/gearboxes/slim-planetary/
@adam do we have more of the new hobs coming? i will put in a slice request for the new mounts
Wed, Jul 11
@Steven @nickp you asked about the spec sheet for the slimline gearbox. I dont have a pdf of the sheet but andy attached part of it in the email discussion. It is guaranteed +/- 25 arcminutes. I can request the datasheet from andy if you would like
Tue, Jul 10
@EricNugent can i get 24x of the adjustable tensioners for these as well
Mon, Jul 9
@kent after our investigation/discussion on friday, we found that this might be able to be corrected with a flexy gasket or something similar for the x bearing holder. Maybe just going to 3 screws too. We were able to alleviate the added drag from the toolhead installation by loosening the x bearing holder a bit. We are seeing when tightening the x bearing holder (the top left screw in particular) that we get a lot of added carriage drag. These two printed parts are not always laying flat against each other and this is causing issues with bushing alignment/carriage drag. I will look at some ways to alleviate this issue
@adam do you want all current alpha prototypes rebuilt with a black extruder mount?
Fri, Jul 6
@kent i think it is a combination of things. Some of the added drag is due to the downward force from gravity on the overall heavier carriage. Also the toolhead is cantilevered off the axis a bit and applies a torque on the whole carriage. Also with how the toolhead is mounted, when tightening the screws tight, there is potential for distortion of the part which might change the alignment of the bushings in the bore
Tue, Jul 3
@Bobby4wd the audio isnt working
Mon, Jul 2
Fri, Jun 29
For a belt driven z axis with a standard nema 17 (1.8 degree step angle), 16th microstepping, 5:1 motor gear reduction, belt with a 2mm pitch , and a 16 tooth pulley we get:
Mon, Jun 25
@benmalouf i think different colors would work well, but if we're going to do that (which will require separate part numbers and everything so it wont really be any different than a completely different part) then we might as well just change some of the visual aspects of the part also.
@logan we can adjust the outer pocket to be a bit smaller so the nut stays retained. Also i was thinking we could print a little insert that goes in after the nylock to hold it in place. I dont think it is necessary now, but if there are a lot of issues with the thicker belts, we might be able print some adjustable tensioners with different gap spacing to accommodate the variations in belt thickness.
@adam as soon as i get the nozzles in from E3D i should have 5 more prototypes in no time
Jun 22 2018
Jun 21 2018
@logan Can you take a pic of the misaligned teeth?
@logan like it is slipping teeth when you pull it through the gap?
I have seen the belts do this and skip 1-2 teeth when installing but they end up meshed properly
@logan theres another set of parts sitting on the bed of your printer
@logan i have had a lot of people try and engage the belts in the mounts and you seem to be the only one who is having trouble with it. Also @samantha and i were able to pull 100N on the belt and there was no slipping. It was a new belt however so the teeth werent compromised. If you are having issues with tooth engagement and slipping i would recommend new belts be installed.
Jun 20 2018
@MikeR Yeah I think just making sure they are being inserted correctly (ie talking to them about it) will take care of the issue. There should be no need for redesign
@EricNugent Can we get 5 sets of the x and y belt tensioners to install on printers in cold environments?
Jun 19 2018
@kent once we have parts can we get some machines with new tensionable belt mounts running in MER for the cold environment testing. We can put some in R&D also. We can use some of @anolen 's machines to check daily tension in cold for the current production style mount/clamp
@david.hall i know you havent identified the printer yet but i was curious if you know if it came off an aero
@david.hall are these on aerostruders? we had an issue with some toolheads overheating and it was related to the crimps on the thermistors
@karrad i bet some people might complain about it but most people in the 3d printing industry understand that better quality = MOAR time
@anolen be prepared to wait forever for your prints! lol
They will come out looking fantastic though!
@DRobertson @anolen @karrad I dont think we should be printing at .25 layer heights with a .25 nozzle. This is generally seen as bad practice. I have mentioned it before but once you have a layer height that exceeds 80% of the nozzle diameter, you start sacrificing adhesion to previous layers. I would be willing to bet the parts printed at .25 layer height on a .25 nozzle are extremely weak.
@EricNugent sorry to change these on you again. The latest changes add a loop at the top belt mount point for ease of installation
Jun 18 2018
I checked spool arms on more machines and here are the results:
@anolen -11 machines total: 8 good, 3 too short
@west - too short
@samantha -too short
@marcio - good
@karrad - too short
@DaniAO -too short
MER - 8 machines total: 5 good, 3 too short
@MikeR cool sounds good.
@MikeR so then are 1/3 of the machines we send out having belts rub the y idler?
@MikeR thanks! any idea how often it is not working?
@kent when we have belts riding at the top of the idler we have been able to correct this with adjusting those screws though, We dont send out any machines that the belt rubs on, so the adjustment is working right?
@EricNugent Here are some revised x ends that improves the printability of the nylock pockets and increases the strength of the nylock pocket on the x idler since it had a small weak point
@kent @logan we can go to a slightly longer M3x14 SHCS screw if you think it is necessary, but as far as i know we havent been having any issues with y belt alignment on the y idler in assembly.
Are we seeing issues?
Jun 15 2018
@benmalouf @karrad We can make changes that dont impact the functionality or cause critical dimensions to change. The fan shroud in particular will be a tricky one to change since we need to avoid altering the air path or it can impact print profiles. Originally in the prototype review i had a separate fan shroud for each toolhead that designated the nozzle diameter. A feature that myself and many others liked. I was told to remove this so that the same shroud and extruder mount that are on the aerostruder v2 standard toolhead can be used for achemon to make things easier for the cluster and internal reference etc.
@kent this is only true if the rod is fully seated in the y idler and the sheet metal is perfect. The intent of the design is to level out the bottom plate flanges so the belt rides in the correct location on the y idler. We never see belts ride too low, when theres an issue they are always rubbing on the top of the idler which means the flanges are bent upward so tightening that screw allows an adjustment to level things out
@EricNugent These work with v2.1 of the adjustable belt tensioner
Jun 14 2018
Jun 13 2018
lol sooo many revisions
@EricNugent the new model has a 400micron wider gap instead of 200microns
@EricNugent I made the adjustments for the nylock pockets for both x and y
@david.hall Thanks! that sounds great
I have corrected a few things with these models. I made the nylocs easier to install. chamfered a few insert holes, and corrected the internal chamfer on the idler where the bearings go.
@EricNugent That should work fine. We just want to make sure the belt holds tension and isnt rubbing anywhere!
@karrad there is no difference between the 0.5 and 0.25 toolheads other than the nozzle size so I dont think a PID tune will be necessary. In initial testing I have not seen any need for one.
It was determined that the belt is no longer actually rubbing, but is very close on some machines. We will investigate this further, but the CAD files show there should be good belt alignment.