WiseOldOwl

OK...I'm here answering my own questions...LOL! Actually, I am putting info here for others. I downloaded the Tinkergnome .hex file and updated the firmware using that through USB cable and Cura (Machine->Install Custom Firmware) - Wow! Fantastic!!! From the front LCD on the UM2 I am able to change steps/mm for any axis including the Extruder. I changed the value to 495. I'll verify the distance and direction proper soon. I reused the E motor connector on the board since I didn't have one here. I do have a bunch of Molex MiniFit Jr plugs, so I put one on the board connector pigtail to connect either the original motor or the Bulldog XL. I always like doing things where I can go backwards if I don't like changes. It is more effort, but... Copper fan shroud needs some tweaking as it will hit the glass before the nozzle. Nothing a few little bends here or there can't fix. Nozzle heats up fine. I don't know how to PID tune yet, but will look into that later. More later...

OK...so the E3D Cooling fan will go to the J20 terminal, which according to this thread supplied 24v whenever the UM2 is powered on. It would be nice to have it come on & off @ 50C like my Prusa i3 does, but walking before we run here. I still need to mod the firmware...maybe take the plunge later tonight. I should only have to modify the configuration.h, for the Bulldog right? I thought that this forum would be more active than it is when I bought one of these machines a year ago...I have no idea where all the activity went or where else to even ask such questions.

Hey guys - I'm currently upgrading my UM2 to an E3D V6 and Bulldog XL. I could use some help from you kids that are 'good under the hood'. I modified a V6 heater block to accept the UM2 heater (39W from GR5) and the original PT100, so there shouldn't be anything to do as far as the heater goes compared to the stock one - or is there? I found the E3D mount on the web and pulled down the UM2 Master file to get the fan shroud. I modified it in software and CNC cut it out of copper. (It's what I had laying around...) I still need to true it up a little to get it perfect & for some reason it only fits on backwards...(front tab to back in order for mounting screws to work) I must have missed something. 1) One issue I have is addressing the difference between the 25mm stock hot end cooling fan which is 5v and the one I have for the E3D which is 24v. How can I do this? 2) I haven't wired up the Bulldog yet, but from another thread I read that the steps per unit need to be changed to 495. I don't recall if this was on a UM1 or UM2, so any help here is appreciated. (Reason I ask is...isn't the UM2 16 microstepping?) 3) I know I will have to get into modifying the firmware for the XY 0,0 location AND for the Bulldog steps...I am familiar with uploading sketches via Arduino front end - is this the most painless way or ??? I read somewhere on here about getting an error loading firmware with the UM2 because something wasn't included...I need some help here... Thanks BIG TIME in advance!!!

I know the part may need to be tweaked, but couldn't you put a piece of sandpaper on a table and rub the part back and forth on it to knock down that extra 1mm hanging down?

Nice! I loaded up bamboofill yesterday and it smelled like a pile of MDF burning...so I swapped it out for PLA before the smoke alarm went off (@190C). LOL! I like your display setup - what firmware are you running? I think the reason my flow was so low on the green thing was because it was doing the spiral outside layer at 3.2mm thick in ONE PASS(!) It was going really well until the top of the model started to taper in & I guess that 'black magic' setting slowed things down and changed the fan percentages...I kept changing it to 100% and it kept changing it back to like 43%...I wanted to stab the machine right then and there...so I had to quit the print before it was done. Plastic was just folding over... It sure makes the spool spin around pretty quick compared to a .4 nozzle! Whatcha running for an extruder setup? Thanks!

(Pic above) Olsson Block 0.8mm nozzle, 0.5 Layer Height CF PLA/PHA @ 40mm/s 1.6 shell & top/bottom Comparison to silver PLA @ 0.1 LH @ 50mm/s, 1.2 shell/top/bottom, 0.4mm nozzle PLA 0.8 nozzle 3.2mm spiralized outer shell, 8.10 mm/s speed, 205C (single outer spiral pass). The start points are clearly visible, as well as some underextrusion on the lower levels where I was tuning the speed and making adjustments. Speed was reduced until extruder stopped clicking - which causes an underextrusion condition. Laying down nice stadium layers...

FYI - my original heater was only 21 watts. No wonder I was having problems :angry: Since the OB nozzle sticks down lower than the original UM2 nozzle, it gets cooled by the print fans more than the original. I didn't want to give up my stainless fan mount or make all kinds of unnecessary changes just to be able to change nozzles. This is not a problem with the heater from the GR5 store. I've been running the OB with .8 nozzle for the better part of the day with some interesting 'schooling' going on with it. I am doing a print now, just spiralizing the outside, (it's like a funnel shape), and to thicken it up, I set the layer height to .5 and shell @ 3.2mm. It is getting it in one go, and the fastest I can go without the extruder clicking is 8mm/s. (started at 30mm/s and reduced it to 27% where it stopped making noise). It's laying down nice thick stadium layers. Cura says @ 8mm/s I am extruding 3.2 mm³/sec It was interesting to see the effects of the extruder motor skipping and be able to clearly see the plastic get sucked back into the nozzle a little bit and the resulting change in extrusion shape. First tests were with 1.6 shell UPET @ 245C, 40mm/s. Testing listed above with ColorFabb PLA/PHA.

Just a quick kudos/thank you to GR5 for hooking me up with a 39 watt replacement for my UM2. It heats up super quick! I now have no problems printing at ANY fan speed @ 250C - even with .8 nozzle. No more heater error! Thanks!!!

No problem...The ONLY way to tell for sure is to try a sample for yourself.

SN recommends 2 coats, so I wouldn't put on the XTC. What I would do is use a light coat of primer as a barrier/bite coat onto the plastic to transition between plastic and SN/top coat. If your part has a lot of detail, SN may not be right for what you are doing. This is where printing a master & doing cold cast metals + buffing makes more sense.

Direct site for SN metal coatings (not paint): http://www.sculptnouveau.com/Details.cfm?ProdID=42&category=6 Google Image search "Sculpt Nouveau" and see if anything catches your eye...

^^^ Very good. Looks much like the excellent water-based Sculpt Nouveau. You can apply it by brush, spray, roller etc. It is really good stuff. You put on a few coats and the last coat you can apply an acid patina to make it appear rusty, green etc. I have used it for over 10 years. I would avoid the metal plating. It just isn't practical for this work. To do it properly, you want to find a plating company that does vacuum deposition for plastics. Let them handle the NASTY chemicals. So that you aren't surprised, the model needs to be absolutely perfect or they won't plate it. In regards to the XTC coating, this is epoxy resin. It is nearly the same stuff useed to laminate carbon fiber, and woven structural fiberglass cloth (NOT stinky polyester used with random strand mat). It is good for what it is, but it should enver be considered as part of the hot metal casting process since it can cause a moisture induced explosion. "Lost PLA" is a hack and not what a pro would do. There are a few ways to create real metal and faux metal parts. A few have already been mentioned: 1) Print your master model. Use it as a sand casting pattern. Remove model & cast real metal into the special sand mix. 2) Print master & create silicone rubber mold. Remove master. Mix polyurethane resin & metal powder and cast into mold. Remove and polish. This is often called 'cold cast' bronze, brass, etc. 3) Print in Brass or BronzeFill filament and tumble to polish. 4) Smooth the part, coat it in XTC and coat it in Sculpt Nouveau.

RE: Key delay OK...so it happens to you too. I was going to start looking for a key logger on my PC...whew!

Thanks. I forgot about that trick. I've been printing XT all day with the Olsson block & .4 nozzle @ 50mm/s, .1 layers, 245C. I didn't have a part with so much flat area before, so 'pock marks'/pillowing on the top of the wings didn't show up until this part. I had to increase from 0.8 shell to 1.2mm shell & everything now looks good. I bought stainless nozzles for the OB, including the one I have been using, because I plan to print more parts in XT CF20 & WoodFill. I see no difference between the steel and brass (which I also have for OB), so I think the whole discussion about brass vs stainless and thermal qualities is probably overated. We shall see as time goes on. PS - Why are my keystrokes delayed when responding? Also, p.ics from the forum when you click on them won't load in Chrome. I can only see the small pic previews. Ideas?

No problem on the 1st few layers or getting good stick. This happened a few layers up from there. Bed is level - I'm a CNC veteran so I've got a dial indicator telling me the real deal.

That's good to know. The stock block the PT100 did fit in deeper than the OB. When putting the PT100 into the OB, I was able to get it in about 1mm deeper than the metal sheath on the sensor end. It told me it didn't want to go in further...so I didn't force it. There isn't much strain relief/protection where the sheath meets the wires, so I didn't want them to snap internally. So the 'Inca Ancient Alien Airplane' test thing came out pretty good. A small bit of pillowing on the wings compared to the PLA one I did months back, so I may have to up the infill. I haven't printed much in XT. I got the block and filament last week. The only major issue is the very tip of the rear rudder is melted pretty good because it was going too slow at that point. Is there an easy remedy for this?

Thanks guys. I'm not sure what the story is...It seems to be printing fine right now in XT @ 250C, 50mm/s @ .1mm w/0.4 nozzle on my test piece. Yesterday I tried it in PLA and it was a complete failure - like it was too cold or something. Material was balling up on the surface of the print. I let it lay down the first 2 layers, had to answer the phone, came back it it was a mess. I will have to investigate this PLA, as it is bread and butter per se... I was very careful & deliberate with removing & reinstalling the PT100. In fact, I had to go through ALL of my allen keys to find the correct size for removing the factory set screw. Seems the $1.99 set I picked up was more useful than the Wiha ones I normally use. Go figure! Since the PS should have the head room, I may replace with a 40w 24v cartridge I have here and a new PT100 just for 'maintenance'. It's been a great printer since Feb with only a few minor print failures. The extra wattage will probably help with avoiding the heater error screen of death, and if the PT100 is working correctly, it may never pull 40w except from a dead cold startup. I probably won't use any heat paste. The factory didn't & the tolerances are close where that added material would lock it into place & pretty much guarantee that it is stuck in the block. Thanks again. I'll post up my findings.

Thank you for the responses. I should have taken a peek under the hood to see the actual voltage. I thought there might be some headroom there with the 2nd extruder. Also thanks for the link to the 35w heater. I may give that a go. I pulled the CF20 out today and replaced with CF PLA (sky blue - fresh out of box) and started a print (with .4 nozzle) it printed about 2 layers and clogged up. I never had clogging with the original UM2 nozzle...so I am wondering it there is some disparity between the sensor and the heater with the OB. The PT100 didn't fit into the OB as deep as the original block (but it is in past the metal end) - I didn't want to force it in further than it wanted to go. So I am wondering if it isn't deep enough in there. The entire PT100 metal end is in there though. It seems contrary to what you would think if the nozzle was running too cool - it wouldn't get to temp until the block portion near the PT100 was heat soaked at the set point. I'll pull it back apart and mic the depth of the original sensor hole compared to the OB and see if the depths are the same - as well as the sensor hole diameters. I might have to ream the OB open a bit... I'll probably try the 35w cartridge with the OB & possibly a new PT100. If i can't get it dialed in, I will just put it back to the stock block. I have some E3DV6s laying around but I don't want to open up a can of worms...change one thing at a time.

Installed Olsen block yesterday. Printed this fan shroud in ColorFabb XT-CF20 tonight using settings listed on YM. It was so stuck to the bed (heated with glue) that it snapped off one of the mounting tabs (long ways) and also snapped somewhere in the middle between layers. No sign of underextrusion...Printed at 250C. Not real happy with the OB or CF20 so far. It did print pretty clean though. I think PLA is a lot tougher. I'm wondering if the temperature is correct with the OB compared to the stock block. Got heater errors with OB and .8 nozzle. Turned fans down and walls just melted. Fans on 100% and I get heater errors. Stock .4 nozzle OK - no errors. This is why I printed this shroud. I have a feeling this needs a bigger heater now. 19v is like a sick joke. 12 or 24v pick one...19v? C'mon...I don't think there are any higher watt heaters at this voltage - Is there? I'd rather not have to do anything real convoluted with the board or electronics just to up the wattage. Ideas? Can the UM2 run a 24v PS instead of the 19v without too much trouble? Thinking of putting it back to stock nozzle and just focusing on my next printer. In stock trim it was 100% perfect/reliable.

Any updates on this thread & the error issue? I agree there should be a setting to toggle that warning on/off - especially for those of us with a UM2 that is now out off warranty. If it fries the heater - "Oh well" - I'll have to replace it anyway. I just swapped out the original nozzle for the Olsen one & I've run into the error using a .8 nozzle. So far so good with .4 nozzle. I read that UM2s are supposed to be shipping with the Olsen block, so from a support standpoint, it would be good to increase the timer value, or at the very least make it adjustable/dynamic.