Folger Tech Kossel Unboxing and First Impressions (Pic Heavy) (Page 2 of 8)

One thing I noticed that I'm not going to fault Folger for but I do think is a design problem:

The print bed is a piece of aluminum bonded to a PCB heater. The bed is not countersunk and they recommend 25mm pan head screws. This means that, on 3 places on the table, screw heads will be sticking up where they can be hit by the hot end. It also means you can't put a piece of glass on the bed, since it will only touch on the top of the screws. I can solve that problem by switching to flat head screws and throwing the aluminum under my drill press for a quick countersink.

There is a secondary problem to this, however. The Kossel kit is built with the idea being that you will use the automatic bed leveler to find your surface before printing, and as such you can't adjust the level. The bed bolts directly to an acrylic mount. To fix this, I will need to remove the 6mm acrylic spacers and replace them with sturdy springs so that tightening the bed down will adjust tilt.

Eventually I will have to come up with a better method (as this method will require removing the glass bed whenever I need to adjust the level) but it isn't a very big modification to get it going.

Edit: picture from their build guide attached in case you don't know what I'm talking about.

Yeah, I just followed the build guide exactly. Didn't think about the "keep out zone", that's a really good point. Still not a big fan of the screws there, and I'd like to have the glass all the way out to the edge (so I can just get it with some clips), but I guess it's not as big a deal as I first surmised. At this point I'm just panicking every step of the way, hoping I'll get a printer running enough that I can print out the parts to get the solidoodle running again so I'll have a spare to print better parts for the kossel.

When you put your effector together, carl, did your hotend fit in the countersunk hole on the bottom so that the clip that grabs the hotend would bolt up flush? Mine sticks out since the hotend doesn't fit in the countersink, but I'm wondering how big of a gap you have. I can take pictures when I get home.

Regardless, I'll be replacing the acrylic spacers with springs so I can level the bed.

I'm used to there being some variance, but mine is way too small, at least 1/8" across the diameter. The hole on the top is so small that I had to remove the tubing connector to get it to fit. Not a big deal, just bothersome. Once it's running and dialed in, I'll print a spare set of all the parts. I have a roll of clear nylon kicking around so maybe I'll give that a shot.

Glad to know I'm not missing out on the bed leveling.

From what I hear, the autolevel is pretty inconsistent. It never does as accurate a job as doing it manually with paper or a feeler gauge, and if you get different results every time you auto level it really doesn't give you good prints. A lot of people also just have a ton of trouble getting it to work properly. I don't mind bed leveling, so I really just kinda considered it to be a free servo and microswitch with kit purchase

I should only need a couple springs to get the leveling setup going at this point. Guess I'll be stopping at Ace on my way home.

It's a fairly well documented feature, just notoriously fussy. Might be better off using a contact probe instead of a servo and microswitch. A hall effect sensor would work well if you had a metal bed.

Yeah, at least a switch without a whisker. At my old job we'd use what was essentially a highly repeatable momentary push button switch on a pneumatic cylinder that was mounted to the z carriage. It was used for surface mapping materials to adjust laser focal height when cutting large materials.

I have used a glass bed + hairspray (aquanet extra hold) to great success for holding down parts on my SD3. The main benefit over aluminum bed, though, is that the aluminum will actually deform slightly from thermal expansion. The glass will stay flat even when the aluminum starts to warp.

Well then perhaps glass and a different switch would help. Maybe the firmware will be updated

I am with carl on the leveling thing - manual leveling is not hard, only takes a minute or two at most, and is usually good for more than one print - unless I get in a hurry to take things off the bed and don't let it cool enough, pulling on it as I try to pry things off...but that would be my own fault. LOL

LOL, i dont leave mine unattended (the thread about the house burning down scares me too much - and I live in an old house - 100+ yrs)
Plus I have so many things I want to print! LOL

but yeah, getting the SD4 heated up can take a while with the thicker aluminum bed - getting that bed to 105 for ABS printing can take 15-20 mins... but once there, it holds it really nice.

um, if the stl files are easy to grab, I would be willing & happy to print you a better one. that is one ugly piece!

My SD4 is dialed in pretty well these days, would be a lot more accurate than that looks.

its only nice to have a project if you have a way of fixing it - no working printers can make that tough! lol