Odd circle test results (Page 16 of 24)

Cool- let me know if you need any help with the lawsy carriage/linear bearings upgrade. I posted a how-to several pages back. It's well worth it.

that will not be the outcome when a 'thread' has more than about 4 pages length (much less 10x that) and lots of off topic or start over posts mixed into actual fixes. when I 1st joined and searched for help with issues I had. I 1st read short topics related to my issues. avoiding long or really long topics like this because I wanted to start printing something ASAP with my investment.

not spend all my time re-posting on the forum like the affore mentioned members who say they have printed and posted useful things, then next post say they havnt been able to print any good prints since getting their printer.

and just because you havnt seen an SD4 print good circles of the few you know of dont mean theres not more than a thousand that do. how many users are going to search for a Solidoodle forum just to brag on how good of circles it prints?? nobody wastes time with that.

on average companies know that customers that complain of problems are a small percentage (maybe 10%) of those that wont even do that when they have an issue.

but at the same time that figure amounts to less than 5% of total sales most times as low as %1

PS. stop using cuss words in posts if you expect posts not to be edited/deleted or worse. this is not the place for it. @ redb...

NO! cussing etc are against forum rules. for good reason. minors plus others on the site dont want to see it. dont matter if your still in school.

I think it will be very difficult to really eliminate backlash without a dial indicator, as I suggested at the google group.  When adjusting the side belts, too loose can give you backlash, and too tight can give you backlash.  If you are just making adjustments and eyeballing circles, you could be just hitting either side of the ideal tension.    I shot some video about this with my SD2 a long time ago and never got around to making it into a blog post, so here is a bit of it-

I don't know what mounts would work with a SD4, but here is one I made to slide over the extruder stepper -

http://www.thingiverse.com/thing:69029  The slots were a tight fit for my indicator, so they may need some carving out or adjustment in the file depending on what kind you have.

Here is another mount that goes on the heads of the 4 screws that hold the extruder to the stepper motor.  Again, I don't know enough about the 4 to know if it will work.  This is from a 2012 thread about Y backlash on the SD2.

http://www.soliforum.com/post/1169/#p1169

Here is another relevant bit from a post I made in 2012-

If you really want to understand what is causing backlash and how the tension of different belts affect it, you will need to be able to measure it directly after each adjustment.   I also eventually bought a stepper with higher torque for Y so I could keep the belt tighter without worrying about skipping.  It was a longer motor and required longer M3 bolts.

It's the side belts that can add backlash either way.  When too tight it might actually be skipping rather than backlash.  Microsteps have less torque, you only get the full rated torque of the stepper at the full step.  So the axis might be hard enough to move that all the microsteps get skipped.  Maybe only 1 full step gets skipped and only on the direction change so you don't notice the sound, and it looks like backlash rather than an offset layer.  There was at least one instance when I had the backlash almost eliminated, and when I tried tightening the side belts to get it the rest of the way, it jumped up to .3mm.

Something else to keep an eye on is those idler pulley mounts.  I printed the extra beefy version from Thingiverse, and even they started to become more flexible over time.

if by some freak of nature Solidoodle does watch these topics. I think the 1st step they should take towards quality checking any SD4s in stock b4 shipping them is to;

do the circle test from this site to see if they need rebuilt 1st.

or just sit back and watch whats left of their company sink.

Nice
I don't think I have problem with the bed shaking. Maybe I just don't understand the issue very well.

As for me:
1) replacing bushings with bearings - waiting for the 686ZZ flanged bearings to arrive
2) Replacement carriage - waiting for the LM8UU bearings to arrive

Also trying to find a dial indicator locally as if I buy online now it might only arrive in 2015.

Here's an update on my work yesterday.

I tried to print side panel mounts with new filament and had a big problem occur.  These new mounts had to be printed with a new role of filament.  This filament was measured with a caliper to be the exact same size as the previous filament and was made by the same company.  This problem started on the 2nd layer of the print and only took 5 minutes to get where it is in the picture.  Well, to make a long story short, here's a picture. 
   

What could be the cause for this?!?

Anyway, this meant I had to take things apart so I decided now is a good time to start my upgrades.

Goal = Lawsy Carriage, Y-axis Brackets

Completion Status = 50%

Summary:
I've dismantled the entire SD4 down to its bare skeleton.  I quickly realized that to get certain items free of the contraption, I had to remove others and before I knew it, the guts were sprawled out on the floor in front of me.  Thankfully, I've done enough troubleshooting to build it by now so putting the pieces back together isn't difficult. My biggest gotcha was having all the right tools for the job.  Having both metric and SAE sets of allen wrenches, socket sets, a hammer and clamp is what I used.

When dismantling the machine, I came across some interesting discoveries:

• The right side y-axis rod was slightly larger at its ends.  This didn't seem to be a problem as the area which the carriage slides was nearly perfect every inch 360 degrees around with deviations of up to .03mm.  At the ends, this deviation was around .11mm which caused problems with extracting it from the frame.

• I noticed a slight but very noticeable slip in the x-axis rods in their epoxied holes on the carraige.  I pulled out the entire x-axis from the system so I could witness any loosness in epoxy and sure enough, I was able to pull off the entire LEFT side carriage from the rods BY HAND (no hammer necessary and with little force).  The Lawsy carraige, on the other hand, had to be put on the rods with a hammer and is impossible to wiggle free by hand.  I didn't epoxy it yet but I'm wondering if the epoxy will just squish out the sides due to no room between the rods and carriage.  There is NO movement on that x-axis with lawsy's carriage as a result, it's TIGHT.
     

• My stock extruder assembly does not fit the hole locations on the lawsy carriage.  This is a big problem for me.  I may end up having to wait until x-mas to put an extruder on top.  I have the e3d v6 with bowden on my x-mas list.

• I am also concerned about the linear bearings not being snug enough in the lawsy carriage.  They do jiggle.  When I'm done, will they be inherently snug by the completion of the process or should I shove some shims in there?

• I'm very likely to have some issues with clogging now due to the shavings entering the hotend from the topside.  Will deal with this if I have to.  The new e3d v6 hotend should inherently replace the current hotend and I won't have a problem again.

The bearings being loose in the Lawsy carriages is a good thing.  Get some Instamorph and squish a little bit into the bearing mounts.  Instamorph is a brand name for Polycaprolactone plastic that comes in pellets.  They will melt in boiling water and stay soft at cool enough temperatures to handle with bare hands.   

When I installed mine, I squished a small amount into the back of the bearing mounts and then shoved the bearings in.  When I installed the carriage on the rods, the movement was fairly tight.  For several minutes I ran a heat gun on the carriage to keep the instamorph hot while I slid it back and forth.  Once the movement became really smooth and easy, I took away the heat and kept sliding until the instamorph cooled and set.  This fixed the bearings in exactly the position they needed for perfect alignment.

You can use your stock hotend with the standard mk5. If you are more interested in upgrading to the e3d anyway, I'd be more than happy to print you an mk5 for it and ship it out. I'll even throw in a 625zz bearing because you will need it for the tension arm (I ordered 10 and only used 1). Shoot me a pm if this interests you. I'll print whichever you want, a stock Mount or e3d, but seriously, just get the e3d and throw that PEEK junk away. Let me know ASAP because a week from Friday I will be away from my machine until January

Your filament issue there is because the stock aluminum extruder does not allow tension adjustment. You will have problems with the lawsy carriage trying to use it. I couldn't feed tougher filaments like t glase without the full mk5. Using non-Solidoodle filament is impossible on the aluminum extruder without shimming the spring. Been there, done that. It's all junk. I suspect this is because SD filament averages 1.6mm instead of 1.75mm. God knows why they're so under-diameter, but it does make your print quality suffer (in my experience).