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williaty

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About williaty

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    General Maker-ism

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  1. EDIT: On Reddit, a bunch of people asked about feed timing and I looked up how to check it, which just raised more questions. Feed timing is referenced to feed dog height so the first thing I had to do was set the feed dog height. When I installed the new feed dogs, I just visually set them so the bottom of the gullies between the teeth came up to flush with the top of the feed plate. Turns out this is way lower than Juki wants them set. I raised the feed dog height at top dead center to the 0.8mm spec Juki calls for. I then leveled the feed dog front to back so that the whole thing was at 0.8mm at the highest part of the cycle. Feed timing is checked by the top of the feed dog teeth rising flush to the needle plate at the same instant the tip of the needle is flush to the top of the needle plate. Turns out that, if you level the feed dog at the top of its travel it's slanty AF at this point in its travel. So the feed timing is correct when the *back* of the feed dog is flush to the surface of the needle plate. If I bring the center of the feed dog flush to the needle plate, the needle itself is already ~2mm into below the surface. Obviously, that's even worse if I bring the front flush. So I now have two new questions: 1) When during the cycle is the feed dog supposed to be parallel to the surface of the needle plate (when below the plate, flush to the plate, at maximum height)? 2) If the answer to #1 means that the feed dog is sloping as it comes up through the needle plate, where along the feed dog do I reference for the feed timing? Additional fact, it does **NOT** do this in reverse. It'll eat lumps and spit them out just fine in reverse. The only difference I see is that the toe of the presser foot isn't applying any pressure at all anywhere near the end of the feed dog slot in the needle plate whereas in forwards travel the heel of the presser foot does apply pressure very close to the end of that slot. The slot has very sharp edges. I wouldn't say they have a burr as there's no snagging feeling if you run your finger over it, just that they were absolutely not softened at all during manufacturing. 1) Everything is definitely burr free. I do have concerns about how sharp the edge on the slot in the needle plate is, but it's sharp, not a burr.. 2) What weight of plastic bag? Like a mylar O2 seal bag definitely isn't going to wad up. I super cheap store-brand ziplock sandwich bag might. Crappy grocery bag might just cease to be!
  2. Video of the problem: https://www.youtube.com/watch?v=b_Arp_nIQhE The problem child is a Juki DLN-5410N-7-WB I rescued from a factory. All of the automated functions don't work because I wasn't able to salvage the brain box. Many parts had been stripped from the machine and I've replaced them. It may be relevant that the presser foot, needle plate (throat plate), and feed dogs were replaced with parts from Cutex listed as the "normal" options for this machine. The needle bar height was reset since it was way off and the timing was corrected according to the Juki manual. The feed timing between the feed dog and the needle appears to be correct as they move in lockstep. The feed differential between the feed dog and needle feed appears to be neutral as they move in lockstep. The fore-aft position of the feed dog has been adjusted to get the needle landing dead center fore/aft in the hole in the feed dog but the needle is offset to the left within the hole. The machine stitches perfectly well at all speeds and stitch lengths. The problem is that the machine will intermittently stop letting the fabric flow out from under the feed dog and start wadding up it. It actually wads it hard enough to permanently crease the fabric and, in one case, actually tore the fabric. It *seems* to happen a lot more often with very limp/soft fabric and doesn't happen often or at all with stiff/heavy fabric. On a test sample, once I had a bunch of lines of stitching in the fabric which resulted in adding some body to the sample, it stopped catching. In this demo video, I deliberately fed the machine a lump of fabric to trigger this problem so you all could see it but it'll happen eventually if you sew flat, smooth fabric long enough. It appears to be catching on the back of the opening in the throat plate that allows the feed dogs to come through but I can't be sure because I (obviously) can't see through the feed dog and fabric. Adjusting the presser foot pressure through the whole range of adjustment has no effect on this problem. Pulling the fabric straight up behind the foot while sewing *does* appear to prevent this from happening entirely but this is obviously not a real-world solution. Any idea what's going wrong or how to fix it?
  3. I am fairly sure this is a place where the differences between how the US delivers electricity and how the EU does it probably makes a difference. In pretty much all single-family residences, we get something that gets called single phase even though that's a damned lie. Our connection to the grid is 2 hot legs, each carrying 120V AC relative to ground, 180 degrees out of phase, and a neutral return connected to the center tap of the transformer on the pole outside. So it's a 2 phase system even if Americans refuse to call it that. Our low-power appliances run off one of the 2 legs brought into the house, providing 120V AC between that phase and neutral. Our higher power appliances run off the difference between the 2 120V 180-degree out of phase legs, which of course is 240V. *Most* of our 240V appliances don't use a neutral return at all but a 4-wire connection (2 phases, neutral return, ground) to large appliances is becoming more common so that the low-voltage portions of the appliance can be run off one 120V phase referenced to neutral. Anyway.. that's a digression... So I need to turn the 240V service I have (which is 2 120V phases 180* apart) into 3 phases separated by 120* and producing a phase-to-phase voltage of between 200V and 240V to make this control box happy.
  4. hmm.. this has me curious. Static phase converters synthesize the 3rd phase to get the motor started and then drop it, right? So the motor runs off 2 out of 3 phases and that's why you see a power reduction when using a static converter. If I understand it correctly, I mean. I wonder if that'd work with this thing since it has "open phase" as one of it's error codes. I suspect it might see that phantom 3rd phase drop out and get pissed. Regardless, I'm looking up prices to see if it's worth trying.
  5. Oh wow, lots of replies I've missed! I'll try to answer everyone's questions in a summary: 1) Yes, the fallback plan here is simply to strip the fancy functions off and power this with a $100 servo motor if there's no way to get the computer running. 2) I am aware of rotary phase converters but there's two major drawbacks. The cheapest ones I've found still cost way more than I paid for both machines put together. The rotaries also make continuous noise and this is for an in-residence business, not a factory so the noise matters. 3) I've been calling around to various Juki dealers and they've all said they either refuse to deal with automated machines at all or refuse to deal with 3-phase automated machines after prior bad experiences. 4) I've asked one shop what it'd cost to buy the current generation control box and motor to refit the machines and I'm still waiting on their quote. I suspect the answer will be more than I can afford though. Part of the problem with both a new control box and with the rotary phase converters is cost. While I'd love to have some of the features the computerization offers (mostly needle-down which I can get from a cheap servo anyway, and the reverse button near the needle with the auto thread cutter a kinda-nice idea), the fact is that I'm not in a full production factory and I'm not too short of time in the day to get my work done. Sure, I'd love to save a little time per piece because who doesn't like more profit, but in reality I'm not going to make enough more money with a more efficient machine to pay off $1,000 in electronics (or less, I know used rotaries are a little less than that) in a timely manner.
  6. I have a Fluke 87 V meter that I've been using to confirm the actual output. Unsurprisingly, the programmed value doesn't exactly match the measured output. I can turn it down to as low as 140V phase-to-phase and the SC-1 still gives the overvolt message.
  7. A DDL-5550N-7 and a DLN-5410N-7. Both running with the SC-1 and CP-130. I found the engineer's manual for the SC-1 and it's how I discovered that the E11 error code is overvoltage, but didn't have any troubleshooting help whatsoever. The machines' manuals don't address the electronics at all.
  8. A local factory shut down and I got what I thought was a "too good to be true" price on 2 of their machines at their closing auction. Turns out, it was too good to be true. So now I have 2 computerized Jukis controlled by SC-1 control boxes that demand 3-phase power that I'm trying to run at home. I grabbed a single-phase to 3-phase VFD and tried to get one of the machines alive just to see if it had any other complaints but it's immediately throwing the E11 (overvoltage) error on boot up and the main power switch kicks out after about 10 seconds. The label on the end of the SC-1 says it'll run off 200, 220, or 240 3-phase power but it'll throw the E11 overvoltage error even if I reprogram the VFD to such a low output that the phase-to-phase voltage drops to 140V. Anyone have any idea what's going on?
  9. Can those of you who chimed in to help here also take a look at my thread on trying to get a Consew 99 to stop skipping stitches?
  10. I found that the Consew 99 manual includes hook timing information but it's buried in the back of the book past the section that only applies to the model 103 so I had never noticed it. The hook timing is bang-on correct, according to the manual. I verified the "straight stitch" control position produced minimum needle swing (it did, about 0.003"). I verified the straight stitch position placed the needle in the center of the needle plate opening. I verified that at maximum needle swing, the zig and zag were symmetrical about the center. I made a timing mark 3/32" up from BDC and the hook arrived EXACTLY dead center on the needle at that amount of rise. So the timing is spot on according to the book. Looking at it carefully, in the extreme right position the hook passes the needle right at the extreme top of the scarf. In the extreme left position, the hook passes the needle right at the extreme bottom of the scarf. So the ZZ movement is using the full height of the scarf and is balanced within the scarf. One thing did bother me though: at the extreme right position, the needle bar had almost zero rise before the hook passed the needle. I mean I almost couldn't even see any movement of the needle. Since the machine is reliably making stitches on the center and left sides of the ZZ swing and missing on the right, I figured maybe the needle wasn't rising enough to form a loop for the hook to catch by the time the hook was passing the needle. I decided to retard the hook timing slightly, assuming that this would give the stitches on the right better odds of being formed even if it might mean I began to skip stitches on the left side. Retarding the hook to give more movement for loop formation actually made it skip right side stitches even worse! What on earth is going on here?
  11. Somehow, you managed to stick my name on top of a quoted post that wasn't me. Not sure if the OP (who you were quoting) will actually be notified or not. Oh, you actually managed to do it two separate times.
  12. To wrestle this thread back on topic after It got way off with that needless argument that just happened... I make the same products. A pair of wrist cuffs or a pair of ankle cuffs runs $100. If someone is going to buy both kinds at the same time, I discount it to $175 because I save about $25 worth of my time not having to deal with them on 2 separate occasions. I have never had anyone be hesitant about the price. About every other aspect of whether or not this is the thing they want, sure, but the price is never a problem. I'm sure that part of the reason why is all my sales are in person. By the time they hear a price, they've handled them, probably worn them, had friends who already own a set, etc. I also act like every set is custom made. They get to pick leather colors, thread colors, hardware finishes, etc but in reality I help them lead themselves along to choosing materials I already have in stock. So they get something they feel like they customized just for themselves but it's no extra work for me. Once in a while someone will be set on something really crazy expensive and I say I'll order it in special for them but they pay extra for the exotic materials. The other thing that helped was realizing that the materials costs are tiny compared to the value of my labor. It meant that I could order the absolute best materials of each thing I could find and only push the price of the final piece up a few percent. However, using "finest imported Italian leather" or whatever helps them sell because it's something the customers can brag about later.
  13. How similar are the 99 and 199 though? I've run into trouble assuming similarities before (with a different machine).
  14. I just bought a Consew 99 zig-zag machine. In a brief test at the seller's, it sewed without a hitch. Of course, now that I have it in the shop, it's refusing to behave itself. There's almost no information online about the Consew 99, so I'm having trouble even figuring out what I need to inspect/verify with it. Here's what I've been able to determine so far. 1) The wider the zig I try to zag, the more stitches it'll skip. It seems to have to problem straight stitching and no problem with very narrow (2-3mm) ZZ. By the time you adjust it up to max width, it's often skipping 80% of the stitches on one side. 2) The smaller the thread, the more likely it is to skip stitches. It's terrible with Tex30 thread. It's only very bad with Tex70 thread. 3) The smaller the needle, the more likely it is to skip stitches. When I tried the Tex30 thread with oversized needles, it got a little better 4) The higher the top tension, the more stitches it skips. It was pulling the top thread to the back so I increased the top tension, which made it skip like mad. I lowered the top tension and then pulled the bobbin case out and lowered the bottom tension and the stitch balance improved (though not perfect) without causing more skipping. However, by the time I got it more balanced the overall tension seemed really low. 5) This one I'm not 100% sure about. There's so many other things going on that I'm not sure I'm really seeing this but... I think the tension balance on the left half of the zig is not the same as on the right half of the zig. The best balance I achieved had it setting the knots properly on one side but still pulling the top thread into loops on the bottom on the other side. Does anyone have reference material for getting a Consew 99 to stitch reliably? Bonus points for videos but even just a service document with clearances to check and stuff would be helpful.
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