okay ive searched high and low and i dont have a spare notebook of comfortable size to set aside for machine repair stuff so my organization notes are going here to edit as i do things, since google docs has been giving me grief about editing on my phone lately, sorry
1) stitch tension not quite correct, using zigzag to test per the manual- the balance looks fine overall, but if i look very closely, there is a small amount of thread from the opposite side showing at the edges of the stitch, inconsistently, on both sides of the fabric. this may just NOT be a problem anymore and i am being too literal/inflexible due to inexperience. im going to call the overall tension fixed and im just being finicky, but i AM still concerned over the tension being.. inconsistent? there are randomly stitches that have thread pulled through to either side for just a handful of stitches. that seems strange. bobbin related?
for anyone who's nosing around strange blogs in the boopfest (me too) this is all just me talking to myself and taking notes while i try to fix up my grandpa's sewing machine from the 70s. I have no experience whatsoever with sewing or with mechanics, so it is not going well, but it is big fun :> and after this one gets sorted there's a manual machine from 1934 to tackle
Problems:
2) stitch skipping. sewing slowly, using zigzag, the machine will miss 1 - 3 stitches per row. sewing quickly can make it up to 6-7 missed stitches. when checking straight stitch, skips exist but very infrequently, 1 - 3 skipped stitches total within every few rows. zigzag skips are about 80% on the left side (thread makes a straight line down the right), with only a handful being right side or multiple-in-a-row skips I HAVE MADE THIS SO MUCH WORSE :3
3) clutch issues? while winding a bobbin there was a small clunk noise, after which problems started. sometimes the clutch spins freely (i think i fixed this?), sometimes turning the hand wheel does not move the needle (but turning the clutch always does), sometimes pressing the foot pedal is clearly providing power/moving things internally but the needle does not move (nor does the handwheel)- this is temporarily solved by manually fiddling with the wheel until i can put the needle in a different position, after which everything is fine for awhile again. if i re-engage the clutch but DO NOT move the needle with the hand wheel, it continues to not work? Calling this fixed, internal winged thing needs to be pointing at 12 and the grippers need to be facing outwards
4) palest purple thread is on a bobbin that may need to be replaced? weird resistance issues when pulling on it, smooth for a bit then very resistant, has broken thread twice- other bobbins fine? i think it was the one that gave me the most trouble when winding too
5) i may have over-corrected the tensioning unit? grandpa had the internal screw too tight, i may have set it slightly too loose. tension 6 was fine for palpably coarser 50wt cotton thread, but switching to a smooth silky 50wt cotton has me setting it on 9? that seems like a lot? not that i'd really know but.. multiple videos explaining the process called for 0 base tension on the spring, and i was very careful to set the screw at the maximum possible height. maybe it should have been a little further down? fixed the tension.. again
6) the internal bobbin hook thingy (official scientific name) wants to fall out very easily when i remove the cover. when i set it in place, whether the machine is upright or laying down, there's quite a bit of wiggle and play in the position of the piece no matter where or how i insert it, until i lock it in with the cover. it still clearly has Its Own Place that it slips into satisfyingly, but until it's locked up, it can shift around a bit. is that normal, or is something wrong with it? yeah i think im just being paranoid, other things say that it just rests there loosely until locked in
7) mystery oil collecting in bottom of case + seeping around bottom case screws. Brown and low low viscosity, can't find what it's from. Oiled parts above it wipe off clean and don't seem saturated. Keeps reappearing after being cleaned out. i think this might be old wd40 or oil in the screw holes themselves? maybe from grandpa trying to loosen them up long ago? but why does it also collect along the lip of the bottom cover?
8) a couple occasions of "motor going but no movement" sounds, where i also couldnt turn the hand wheel- it just felt blocked. i couldn't move it forward at all, COULD move it backwards, but only a very short distance before feeling blocked again. these all occurred with the needle well above the plate. i.. think?? that it's the bobbin case somehow occasionally touching or blocking the hook/hook driver?? despite being locked into place securely?
Things to try (unrelated to the order of problems):
1) REMOVE NEEDLE AND ALL THREADING, open top of machine, check belt for damage, examine internal clutch parts- find video for disassembling clutch
2) open bottom of machine, search for something that might have broken or fallen out of place? maybe gravity will help me figure it out, clunk doesn't just happen (clunk likely from something about the clutch assembly slipping out of place during use and probably fixed now, but i should still open it up and look)
3) if 1 row then skipping, skipping may be from something damaging the needle? examine bobbin area more closely and try to figure out if the needle is going too far? i've tried this a little and found nothing, but maybe there's a proper way to verify. remove bobbin casing cover from the bottom, examine needle position and hook timing from front and back- use zoomed in camera and hand wheel to check ON BOTH SIDES OF THE ZIG ZAG (left side stitches are what's being skipped most) (idea taken from "sewing machine tips and tricks" youtuber's video on skipping) yeah this is the problem, timing is clearly off- repair shop necessary
4) check for burrs along thread path
5) just buy new bobbins, these are all old ones from grandpas stash- most are in okay condition, but some tarnished, some slightly wobbly looking. i think i mostly picked okay ones to use, but the only way to be certain is comparing with new- also buy (manual not the crazy digital ones) bobbin tension measurement tool, grandpa must have made some wild adjustments to this machine when he worked with leather, and i probably will too
6) play with the gear timing myself? if a tech is gonna have to adjust it anyway, it may as well be fucked up real good from me trying to learn, shouldnt make much difference to them mistakes were made
7)??? repair shop?
Have attempted:
1) new needle (no benefit), smaller needle (1 perfect row, then skipping), bigger needle (1 perfect row, then skipping), rethreading many times.
2) removing clutch knob, pulling hand wheel partially out, cleaning shaft (with bluecreeper, tons of black gunk came out), re-oiling. replaced clutch (prongs pointing at at 2 and 10, tabs outwards). still had random issues with engagement (though this time the handwheel was spinning, even if the needle wasnt). removed clutch again, rotated the inner prong'y piece (pointing at at 12, tabs outwards), and put it back on. haven't tested enough to find if the engagement issues continue yet. -- 6ish rows later, no engagement problems yet? -- THIS IS FIXED
3) examining belt- no damage on the big upper belt, nothing different from when i started
4) took closeup photos and video of hook/needle timing, which is clearly off
5) have checked for burrs with fingers and qtip, along threading path, needle area, and bobbin area- found nothing, but don't have pantyhose material to be fully sure. found a burr on the needle and replaced it, to absolutely no change whatsoever.
6) finally got throat plate off, all hail penetrating oil. feed dogs were mostly clean in active/moving spots, scrubbed everything with alcohol anyway. how did grandpa get everything so STICKY all the time? no benefit, but at least gunk has been washed
7) opened up gearbox under shuttle. I don't know what used to be in there, but it transmuted to disgusting ass earwax in the intervening years. I don't know if the grease i use for my fountain pens pistons (finish line ceramic grease) is actually the right grease for the job, but I do know it's better than a lump of earwax and I can clean it off later if I need to. He's already SO MUCH QUIETER my poor darling, even if it hasn't done anything to change the skipping. The sound of this machine up til now has been the exact same chugging sound I remember from my childhood, so those poor gears must have been grinding for longer than I've been alive
8) also checked through bottom of machine. All good, nothing out of place, everything pretty clean besides weird mystery oil on the bottom.
9) re-re-re-re corrected the upper tension internals
10) adjusting needle bar height. on one hand, i regret EVERYTHING, and on the other, i regret nothing that lets me learn more about how to work on this thing. made everything SO MUCH WORSE, then corrected it to being.. roughly as bad as it was before. if it's possible to fix the overall problem with just this adjustment, i physically lack the ultrafine microscopic visual acuity and dexterity to see and adjust the fractions of millimeters it would take without some sort of purpose-made tool -- continuing to fuck up the needle bar height. this is fun and also going nowhere
11) tried to adjust hook timing- this is weird and difficult. how do i make it MOVE to the position i want it to be in? i think i got it to where it should be, ish. everything i can find says that the hook should be passing the needle when the needle has risen by 2 - 2.5mm from its lowest point.. mine wasnt passing until the needle had lifted around 4.5-5mm. skipping is slightly-but-not-much worse after my adjustments, but the stitches do feel more.. responsive? decisive? something about the actual stitching action feels more nebulously Right. i think part of the reason i had so much trouble figuring out how/where to start adjusting is because most of them show the adjustments being made on the main drive shaft outside the gearbox. i had to loosen screws inside the gearbox to change the hook position. not confident that was CORRECT or the way it SHOULD be done, but it tracks with how i've seen most gearboxes packed with grease and mine only had a minimum amount- being packed would block access to the screws i used. -- i badly want to tinker with this more until i get it right, but i also want a working machine in the near future, and adjusting it was incredibly difficult with the tools i have available :( not to mention dangerous for the machine, as i had to go at odd angles that wanted a slim bent tool when all i have is a bulky straight one
