Greystone Report post Posted October 19, 2013 (edited) I've followed several post on belts and had a go at it , Belt turned out nice and went about wearing it and decided I wanted some stitching on it and well the pics tell the rest, What needs fine tuning and or adjusting?? belt details 1.5" wide with English bridle 7-8 oz and backed with vegtan 10 oz and skived the the outer third of the backing top and bottom/ edges down to 8 oz+- and left the center thick, Finished total center thickness @.28-.30" edges are 0.23 -0.25" thread 277 Cobra 4-25 had a practice run on the smaller piece and thought I had the set up tuned in the test section was the finished belt cut off test fronttest back the put the belt under and pressed away and got a nice start and kept the speed manageable Belt finished front n backfrontbackside missed a stitch and another and ,,,said well its just a nice work belt now and ran the length up and back and had a few more dropped stitches and mark this down to an expensive learning lesson backside what do I need to do, to get on track, timing looked ok ?thread? different needle? feed back NEEDED and welcome David Edited October 19, 2013 by Greystone Quote Share this post Link to post Share on other sites
Red Cent Report post Posted October 20, 2013 (edited) The C4 problem, eh? I am sure you have watched the videos and talked to Steve or someone at the shop. And I can attest that there are some of us who have ventured into the scary arena of thread tension. And, for what it is worth, here is where I landed. First I switched to polyester thread. 277 top and 207 bottom. I thread from the spool, up to the arm, then to a lube pot. Filled with glycerin sadle soap. From the pot to the wire eyelet, over the top and down. Not around the disc. I do click it into the disk. Down to the next wire eyelet and counter clockwise around the disc but out and through the spring eyelet. I do not go around the disc twice. Up to the take up arm and the rest as usual. I have learned to do what John Bianchi does when he gets ready to sew. Sew about a foot on scrap the same thickness as the piece you are getting ready to sew. The other day, after a number of projects, I rewound a bobbin, got it ready to sew and the top thread was not pulling through very well. A 1/4 turn clockwise on the top disc solved it. Oh yeah. My tension screws are backed out all the way. Just enough tight to stay on the spring. Sounds weird and maybe blasphemy. This through two 8-9 ounce veg tanned. Other is 8-9 with 4-5 outside. I have not had a skipped stitch in a long time. And my stitches are very uniform. I hope others will post and let them show you good work with full tension. The other day, I communicated with a C4 owner and he was putting the post on top of his C4, just like the Cowboy 4500. They are the same machine. Leather Machine Company tossed the post stating that their test found it was not needed. I have said it before. There is probably 379 (I think that was the number used) ways to thread the C4 and get a good, consistent stitch. Good Luck. Edited October 20, 2013 by Red Cent Quote Share this post Link to post Share on other sites
Red Cent Report post Posted October 20, 2013 (edited) Another one. BTW, I have been at this for a few months. The machine has a decent learning curve. Read, read, read, and watch videos. Edited October 20, 2013 by Red Cent Quote Share this post Link to post Share on other sites
Red Cent Report post Posted October 20, 2013 C'mon C4 owners. Help this guy out with some suggestions. Quote Share this post Link to post Share on other sites
Rayban Report post Posted October 21, 2013 I'm not one of the C4 owners (Cowboy 3500 here) but I learned the hard way that there are several ways to get them skipped stitches.....it's clear by the pictures that the tension isn't right. Hope you didn't mess with the bobbin tension, you shouldn't if you don't know what you're doing...that's one of the first things I learned the hard way. Any adjustment you need to do can be done with the two top tension disks. Make sure the machine is threaded correctly. Check the needle, if it has a burr at the tip, it could cause it. I learned that cheap, improperly tanned leather can give you fits.....small areas of rawhide can still be in the veg tan, very hard stuff, and when the needle hits it, it don't like it....causing a burr.....causing is to not pick up the loop just right.....walla, skipped stitch. Quote Share this post Link to post Share on other sites
Red Cent Report post Posted October 21, 2013 (edited) There is a leathercrafter here and at Cas City. He posted a way to get the bobbin tension "correct" on the C4. And It would apply to the 4500. I did it and it works very well. I do agree that most tension problems can be solved with the top tension discs. Some or most may not agree with the correct way to thread a C4 but the proof is in the leather. As I have stated, I have communicated with a couple who did it their way. And I like the polyester thread. Surprised Steve has not hopped in here. http://www.cascity.c...ic,47819.0.html Edited October 21, 2013 by Red Cent Quote Share this post Link to post Share on other sites
Greystone Report post Posted October 21, 2013 (edited) Quick follow up Thanks Red Cent, Rayban first test sew, on the short cutoff strap looked "ok" pics seem to make look worse than it is rest of the pics show a inconsistency top and bottom as well as missed stitches so I'm not sure if top tension is the bug or bottom I rechecked things prior to sewing as I had switched feed dog and feet to do some heavy canvas repair, and had a stitch length variation, which was solved by another post with the same issue reset feed dog height and recheck all normal things threading machine clear thread path no dirt/dust general normal stuff just looking to shorten the fight/curve and get a list of fix and see what works will try re thread non factory way and move on with tension resets and recheck needle hook pick up thanks and will keep at till, I GET THE Proper STITCH I WANT to see on a finished product David more detail, 277 bonded nylon top and bottom #23 organ needle supplied with machine top tension and 2nd tension springs are lightly set if any at all just so they are not flopping around quick note leather was contact cemented together both pieces were back cuts and firm and good quality,,, imho Edited October 21, 2013 by Greystone Quote Share this post Link to post Share on other sites
Ed in Tx Report post Posted October 21, 2013 I have a Cobra 4. One thing I see right away that may be an issue is the size needle you are using, you say you are using thread size of 277 and a #23 needle, the proper needle size for 277 is a # 24 not a #23. That isn't specific to Cobra or Cowboy, that is the recommended needle size on several sites regarding thread and needle sizing. I recently purchased a lube pot and found that I had to back the tension off on both tension springs. I plan on playing with it a bit more before I start using the pot on a regular basis. Bottom line, try a size #24 needle for 277 top thread. Quote Share this post Link to post Share on other sites
dbusarow Report post Posted October 21, 2013 I'm going to agree with Ed in TX here. A #23 with 277 is too small. It will give you fits trying to adjust tension. The thread is not going to be sliding smoothly through the needle so it acts like the top tension is too high. BUT the hole punched in the leather is too small so it can act like the top tension is too loose. And these two do NOT average out. Use a #24 or a #25 for 277. Dan Quote Share this post Link to post Share on other sites
Red Cent Report post Posted October 21, 2013 I use a #24 or a #25 needle. I used the 277 bonded nylon top and bottom with a 25 needle as the machine was set up from the shop. I strongly feel the use of 207 on the bottom helped. And I believe the poly threa helped. 379 ways. The tension on the thread can be affected with just a little resistance. I had some trouble with skipped stitches and out of the side of my vision, I noticed the thread was just so lightly "snagging" on the spool. Then I noticed everytime the snag happened, I got a skipped stitch. It always mystified me what kind of tremendous resistance the double wrap around the bottom disc caused. I think I increased the resistance at that spot when I started to using the lube pot. Had to. Since I don't wrap twice, I can pull excess thread out when I finish. I still have scars on my fingers trying to pull the thread out. And the presser foot was raised. Quote Share this post Link to post Share on other sites
Hillbilly tim Report post Posted November 1, 2013 Well I'll jump in here as I also have a class 4. For what it's worth, I have the same basic setup as Harold, redcent, has come to use. I however still use bonded nylon, I do use a lubepot with gly. saddle soap too. 277 top always and 207 and 277 bottom depending on what i'm doing. I do think in my testing that 207 on bottom is less problematic. I tested the 207 in the bottom by buying prewound bobbins of it on a paper core from springfield at 0.39 cents each. oddly enough, it works better loaded turning in reverse from how I load the 277 in the shuttle. Go figure!! I do agree with harold somewhat but I think there may be many more than 379 ways to thread a class 4. I had considered adding the threaded rod in top of the machine like the cowboy 4500 runs but, if you think it through it will only increase tension on your top thread because of the drag going through the 2 holes thereby exacerbating the problem. That said I do love my machine but, still have problems if I try something too thin. Yuk, what a mess it'll make!!!! Bro Tim Quote Share this post Link to post Share on other sites
silverback Report post Posted November 1, 2013 Hi,Greystone. You said the edges were cemented,did you allow enough dry time before sewing as I found if I get too keen the damp contact causes all sorts of problems acting as a tensioner.Hope this helps in some way. Quote Share this post Link to post Share on other sites
Rayban Report post Posted November 1, 2013 HB Tim, you mention thin stuff.....I usually, run 207 top and btm with a #25 needle, 6 spi, on most stuff I make. On thin stuff, like belt keepers, I leave the thread and tensions alone and drop to a #23 needle. I get a much better looking stitch. MMV, but it works for me. Quote Share this post Link to post Share on other sites
Hillbilly tim Report post Posted November 1, 2013 Hmmm, I haven't tried that as yet. I'll give it a go, thanks!!! Bro Tim Quote Share this post Link to post Share on other sites
Cobra Steve Report post Posted November 1, 2013 Hello. In my opinion, this is a needle size/thread size issue. Ed and others are correct. Either drop down to a 207 thread top and bottom with the #23 needle, or use a #24 needle with the 277 thread. I prefer the first option. Thanks, Steve Quote Share this post Link to post Share on other sites
Greystone Report post Posted November 1, 2013 went up to a 24 needle and saw no difference then went up to a 25 and looks ok but a little large hole imho contact cement had 24 hrs drying outside inward,, row 1 with the 23 row 2 is with a 24 row 3 is the 25 front and back view might have it worked out David Quote Share this post Link to post Share on other sites
Red Cent Report post Posted November 1, 2013 (edited) Today, after reading about all the suggestions about needles fitting a certain thread, I changed my #25 needle out for a #24. I use 277 poly on top and 207 poly on bottom. The result, sewing 2 pieces of 8-9 and one piece of 4-5 together, was the top thread laying flat with bobbin thread showing. Removed the old thread from the leather piece, replaced the needle with the 25 and it sewed great. And subsequent pieces also. 'Course, you have to remember how I have things set up. Edited November 1, 2013 by Red Cent Quote Share this post Link to post Share on other sites