Members dikman Posted June 15, 2018 Members Report Posted June 15, 2018 (edited) Jimi, a couple of photos. Plinker, apologies for a partial hijack First photo shows everything assembled, second I've removed the unnecessary bits.The arrow points to the hole where the push rod fits, the sliding part in front is attached to the outer presser foot lifting shaft, you can see the cutout so the push rod isn't activated with the presser foot down. Third photo is the outer presser at the top of its stroke during a normal stitch cycle. As you can see, there's no way to stop the rod being pushed and releasing tension during normal use. As I said, I'm slightly perplexed by this as it appears to be deliberately designed to operate this way. Edited June 15, 2018 by dikman Quote Machines wot I have - Singer 51W59; Singer 331K4; Seiko STH-8BLD; Pfaff 335; CB4500. Chinese shoe patcher; Singer 201K (old hand crank)
DonInReno Posted June 15, 2018 Report Posted June 15, 2018 During normal operation the presser foot shouldn't rise far enough for the sliding gizmo to engage the release pin - only when the foot is lifted beyond its normal range of motion by either hand lever or knee lifter. The large gap between the hand lever and sliding gizmo appears to show the sliding part is too high up on the shaft with presser foot down so it's engaging the pin as the foot rises when it shouldn't. 11 hours ago, dikman said: Quote
Members jimi Posted June 15, 2018 Members Report Posted June 15, 2018 Yes i think you are spot on don i sent a couple of pictures to dikman of mine and the foot rests on the take up lever when up, so it would probably be just slackening off the 2 screws to let it rest on the take up lever when raised. Quote
Members dikman Posted June 15, 2018 Members Report Posted June 15, 2018 Don, I agree but was perplexed because it was like this when I bought it (it had been used in a small factory then eventually replaced) and I made an assumption that it had been correctly adjusted but something must have broken. Jimi's photos showed that the correct parts were fitted and nothing was broken, so as you said the lifter has to be incorrectly positioned on the shaft (I'm guessing it happened a long time ago and no-one knew how to fix it so removed the tension release pin and fitted a manual version). Now I know (at last) what to play with to fix it . Quote Machines wot I have - Singer 51W59; Singer 331K4; Seiko STH-8BLD; Pfaff 335; CB4500. Chinese shoe patcher; Singer 201K (old hand crank)
Members dikman Posted June 16, 2018 Members Report Posted June 16, 2018 I think I've finally got this thing sussed out (it doesn't help that there's virtually no information on these old ones). I'll post it here so anyone searching on Pfaff 335 will find it. After a lot of adjusting and re-adjusting I've found that when it's set to operate correctly, i.e. the tension discs release when the lifting lever is operated, there is 1/4" (6mm) clearance under the feet. Any thicker leather and the outer presser foot will go higher and start releasing the tension discs! If the release pin is removed and the curved slotted arm on the back is adjusted then you can fit 5/16" (8mm) under the feet. If you leave the pin in it will release tension during a stitch cycle. If the release pin is removed, the slotted arm adjusted and the arm (next to the yellow arrow in my pic) re-adjusted on the outer presser foot shaft, as mine was, then you can just squeeze 3/8" (10mm) under the feet. For the second and third options you will need a manual tension release like mine has. It looks like mine was deliberately set up for maximum clearance under the feet, but I decided to compromise and set mine to 5/16" as at 3/8" the needle bar is almost hitting the leather during stitching. Quote Machines wot I have - Singer 51W59; Singer 331K4; Seiko STH-8BLD; Pfaff 335; CB4500. Chinese shoe patcher; Singer 201K (old hand crank)
Members jimi Posted June 16, 2018 Members Report Posted June 16, 2018 Aha so you got it? well sussed. I think the H3 might have a bigger foot lift on it, but mine is like yours with 6-7mm. that seems to be what it was designed for. if I get tough leather under it, the spoked hand wheel can´t handle it, it has to be soft. if I can change it one day for a solid one then I am sure it will go through a little tougher leather. I personally would leave it where it was supposed to be and use a bigger machine for thicker leather. ( just another excuse to get some more old iron ) glad you finally got that one fixed. now wash your hand´s because your coffee is cold AGAIN! . jimi. Quote
DonInReno Posted June 16, 2018 Report Posted June 16, 2018 That's great news - sorting out tension release issues can be a challenge! Also keep in mind that with many makes & models with this type of tension release you can get additional foot lift without activating the pin by varying how far the tension assembly sits in or out. I'm not familiar with the bits the pin affects on the front side, but there is surely an adjustment like any Singer style. Normally the backside is adjusted to specs then the front side tension knob assembly is fine tuned to release properly, so we're talking about it somewhat backwards. Quote
Members dikman Posted June 16, 2018 Members Report Posted June 16, 2018 I hear what you're saying Don, but due to the design of this machine there is no "fine-tuning", it either pushes on the release lever at the back of the tension assembly or it doesn't. If you move the assembly out then it doesn't work. No matter, now that I understand how it works it's not an issue. Jimi, before I readjusted mine I was putting just under 3/8" veg under the feet and it punched through without too much trouble (servo, 45mm pulley and large pulley on head). I don't think I'll make a habit of that but it's a pretty solid bit of engineering in these things. I tend to use my Seiko for thicker stuff. Quote Machines wot I have - Singer 51W59; Singer 331K4; Seiko STH-8BLD; Pfaff 335; CB4500. Chinese shoe patcher; Singer 201K (old hand crank)
Members DanishMan Posted May 26, 2019 Members Report Posted May 26, 2019 Hi Dikman I recently bought a 335 H2L B17 exactly like yours - also with the manual thread tension release lever. Thank you for your effort in sorting things out. It will be of great help to me. I will probably fit a rod and make it work like normal. Brgds Danishman Quote
Members dikman Posted May 26, 2019 Members Report Posted May 26, 2019 Well done, those manual releases appear to be rare as I haven't come across another one in all my searching! It means you can actually fit thicker stuff under the feet than it was designed for, but the downside is remembering to release the lever before sewing!! Trust me, it makes a mess if you forget. Quote Machines wot I have - Singer 51W59; Singer 331K4; Seiko STH-8BLD; Pfaff 335; CB4500. Chinese shoe patcher; Singer 201K (old hand crank)
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