Help! Wanted Techsew Stitching Nirvana, Got The Blahs Instead

[Dakman]

That is not the screw to adjust the lower thread tension. The lower tension is set with the one of the screws that holds the flat spring on the bobbin case.

Mark

[Dakman]

Oops, I guess I wasn't looking at your picture correctly. I believe you are correct and that is the adjustment for lower thread tension.

Mark

[Northmount]

Look at the Consew 227 variants manuals here: http://www.consew.com/Resources/

Manuals have bobbin tension instructions, though the 2 screws may be labelled opposite.

Tom

[YinTx]

Goldmine for me, thank you! I'll read them through so when I talk to Ron at Techsew, I can at least speak the same language.

YinTx

[JLSleather]

Definitely call Ron, seems like that would be the guy to see for your machine. Meanwhile, your "LR" needle may be rotated and not oriented quite right - that hole looks awfully oblong (l to r).

Here's that pic again... this is a "LR" needle and an "S" needle, with everything else unchanged.

207 thread / #23 needle / 5.5 spi (or some metric equivalent)

[YinTx]

on the small machine:

Fiddled around with it, since the bobbin was now spinning better. read the 227R-2 owners manual up to where they discuss the safety clutch. Very difficult to understand but I did what I could with it. Suddenly, the needle was going through the leather! I have no idea what I did. When I learn, I will type it up for sure. Since it seemed to be running a stitch, I went ahead and started on a strap. First 2 feet came out ok, so spun it around and started the second side. Not so good, results in the photo below.

One thing I have noticed is that the presser foot pedal seems to bounce when the machine is running. Don’t know why.

On the upside, I have some stitches now. So seeing improvement. Definitely more to go, so if any of this clues anyone on an idea, please share!

Now on to the 4100:

After opening, cleaning, oiling everywhere something was rubbing metal to metal, bearings, etc. I discovered a few things. While turning by hand, there is binding in the head and near the bobbin area. I discovered the presser foot spring was catching in the threads on the adjusting screw, so I turned it over, which seemed to help. Also found that a shaft is catching the same spring and binding it up randomly.

This seems to lift the presser foot while stitching, in additition to making the machine hard to turn by hand. The outside presser foot jumps and jambs during the cycle when it should be down. If you hold the presser foot pedal slightly, this reduces the incidents of binding. When it does bind, the presser foot pedal is hard to push, and it releases very suddenly and everything runs fine again. Photos of the shaft binding with the spring attached. You can see slightly the spring is compressed on the top, and looser on the bottom. The round shaft directly in line with the take up lever and behind the spring appears to be what is binding.

I have also attached photos of the needle position to verify it is installed correctly. The clearance in the bobbin area is so tight, I can’t imagine turning it without it binding and deflecting the needle. Perhaps I am wrong.

I ran some new stitches over 4 layers of soft veg tan. Photos below. Still not entirely happy, and don’t like all the binding noises in the machine. The machine does stop itself and I have to push the presser foot lifter pedal to unbind before moving on. Because of this I have done very little practice/test stitching.

Image of back of threads from 4100 on 4 layers veg tan.

[YinTx]

Here are the instructions for the safety clutch adjustment. If anyone understands this, please let me know and help clarify!

Also, the instructions for adjusting timing, if anyone understands this, please let me know and help clarify!

[YinTx]

Around midnight last night, while working diligently to see where the issue may be in the Techsew 4100, came across this. There are apparently two main areas of rubbing/binding, one in the head area and one in the bobbin area.

Bobbin area:

When I pulled the plate off the top of the cylinder arm, noticed a heat mark on the guide around the bobbin. (see color marked steel that I am pointing to with tip of screwdriver).

Looked underneath, and saw where the hook had been impacting and wearing metal from this guide (pointed to by tip of hook).

This is not the only area rubbing down here from what I can hear as it turns, so something is out of alignment.

Head area:

Still not sure exactly what is causing this, but the collar that rides the presser foot tends to rotate about 1/64" every 3 to 5 rotations of the handwheel. This causes the roller to bind against the case and the presser foot rod to bind on the collar/bushing, and the foot jumps about as it binds/unbinds. If you lift the presser foot with the pedal, everything frees up and carries on for another 3 to 5 rotations.

YinTx

[JLSleather]

That discolored area is your shuttle race. I don't know if that level of heat could ever be produced by operating the machine - even if it was oiled , say.. never. More likely, that part was broken (by impact) and received a less than stellar repair. You may be able to see an issue by removing it from the machine, setting it upside down so the bobbin assembly can turn in there, and then turning the shuttle / bobbin. I'm not there, but just looking at a picture, wouldn't be surprised to see a welded race had warped enough to cause picture 2. Guessin, still.

The machine in the video doesn't say techsew, at least not above the paint job. Still, an idea of how that might look working. White thread used on top / black on bobbin just for easy viewing... https://www.youtube.com/watch?v=n7MVSikaYEk

That other part, not sure which parts you are describing. what I THINK you are calling 'collar that rides the presser foot" is in fact a clamp (of sorts), and I'm not trying to be insulting when I say I assume that you have checked those screws for tightness.

Edited January 22, 2015 by JLSleather

[YinTx]

JLS,

No offense taken at all. Unfortunately my newfangled laptop doesn't have software to let me draw arrows and numbers on photos, or I would. The clamp is actually above the collar, the collar pushes up on the clamp, which is where the spring resides. The roller I mention getting pushed into the casing is attached to that clamp. There is normally about a 1/64" gap between the roller and the case, and it generally never touches until it binds. The roller moves freely on its own until it is jammed into the case. The collar should go straight up and down, as the rod does not change angles. Any change will cause the bushing in the collar to bind on the rod, hence why only about 1/64" does it in. I have tried all the screws in the head to verify they are tight, unless I have missed one.

I think the heat was generated by the hook impacting the race, as you can see clearly in the photo where it has chewed out a significant amount of metal from the race. It is possible this is a new shuttle, since I would expect the damage to the race would be more evident on the shuttle.

On the Cobra diagram I have, the roller is part #21, the bushing/collar that binds is part #7.

YinTx