Thread Injector: Metal or Plastic?

[ferball]

Now I know there are few posters on this board whose knowledge of thread injectors and sewing machines is superior to mine and I hope that I will be corrected if the apostasy I am about to spout is completely wrong.

The most overwhelming advice offered when some one asks about purchasing a machine is: "A metal machine is the only way to go." or some derivation of that sentiment. I would like to put an end to that misguided advice.

This advice stems from the late 60's and early 70's when Singer tried to bring the cost of sewing machines down by introducing plastic gears. It went horrible wrong. The space aged plastics of the day (or at least the plastics Singer used) did not react well to the lubricants used in the machines. The oil and grease would cause the plastic to become brittle and break easily which led to stripped out gears.

You will be hard pressed to find a modern sewing machine that uses all metal gears. Most will have a combination of nylon, plastic, and metal internals. Not only is there a cost savings with synthetic internals, there is a huge maintenance bonus. Most modern machines do not require a strict maintenance schedule or frequent lubrication. Weight, noise and other benefits are also a by product of modern materials and engineering.

"...But I am doing heavy duty sewing and metal gears will hold up better". Have you ever stripped a gear before your needle breaks? The gears are not the weakest part of the system, further more if you are doing something that will strip a "plastic gear" what is it doing to metal gear? I would rather have a destroyed gear and know where my problem is than have a slightly bent/warped gear that is throwing off my timing and making my problem impossible to troubleshoot.

Metal or Plastic? An inferior machine is an inferior machine if it is made with metal or plastic. Price adjusted for inflation of all of 40 year old machines that are still in use today would be $1200 and up if you had to buy it new. Keep that in mind when machine shopping. 50 bucks for an old straight stitch model with a proven track record is not a bad deal, and a$750 price tag on a new machine is not outrageous if you are only gonna buy one machine for the next 25 years.

Just one guys opinion, old timers and experts feel free to crucify me for my heresy.

[Loneoak]

Hoping my old Singer 401 is still sewing like it does in 25 years for a 50+ yr old machine that I paid less than $100 for It does all I need so far.
Ain't no way I could afford a $1200 dollar one......ouch

[Ramblinrev]

I've made that very point numerous times. With one important caveat. Weight matters. A good machine has a heft to it so it does not skitter across the table. But things are not a neat and tidy in the world of gear making.

All gear making _requires_ is a straight stitch, reverse and an occasional zigzag if you are anal. An older machine is by far a better value for the gear maker who is not going to go beyond that niche and enter into the wider world of sewing. Stretch stitches, blind hem patterns, lapel interfacing are beyond the realm of the gear maker.

IF you want to _sew_ then by all means get a top quality new machine. [Cheap machines are still cheap machines and won't last.] But if gear making is what you aspire to.... with an occasional rain jacket or so... then a used machine, pre-crap Singer (they were not the only ones) is the best value. In a used machine of that ilk.... metal is the touchstone to search for.

[nothermark]

As I recall L's Bernina was the last of the line that was a basic straight and zig zag all metal machine. It was around $950 in around 2000. It is no longer offered as most of the new machine buyers are looking for programmable quilting machines.

Singer cheap machines in the 70's used plastic gears and a rubber cogged belt. Got one.

[Pag]

I am one of those that cheer for a metal body machine. As far as drive systems I really don't care. I find breaking a $15 belt annoying but far better than jamming 3 $50 gears on the all metal drive Vikings that coincidentally had plastic frames that flex...hence the jamming gears. For my tastes the new pfaff hobby line uses belt drive, and a plastic cogged drive gears with a shaft drive hook and most importantly a metal frame are preety appealing.

Space age plastics sure do have some great spots in machines, body's however are best left to metals that do not flex under load.

[Ramblinrev]

Most modern machines do not require a strict maintenance schedule or frequent lubrication.

I beg differ with this statement. While it is true the more modern machines _might_ require less lubricating that is potentially very dangerous statement. Some manuals caution against customer oiling of internal parts. This is _not_ because the machines do not need it. Rather it is because the bearing and bushing houses are pre-lubricated with special materials and sealed. They _do_ require those sealed housings to be replaced on a determined schedule and I can assure you the process is not cheap.

The maintenence schedule can be even more more strict because fewer and fewer parts are customer serviceable. The heat some of the circuit boards are subjected to can be very damaging and if the innards are not properly cleaned of lint and dust you can be looking a the price of a new machine to replace them _if_ they can be had at all.

Service to a more modern machine now requires specialized training because of circuit boards, capacitors, solenoids and relays. You need to be more an electrical engineer than mechanical.

Per Pag.... I do not have that much of a problem with the modern plastics being used for the drive train and such. I don't much care if the exterior is plastic. But that frame had dang well better be solid because if it isn't ain't nothing going to stay in adjustment or work properly for long. Any machine that does not have a heavy duty metal (usually aluminum) frame is a kids toy as far as I am concerned. Sure you may get a few years out of it but there is absolutely no excuse for a sewing machine not to last at least a full generation.

[ferball]

I beg differ with this statement. While it is true the more modern machines _might_ require less lubricating that is potentially very dangerous statement. Some manuals caution against customer oiling of internal parts. This is _not_ because the machines do not need it. Rather it is because the bearing and bushing houses are pre-lubricated with special materials and sealed. They _do_ require those sealed housings to be replaced on a determined schedule and I can assure you the process is not cheap.

I won't disagree with you on that point, I guess strict was a bad word to use, frequent would have sufficed. Most old timers still sewing on a feather weight will oil the machine every time they use it. I clean and lube my machine about once a year, and it gets alot of use 15+ hours a week.

A note on plastic bodies. The higher end machines will have a metal sub frame keeping the flex and what not to a minimum.

I still agree with every one here that an old metal straight stitcher is perfect for gear making, but an early 90's kenmore would work great too but may often be overlooked because of the plastic.