How To "test Drive" A Used Industrial Machine.

[nascenta]

I've searched for a while now and can't find much of a checklist of things that you want to look for when checking out an industrial sewing machine. If there is one please post a link.

I'm looking beyond just having proper thread tension on a sample I sew on the machine; things that might indicate parts that need replacing.

For example:

play in the presser foot height once it is up.

Stitch length that doesn't vary very much.

How to check the effective range of the tension adjuster?

Greater than expected resistance in the mechanism by hand rotating the flywheel.

Do you try to inspect the shuttle hook, or other components? What do you look for?

In other words, I am asking if there exists a list of these useful tests and the desired result or the probable diagnosis if the machine fails the test.

Am I making sense?

This weekend I am going to be purchasing, maybe, my first industrial sewing machine and I want to make a wise, informed decision. I am aware that some of these 'tests' might be model specific, given weaknesses in design, etc. I am looking at a Singer 31-47 made in 1943.

Any insights or direction would be appreciated. Thanks.

Edited March 9, 2016 by nascenta

[Uwe]

If the machines actually sews, that's a really good sign right there. The rest are often details and adjustments, depending on the machine.

Look up some key parts like shuttle hook etc. to see if you can buy them and how much they cost. I would go in with the expectation that you have to replace those parts. Mentally add the cost of these parts to your purchase price and see if you're still comfortable with it. If it turns out you don't have to replace them, good for you.

Some wear parts are often readily available, like hook shuttles, tension assemblies, bobbins, needle bars, etc. I looked up a shuttle hook for your machine and they run $30 or so - that's cheap in the scheme of things.

Other parts are often nearly impossible to get, like hook driving shafts and other internal major components or cast metal housing parts. If those are broken, missing or bent, just walk away.

Old tables and old clutch motors are nearly worthless (at least to me) unless they're super nice. If the machine head is worth bothering with, plan to spend $300 for a nice table and motor in the long run. I stopped bringing nasty tables and clutch motors home. "Just the head, Ma'am" is my recent motto.

Things that are easy to fix: Grime and dirt, oil residue, lack of lubrication (unless they ran the machine dry). Certain missing parts (standard thread tension assembly, bobbins, cover plates, etc.)

Show stoppers in my book: The machine won't turn over at all or hits a hard stop that is not an obvious and easy fix. Bent arm shaft or hook driving shaft. Rusty hook or other signs of water/damp damage (left out in the rain during garage sales, flooded basements, etc.) Seriously abused bolts and screws underneath. Bad repaint to mask problems.

The rest comes down to how much you're willing to gamble. It's good have a cheap machine that works and allows you to tinker with is without feeling super guilty if you mess up. You'll know MUCH more when you buy your next machine, which is only a matter of time.

I'd be leery spending more than $200-300 on a machine like the Singer you're considering, unless it's super nice. Leave room to buy parts, new motor, and pay somebody to give it a thorough cleaning and adjusting at $90/hr.

Edited March 9, 2016 by Uwe

[Tejas]

Buying a used machine, especially from an individual, can be challenging. I've looked at many machines and bought four different used machines from individuals, and all had later discovered surprises such as missing parts or gummy lubrication that interfered with operation. This is what I have done. I'm quite interested in what other folks recommend.

Try to find a manual online, or at least a few pictures. Sometimes machines are not even complete.

Take scissors, small screw drivers, thread and sample material(s), needles and of course the manual. Using different colored thread for needle thread and bobbin thread helps to be able to see the stitches and tension.

Ask the seller to demonstrate the machine if they can -- sometimes the seller is selling for someone else. Look top, bottom and underneath at overall condition and especially for rust. The condition of slots in screws can indicate heavy-handed maintenance. The electrical connections on older machines can also be a problem. Test all the functions you are interested in.

Wind a bobbin with your thread and using your top thread, sew your sample material(s). Verify that the stitches look OK top and bottom.

To test stitch length, set the stitch length, un-thread the needle and with the hand-wheel operate the machine sewing forward, “sewing” a piece of light cardboard or heavy paper for a few inches. Then with the hand-wheel operate the machine in reverse. The needle holes in reverse should perfectly match the holes going forward. Remove the cardboard and measure the actual stitch-length versus the setting. Do that for the start and end range of the range(s) you are interested in.

Edited March 9, 2016 by Tejas

[dikman]

You make me feel ignorant! Two of mine I bought from a chap selling off excess, no longer used surplus machines from his business. He'd run them to prove they stitch and I turned them on to make sure they worked! I may have been lucky, I guess, as he was a nice bloke and the machines had been serviced regularly. The next one I made sure it turned over by hand and that was it. The machine hadn't been used for a few years (?) and the motor and table were cheap **** - but it was a very good price for the head unit. The fourth one (head only) was free, I turned it by hand, which was fine, so figured it was a good price!!

Like I said, I may have been lucky as there were no broken bits (just one very worn shuttle).

[Uwe]

Who you buy the machine from makes a difference. A long-time owner and operator selling some of their working, surplus machines is a different story than some shifty character meeting you at their hoarder's delight storage unit with no power or lights.

"Works great and sews everything" are statements made by people who have no clue about sewing machines. Proceed with extra caution.

If you're buying from a dealer, make them demonstrate that the machine works perfectly and then sew on it yourself.

Price negotiating tactics is also a factor. If you spend an hour verifying that the machine is perfectly adjusted in every way, the seller will be less inclined to give you a price break. A brief sanity check and basic operation check followed by a quick summary of everything that could be wrong with the machine is a better negotiating position.

Personally, I only check for very basic operation and missing/broken parts. If the basics are okay, cleaning, adjustments and fine tuning can be done after you get the machine home.

So far I've been somewhat lucky as well in that all the machines I've bought none of them have turned out to be door stops. I did walk away from a few that were beyond reasonable repair even at a quick glance.

[Uwe]

Just for reference, there's a Singer 31-15 for sale on my local Craigslist for $350 by somebody who used the machine to make a living, so presumable kept it in good working condition:

Edited March 10, 2016 by Uwe

[Wizcrafts]

Several years ago I bought a very, very old Singer 31-15 from a Craigslist seller whose Mother was supposedly the original owner. It was a two hour drive and I arrived late and only turned it on briefly to verify that it wasn't seized and that it sewed manually. Big mistake. The shuttle, race and bobbin case mounting bracket were badly worn. The bobbin case rotated in the housing when I powered it on at home and jammed the shuttle. I had to waste a lot of time and money on all the required replacement parts and adjustments to get it to sew reliably. Now, it is just fine.

Purchase price: $250

Replacement parts: about $100

Time to replace and adjust to get it sewing: 8 hours

Loss: about $300 vs a properly maintained and working machine.

[nascenta]

This is great information! Thank you very much, all of you. This is exactly what I am after.

I recall that someone in the forum has talked about the clearance height of the foot lowering over time (or maybe is was the needle bar) as something wears. Is this an issue?

Wizcraft, those parts that were worn that you mentioned, would they have made themselves known if you had actually sewed with the motor? If you do a visual on the parts what do the worn ones look like compared to healthy ones?

[Wizcrafts]

This is great information! Thank you very much, all of you. This is exactly what I am after.

I recall that someone in the forum has talked about the clearance height of the foot lowering over time (or maybe is was the needle bar) as something wears. Is this an issue?

Wizcraft, those parts that were worn that you mentioned, would they have made themselves known if you had actually sewed with the motor? If you do a visual on the parts what do the worn ones look like compared to healthy ones?

The problem was not visibly obvious. It manifested itself when I got the machine home, powered up the motor and floored it for a couple of seconds. The bobbin case rotated out of its mooring bracket and spun with the shuttle. This caused a lot of damage. As I began the repairs I discovered that some bobbin cases held their locked in position better than others, which popped out easily..

[Uwe]

One quick and easy check you can easily do is to try to wiggle the needle bar by hand front/back and sideways. It should NOT move. A good machine will be "tight" as in turning over easily by hand, but without any noticeable play (the handwheel itself may have a little play as you change direction, but not the feed and needle bars). If you can move the needle bar by hand more than a millimeter, it indicates worn bushings and linkages - the machine in this case is unlikely to make consistent stitches and may require major repair work.