We have been doing some heavy duty canvas work for our boat, dealing
with Sunbrella fabric. We were using a Brother home sewing machine. The
last project, a sail cover, spelled finis for that machine. It just
burned out but it had delivered yeoman service for many years.
Now we have a new project rebuilding the dodger. (A dodger is a canvas
-- Sunbrella -- enclosure with heavy clear vinyl windows, all supported
on a metal frame with various big zippers to enable installation,
removal and folding.) This job would need more than a small domestic
sewing machine. So seeing a good buy, we bought an industrial high speed
lock stitch sewing machine, a Yamata GC8500. This is one humongous
mother of a sewing machine! It does 5,500 stitches per minute, is driven
by a ½ HP motor and weighs, all up with table and motor, some 225
pounds. (For those interested, we bought it from Harbor Freight.
Shipping for the whole shebang was only nine dollars. But some! assembly
was required, like two weeks worth.)
We have figured out how to make straight stitches in any number of
layers of fabric, though controlling the speed of this monster is a real
and not yet mastered art. The problem lies with the clear vinyl plastic
windows. We did this job once before with the old and now defunct
machine and had no problems. But this machine is so fast it literally
melts the vinyl, even causes it to smoke. We are not able to get more
than a few inches of stitching of vinyl to Sunbrella before any number
of bad things happen. The thread balls before the needle. The upper
thread breaks. The upper thread shreds. There?s a bird?s nest on the
bottom side. Etc., etc. Correcting one problem seems to cause another.
We are using best quality polyester thread. We bought a new presser foot
made of plastic. We are using No. 18 needles.
Any ideas on how to deal with this problem would be most welcome.
Hi, I have a Yamata industrial also, cant think of model # but it does
both straight stitch and zigzag. Have you tried a teflon foot, or is
that the plastic one you mention?
I believe most industrials can be tweaked to not go so fast, but no idea
how to go about it.
Have you had the assembly of your machine checked by a professional?
Speed can be adjusted by changing the pulley.
Sounds like you have your machine threaded incorrectly or the needle in
Practice on scraps is another way to learn to control the speed.
You might be using the incorrect thread for your weight project.
Can't tell from the pics I found online, but that is NOT a walking foot,
correct? Your project would feed a whole lot better if you had a walking
foot machine. It may be that you purchased an industrial that's suitable
for garment making, but not heavy work.
5500 spm!! I would temporarily slow that bad boy down by changing
pulley size, rather than relying entirely on feathering the clutch to
control speed. You won't lose too much time in the overall project, my
guess. (My mom said in jest that I always took my photographs at 1/1000
second because "He's so impatient"; same principle)
Maybe add a thread lubricator too. The needle is getting very hot,
obviously. Maybe put a dry lubricant like teflon powder on the vinyl
along the seam path. Maybe a leather needle would work better on vinyl
to cut through, too.
It pretty much is the wrong machine for the job. You should have looked into
walking foot machines.
That said you can do one of 2 things, aside from practice feathering the
clutch and that will get better with time as it wears in. Change the motor
pulley to a 2 inch O.D. pulley should reduce the maximum speed by at least
1/3 maybe half depending on how they set it up.
The other is far more expensive but it will allow you vastly more control
over speed, purchase and install a servo motor for it these have a radio
like dial on them to turn the speed to near zero or maximum and everywhere
in-between, it has no clutch and is the next generation of industrial
You wouldn't be the first one that's made a poor "Industrial
machine"purchase. Industrial machines are very single purpose, they are not
all the same. I too purchased a too-light duty machine for my first one, so
don't feel too bad.
I haven't seen any good Yamata machines, and Harbor Freight is well
known for having low-quality merchandise (my son uses his for a
flyswatter and says that's its best use, although he enjoys perusing the
things they sell). Sounds like you need a Sailrite machine.
Many thanks to all for your comments.
After a great deal of twiddling and fiddling with timing and tensions we are
getting it to work properly. It ain't pretty yet but it is secure. Just
needs a lot more practice on feathering the treadle but we are not burning
the vinyl anymore, have stopped breaking threads, no more rats' nests on
the bottom side and are getting even and good looking stitches. Straight
stitching not yet but the first part of the job was a circular window and
As to individual comments: no, it is not a walking foot. I can certainly see
how that would help. The Teflon presser foot does help.
Changing the pulleys is top priority. There is just no way we need anywhere
near 5,500 stitches per minute.
I am no judge of sewing machine quality but this one impresses me as very
well built indeed. One thing it's not going to do is jump around the floor.
It does appear to be a discontinued model since the site now mentions an
8500 but not GC8500.
As for Harbor Freight, we have bought a lot of stuff from them and have had
no complaint about anything so far. They slap everything with their own
brand name (mostly Chicago). Dig a little on the Model 03914 Sewing Machine
Single Needle and you find a Yamata GC8500. How they ship this thing,
including motor and table, from California to New York for nine dollars
We buy a lot from Sailrite but not sewing machines. I have also had very
good advice from them on their web site. But they are not cheap. And the
Sailrite 111, top of their line, is in fact a Yamata but geared down with
different pulleys to 3,500 stitches per minute. They also sell the servo
controled drive for this machine. Big bucks.
For the kind of sewing we will be doing, this machine will be fine. We also
have a table top machine with all sorts of bells and whistles. It's not up
to this job. An elderly friends gave us an ancient machine that folds away
into its table and doesn't work. And we have a tiney littl;e machine taht my
wife got from some mail ordser place that actually works off batteries for
tiny jobs. We keep it on the boat.
When all else fails there is always needle and thread and a leather palm. My
wife's hand sewing puts most machine sewing to shame.
Good thing it is the stuff you use and not something you sell. If you can
get it to sew with size 69 thread that is a near miracle and anything
lighter is just poor choice for that type work 99 or 138 would be far
Good luck in your endeavor.
In article ,
Grin. You betcha. We are calling this our Mikado Dodger. A thing of rags and
If you can
I know nothing from thread size numbers. What we are using came from
Sailrite. The label says "Ultra Dee Bonded Polyester" Also "DB 92" and
"T-90." Is one of those the thread size?
There is much more work to do. Cushions and upholstery.
I can't tell you, people, what a huge load off my mind success with this
thing is. I was sure we had bought a very expensive anchor. We have had this
thing since early March. In the end, proper timing seems to have been the
solution. But you won't find much help on that in the manual. Sailrite's web
site steered me correctly.
That is because you are trying to pull to thick of thread through the thread
Take a look at the hook, at 12 o'clock there is a position finger. Watch the
thread while turning the machine by hand. Be sure there is some materiel
under the foot. You should be able to see it bind there. That clearance is
to small for that heavy of thread.
The machine is designed as a dress makers machine for light to medium weight
materials. and regular all purpose sewing thread.
I wish you luck
In article ,
Again, thanks. Job finished. The sewing wasn't complex but the geometrics
were. The "Mikado" dodger is quite a complex shape. It might have been easier
to builkd a new one from scractch. Now we are just doing yards of straight
I have bookmarked your sites.
On Sat, 27 May 2006 07:01:10 -0400, Gogarty
You should give Ron's opinion a lot of respect. He's been a sewing
machine repairman for lo these many years. How long is it that you
say you've been sewing?