Replacing Thread Change Potentiometer on Butterfly Commercial Machine

On multi-needle commercial machines, there is a sensor that tells the machine which needle is currently selected.  This sensor also keeps the drive mechanism from trying to sew between needles or other such potentially destructive things.

On my machine, the Butterfly 1501 B/T, the sensor is a 10 turn 1kohm potentiometer that is held inside the needle changer cam drive with a set screw. Well, it broke.  The potentiometer would not turn, which I verified by taking out the set screw and trying to turn the potentiometer in both directions.  

The company I bought it from was unresponsive, so I found the part number and ordered a replacement.  The part number in the manual is not the actual part number though.  The true part number is 7276R1KL.25 manufactured by BI Technologies.  Be careful and check your machine as there are 3 parts that are almost identical. The 7276R1KL.25, 7276R10KL.25 and 7276R5KL.25 all look exactly the same; the difference is how many ohms they are (1k, 5k, or 10k).  According to the part number, my machine used the 1kohm version; 7276R1KL.25

The potentiometer is soldered directly to the wire harness, so first it has to be removed.  Notate which color wire goes where so you remember for the replacement.

Once all wires are cut, you can either solder on the replacement, or do what I did; build a connector.  I used the header from a 60mm computer fan and the socket connector for the same.  First, I soldered on the 3 pin connector to the replacement potentiometer and used shrink insulator around the terminals.  Grid is 1" squares by the way.

Then, I soldered on the 3 pin header to the existing wires on the machine; again covering with shrink insulator.

Once the replacement is connected, you have to manually turn the potentiometer before tightening the set screw so that the machine is set to the correct needle.  Meaning if the machine is on needle 6, turn the potentiometer until the display on the machine says needle 6, and tighten the set screw that holds the shaft of the potentiometer into the needle change motor shaft.

Test it by moving it by hand from needle 1 to needle 15; making sure the machine is displaying the correct needle number at each needle.  If the machine doesn't, readjust the potentiometer until it does.  Once completed, have the machine change needles a few times to make sure it can automatically understand the needle setting.

Parasprite Embroidery Set

This is a set of 3 embroidery files in PES format for Sugarstitch's parasprite pattern.  You can download the embroidery files here.

The embroidery designs are sized to fit SugarStitch's pattern printed on 8.5" by 11" paper.  The Large and small parasprite wing embroidery designs have been rotated by 45 degrees counter-clockwise so the design will fit in a 100mm by 100m embroidery hoop.

Butterfly Embroidery Machine Details Part 2

I have received lots of questions on my experiences with my Butterfly 1501B/T embroidery machine from folks looking to step up to a commercial machine.  I have mentioned before that I have done some upgrades and replaced some parts, so I want to explain that in detail for those that have the Butterfly on their list of machines.

Quick stats of the Butterfly 1501B/T. Note that some of these specifics are different than the official documentation on the butterfly 1501B/T because the official documentation is wrong.

Needles - 15
Auto thread cutter - Yes
Auto Bobbin Cutter - Yes
Max embroidery size - 450mm by 300mm
Minimum Stitches per minute - 100
Maximum Stitches per minute - 1200
Usual Run Speed - 700 to 750 spm
Pattern Loading - USB or Ethernet
Pattern type - DST
Memory - 15 million stitches
Maximum stitch count per pattern - 15 million
Max designs stored in memory - At least 250


I purchased the machine from http://www.butterflyemb.com which is owned by http://www.plrelectronics.com/, except I used their listing for the machine on eBay because they wanted to charge a additional $250 fee for not using cash unless I used eBay.  I don't understand this policy since PayPal fees on their side are actually more than a regular credit card.  I have also learned from previous issues with merchants that using PayPal funds can leave the buyer open to issues, so I used my credit card with PayPal as an intermediary just to be safe.  That way, if something went really wrong, I could call my credit card company and they could assist me.

The machine was delivered about 3 weeks later via LTL on a full pallet.  It was packed very well, and there were 15 spools of RA thread in it that the company must have used for testing when they received the machine from china.  The crate it came in was made of 1/4" plywood with steel corners and it probably took about 2 hours to unpack including all the thread that had gotten tangled up in the machine from the transport.  I ended up recycling the steel edging as part of the extra stand I built for the machine.  There's probably still enough left to build another 1/2 stand.

I spent a day or 2 setting the thread tension with a tension gauge (absolutely required) and testing out different settings.  I found that 150 gram on the top thread and 25 gram on the bottom seemed to work the best for 40 weight polyester from RA, Merida or Marathon.  For 30 weight rayon, I use 200 gram top and 30 gram bobbin. those are still the settings I use today. 

Don't try to guess, use a tension gauge.  I tried guessing by pulling at first, and I ended up with between 100 and 250 grams when I thought they were all roughly equal.  I am much better now by just pulling and can get between 140 and 160 grams without a tension gauge.The first design I made was the biggest Rarity I could fit in the machine.

This is where I learned that the maximum size was not the 500 by 400mm that was advertized.  The maximum Embroidery Field size is 500 by 400mm, which is much different than Maximum Embroidery Area.  The field is measured by maximum hoop size plus hoop bracket size that will fit in the machine.  The machine can't actually sew to the edge of the hoop, the pantograph can't move that far, it hits limiter stops in the machine well before that.  Even if it could move the full 500mm wide, it would have to sew though the hoop and bracket itself, which obviously won't work.

I measured a maximum embroidery area size of just over 450mm wide by 300mm tall.  This is only 67% of the advertized maximum embroidery size of 400 by 500mm.  In all honesty, I did not care overmuch.  I only needed 300 by 300, so anything over that was icing on the cake.  If I needed the full 400 by 500mm size, I would have been very unhappy.  I told them of the error (I assume it is a typographical error) but they have not fixed it yet. I have only made 4 or 5 patches that have been bigger than 300 by 300 (12" by 12"), such as Applejack here.  The small patch of AJ is 4" tall and the squares on the background are 1" by 1".

The first thing that broke on the machine was the reciprocator.  This is the part that changes the rotational motion of the motor into the up and down motion of the needle.  The reciprocator also has quite a few more functions, such as grabbing the needle bar that connects to the needle and releasing it to 'skip' stitches.  This part is plastic, and is made to break if the needle hits something that can not be moved; such as the embroidery hoop.  That way, something more important such as the motor, shafts, belts, or needle bar don't break. Think of it as a fuse.

Butterfly Reciprocator Assembly

What happened on my machine is that the pantograph pulley slipped because it was not tightened down during manufacture or had loosened while being shipped.  The pantograph only moved left and slipped to the right, so the hoop moved all the way to the edge.  The needle then hit the hoop at about 800 stitches per minute, which caused the plastic part of the reciprocator to snap off and fly 16 feet straight up into my ceiling.

I tried contacting the company I ordered from since I expected this to be covered under the 5 year warranty (seriously, 5 years!).  Even if it wasn't covered under warranty fr some reason I needed to get a replacement.  the warranty is good, I was told it 'covers everything' when I asked.  I took that to mean it covers replacement parts if something breaks, but not labor to put them in.  My guess is that PLR would cover labor if the machine was brought to them in TX. After a week of no response from PLR, I started getting creative.

The part numbers in the manual for the reciprocator would not come up anywhere. I called a few local embroidery folks to see if they knew how to replace a reciprocator or if they knew a reputable service company. None of my friends or acquaintances could replace it (or even do maintenance on their own machines), and the service companies wanted around $250 to come out and just look at it.  To be fair, that's a great deal to have someone come to your house to fix an embroidery machine. My PE770's cost $150 to have looked at by a shop and I had to bring it.  However, I don't have qualms about taking stuff apart, so I dived right in to get the reciprocator out.

According to some videos I watched like the above (because videos are the authority, right?) it should take a tech around 4 hours to replace a reciprocator.  I used that video (and others) to research how to replace the reciprocator on my machine and decided to do it myself. It took all day to do the first time, but I was successful.  I also took lots of pictures as I was disassembling it in case I had an issue putting it back together.


I found a cool company called SewManyParts that sells commercial embroidery machine parts and supplies.  Their website is dated and to use the search you have to know what you are looking for to find it, but it had the most important part for me; pictures!  I started browsing for hours going though pictures trying to find the reciprocator that is in the reciprocator assembly.  I picked 5 part numbers that looked like they could work. Remember, I had only a broken part to go off of, so I wasn't positive what it looked like in 1 piece.  Of the 5, one was close, but not exact.

Close, but not exact. Part 080210240S3A

Part number 080210240S3A was really close, but that black bar you see on the right was shorter by about 1/2 inch, which I determined when I got it.  This is where a lever in the machine pushes to disengage the reciprocator from the needle bar.  Since I had nothing else to do, I put together the assembly and tried it out by manually moving the needle bar and the disengage motor.  There was more than enough for it to work, so I left it in the machine and reassembled it.  I tested again by manually turning the machine, which worked.  So I made a design that was 90% jumps and set the machine as slow as it could go to test it again.  just like before, no issues.  So I slowly cranked the machine speed up to max, and again no issues.  I took the machine back apart to look for anything out of the ordinary (such as wear patterns) and found nothing amiss.  So I called it a win and went back to using the machine as normal. The obviously wrong reciprocator gave me no issues.

After about a month of emails and phone calls to PLR Electronics, I gave up with them.  Surprisingly, about 2 weeks after I gave up, I got a replacement reciprocator assembly from them in the mail with no contact from them at all.  Super strange, and not very good service.  The issues I have had with the machine I can't really blame on PLR, and they do have good training material on how to do things with the machine including repair, but I still don't get why they couldn't return an email or phone call on the issue.  Just for funzies I tried ordering a replacement hoop from them and suddenly they were all back in the office and would reply to email.  I don't know if this was just because of the holidays (this started around mid-december) or if they were just super behind, but since they didn't respond to me, I am left guessing.

After a few months, the replacement reciprocator I got wore out.  This was the 'not right, but still works' reciprocator.  The bearing was sticking, and was not always grabbing the needle bar.  Since I had the replacement from PLR, I took a bunch of pictures of it and measured it, then sent the pics and measurements to SewManyParts hoping they would be able to order one since I didn't see anything close on their list.  I wasn't really expecting them to answer since I had only placed one order with them, and it would take work to compare my pictures to theirs.  I figured it woudln't be worth it to them and they would ignore me.  I was pleasantly surprised when I got back an email in about 5 hours with a guess as to the part number, and it was one that I had not ordered but was on their site.  The picture they had took just made it look like it wouldn't fit my machine.  I ordered one and it was a perfect match. Since then, I have replaced it 3 times.  I can now replace it in under 30 minutes.

Because of that and other awesome service I have gotten from them, SewManyParts is now my go-to place, even if they are more expensive.  I should also point out that I have never returned anything from them that did not fit my machine when I was shotgunning parts.  It's obviously not their fault that I don't have correct part numbers, and restocking stuff is a pain (I know from experience).  So I have a big box of parts that don't fit my machine.  I'll probably mail it back to them as a gift or something since they have been absolutely awesome and I can't use them.

Correct springs, Part 507605030044

While I was replacing the reciprocator the first time, I came across something on the machine that annoyed me as an engineer.  The needle bar springs were cut from a longer spring to fit. I am almost positive this has nothing to do with PLR and is from the manufacturer.  I just ordered a dozen different springs from SewManyParts and figured out which was the correct one.  Part 507605030044 is the correct one by the way.  I have used more than 30 since I got the machine; they are the fastest wearing part besides the bobbin case.

At the same time, I noticed the vast majority of the cap screws and bolts were the wrong length (too short) as well, were cross threaded, or the wrong pitch for the tapped hole.  To fix this, and to verify that every single bolt, cap screw, screw or other fastener was up to snuff, I replaced them after cleaning the threads in the machine.  Every single one.  Let me repeat that, as it bears repeating.  I replaced every singe bolt, cap screw, set screw, washer, or other fastener that was in the machine.  Lots of them were lose, and more than 90% of them were too short.  the only ones I did not replace were the 4 that hold on the feet to the bottom of the machine.  The total cost for that was about $800, and I highly recommend that if you get the butterfly machine that you replace them as well.  It was cheaper to buy them as an assortment than it was to get them one-off from the hardware store, so I did buy way more than I ended up needing (probably enough for another 5 machines).  So if you do end up getting a butterfly machine and want to replace all the fasteners, let me know and I can send you replacements for way less than the hardware store since I have extra.

Rotary Tension Case

Though the past year, I have also replaced other parts on the machine as they wore out.  Here's the ones that I have written down in my notes, but I have lots more in my parts box that I can look up if needed.  The Reciprocator is funny to me because the body is a SWF while the insert matches a Tajima part.  The butterfly machine seems to be about 40% Tajima, 40% SWF and 20% someone else.  these fit my machine, but as always, your mileage may vary.  Always test.

Presser foot (exact) - 090460070A00
Presser foot bushing (exact) - 090460040020
Disk Tension Spring (exact) - 507725010012
Reciprocator Insert (exact) - 080210270S49
Reciprocator Insert (not exact, still works) - 080210240S3A
Reciprocator Body (must replace the reciprocator) - 03040BM-CT01
Needle Bar Spring (exact) - 507605030044
First Tension Set (not exact, works) UD1100000000
Rotary Tension Disk (exact) - 0C0230120011/FN0901010000

Stuff that I have replaced so far that I can remember off the top of my head: (cost doesn't include shotgunning)
Every fastener - $800
Reciprocator - $150 (replaced 3 times completely, 1 time insert only)
Needle Bar - $24 (replaced 4)
Needle bar springs - $3 (replaced 30)
Presser Foot - $20 (replaced 5)
Needle plate - $50 (replaced 2)
Rotary Tension - $15 (replaced 5)
Hoops - $50 (about a dozen)


The reciprocator is the only repair I would call a major one.  However, I did have something else break that a lot of people would have a hard time fixing.  the pantograph moves on 2 arms on each side of the machine.  The arms each have a cover over them, and the bracket that holds the cover on snapped off.  It was not spot welded correctly when originally made.

I ground off the paint and used my mig welder to weld the bracket back on. Cost was only $2 for paint, but that isn't something that can be done by a tech; the part would have had to have been replaced, and this is one that would have had to come from PLR.  Fixing it probably only took an hour, most of which was spent lining up the bracket so it would go back into the machine.  It's kinda hard to unweld something if it is welded on incorrectly, so I took a lot of time.  After testing it out, I painted it again.  I didn't bother sanding down the paint to feather and make it look better since I'm the only one who will see it.  I just used a grinder to remove the paint before welding it. Still got decently close on the paint color.

Overall Impressions
Would I get this machine knowing all I know now?

I would definitely take a longer look at the original machine I was going to get, the SWF-1501C.  That machine is about $13,000 vs the $8,500 for the butterfly.  However, I have spent about $2.5k repairing/improving the butterfly over the past year and a half or so, making the cost about 10k to 13k.  I am much more familiar with the butterfly embroidery machine now, and I have actually considered getting another so I can sew custom designs faster. I haven't gotten one because I still haven't paid off the first one, but if I was doing this for profit, I would have paid it off long ago and would get another.  However, I wouldn't get the butterfly immediately just because it is cheaper, I would get the butterfly because I know the machine.  This is definitely a case of "The Devil you know vs the Devil you don't".