kgg

Personally I have never had a much of a problem with belt slippage on any of my machines and haven't needed to fiddle with the servo motor pulley size. When belt slippage has happened I was asking/hoping it would punch through something that was beyond the machines sewing limits. In those cases the belt slippage was a good thing and prevented possible damage to internal parts. lf I were to consider putting a speed reducer on or changing the servo motor pulley size it would be just to gain lower speed control not for extra punching torque. In the end I guess the Engineers who design the machines have to take into account the stress that can be placed on internal parts and what size of motor / pulley sizes that would best accommodate the majority of users for a particular machine. kgg

I came across a 98 percent complete Singer 29K70 for a steal. It was dragged out of a guys basement. According to the serial number it was built in 1944 at Kilbowie, Clydebank, Scotland. The oddity that caught my eye was the little domestic type sewing machine motor that was attached buy a rubber belt to one of the pulleys. The motor works but needles a foot controller or I may just replace it with a new one unless I can find a proper Singer treadle stand. It is in desperate need of a good cleanup, few touch ups on the paint, a good redneck oiling and a few warlock attachment upgrades. The top thread oiling pad is even still in the top wax pot and an old threaded bobbin still in place. There seems to be a couple of small pieces missing or needing replacement but the machine is free moving on the hand wheel, the presser foot and the needle are all moving as they should. My other Singer 29K71 made in 1949 but released in 1951 is a short arm, small bobbin while this one a Singer 29K-71 is also a short arm, small bobbin. Both have the ability to mount the hand-wheel on either the front side or the end. The difference so far appears to be the Singer 29K71 handwheel was cased without the ability to accept the small wooden crank knob for easier hand wheeling. I think it is probably worth saving from the scrape pile. kgg

A good example of the belt contact surface would be: i) a 75mm diameter circle would allow a belt to contact with half of the circle at any given time. That means the belt actually contacts 117.81mm of the pulley surface ii) a 50mm diameter circle would allow a belt to contact with half of the circle at any given time. That means the belt actually contacts 78.54mm of the pulley surface iii) a 40mm diameter circle would allow a belt to contact with half of the circle at any given time. That means the belt actually contacts 62.83mm of the pulley surface A 40 mm circle would only have 53.33 percent of the contact surface as a 75mm circle. kgg

There are a lot of clones of the Juki 1341 the Kobe LS-1341 and Techsew 2750 to name a couple. That makes access to attachments and replacement parts really available. However the genuine Juki parts are of better quality / consistency and with that comes the premium price. Even simple items like after market bobbins may work, may not but Juki bobbins always work. I use after market items off such sites as Aliexpress or Amazon for binding attachments made for flatbed machines so I can utilize them on all my machines rather then having a dedicated set for just the 1341. This for me is cost effective. Flatbed binders cost less then $15 ea while 90 binders are $100 each. The downside is that you can't get the item being edged as close to the needle as if you were to use a 90 degree binder. It will depend on your pocket book and what you are binding. If I were you I would consider using your Class 4 with the needle plate that RockyAussie developed. Topic ( "A liitle change to make a BIG differance on Cowboy sewing machines" ). It maybe worth looking into and potentially saving the cost of another machine. kgg

A good reference chart for thread size versus needle size can be found at www.tolindsewmach.com/thread-chart.html compliments of Toledo Industrial Sewing Machines. kgg

The bobbin assembly is similar to other similar machines. The video I am linking to may provide some help even though it was for a one armed bandit, Tippmann Boss, which was having problems. Since you are not the original owner who knows what they done with adjusting the bobbin tensioner and may have over tightened it and flatten it so that it doesn't provide any tension anymore. At about 1:05 into the video is a good place to start: www.youtube.com/watch?v=GwJTdFLhvOQ&t=194s Hope this helps, kgg

The #25 needle is good for T270 in thinner / less sticky / less tough materials so go up one size to give a little extra spacing in the hole for the top thread to be able to pull up the bobbin thread. Since most times you will be reversing to lock a stitch the problem will be even worse if the forward and reverse stitches don't match. A good reference chart for thread size versus needle size can be found at www.tolindsewmach.com/thread-chart.html compliments of Toledo Industrial Sewing Machines. kgg

Couple of additional questions: i) What thread size are you using? ii) What size of needle are you using? iii) Are you using the same size thread in the bobbin as you are in the needle? iii) Have done a test of the stitches in forward verses the stitching in reverse? This is done simply by putting a piece of paper (heavier stock or cardboard) under the presser foot as if you were going to sew but without the thread in the needle. Sew as normal for a few of inches and then reverse. This will tell you if the forward and reverse stitch is the same as the needle should fall into the same holes as what was made in the forward direction. It will also tell you that the stitch length you have selected is actually what you are getting. kgg

A couple of simple formulas: 1) Horsepower measured in HP or Watts where 745.7 watts equals 1 hp 2) Horsepower = Voltage (measure in volts) X Current (measured in amps) 750 watt motor would have a max current draw (not including any inrush on startup) of: i) 3.4 amps at 220 volts ii) 6.8 amps at 110 volts 3) Horsepower = Motor speed in rpm X Torque measure in Nm or lbf-ft / 7127 (metric) or 5252 (imperial). OR i) HP = 0.000140304 x T(Nm)*rpm ii) HP = .000190403 x lbf-ft x rpm kgg

Interesting your signature links to Wattsan a Chinese manufacturer of laser and CNC equipment with "An Lee" as a their CNC Specialist. kgg

Definitely, but sometimes it does happen. kgg

They would have been better to have a done a pre release review like a lot of computer companies do when they are about ready to release new hard drives/ chip sets / coolers / motherboards / etc to qualified reviewer users. kgg

I liked how they use a block and tackle to help move the sail material forward while sewing. Those are really nice sewing machines and I would guess cost a pretty penny. kgg

While you are checking with your Engineer please also ask if the motor and or components are CE, UL or CSA approved. kgg

The Consew 205RB and the Juki 1181N are similar and I have done this on my Juki 1181N. What I have done is slowly reverse back to a couple stitches before where the bobbin thread ran out, pull back the access / slack top thread back through the top tensioners, replace the bobbin and pray it works. Doing this may work depending on the material and thickness. If it doesn't work there is going to be at least a mess, possible machine locked up and possible damage to the bobbin area. The safer way is to remove the item and get the bobbin thread up, put the material back and place the needle back down a couple / three stitches back from where the bobbin thread ran out, hold both the top and bobbin thread for a couple / three stitches and slowly stitch until you get into fresh material. Unless you have changed the stitch length the stitches should fall into the same stitch holes. kgg

I would say you have a disconnect between the Engineering guys and the Advertising guys. The information so far is really not helpful. There is no way the numbers work out even on 220 volt systems as the motor tested was made for EU systems. To use their motor on a 120 volt system the amp draw would be approximately twice or according to their figures 320 amps. Most new homes in North America only run 200 or 225 amp main services. kgg

Must be a typo. If it pulls 16 amps on startup it may pose a problem for some 15 amp main circuit breakers particularly if they have anything else on that circuit. So I am going to assume you meant to say 1.60 amps. At 4.43 seconds into the video the nameplate is for Voltage : AC 200 -240 50-60 HZ so what is the expected current draw on the standard North American household voltage of 120 volts on a 15 amp circuit or does this motor require a dedicated 220 volt 20 amp circuit. kgg

Must be a typo. If it pulls 16 amps on startup it may pose a problem for some 15 amp main circuit breakers particularly if they have anything else on that circuit. So I am going to assume the OP meant to say 1.60 amps. kgg

Damn nice, congratulations. kgg

I would have too consider: i) The machine Ferdco Pro 2000, is not a Juki TSC 441 but a Taiwan clone. Keep in mind a quote from Keystone Sewing website on the history of these machines from back in 2018. "The Pro 2000 was designed by Ferdinand JeanBlanc in 1991 using a Juki 441 frame from Juki USA. In 1995 we went to a Tiawan manufacturer and had the 441 changed to our new specifications which we use now. Once the casting is delivered to us, we convert the 441 into the Super Bull Pro 2000 that you see advertised today. You may be familiar with some of the other proceeding versions of the Bull or heavy stitchers Ferdinand has designed and built in the past. These would be: The Chandler 305 Bull - From 1964 to 1968 The Alder 105 Bull - From 1968 to 1979 The Adler 205 Bull - From 1980 to 1985 The Ferdinand 900 Bull - From 1985 to 1993 The Juki Pro 2000 - From 1993 to 1995 And the Ferdco Pro 2000 'Super Bull' - From 1995 to Present” ii) the price difference between the two machines iii) availability and cost of parts and accessories In the end I would probably go with a new or newer Cowboy 4500. kgg

Great question, as some people have had problems in the past when trying to combine a speed reducer with a needle positioner on a electronic controlled servo motor. I didn't see one on the second machine with the speed reducer. Since price is always a factor what is the price of the servo motor and needle positioner? kgg

My cardinal rule for auctions whether live or online is set a price and if it goes for one penny over that amount let it go. Online auctions are so much easier then live as you usually have a few days to do a spread sheet of the items of interest. I use a spread sheet where I can plug in what I want to bid and see what the actual out of pocket expense with the Buyers premium and taxes calculated versus typical retail / used market prices. kgg

The prices lately for the online auctions are generally becoming expensive as it is too easy to hit the Bid button without thinking of the additional 30 percent charges at the checkout. New 29k clones in Ontario can be had from Amazon.ca ( https://www.amazon.ca/INTBUYING-Industrial-Machine-Leather-Stitching/dp/B09VXL421L/ref=sr_1_28?crid=5NS7O28M43WS&keywords=leather+sewing+machine&qid=1664988624&qu=eyJxc2MiOiI1LjQxIiwicXNhIjoiNC42MyIsInFzcCI6IjMuNzgifQ%3D%3D&sprefix=leather+sewing+machine%2Caps%2C119&sr=8-28) for $739 plus 13 percent sales tax from an Ontario based company. Quality ???. kgg

I do browse some of the provincial auction sites as you never know when a good buy maybe had. Today there was an ex factory online auction with a couple of items that did catch my eye. There were Pfaff's, Alder's and a couple of Juki's most with ELKA's. 1. a repainted SINGER 144W204 sold for north of $800 plus additional 29.95 percent for the hammer fee and provincial sale tax so north of $1039 CAD 2. a SINGER 29K62 with possible missing / broken drive rack, connecting drive rod not connected sold for north of $1150 plus additional 29.95 percent for hammer fee and provincial sale tax so north of $1494 CAD kgg

Some of the problems with the servo motors has to do with the number of internal coils the motor has. The more internal coils the better low start control you will have. I think maybe installing a speed reducer may help overcome this bottom end startup problem. I run 550 watt brushed servo motors with the simple knob limiter and no speed reducers on all my machines like Wiz has suggested. kgg