kgg

I use an office chair with caster on all my machine without any difficulty. I have seen the foot lift to be more difficult then the using the rear presser foot lift lever for two reasons. 1) a missing washer on the pivot point of the the foot lift lever at the rear of machine and 2) the point of contact of the foot lift lever at the head needed to be adjusted / oiled where it made contact to lift the presser foot. You should check and see if the knee lift shaft is binding which maybe contributing to the hard lift when using the pedal to lift the pressure foot. Also: 1) The location of the cable to the foot pedal should be mounted to a bracket that is mounted to those two rear holes in the pedal. The closer you move that cable to the pivot point of the pedal the more difficult it is to operate. 2) Since you like using using a knee lift there should have been one come with the machine and it bolts to the shaft extending out of the base of the machine. 3) You should check and see if the knee lift shaft is binding which maybe contributing to the hard lift when using the pedal to lift the pressure foot. kgg

As a suggestion try doing a test piece and compare the result with your present method. Test piece i) Oil the top side of the leather by airbrushing (above 34 psi) first and then lightly oil the backside after letting the topside sit for a few minutes. Let the leather sit for 24 hours to soften and let the oil spread the leather fibres. ii) Then airbrush the top side of leather with the dye (50/50 mix at an air pressure of above 34 psi). Then lightly airbrush the dye to the backside. Let sit for 24 hours or longer then to allow the dye to spread and darker slightly. Then a final light coat of oil. Compare the result with your present method. kgg

I am assuming you are trying for something like the following photo where you have pouch attached to a shealth: You seem to be trying and fold under the bottom of the pouch during your wet molding. I would approach it using a form where the wet leather is placed over the shape form that has the side edges extending about twice the height of the form, place the wet leather over the form and clamp one side down, form the leather over that side and then move to one of the other sides and clamp. I would probably use a 2 inch "O" ring to shape the leather. Let dry for about 24 hours and then damp wet areas that need to be reshaped. This topic shows the shaping tool I would us. kgg

I prefer to use the single action airbrushes and the two main ones I use are the very inexpensive suction style at $21 CAD rather then the gravity feed type. Load up the dye bottle, push the button and you are spraying. If you are planning on using it indoors a regular compressor can be very noisy when it has to recharge the air tank and really is overkill for an airbrush. Keep in mind the dye will darken and spread in the leather after a few days. So you have an initial photo of the project so take another photo a few days down the road for a comparison.

If the item is going to be exposed a lot to UV rays or bleach type chemicals Bonded Polyester would be the better choice. Generally other items Bonded Nylon is a good choice. I mostly use Bonded Nylon. As a note: i) Bonded Polyester for a given thread size is a touch smaller then Bonded Nylon ii) Darker thread colours are stiffer then light coloured threads due to the dying process iii) I find that the 1 lb spools are better then the smaller spool sizes due to less spring memory as a result of being coiled onto the spools. iv) Only load up enough bobbins to complete the project. If left for more then a few days or less the bobbin thread comes off the bobbin looking like a coiled spring. v) Always buy good quality thread. kgg

I think you will be get better results with the airbrush. My basic procedure is oil / dye / oil and I don't use a top coat for my projects. You will need proper air pressure to drive the dye into the leather. From what I have seen on youtube people are using pressure settings in the sub 20 lb pressure range and then the dye is basically a top coating. Probably because most people are painting model figures/cars/nails/cakes/etc. I use a 30 lb pressure setting and am now moving up to 40 lb when applying the dye with multi coats in different directions to get a more even dying which I apply after the oiling process. My basic process is oil/dye/oil. Here is a link to two of my topics on airbrushing. I don't use NFO and can't speak to it's application with an airbrush. I use JoJoba oil and spray it on without any dilution. kgg

The Cobra Class 26 uses the system 135 x 16 or 135 x 17 needles which have a size diameter of about 1.0 mm (0.0394 inches) while the needles for a Class 441 machine the 794 needles are 2.5 mm (0.0984 inches). The Cobra Class 26, is the model number not the class of the machine and is a hybrid clone similar to the Juki LS-341 a Class 341 machine. The Cobra Class 26 like the Techsew 2750 and others model designations can be confusing but all are Class 341 machines. I agree with @Wizcrafts and as a note I don't use anything smaller then V92 in any of my machines. kgg

Very nicely done. It would also be good for hammering down the thread in seams. kgg

What I found too work the best whether it is chrome or veg tan is to apply one coat of contact cement let sit to soak into and dry. Then apply a second coat and when it has dried to the point of not being sticky to the touch put both pieces together, clamp or weight down depending on the size. My theory is the first coat seals the fibres of the leather and the second binds both pieces together. kgg

My two cents worth: i) it is a class 441 machine just based on the needle system it uses. ii) the size of the hole it will punch is equal to basically a 2 1/2" finishing nail. iii) the max size thread it can handle is V346 minimum size is V69 iv) the max thickness the machine will sew is rated for 1/2". v) the cost for a new machine is about $2200 USD The questions: i) What is the asking price which will depend on the condition? Any photo's? ii) What size of thread do you what to use? iii) How thick is the thickest leather you will need / want to sew. iv) How often you will use the machine? If it is infrequently maybe consider a Cowboy Outlaw( new ~ $1400) or Tippman Boss (new ~$1000) kgg

Very nicely done. kgg

That is a great idea. kgg

Hum, that can't be right. I know casting, how can I make it easier. As a replacement to the lost wax method of casting maybe use 3D printed castings. kgg

I think for photo's they maybe good but not so much for spraying as the LED's would probably get covered from overspray. Thank you. I think some of the fumes comes from the thinner being used. I use alcohol as the thinning agent. I think that would work really nicely. But remember no project is complete with 3D. You must have a bit of Newfoundlander in ya. It's always nice to scrounge materials. kgg

This is a followup to my topic "Airbrushing" for dying leather with a short video of my setup at the end of this long post. The video was done setup on my deep-freezer just for ease. Airbrushing has a natural pocket emptying progression just like sewing machines. Get a Airbrush and a Compressor it'll be easy but what about where to actually do the airbrushing??? The great outdoors when it's + 30 C or - 30 C or the comfort of your leather room, basement, etc. That leads to dealing with any unwanted fumes contaminating the area or dealing with possible over-spray landing on other projects / tools / leather. My solution was to build a fairly inexpensive spray booth and indoor filtration system for indoor use. I didn't want to cut a hole through the side of the house and deal with spray staining the siding or poke a hose out a window particularly in the winter. To that end I decided to use: 1) A clear 102 litre (27 US gallons) plastic tote for a couple of reasons. i) Lighting: Allows room light inside the tote ii) Interior Surface: All totes are not equal the one I choose has a real slippery surface and even a permanent maker will not mark it unlike other clear or colored totes. iii) Size: 102 litre (27 US gallons) iv) Price: $20 CAD 2) Exhausting: i) The interior lighting via a 12v DC LED at a 45 degree angle. ii) The interior of the tote by using two 140mm 12v DC computer fans that suck at 1.8m/s each (measured with air gauge), are almost silent and will empty the interior air space of the tote in 1.7 seconds with 1.8m/s at the exhaust vent of the bucket. iii) I connected two 5" x 8' flexible ducts to the fans. iv) Price: $40 CAD as the LED and fans were left over parts from other projects. 3) Filtration: i) one 5 US gallon bucket and cover. ii) Window Air Conditioner fabric, HEPA filter, iii) Price: $12 CAD 4) Power: i) 120v AC - 12 DC, 150 w Power Supply ii) 120v AC Power Bar to supply spray booth fans, light and airbrush compressor iii) Price: $35 CAD 5) Miscellaneous items i) 3mm nut /bolts / washers ii) 3D printed housings for Fans, Duct Connections to Fan Housings, 5 gallon Filtration Bucket, Power Supply, Airbrush Holder, Rotating Platter Support and LED supports iii) The Rotating Platter was a 5 gallon bucket lid with a 1/4" bolt and some cardboard iv) Price: $20 CAD Total Cost: $127 CAD Now you got to remember that I am an cheap old geezer and depending on what you have kicking around your costs / results may vary. All comments appreciated but be gentle as I am not comfortable with video's. kgg

For a V92 thread you need a #20 in thin leather or a #22 in thick leather. Here is a good needle size vs thread size chart ( condiments of @CowboyBob ).https://www.tolindsewmach.com/thread-chart.html One layer unless it is fairly thick can be difficult to bury the knot in. To small a thread for the needle size will look slack. Don't forget to hold the top and bobbin thread ends for the first few stitches and there are two ways to start. i) most common method is to hold the thread ends, stitch 3 or 4 forward, reverse back 3 or 4 stitches to lock them and go forward to continue your seam. ii) less commonly done but gives a nicer, less bulky stitch at the start of your seam. Start your stitch line in the distance of 3 or 4 stitches and while holding both thread ends reverse back 3 or 4 stitches and then go forward to do your seam. kgg

For the leather part up to 3/8" thick of your planned sewing I agree with @Wizcrafts. However the biothane is a completely different beast as you are basically sewing through sticky rubberish material so you may have to go up to a Class 441 machine like a manual one arm bandit ( Tippman Boss or a Cowboy Outlaw) or motorized Class 441 like a Cowboy 2500, 3500 or 4500. A lot is going to depend on the thread size you want to use, thickness of item and how deep your pockets are. kgg

@AlZilla , @Rogueshoemaking The Singer 236G136 and the Singer 236W131 are almost identical except: i) 236G131: letter G shows it was produced in Germany, typically at the Karlsruhe factory. ii) 236W131: letter W shows it was produced in the United States at Elizabethport, New Jersey plant. iii) the Singer 236W131 (U.S. model) uses the 134 (DP×5) system, while the Singer 236G131 (German model) uses the 287 (16×21) system. A parts manual for the Singer 236G131 can be found at Henderson Sewing http://hensewfiles.com/PDFs/SINGER 236G130.pdf Using a small size needle with V45 (60) thread you might want to also order some #18 needles for thicker items. kgg

You gotta be careful with all adverts as they typically lie like a cheap rug's. I figured as much but most of the better programs can do those conversions. I mention .step file format as that is what I use in Fusion 360 as it can be ported easily to other programs. kgg

Your machine according to, The Thread Exchange ( https://www.thethreadexchange.com/miva/merchant.mvc?Screen=CTGY&Category_Code=needle-systems-singer-236-B-to-391-A ), the Singer Model# 236-G All Classes use needle system 287 Equivalent to 287 H, 16X21, 16X269, 376, CANU 11:60. The size of the needle will depend on the thread that you are using. Here is a good cross reference of thread to size of needle: https://www.tolindsewmach.com/thread-chart.html kgg

Once again, a very nicely done video. It would have been nice to see what files could be imported directly to the lasers software like .step files or if certain formats need to be converted before being imported. I think if you want to reduce / eliminate those fumes that are now leaking into the room from the machine I would suggest: i) enclosed the unit in a secondary enclosure. ii) install a couple of 120mm computer fans to exhaust the fumes to a 19 litre (5 US gal) plastic bucket with a carbon filter on the buckets exhaust. kgg

The Ikonix ks335a is a clone of the PFAFF 335 so a presser foot for a PFAFF 335 should fit. Look on Amazon for " CKPSMS Brand -#KP-19029 Double Toe&Left Toe& Right Toe Compatible with/Replacement for Pfaff Brand 335 145 245 545 1245 Sewing Machine ". kgg

@Constabulary I really enjoyed those video's. A bygone time when there was pride in workmanship right down to the making of needles. Notice the overhead drive system for the lathes etc. kgg

I would suggest taking a sample, like a leg of a pant and going to a dealer to test what machine would work best. kgg

In the video you referenced. i) They are using some sort of adhesive probably double sided basting tape as noted by them pounding the patch onto the jeans and the roll of 1/2" wide basting tape on the table. ii) The patches appear to be 2 oz chrome tan. ii) The sewing machine appears to be a flatbed drop feed Juki DDL-8700 H with a Teflon presser foot. iii) The thread appears to be V69 or V92 but the photo's appear to be V92 or V138. The Juki DDL-8700 can only take V69 max and the DDL-8700H can take V138 max. iv) The needle system of the Juki DDL 8700H uses the DBx1 needle system up to size #18 (110) needle for V69 and for thread above V69 uses a needle system 134. v) as seen in the later part of the video they have to crunch up the jeans to sew the patch in place which is what you would expect for a flatbed machine. I would Not recommend the Juki DNU-1541 even though it is a really good triple feed Japanese made machine for a few reasons. i) the hole in the feed dog is very large and has a tendency to suck thinner materials down into the needle plate. ii) absolutely hates thinner materials that is why I also have a Juki DU-1181N to cover off the thin stuff. I would recommend if you are only planning on sewing flat items like a wallet / belts get a flatbed. If you are going to sew items that are circular like pant legs get a cylinder arm with a flatbed attachments like a Juki LS-1341 or clone. Most people go with a clone machine as a Juki LS-1341 will cost north of $5000 while a clone will run about $2500. kgg