The internet has been a fantastic way for treadle enthusiasts to share their knowledge with others. I have mentioned the Treadle On website a number of times as a great resource for treadle (and other people-powered) machines. But Treadle On isn't the only site with plenty of info; all it takes is a quick Google search to find illustrations, manuals, videos and all manner of helpful instruction.
I thought I would add to the body of knowledge by sharing some tips to make your treadling experience just a little bit smoother. These are based on my personal experience with my machines; your experience and machine(s) may be just a little bit different. Whatever - don't be afraid to jump in and give your treadle a whirl - you'll be glad you did!
One of the first things you may want to try is to align the balance between the treadle wheel and the needle position. First, manually turn the sewing machine balance wheel so the needle is in the highest raised position. Now look at the wheel on the treadle mechanism - there should be a small weight on the outside of the wheel somewhere. I've circled it in red in the picture above. Manually adjust the treadle wheel (move the wheel while holding the belt in place) so the weight is at the lowest point in it's circle. Now as you treadle, when the weight is at the bottom of the cycle, your needle will be in the highest raised position. This may help avoid that pesky tendency of the machine wanting to want to sew in reverse when you want to go forward.
This gadget is the belt shifter. Use it to take the belt out of the treadle wheel groove when you need to move the sewing machine head. Slowly treadle and move the handle on the shifter until the belt comes out of the groove. You'll want to take the belt out of the treadle wheel if you're lifting the machine head up to oil underneath, or if you're folding the machine head down into the cabinet.
Treadle belts come equipped with a large staple to hold the belt ends together. I prefer to sew my ends together. After cutting the belt to the right length and making holes in either end of the belt, I thread up a big ol' tapestry needle with several thicknesses of upholstery thread. I pass the needle through the holes several times so there are multiple layers of thread holding things together. Then I make sure the ends are snuggled up and tie the thread tightly. I don't have to worry about the staple rusting or breaking and the thread makes for quieter treadling. The thread does eventually wear out and break, but a spool of upholstery thread lasts a long time!
Sewing machine oil is a treadle sewing machine's best friend. Buy sewing machine oil. Using any other oil or lubricating product will make your machine unhappy in the long run. A manual with oiling instructions can be helpful, but isn't required. The machine needs oil on any place where two metal parts work together. Most old machines have small holes located strategically around the machine head - these holes are for oil. On the rear of the machine pillar there is often a disc that can be opened; this is also to allow access for oiling. Once you've oiled the upper part of the machine, remove the treadle belt from the treadle wheel and carefully tip the machine head back so you can oil all the vulnerable spots under the machine as well.
An adage to remember about oiling the machine: "Just a drop, not a lot."
While you have the oil out, don't forget to put a drop on all the working parts of the treadle mechanism, too!
A straight-back, stationary chair is a must for happy treadling. Find a chair with the right height so you can sew in an ergonomic position, but you're not bumping your knees on the underside of the cabinet. Having your treadle machine on a smooth floor is a big plus, but it's possible to treadle on carpet, too. You may need to put runners under the treadle legs to create enough clearance for the treadle pedal to move properly, but that's not a difficult fix. Furniture casters may do the trick - just experiment to see what works.
I've got more suggestions, but I'll save them for another post. In the meantime, if you have questions about treadling or treadle machines, leave them as a comment and I will do my best to answer. Happy treadling!