Announcement

Collapse
No announcement yet.

Mini lathe chain drive conversion dead idea?

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • #31
    Mc gyver, What a sheltered life you lead ! Chasing 10ths on machines intended to work to those tolerances. At least he did not take an angle grinder to the bearing caps to tighten the mandrel !. Long , long ago, an instructor at a trade school told us" Some of you will end up making watch parts, some of you will work repairing equipment in mines and quarries, the basic skills are the same, it is just the scale of the work which will be different" regards David Powell.

    Comment


    • #32
      One of the first question I ask myself when considering modifications to a machine already designed a certain way is - "What is going to break first if things go wrong?"

      A vee belt drive will slip fairly easily if you have a crash. A chain perhaps not so much. And having seen and repaired plenty of broken machinery of all types that were chain driven, I would be leery of swapping out a designed belt drive for a chain drive.

      But you do you.
      If you think you understand what is going on, you haven't been paying attention.

      Comment


      • #33
        Run that chain through a cleaning cycle, then a bath in a good racing chain lube and off you go! On that large lathe I don't have a problem with the final drive being chain. As far as the gearbox- I always wondered how well you could adapt a motorcycle gearbox to a lathe. Lots of speeds, not too large, and hey- output shaft has a sprocket-

        A lot of motorcycles went to belt drive. What were the reasons to stray from the tried-and-true chain system? Same reasons it would be advantageous on a lathe. My dilemma has been do I use a toothed belt system or a V or micro V belt. I've already done significant work to my lathe to get rid of noise, and in that regard I would stay away from the toothed belt system too. Over the years I've opted away from regular V belts and gone with the link belt system- and not looked back. Even my 4x6 bandsaw has a link belt now. A couple of my 'work in progress' projects are built using micro v belts, and I like that system. There's no way that a chain drive would make any sense on any of these smaller machines.

        But though I say that, I must admit that I found it relatively easy to make up a custom sprocket or three for my experimental electric trike some years back. That ran quite smoothly- I had no complaints about it. It would have been more difficult for me to make custom toothed wheels for toothed belts. I did make some custom multi V pulleys, and they seem to run well. There is no periodic noise generated, and I'm inclined to think that they would be optimum for something like a precision lathe.

        I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

        Comment


        • #34
          Originally posted by darryl View Post
          .....As far as the gearbox- I always wondered how well you could adapt a motorcycle gearbox to a lathe. Lots of speeds, not too large, and hey- output shaft has a sprocket-......
          My father's old big lathe had an old standard 3 speed with reverse car transmission mounted up high with the 2hp motor feeding into it and the other end set up with one of the big flat pulleys that worked with a 3 inch wide belt onto one of the head stock steps. That's all we ever used for shifting speeds..

          If you want to try a motorcycle transmission it would pretty well have to be a Harley or similar. Almost everyone else uses single unit engine and gearbox with the whole works sharing the same oil supply. Plus the input to the box is internal in the clutch. Far easier to use a standard transmission from a car.

          Chilliwack BC, Canada

          Comment


          • #35
            A couple years ago I had an opportunity to pick up a big 16' bed lathe for the price of taking it away. It was before I had my flat bed trailer, so I would have had to borrow one, and I didn't really have a spot to put it. My plan was to stick it in the barn, and power it via shaft through the wall to the tractor PTO. Janky? Yeah, big time, but I only have 15amps of 120v out there, and for the types of jobs I'd be doing on it, it would have been just fine. In the end I passed on it (see unfinished projects thread for details....). I still think it would be a viable solution to remote powering a big lathe like that.

            For a smaller lighter duty lathe I think a belt would be a better option for final transmission. I "think" a chain drive would translate to the finish too much, but there's only one way to find out.....

            I'd actually be interested to see that conversion. Would you incorporate a derailleur for speed changes on the fly .

            Comment


            • #36
              No experience here. But a question arises. On smaller lathes, wouldn't a chain drive eliminate the belt drive's slippage, sort of a "fuse" in the drive system that might prevent damage to other, more expensive parts if the lathe were stalled?
              One other is bike chains may introduce some "slop", or am I not thinking this would show through on the work piece.

              S E Michigan

              Comment


              • #37
                Belts rock,,, you would be taking the elasticity out of your system and introducing all kinds of deviation and chatter and for what? it would be taking a good idea (belt drive) and putting lots of effort to make it bad,

                plus belts wear - you just spend 5 bucks and get a new one - chains wear and your limited with having to also replace sprockets every other time or more....

                you machine would sound like crap - cut like crap - and basically be crap...

                Comment


                • #38
                  Originally posted by David Powell View Post
                  Mc gyver, What a sheltered life you lead ! Chasing 10ths on machines intended to work to those tolerances. At least he did not take an angle grinder to the bearing caps to tighten the mandrel !. Long , long ago, an instructor at a trade school told us" Some of you will end up making watch parts, some of you will work repairing equipment in mines and quarries, the basic skills are the same, it is just the scale of the work which will be different" regards David Powell.
                  he lost me with power wash, then the chuck key, what looks like loomex wiring and so on.

                  imo It doesn't matter watchmaking or hitch pin making, tolerances must suit the job. However whatever tolerances are required, there is a way to deal with machinery that will make it safe and long lasting. For example, if I ever felt the need to power wash a machine it would precede complete disassemble, cleaning and lubing. I would not start up a plane split bearing lathe without pulling the bearing caps and cleaning and lubing.

                  Its their lathe, so they are free to do as they like, but to me he comes across as a hack (maybe unfair, I don't know him, but that's the strong impression I'm left with). When I don't know what I doing I usually ask .....and I don't mean asking to "hold my beer" while I make a video of it lol
                  Last edited by Mcgyver; 11-13-2021, 11:36 AM.
                  in Toronto Ontario - where are you?

                  Comment


                  • #39
                    Some top high end lathes, like 10EE have belt drives to minimize vibrations from drivetrain, and they actually used flat belts for some options to allow slippage for finishing runs because apparently v-belts could induce some inconsistencies via gripping if the drivetrain has some vibrations.

                    Ok, this is a stupid question, but how much belts can take load before breaking? I noticed that many applications that give quite a lot of torque have actually pretty flimsy belts. My first and only reason to look for other options is that the orginal drive belt of this petty lathe is 9.5mm wide 5M belt, and if I'm gonna consistently run it with tough steels, it must hold up to that, at least long enough to warrant a belt change which costs about 5$ a piece, so, really, not that long actually.
                    Last edited by amillertobe; 11-13-2021, 02:27 PM.

                    Comment


                    • #40
                      The flat belt on my 10EE looks pretty thin but who is going to criticize a 10EE design choice?

                      Comment


                      • #41
                        It doesn't have to be any stronger than it needs to be. Over-engineering is the next common thing after under-engineering in practices, but it would just likely create drag and reduce efficiency. What's there to criticize, if it has worked over half a century for good?

                        Comment


                        • #42
                          My 8x18 came with a belt drive- a very narrow section V belt- 6 or 7 mm wide I think. It lasted a long time. Then someone on this forum sent me a spare many years ago (thank you again) and it still looks like new. Never had a slipping issue, and I kept the belt when I changed to a treadmill motor. It looks kind of funny- it's now a compound system with two belts, and the primary belt is fatter and wider than the final drive belt. Still quiet and smooth- especially with the 'back gear' hardware removed. For slow speeds I mount a 12 inch diameter pulley to the existing spindle pulley and drive that from a geared motor- still using a belt. I forget now, but that gets me down to something like 2 rpm, maybe less. My only caveat- use decent belts, not the hardware store V belts. Those are lumpy and rough- any machine that I have with those get retrofitted with a link belt.
                          I seldom do anything within the scope of logical reason and calculated cost/benefit, etc- I'm following my passion-

                          Comment


                          • #43
                            Well, it is pretty conclusive that belts are superior to chains in pretty much any ways in this context. But, at least we learned something new.

                            Comment


                            • #44
                              Originally posted by amillertobe View Post
                              Some top high end lathes, like 10EE have belt drives to minimize vibrations from drivetrain, and they actually used flat belts for some options to allow slippage for finishing runs because apparently v-belts could induce some inconsistencies via gripping if the drivetrain has some vibrations.
                              The flat belt on my 10EE looks pretty thin but who is going to criticize a 10EE design choice?
                              HIgh end lathes like the 10ee use a direct belt to spindle arrange which isolates the spindle from things like gear noise. Unlike the common arrangement of belt from the motor to gearbox.

                              The problem with V belt is that you have to have a very consistent profile of the entire belt. Any deviation creates a tight spot as it passes over the pulley, hence can be a source vibration. In the cast of low products like you get at Canadian Tire, a retailer here, it can be extreme. Of course there is never perfection and there will be some deviation in the profile....perhaps that is argument for flat belts if one is chasing the the best possible arrangement. Or maybe its most just on old equipment and makes little difference....I've a number of flat belt lathes and have never found them lacking. For a V belt driven lathe, seek out a good quality belt from an industrial supplier and avoid the hardware store crap, it can be brutal.
                              in Toronto Ontario - where are you?

                              Comment


                              • #45
                                Yes I actually have experience on car V-belts and they are.. crude. Even on lower accuracy machines they don't seem to run too smoothly. What I'll look into most likely is PolyV belt, I can make the pulleys myself to any size I want as I get a HSS profile cutter for it and they seem to be available in multitude of sizes with decent price and have the best of both flat and V belts.

                                Comment

                                Working...
                                X