# Flat Belt Reversing Mechanism



## Brian Rupnow (Aug 2, 2018)

With the end of every project, I declare that I've had enough machining, and I'm going to take a break for a couple of months. Then I lay in bed at night, and it isn't sugar plum fairies that dance thru my head---it's machinery!! One of the things that fascinates me is how they shifted flat belts pulleys into reverse on the old lineshaft machinery. I've seen pictures of it but never have seen it done in "real life". I just happen to have a small flat belt, about 5/8" wide x 0.100" thick that I scavenged from somewhere, and time on my hands. So--I spent this morning modelling a flat belt reversing mechanism.   In the attached picture, the power is input to the beige colored counter-shaft in the lower left hand corner. This will make the gear which meshes with it rotate in the opposite direction and carry the green pulley closest to that gear and the shaft it rides on with it. However, the belt is at the other green pulley on the far side from the yellow gear, so what's going on here?


----------



## Brian Rupnow (Aug 2, 2018)

If we look at the mechanism from the other side, we see that since there is an idler gear between the countershaft gear and the driven pulley gear, the green pulley on the far side will always be rotating in reverse to the first pulley we seen over by the input end of the countershaft. And in the picture as shown, the pulley will be driving the flat belt and the pulley at the far end.


----------



## Brian Rupnow (Aug 2, 2018)

Now there is a trick here at the end with three pulleys. The center pulley and shaft which it rides on are not driven from either side. The center pulley and shaft just free-wheel. The two outside driven shafts are hollow. The shaft with the center pulley on it is supported by the two outer driven shafts, but it is not keyed to them. The center pulley and it's shaft free-wheel. The second picture posted is actualy a section taken thru the 3-pulley shaft, to show how this is arranged.


----------



## Brian Rupnow (Aug 2, 2018)

This picture shows the belt shifted to the center pulley which is the neutral position. Since no power is being transmitted to the shaft which supports the center pulley, the belt will not be driven.


----------



## Brian Rupnow (Aug 2, 2018)

So, what mechanism is used to move the belt into one of it's three possible positions? (note that the pulley at the far end has the same overall length as the three shorter pulleys combined) The belt shifter mechanism. This shifter mechanism can be moved by means of a lever, a screw, or even finger power in this case. It is guided in it's travel by matching holes in the two side frames. Since the top run of belt and the bottom run of belt are moving in opposite directions, the bronze colored rollers which contact the sides of the belt must be able to revolve independently, one clockwise, the other counter-clockwise.


----------



## Brian Rupnow (Aug 2, 2018)

And here is a final picture, in which the belt has been moved to the opposite side pulley from the very first picture posted, so the belt will be rotating in the opposite direction from the very first picture posted.


----------



## Brian Rupnow (Aug 2, 2018)

Will I actually build this?--The answer is "probably".  I never have much "real work" in the summer time, and although my good wife and I have some small day trips planned this summer, that is still going to leave me with a lot of time on my hands.---Brian


----------



## Cogsy (Aug 2, 2018)

Another intriguing mechanism. This will be interesting to see built (of course I have no doubt you'll built is, you've probably already got the first part made...).


----------



## mortimer (Aug 3, 2018)

I must be getting Old , I worked on flat belt lathes as an apprentice. if you got things right . you throw the lathe on.  then shift the leaver into reverse  and the 3 meter belt would jump off the top pulley . and then you had a nice long rest until the maintenance crew came to put it back on again . I worked for Churchill Machine tools in the UK way back in 1962


----------



## Brian Rupnow (Aug 3, 2018)

One of the first things I had to do was to measure the true center to center of the belt when it was on the pulleys. I made up all four of the pulleys this morning, then took two into the machine shop. I zeroed out the quill using my DRO with the long pulley clamped in my vice, then locked the y axis and moved the table in the x axis until I could get the belt on both pulleys. The height of the quill was lowered to match the pulley in the vice. Then it was simply a matter of cranking the table in the X axis until I felt that the belt had proper tension on it. The center to center turned out to be 5.167".


----------



## Brian Rupnow (Aug 3, 2018)

One thing about turning--It goes fast.


----------



## ShopShoe (Aug 3, 2018)

Simplicity itself, once you understand how it works. I like the things you come up with.

thank You for posting,

--ShopShoe


----------



## abby (Aug 3, 2018)

Mortimer was that Churchill -Matrix ?
Dan.


----------



## Brian Rupnow (Aug 3, 2018)

I think maybe Abby posted in the wrong thread. I found a left over piece of cast iron large enough and long enough to get two 30 tooth gears out of. I like to do all my turning to size and boring the center hole all in one set-up. Tomorrow I will cut both gears at once in one set-up, then part them off as individual gears after all the teeth are cut.


----------



## Cymro77 (Aug 3, 2018)

Well, well!  I didn't have to wait long for my next "figuring and machining" lesson!!  Keep up the good work Brian - you are a great teacher.


----------



## Johno1958 (Aug 3, 2018)

Second that.


----------



## GregNixon (Aug 4, 2018)

I don't think the mechanism is nearly as precise or complex as you think. Take a single machine where the motor is on the machine and drives the drum. The drum has two flat belts which can be moved over to one of three positions.  One of the belts is crossed over for reverse and drives a 'fast' pulley which is fixed to the shaft.  The other belt drives the 'loose' pulley which just spins around on the shaft, sorta like a neutral position.  The pulleys are now in 'reverse'. To change to forward, the belts are moved over as a pair. The crossed belt is now on the 'loose' pulley and the uncrossed forward belt now drives the pulley shaft.
The belt is moved via that shifter mechanism. The belts are not tight, and the belts are moved slowly. I'll will dig out some photos of the drive overhead at the local blacksmith museum.


----------



## Timehunter (Aug 4, 2018)

You might want to take a look at an old flat belt log sawing machine and how they reversed the carriage for the next cut.
I have an old sawmill in pieces that I would like to put together one day.
Some pieces are broken so I will have to research that subject one of these days.
For power it uses a big old GM 3 cylinder Detroit Diesel engine.
Might be a short cut or simplification in there for you???


----------



## Brian Rupnow (Aug 4, 2018)

This morning we get to do the whole thing over again. These two blanks are for the 25 tooth gear. I lucked out this time and found  some 1144 stress proof. Next step will be to mount the rotary table and indexing plates onto the mill and cut some teeth. I might actually drill and tap all the gears for grub screws before I cut the teeth and part them off. I'm not concerned about the 1144 stress proof steel, but cast iron can always be a pig and 'break out' when you are tapping close to the edge.


----------



## tornitore45 (Aug 4, 2018)

In the old days any solution that avoided gears was highly preferable for obvious reasons, that is why they used the crossed belt method.


----------



## Brian Rupnow (Aug 4, 2018)

For those of you who get a thrill looking at gears--Here is a shot of the 30 tooth gears just after being cut. I haven't taken them down and parted them off on the lathe yet. And then in the group picture, the four gears I cut today, and one brass gear that was left over from another project and will become my idler gear on this project









.


----------



## Brian Rupnow (Aug 4, 2018)

Here is my "tip of the day" for calculating center to center distances for spur gears.---Brian


----------



## Johno1958 (Aug 4, 2018)

Thanks for that Brian.
I am nearly up to the stage of having a go at making my own gears and I would like to know if you cut 
your gears with one pass. By the the way those gears look neat.

John


----------



## Brian Rupnow (Aug 4, 2018)

John--Nice to hear from you. In Australia I assume you will be cutting metric "modular" gears. My gears are "inch" system gears and are #24 diametric pitch. I always cut full depth on each pass in steel or brass. My full depth cut is 0.09" deep. I shelled out about $550 for a complete set of cutters, which will do anything from 12 teeth up to about 108 teeth--that upper limit is determined by the size of my mill, not the cutters. The lower limit is determined by the fact that once you get lower than 12 teeth, you have no room left to bore for a shaft.


----------



## Johno1958 (Aug 4, 2018)

Thanks Brian.
Yes I have the two modular sets 0.7 and 1 the one being very close to yours. Mine are cheap Chinese cutters from CTC Tools , a little over a hundred bucks a set so I hope 
they will cut brass ok....Just because I like the look of brass gears for the contrast .
Cheers
John


----------



## Brian Rupnow (Aug 5, 2018)

Prompted by J Tiers, I have been doing a lot of thinking on this reversible belt business. I was under the impression that the belt itself stopped and changed direction, and that was my intent with this model, to see if I could replicate this movement. After listening to Jerry's advice and watching a bunch of old sawmill edger and shaping machine videos, the belt doesn't reverse. It is the machinery the driven pulley drives that  has the reverse function built into it. The belt always turns the same direction without stopping, but the fact of shifting the belt from side to side and driving the two different pulleys is where the reverse is happening. This doesn't effect the model at all, except the model will be driven from the end with the single wide pulley on it. Now I'm not certain if I need the center "neutral" pulley or not. I will build the mechanism with this center neutral pulley first, because it is already made. Depending on what happens, I may get rid of the center pulley and just have two pulleys at the driven end. It is the countershaft that reverses direction.


----------



## Brian Rupnow (Aug 5, 2018)

Once a design has been completed for concept, I have to look at what has to be done to make it practical to build. In my case, this means changing the endplates from 1" thick to 3/4" thick, changing the sideplates to 1/2" thick from 3/4" thick, making the endplates an inch higher to move my pulley centers up an inch higher, and adding "foot plates" so I have a means of bolting this thing down. I have made the changes to the model, and pulled detail drawings off the model, so now I can start to build the frame of this machine.


----------



## Brian Rupnow (Aug 5, 2018)

It would have been a lovely day to be at the beach----but I wasn't. Wife was having a lazy day---all my grandchildren were spoken for--So, I worked in my shop. Finished the mechanism which shifts the belt side to side. It looks simple, but there are 11 parts there plus 4 circlips.


----------



## werowance (Aug 6, 2018)

i see what you did with the shifter,  the brass are rollers so as to not wear when the belt rubs on them or to drag on the belt when shifting. 

I like it.


----------



## Brian Rupnow (Aug 6, 2018)

One of the major disadvantages of working at "scale model" level, is that some things simply don't scale down that well and still remain functional. I am finished all of the parts for this project except for the end plates that support the shafts.  (I have to buy some material.)  My plan is to manually push or pull the shifter to left or right by hand to see how well the belt moves as I slide it from one pulley to another. On a full size rig, I would have a long lever, pivoted at the bottom and a link from the lever to the end of the slider mechanism. The belt can only be moved from side to side while it is running under power between pulleys. I was able to find this animation on YouTube which comes close to what I am trying to do.


----------



## Brian Rupnow (Aug 7, 2018)

-I got some more insight into that neutral center pulley. This set-up was used to drive the cable drum on the carriage of sawmills.  As soon as a board was cut off by the mainsaw you could go quickly from foreword to reverse to retract the carriage. However, when the carriage got to the load end, the belt was moved onto the neutral pulley so the carriage paused while another log was loaded, or the log being cut could be "dogged over" the width of a board and then the belt was moved from the neutral pulley over to the one which advanced the carriage into the saw.--Belts used on a large line shaft driven shaper didn't need a pause at either end of the stroke, so shapers only had a forward and reverse pulley side by side with no neutral pulley between them.---- Brian


----------



## Brian Rupnow (Aug 8, 2018)

Just got home from a great 2 day mini vacation. Wife and I drove over to Peterborough and spent the afternoon telling lies and drinking wine with a good friend I worked with for five years in the zinc die casting business. Him and his wife were great hosts and a good time was had by all.---Now, as to the mechanism--I have thought about the "over center spring loaded toggle" for an automated belt shifting reversing system.. However, I tried that on a different reversing mechanism using gears and a rack this past year, and it failed rather miserably. If the moving parts had enough momentum to let them coast  the last bit of stroke, the toggle would have worked fine. However, at small scale and relatively light weight, as soon as the toggle was moved almost to the tipping point, the moving components stopped and just sat there.-Fully disengaging one gear from the rack, but not tipping over far enough to engage the reverse turning gear with the rack. I tried many adjustments and refinements of this system, then decided it wasn't going to work. I will do some thinking on Miners quadrant gear solution, but first I have to buy some material tomorrow and finish the two sideplates and assemble this thing to see it work. Sometimes just seeing a new mechanism work will inspire me with solutions to further progress.


----------



## reubenT (Aug 9, 2018)

I ran a woodmizer sawmill for 25 years,  then sold it and assembled and ran an old flat belt driven round blade sawmill from a pile of rusty parts,  sold it after 2 years and bought another band mill.   The forward/reverse carriage drive was just two flat pulleys on each end with loose belts on both,  one flipped over,   belt tensioner rollers on a rocker lever tightened one or the other with a forward reverse action of the handle.  I used rubber round baler belts,  but they tended to warm up and grab, had to use talc powder to keep them slipping properly.     leather or woven cotton belts would have been better.       I've seen the belts on line shaft equipment set up the same way, with those two sets of belts overhead and a handle hanging down to flip the tensioners onto one or the other, as well as a bar hanging down to flip the main belt back and forth on a stepped pulley to change speed.    The simpler it's made the less can go wrong with it.   But gear reverse boxes are good for it too.  My old line shaft lathe has an aftermarket electric motor on it with reversing switch driving an overhead flat belt pulley,  so they eliminated the crossed belt thing.  But for some crazy reason I like the old method.  Maybe set it back up that way myself someday,  being I have a second flat belt lathe now.  Although running the shop on steam might be inconvenient, since my usual use of the equipment is a little once in awhile.


----------



## Brian Rupnow (Aug 9, 2018)

Thank you reubenT--I have no real experience with flat belt drives, but I'm having fun with this.---Brian


----------



## Brian Rupnow (Aug 10, 2018)

Here we have the first full assembly._ *I*_ have some serious rework underway with the belt shifting mechanism, and the belt is a little looser than I would have liked, but we are underway.


----------



## Cymro77 (Aug 10, 2018)

Lost somewhere, waiting, watching!


----------



## Brian Rupnow (Aug 10, 2018)

Its hard to tell by looking at a 3D model how big or small something is going to be. The shafts on this thing are only 3/8" cold rolled steel. I just finished getting the gear train all sorted out, and it is working as I had intended. Tomorrow I will remake the belt shifter mechanism. I couldn't get the two 1/4" rods which support the belt shifter any closer to the pulley because the idler gear was in the way. Today I decided to go with an offset belt shifter to keep the side guide rollers as close to the pulley drum as I can get them.


----------



## Brian Rupnow (Aug 10, 2018)

It seems to be a bit of an art to get exactly the right center distance between the pulleys. Built as per my original design, the belt is just a bit too slack, and will slip on the pulleys instead of transmitting power. This picture shows the mechanism with four flat washers 0.055" thick between the one endplate and the sideplates, and this seems to make the belt a bit too tight.  I'm starting to feel a bit like Goldilocks. Tomorrow I will try it with some 0.030" spacer washers.


----------



## Brian Rupnow (Aug 11, 2018)

Here we have a video of the first "run in" of the flat belt reversing system. I do not have the belt shifter installed yet. This is just a run in for half an hour to take any tight spots or binds out of the mechanism. I have to have everything moving very freely before I reach a final decision on center to center of belt pulleys.--NOTE THAT IN THE VIDEO I TALK ABOUT A 30 MILLIMETER SPACER--SHOULD HAVE SAID 0.030 THOU.-Brian


----------



## Brian Rupnow (Aug 11, 2018)

For those of you who are asking about a crown on the pulleys.---The long single pulley, which is being driven by the flat belt in the video will eventually end up as the "driver", not the driven. The belt has to scoot sideways from one end of the pulley to the other when I shift the belt, so it will not have any crown. The two outer pulleys at the other end MAY have a crown if I determine that they need it. The center pulley at the far end may get a crown, or may not. Before I crown any of the pulleys, I have to build the belt shifting device and install it. It is very possible that the belt shifting mechanism will make the belt hold position so that none of the pulleys require crowns.---Brian


----------



## Brian Rupnow (Aug 11, 2018)

I've just had a small surprise---In all the solid models I have posted, you will see that I have the belt shifting mechanism closest to the three individual pulleys. In reality, as per testing just done in the garage, the belt shifts sideways far easier if the shifter mechanism is close to the one long single pulley which is the driver. (I have changed the 6" pulley around to drive the single long pulley since the video was posted.)


----------



## Brian Rupnow (Aug 11, 2018)

And---We have a winner. Rather crude set-up and background, but everything works as I had hoped. I will clean things up a bit and post a better video later, but this first run has made my day!!!---Brian


----------



## Brian Rupnow (Aug 11, 2018)

Today was a good day. The mechanism works exactly the way I had anticipated. This is the first thing I have built in ages that didn't cost me anything. I had all of the material left over from other projects except for the end plates. I was at a customers, looking at a job, and I happened to mention that my next stop was going to be at a metal suppliers to buy some 4" x 3/4" aluminum. My customer walked over to his rack and gave me a piece of aluminum long enough to get two end plates out of!! I'm not horribly impressed with using a pair of vice grips to move the belt shifter, so I may do something a bit classier there. As far as automating the belt shifter, I don't think I'm going to try to do that. The system doesn't have to transmit a lot of power. I know that belt tension plays into how much power can be transmitted, but my main aim in building this mechanism was to see about the ability to reverse a shaft, not to transmit a lot of power.


----------



## Brian Rupnow (Aug 12, 2018)

Now we get to the part I was talking about earlier, where not all things scale down that well. I have proved by my tests yesterday that this mechanism does indeed allow reversing the output from a flat belt. The vice grips were very crude but they did allow me to move the slider to shift the belt. Now I have designed something with a lot more "cool" factor, but it forces me to do some things which are not scalable. My hand which operates the shifter mechanism is "full size", therefore, some of this mechanism has to bridge the gap between miniature and full size. You will see that the end-caps on the shifter rods have been changed to a shape that extends from side to side forming a bridge. Mounted to the top of this bridge is a 2" long piece of 24 dp rack. Meshing with the rack is a gear quadrant with a 6" handle that when inclined 30 degrees to the right or to the left moves the slider thru its full range of movement. The large dark blue piece at one end of the frame is the support for the pivot shaft .


----------



## Brian Rupnow (Aug 15, 2018)

I haven't disappeared--I've just taken a short break. I have a friend who, over the years has supplied me with a small fortune in brass angle and brass hex rod. I asked if there was anything I could do for him in return, and he answered that he would like to have a small cable winch to mount under the back of his truck to winch the spare tire up into place. He supplied the aluminum and the gear and pinion and this is what I built for him.


----------



## Brian Rupnow (Aug 16, 2018)

Slowly and somewhat randomly, the changes are happening to put a reversing handle and sector gear on the reversing mechanism, to make it match the most recent 3D model. There is nothing difficult here, just somewhat time consuming. The overhead bridge that will support the gear rack was finished off this morning. The round blue disc is destined to become an 82 tooth gear. I won't cut teeth all the way around it, because I only need a total of 62 degrees to interact with the rack to move my belt shifter from side to side. I find it almost sinful to be doing things in my shop in the middle of such incredibly beautiful weather. My good wife would gladly lay around all day in the air conditioning, but I have to get out and enjoy this weather while it is here. In the middle of January and February its remembering weather like today that keeps me alive until spring. If you are enjoying this thread, give me a shout.---Brian


----------



## werowance (Aug 16, 2018)

i am enjoying the build.  but understand the need for fresh air to.  enjoy!


----------



## Brian Rupnow (Aug 16, 2018)

HA!!!--Just went out with good wife, oldest son, and second youngest grandson to the Dairy Queen. Banana splits all around. Life is good. Now, back to work on the beast.


----------



## Brian Rupnow (Aug 16, 2018)

If any of you think that maybe I'm making this up as I go along---You're absolutely right. I have finished and installed the new bridge that connects to the end of the belt side-shift rods, and mounted a 2 1/2" length of 24 DP gear rack to it. The blue disc which is destined to become a sector gear is attached to a piece of 3/4" diameter cold rolled steel with a 5/16" shoulder bolt. I don't want to take a chance on it spinning while I am cutting gear teeth on it, so I have drilled and pinned it in place with a piece of 1/8" cold rolled steel. You can see the shape it will eventually have scribed on the face of the disc.


----------



## Brian Rupnow (Aug 17, 2018)

I have reached the point where if I had one more part I would be finished. I cut the sector gear today, then trimmed away the sides and welded a handle to it. Now I have to make the aluminum pivot support to mount the sector gear and handle on.


----------



## Brian Rupnow (Aug 18, 2018)

So here we are with the finished flat belt reversing mechanism being driven by my Philip Duclos designed Hit and Miss engine . The build is a complete success, and I am very happy with it. I'm not sure that I have any real use for it, but it was a challenge to build and I learned a bit along the way.---Brian


----------



## Brian Rupnow (Aug 18, 2018)

Can anyone see the video when they click on the link in the previous post? I have somebody on another forum saying the link doesn't work for them.---Brian


----------



## 110samec (Aug 18, 2018)

All the videos work fine for me. congrats on another interesting project btw, cant wait till i get my new lathe installed and can get back to making swarf


----------



## Brian Rupnow (Aug 18, 2018)

Thank you 110samec. Sometimes I have a problem with Youtube videos, and I depend on the people on the forums I attend to let me know if they are working or not.---Brian


----------



## Johno1958 (Aug 18, 2018)

Well done Brian.
I was just thinking ( I know......) ,could you make a variable speed mechanism the same way with two reversed cones.
Cheers 
John


----------



## Brian Rupnow (Aug 19, 2018)

Yes Johno, you could. I've seen illustrations of that in "501 Mechanical Movements."


----------



## Cymro77 (Aug 19, 2018)

Another great instructional piece Brian.  Now take another "Vacation" from your hobby so we can see more
111
Thanks for sharing your incredible wisdom.


----------



## Brian Rupnow (Aug 19, 2018)

I was having a little bit of trouble with the belt slipping on the smooth face of the three part pulley system. The pulleys are far to small to put any kind of lagging on, so I used a vibrating hand held engraver to make a "pattern" on the face of the two outer pulleys. This fixed the belt slippage completely.


----------



## werowance (Aug 20, 2018)

i really like the gear rack setup.  that's just to cool.


----------



## Brian Rupnow (Aug 20, 2018)

Werowance--It is cool isn't it. There were about six different ways to do that, but the rack and sector gear had the highest 'Cool' factor.---Brian


----------



## Brian Rupnow (Aug 20, 2018)

One last video before I call it quits. Turn your audio up so you can hear me speaking---I promise it will be funnier!!--Somebody PLEASE let me know if you are able to view the video.--(For some reason I have trouble ensuring that my YouTube videos are set on "public" and not "private".


----------



## Cogsy (Aug 20, 2018)

Video is showing fine for me. Quite the interesting drivetrain you have happening there.


----------



## ShopShoe (Aug 21, 2018)

I see the video fine, Brian. I didn't even need to turn the audio up.

--ShopShoe


----------



## humungus (Aug 21, 2018)

Great video Brian, it was because of your u tube videos that I joined this group recently. It must be extra effort and time to film and post videos, I really appreciate it, thank you.


----------



## Brian Rupnow (Aug 21, 2018)

This morning, tired of the belt slipping on the driven pulleys, I removed both pulleys and put a full knurl on the face of each one. I left the center (idler) pulley with a plain face. The head pulley is still smooth. I find that although the set-up is great for demonstrating the fact that I can reverse the output shaft by shifting the belt from side to side, it isn't that great if there is much of a torque load on the output shafts. More experimenting this morning showed that sometimes it could drive the funky corner joint mechanism, and sometimes it wouldn't. The engine wouldn't stall out, but the belt would slip on the head pulley about half the time, unless I grabbed one of the wheels on the funky corner joint and "helped " it to get rolling. I think this is purely a result of the vacuum cleaner belt that I am using as my flat belt. Anyways, this has amused me for a couple of weeks, and we've had a bit of fun with it.---Brian


----------



## Rickl (Aug 22, 2018)

GregNixon said:


> I don't think the mechanism is nearly as precise or complex as you think. Take a single machine where the motor is on the machine and drives the drum. The drum has two flat belts which can be moved over to one of three positions.  One of the belts is crossed over for reverse and drives a 'fast' pulley which is fixed to the shaft.  The other belt drives the 'loose' pulley which just spins around on the shaft, sorta like a neutral position.  The pulleys are now in 'reverse'. To change to forward, the belts are moved over as a pair. The crossed belt is now on the 'loose' pulley and the uncrossed forward belt now drives the pulley shaft.
> The belt is moved via that shifter mechanism. The belts are not tight, and the belts are moved slowly. I'll will dig out some photos of the drive overhead at the local blacksmith museum.


Had


GregNixon said:


> I don't think the mechanism is nearly as precise or complex as you think. Take a single machine where the motor is on the machine and drives the drum. The drum has two flat belts which can be moved over to one of three positions.  One of the belts is crossed over for reverse and drives a 'fast' pulley which is fixed to the shaft.  The other belt drives the 'loose' pulley which just spins around on the shaft, sorta like a neutral position.  The pulleys are now in 'reverse'. To change to forward, the belts are moved over as a pair. The crossed belt is now on the 'loose' pulley and the uncrossed forward belt now drives the pulley shaft.
> The belt is moved via that shifter mechanism. The belts are not tight, and the belts are moved slowly. I'll will dig out some photos of the drive overhead at the local blacksmith museum.


Had the same system on chaffcutters.


----------



## Rickl (Aug 22, 2018)

Greg Nixon....In the early 60s the chaffcutters at the feed mill was similar belting. They were about 20 feet long.


----------



## werowance (Aug 23, 2018)

i really enjoyed this one,  whats next Brian?  a 2 stroke pencil sharpener maybe?


----------



## Brian Rupnow (Aug 23, 2018)

werowance--I am bored, and that is a dangerous thing. Today I started a new thread about making a muffler for an i.c. engine.---Brian


----------



## werowance (Aug 24, 2018)

great,  ill be sure to watch.


----------

