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Matt S

I bought a band-knife splitter

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Perhaps this should be alternatively titled "Matt's 800lb pig in a poke".

I've wanted a band-knife splitter for a while. There's one I use in a workshop an hour away from me but that's not very convenient and it has reliability problems. I got a quote on a new one and, realising that the number the man said to me was the price rather than his phone number, I managed to find one used for a far more reasonable price. However the seller was a dealer in general industrial machinery and didn't know much about such machines so it was sold "as seen".

It appears to be a Fortuna/SAS UA, which is an older model with a 12" capacity. I asked a couple people what to look for and spent Christmas poring over service manuals. (I sure know how to have fun.) In the new year I drove to the warehouse in the English Midlands for a bit of a look-see. The Midlands used to be a sprawling mass of industrial production the envy of the world. Nowadays it makes Pripyat look like Paris, but I managed to leave before the shellsuit-wearing locals roasted me over a tyre fire for their dinner so it's all good. The machine looked fine apart from a little cosmetic rust, probably from being rained on briefly. Nothing crucial appeared corroded, all the grease and oil points were still greasy and oily, no buggered screws, and all turny bits turned smoothly, which I hope means the bearings are in good nick. Nothing was at its maximum adjustment, which is usually a good sign. The knife tension assembly looked like it wasn't worn out or broken, which I had been told is a mission-critical check. So the man made me a cup of tea and we had a chat (during which he tried to sell me a Pederson clicker) and he told me that the splitter had come from a company that used to make laptop bags but they'd stopped certain lines so it was no longer needed. Now I've always been taught that you buy the car not the story it comes with but this did give me another indication that the machine wasn't worn out. So I decided to take it.

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I had it delivered on a tail-lift truck and persuaded the driver to get the pallet onto my driveway. So much for the easy bit. You see, this machine weighs 350Kg, which is nearly 800lb, and I had to shift it 30 yards through very tight areas, across 7 level changes, uneven ground and turf.  Notice also that the machine is significantly wider than the gate, and that's not even the narrowest part of the access to where it need to me. This was going to be fun.

shrinkwrap.thumb.jpg.97af79912f52651aee2be95e7878a259.jpg

 

Edited by Matt S

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Way to go, Matt...

Waiting for the next chapter.:rockon:

Genuinely jealous,

Harry

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Luckily I have a friend who amongst other things is a tree surgeon and machine dealer so we put our heads together and figurated a moving plan. I removed everything I reasonably could to reduce weight and sticky-outy bits. Also, because there's no specific lifting points, it's important to remove any sheet-metal guards that might have weight borne on them during a lift.

Now because people these days seem to have difficulty quantifying risk and taking responsibility for their own actions I sadly need to point out the bleeding obvious: we knew (vaguely) what we were doing, one of us is qualified to handle loads many times this weight, we were willing and capable of making good any damage we caused, and we put a great deal of homework into this move. I recommend that anyone who doesn't meet these criteria (or even if they surpass them) to seek the services of a professional moving firm.

As you can see the prime mover in our endeavours was this used and abused engine crane. If the access were flat and a little wider we could have just wheeled it along and finished the job in an hour. As it is, it took eight, split across two days. Here is my friend suddenly realising what he's got himself into:this.jpg.afaf939d5805744f60b2e2d00ff7367f.jpg

Our primary method was to rig the machine, via lifting straps, to a large eye bolt on top of this heavy 12ft length of C-channel. One end was rested in a pocket on a very sophisticated piece of rigging cunningly fashioned from two old pallets and some scrap wood. The other end of the steel was lifted with the crane until the machine lifted off the floor and the eye bolt rotated by hand to roll it down the slope. The man on the crane lifted in time with the machine advancing forwards, so at any one time it was no more than an inch from the ground. We were able to adjust the slope of the steel and the braking effect of the lifting straps on the rough steel to be very closely balanced, so you could move the machine with nearly zero physical effort. It was actually a lot less shonky than it looked and most of the time was taken in setting up each move as securely as we could, building temporary structures to level the floor and screwing braces from the pallets to whatever we could.

This was probably the dodgiest part, as the crane didn't really fit on the step. You cant see it but the crane and pallet are pretty securely strapped and braced from moving in any direction. All wooden structures are screwed together, with none of the weight bearing a shearing force on the fixings. Here I am guiding the machine with less force than it takes to open a stiff door.

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Once we were on the grass things moved a lot quicker -- maybe 15 yards in 15 minutes, rather than 15 yards in 6 hours. As you can see we put the machine on an industrial dolly, and ran it over sacrificial 1/2" ply. It was a bit top-heavy so a third pair of hands was borrowed for this section of the move, which made things run even smoother and stopped the thing toppling head-first into the mud.

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All in all the move took about 8 hours split over two days. Zero injuries to men or machines, though there were times I was glad to be wearing my brown trousers. Two doors to rehang, and a few patches to paint.

I want to stress again that we knew (vaguely) what we were doing and that we followed a great deal of safety procedures not mentioned above. We had contingency plans and backup contingency plans, including separate means to lift the machine if it fell on top of somebody. It is in no way intended as a "how to", more of a "how we did".

*To be continued*

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30 minutes ago, hwinbermuda said:

Way to go, Matt...

Waiting for the next chapter.:rockon:

Genuinely jealous,

Harry

Thanks Harry. I know not many small concerns have splitters like these, and I understand why -- cost, space, expense, weight, complexity. Once/if I get it serviceable it'll give me a massive flexibility in what products I can offer as well as consistency of product. If I can't, it'll form an interesting conversation piece on the futility of hubris.

So long story short, we wrestled it into the shed, though the last bit was fairly tricky. My mate had to re-rig the whole machine to rope rather than straps to get through the reduced height doorway into the shed. Tight? I almost called my midwife aunt for advice.

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So it's in. I've left it in this position for better access while I get it running. On the plywood I can just about move it by my skinny self but it's fairly easy with two.

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I've now had time to go over the machine more thoroughly. Cleaned the majority of the grinding muck offn it. Filled the oil tank. Fixed the upper feed drive. Whispered it a few sweet nothings. Good news is that the machine appears to have made the move intact, the only damage being the control panel and thickness gauge. Now neither was in the finest of health when I bought the machine and the wiring to the control panel is fairly complicated so I didn't want disassemble it until it was in a well lit environment like my shed, figuring I was going to replace it anyway.

Next installment: electrickry.

Edited by Matt S

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On 1/28/2019 at 3:59 PM, Matt S said:

realising that the number the man said to me was the price rather than his phone number

:rofl:

That sounds like a plan I might come up with .. put it in teh back yard and then build a shed around it!

 

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Ahhh..memories of moving my first clicker press into my shop. We wound up buying a used pallet jack for about $20 and with the help of a buddy we cut the pallet jack in half, took 6" out of the width and welded it all back together. This made the pallet jack as wide as the base of the press on its sideways (narrowest profile) so we could get it through doorways. We had 4 or 5 places we had to go over a change of elevation of a few inches. All of this was accomplished by either rolling the press onto pipes or using two hydraulic floorjacks depending on if we were going up or down. Took about 5 hours if I remember right with two of us doing the work, five friends who were the peanut gallery and the women who helped us by telling us we were crazy..it will never work...be careful..don't hurt yourself...and other useful advice. And then 4 years later we moved it to the new place and did it all over again. At least the new shop has garage door access and a cement floor!

That being said, I just took delivery of 1600sqft of leather I purchased from nstarleather (thanks Mike!) that I have to hand carry up a flight of stairs to my leather room.  Guess what i'm doing for the next hour or so. This is why I usually only purchase a couple hundred sqft at a time but sometimes you gotta take the deals when you can get them!

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Was that your wife Matt i met in the estate agents, who said she had just found the ideal new house and going to surprise you next week with the news, just thought you should know :lol:

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2 hours ago, Mark842 said:

Ahhh..memories of moving my first clicker press into my shop. We wound up buying a used pallet jack for about $20 and with the help of a buddy we cut the pallet jack in half, took 6" out of the width and welded it all back together. This made the pallet jack as wide as the base of the press on its sideways (narrowest profile) so we could get it through doorways. We had 4 or 5 places we had to go over a change of elevation of a few inches. All of this was accomplished by either rolling the press onto pipes or using two hydraulic floorjacks depending on if we were going up or down. Took about 5 hours if I remember right with two of us doing the work, five friends who were the peanut gallery and the women who helped us by telling us we were crazy..it will never work...be careful..don't hurt yourself...and other useful advice. And then 4 years later we moved it to the new place and did it all over again. At least the new shop has garage door access and a cement floor!

Mate that sounds crazy. Got any photos? I'm going to steal that pallet jack idea.

The guy who sold me the splitter tried to sell me one of those enormous old Pederson clickers too. It's still there.

27 minutes ago, chrisash said:

Was that your wife Matt i met in the estate agents, who said she had just found the ideal new house and going to surprise you next week with the news, just thought you should know :lol:

:lol: If we could afford to buy a place of our own I'd be happy to move the splitter!

3 hours ago, JLSleather said:

That sounds like a plan I might come up with .. put it in teh back yard and then build a shed around it!

That was the fall-back plan... but then I'd have to give up the space I want for my metal-work shed...

3 hours ago, Itch said:

Nice Work ..

Cheers Itch, and thanks again for your help and advice. I think I may be bothering you again fettling the damn thing.

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Glad it all landed safe for ya.

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In this episode: Matt plays around with dangerous electrics. Best not to copy me if you're not familiar and comfortable with the risks.

As noted earlier the control panel got damaged in the move. The 60 year old plastic had the structural strength of vintage cheddar so I built a replacement. Bit of an awkward setup but luckily there was plenty of space in the casting for a choc block to extend the original wires.

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This machine is built to run on 3-phase electricity. Same voltage and frequency of angry pixies as normally come out of the wall sockets in my country but each 120 degrees out of phase with the previous. This allows a smoother supply, especially for higher-consumption appliances. The splitter is only rated to consume 1100W so I presume that it's purely because 3-phase motors are simpler and more reliable than single-phase, and this machine was designed for use in a factory. What idiot would try to run one in a small workshop eh?

Unfortunately I don't have 3-phase laid on so I had to make other arrangements. Upgrading to 3-phase supply would cost about as much as a brand new machine. Replacing the 4x motors with single-phase ones would cost £400, even if I could find cheap drop-in replacements. VFDs would require one per motor, connected directly, with the switchgear rebuilt -- not cheap and I wanted to keep the switchgear as original as I could. Cheap 3-phase petrol generators are minimum £350, noisy, and of questionable quality. So I needed some sort of phase converter.

After some study on the subject I decided a rotary converter would be better. Prices were not attractive so I built one out of £150 of parts.

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Then I toasted the idler motor in my converter. Whoops.

burnt_motor.jpg.761d91693b64f15128bdaf5c5343abc1.jpg

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Long story short I went back to the KISS approach: a Steinmetz arrangement (static converter) on the largest motor on the machine. Cheap, simple, imperfect but adequate. What I should have done all along. 

She lives.

 

A little fiddling with balancing capacitors later and I've got it about as sweet as it's going to get. The machine at idle consumes less power than my previous converter did alone. (Temporary control panel installed in spare space under my clicker press -- which means it'll be there permanently.)

converter_controls.jpg.f5784cc67346a052667c95b147276ea6.jpg

Time to tidy up the electrics and put he machine back together. I bloody hope this is going to be worth the trouble...

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Looking good, Matt, keen to see the results when its splitting.

Well perservered

H

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With the electrics mostly functional it's time to get the mechanical arrangements sorted. All the pieces went back together without too much trouble and I could revel in its yellow formica beauty.

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Then I had to put the blade in, which required me to remove the upper blade guide. And I was not pleased with what I found.

First a little background. A basic/classic band-knife splitter like mine is not the most complicated machine in the world. Essentially it's a two-wheel bandsaw turned on its side with motorised feed, a motorised blade grinder/sharpener and a dust extractor. However what it is is incredibly accurate and rigid. It has to because we're talking about a machine intended for reliably splitting materials with a variance of a fraction of a millimetre. The blade, just 0.4mm thick, is kept dead flat during the 12" length of the cut by a pair of blade guides, very flat and smooth steel plates which sandwich it from above and below. There is also a pair of blocks which slide forward and back between the blade guides. These are the blade gibs and their job is to prevent the blade from moving backwards under pressure from the work being fed into it. They have to be adjustable because the blade gets a little narrower every time it's sharpened. As everyone who's operated a bell skiver understands, the position of the blade edge, relative to the feed wheel, is essential. Everything has to be very flat and smooth. And this is what I saw when I removed the top guide:

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Yep, that's rust. On precision ground surfaces. So, choking on the emulsifying oil I sprayed all over the machine and myself I set about with rags and a flat-head screwdriver scraping off what I could. (For reference we're looking down onto the top of the machine from the front. That big knurled wheel is the thickness adjuster. The knife runs in the groove just visible above the adjuster, and the gibs are the two narrow steel blocks immediately above the groove.

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Big improvement and probably as good as I'm going to get it without removing more mechanism than I wanted to, or getting in there with a dremel. This photo is taken backwards form the previous and was after I'd removed the gibs for polishing. The knife groove is a little more visible here, as indeed is the back edge of the knife, far too far forward for actual use.

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A little more of the endless endlessness, you lucky people.

With the blade in its proper place and the gibs moving smoothly it's time to adjust the tracking. This is a minute adjustment of the angle of the idler wheel, which changes the angle of the knife. Just like a bandsaw or belt sander. The idea is that the back of the knife bears evenly on both gibs, judged by comparing how warm each feels after running for a while. The previous owner of mine apparently had the knife running at an angle for long enough to wear a deeper groove in the right gib than the left so it can never run true. I didn't feel confident grinding the wear surfaces level with enough accuracy and couldn't find any for sale online. So I shimmed the right-hand gib. There's only one type of shim-stock I had handy, and it comes wrapped around beer.

Much better.

shimmed_gibs.thumb.jpg.ff960e043ee2f9de28ae555f6f4f26d3.jpg

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5 hours ago, Matt S said:

There's only one type of shim-stock I had handy, and it comes wrapped around beer

No non-alcoholic versions around, I presume? From your PM yesterday I had presumed a leaning to H&S :P

Doing well on an interesting project there, Matt.

 

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5 hours ago, Matt S said:

A little more of the endless endlessness, you lucky people.

With the blade in its proper place and the gibs moving smoothly it's time to adjust the tracking. This is a minute adjustment of the angle of the idler wheel, which changes the angle of the knife. Just like a bandsaw or belt sander. The idea is that the back of the knife bears evenly on both gibs, judged by comparing how warm each feels after running for a while. The previous owner of mine apparently had the knife running at an angle for long enough to wear a deeper groove in the right gib than the left so it can never run true. I didn't feel confident grinding the wear surfaces level with enough accuracy and couldn't find any for sale online. So I shimmed the right-hand gib. There's only one type of shim-stock I had handy, and it comes wrapped around beer.

Much better.

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Hey @Matt S, Congrats on obtaining a splitter. Just a thought on those wear blocks (gibs) check the depth of the groove wear in them as they can help generate excessive heat if they come over more than 1/2 mm or so. The excess wear on the right is normal as the way the blade spins it is the first to cop the pressure. I normally grind them down until there is only a minor wear line from the blade left and check from there. The steel is super hard like tungsten or something on both the Elbiko  and the Comoga I have, but interestingly the Comoga also came with a few extra wear block that I think are teflon or some extra hard nylon at any rate. They do wear faster but don't seem to generate the heat as much. If the heat is too much it transmits through the blade and you will find that they put cracks all around and through the blade until of course they snap through. The German blades are better and last way better. Feel the back of the blade occasionally and sand of any excessive burring. On the adjuster for adjusting the blade forward there is a spring that pushes a steel tab into the toothed wheel you turn by hand. It is not in your pictures but I assume you have it and the tab piece. Make sure that spring is fairly strong as some times when the leather goes through it can knock the adjuster back and of course the blade goes back with it. Better to check now and not have to pull it all off and have to go through the joy of having to carefully adjust the top plate down again. Amazing how a great hunk of steel can bend around like butter. Last thing ....check that the blowers air intake is clear and that there is plenty of air flow blowing down the chute right across. Just hold a leather strap in the chute and see if it shakes around and wants to go through. Some times the chute can get clogged up and it is super annoying when you find that the leather your trying to feed through is obstructed by a build up of waste in the chute. This is one reason I like my old Albeko better as it's waste comes out to the front and straight into a bin to the side. Have fun and again congratulations on a fine pick up.

 

 

 

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Great stuff Matt, Its looking good...

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4 hours ago, RockyAussie said:

Hey @Matt S, Congrats on obtaining a splitter. Just a thought on those wear blocks (gibs) check the depth of the groove wear in them as they can help generate excessive heat if they come over more than 1/2 mm or so. The excess wear on the right is normal as the way the blade spins it is the first to cop the pressure. I normally grind them down until there is only a minor wear line from the blade left and check from there. The steel is super hard like tungsten or something on both the Elbiko  and the Comoga I have, but interestingly the Comoga also came with a few extra wear block that I think are teflon or some extra hard nylon at any rate. They do wear faster but don't seem to generate the heat as much. If the heat is too much it transmits through the blade and you will find that they put cracks all around and through the blade until of course they snap through. The German blades are better and last way better. Feel the back of the blade occasionally and sand of any excessive burring. On the adjuster for adjusting the blade forward there is a spring that pushes a steel tab into the toothed wheel you turn by hand. It is not in your pictures but I assume you have it and the tab piece. Make sure that spring is fairly strong as some times when the leather goes through it can knock the adjuster back and of course the blade goes back with it. Better to check now and not have to pull it all off and have to go through the joy of having to carefully adjust the top plate down again. Amazing how a great hunk of steel can bend around like butter. Last thing ....check that the blowers air intake is clear and that there is plenty of air flow blowing down the chute right across. Just hold a leather strap in the chute and see if it shakes around and wants to go through. Some times the chute can get clogged up and it is super annoying when you find that the leather your trying to feed through is obstructed by a build up of waste in the chute. This is one reason I like my old Albeko better as it's waste comes out to the front and straight into a bin to the side. Have fun and again congratulations on a fine pick up.

Thanks mate. My calipers wouldn't fit in the tiny groove but measuring with my mk1 thumbnail I reckon it's less than 1/2mm deep. Do you have some special arrangement for grinding them? The blade is pretty clean apart from a few minor rust spots.

Yep the adjuster spring is present and pretty firm. What should I look for when snugging down the top plate?

Blower's working okay but I've got it disconnected right now as it was running a little warmer than I thought right and I don't need it for the adjustments I'm making right now.

3 hours ago, jimi said:

Great stuff Matt, Its looking good...

Thanks Jimi, it's really coming together now. Despite a few maintenance issues it's not in bad nick for its age!

5 hours ago, hwinbermuda said:

No non-alcoholic versions around, I presume?

Tea bag boxes ya mean Harry? Not so good for shimming steel-on-steel. :P (Actually I've shimmed steel-on-wood bearing surfaces with card before. Soak the card in linseed oil before snugging down and it polymerises to a hard, firm surface that can be peeled off with no damage if you need to. Works great on Lee Enfields where the wood has shrunk a little.)

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Quick question for anyone who's operated a splitter like this before: could you please describe the action of the grinder timer? Mine has never worked, it's beyond economical repair and I've decided just to replace it. The manual says to set it for 10-15 minutes depending on how tough is the work. But what it doesn't say is what the operation of the timer actually is. Is it, for instance, an interval timer where it switches on for 1 minute, off for 10 minutes then on again ad infinitum, or an on-delay timer where it's manually switched on but switches itself off after 10 minutes.

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48 minutes ago, Matt S said:

Tea bag boxes 

I thought the ubiquitous Red and White soda cans, :rolleyes2:

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I really like to follow your work on this splitter, and I'm looking forward to updates. Do you have an exploded view/parts list of the gibs and "guides" It would be nice with individual adjustment for the gibs. I'm thinking something like this (If i understand the construction correctly.) This way you could regrind your "guides" individually if needed.

 

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Edited by Danne

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9 hours ago, Matt S said:

Quick question for anyone who's operated a splitter like this before: could you please describe the action of the grinder timer? Mine has never worked, it's beyond economical repair and I've decided just to replace it. The manual says to set it for 10-15 minutes depending on how tough is the work. But what it doesn't say is what the operation of the timer actually is. Is it, for instance, an interval timer where it switches on for 1 minute, off for 10 minutes then on again ad infinitum, or an on-delay timer where it's manually switched on but switches itself off after 10 minutes.

Mine are inoperative as well and I would not want them operating anyway. A lot of factors come in to how often a blade will need to be sharpened and generally 30 seconds to a minute is fine. Some leathers, even soft leathers will blunt a blade in no time and some you can go for a half hour or more. Generally the split will start to look choppy and sawn and therefore it needs to be sharpened. Except for foam I never have the blades sharpening while splitting and that is rare as well. A new blade can take a half hour to sharpen. Make sure to clean the felt guides well when changing the blade and on the odd occasion as well. I tend to scrape them with a knife and sometimes rough sand them if they need it.The blade should be fine sandpapered to get rid of the rust and sometimes I give the blade a light sand on the run but THAT IS SUPER DANGEROUS and absolute full undivided attention is a must. I should be saying DONT do it. Make sure the blade only barely wants to go backward toward the wear blocks (gibs) and do plenty of quick stop starts after to check that it does. TOO much will create overheating of the blade and wear blocks. New full size grindstones will make sharpening a matter of seconds instead of minutes unless your rubber belt that runs the grindstones is overstretched and worn out. Another reason why auto is no good. With regards to the top plate tightening it would be best to check with the manual. My Comoga has 11 screw downs with 11 screws to set the stop points. Main thing is when the blade is in position when you do the front ones up and they put any pressure on the blade when you are hand turning it you back it off just barely and reset the stopper. A piece of paper should be too thick to go between the blade and the upper or lower plates at the front. I try and get all bolts to touch and then back off until I can turn the blade just freely. If it can deflect up or down overly then so can your thicknesses. Getting the blade to show even amounts either side when sharpening is a must and helps to keep the blade in the middle of the gap and therefore the consistency of the split thickness.

8 hours ago, Danne said:

I really like to follow your work on this splitter, and I'm looking forward to updates. Do you have an exploded view/parts list of the gibs and "guides" It would be nice with individual adjustment for the gibs. I'm thinking something like this (If i understand the construction correctly.) This way you could regrind your "guides" individually if needed.

 

gib2.jpg.5f4f60bbce6e5cf77014a28531426d1d.jpggib1.jpg.bd05091552b9d49cb79eecd55396c7b9.jpg

@Danne The idea looks good and your drawing skills are excellent but I have to say the person doing the adjustments would have to know these machines very well. Is it desirable that both blocks should be the same measurement and if not what should it be??? When you cut a piece of leather by hand is it easier to have a broad flat blade and cut in one hit or a angled blade that slices through? How important is it to run the job exactly in the centre? Many job pieces are not square so that changes the pressure points as does the spring pressures left as against right on the feed roller. The variables in that area are a more difficult thing to get adjusted to be suitable and improvements in that area are more important in an engineering sense to me. So far if a piece comes through thick one side and thin the other you either may need to adjust one side tighter or looser or sometimes just move the job further to one side. I do think your idea has merit but perhaps only in the manufacturing stage as elongating the slots would take a fair bit of expense for the little bit gained.

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38 minutes ago, RockyAussie said:

@Danne The idea looks good and your drawing skills are excellent but I have to say the person doing the adjustments would have to know these machines very well. Is it desirable that both blocks should be the same measurement and if not what should it be??? When you cut a piece of leather by hand is it easier to have a broad flat blade and cut in one hit or a angled blade that slices through? How important is it to run the job exactly in the centre? Many job pieces are not square so that changes the pressure points as does the spring pressures left as against right on the feed roller. The variables in that area are a more difficult thing to get adjusted to be suitable and improvements in that area are more important in an engineering sense to me. So far if a piece comes through thick one side and thin the other you either may need to adjust one side tighter or looser or sometimes just move the job further to one side. I do think your idea has merit but perhaps only in the manufacturing stage as elongating the slots would take a fair bit of expense for the little bit gained.

4

My experience with splitting machines is "I have seen a machine one time" :) But I have worked a lot with old machines with high tolerances, and also worked as a CNC-programmer. And I hope to find an old Fortuna splitting machine. Preferably something broken that needs repair.  (I don't need one, since this is my hobby, and I'm looking for a bell knife skiving machine too, which is a lot less complicated and would work as a splitter for my smaller projects (Wallets, watch straps)

So the time it would take me to repair it and "figure out" the machine doesn't matter. When I read your answer to Matt, it's clear you have good knowledge of these machines. Your machine work because you understand HOW it works. 

Of course what you say make sense. why should he have someone to manufacture those "adjustment parts" for him? A better solution would be to ask a shop to regrind his wear guides together with a surface grinder when needed?

If you have a user manual and/or parts list/exploded view of any band knife splitting machine it would be very interesting to look through them if you want to share.

 

Btw, thanks for sharing your knowledge here, I find it very interesting.

 

 

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On 3/7/2019 at 2:54 PM, Danne said:

I really like to follow your work on this splitter, and I'm looking forward to updates. Do you have an exploded view/parts list of the gibs and "guides" It would be nice with individual adjustment for the gibs. I'm thinking something like this (If i understand the construction correctly.) This way you could regrind your "guides" individually if needed.

Tack, Danne I'm glad you're enjoying it. I'm sorry it's such a strung-out saga but I'm spending the odd hour on this machine whenever I can around my other commitments. Right now I don't have the time or resources to properly rebuild this machine (and I don't think it really needs it) so regrinding the the gibs is something I'm avoiding if at all possible and for now.

On 3/7/2019 at 11:55 PM, RockyAussie said:

Mine are inoperative as well and I would not want them operating anyway. A lot of factors come in to how often a blade will need to be sharpened and generally 30 seconds to a minute is fine. Some leathers, even soft leathers will blunt a blade in no time and some you can go for a half hour or more. Generally the split will start to look choppy and sawn and therefore it needs to be sharpened. Except for foam I never have the blades sharpening while splitting and that is rare as well. A new blade can take a half hour to sharpen. Make sure to clean the felt guides well when changing the blade and on the odd occasion as well. I tend to scrape them with a knife and sometimes rough sand them if they need it.The blade should be fine sandpapered to get rid of the rust and sometimes I give the blade a light sand on the run but THAT IS SUPER DANGEROUS and absolute full undivided attention is a must. I should be saying DONT do it. Make sure the blade only barely wants to go backward toward the wear blocks (gibs) and do plenty of quick stop starts after to check that it does. TOO much will create overheating of the blade and wear blocks. New full size grindstones will make sharpening a matter of seconds instead of minutes unless your rubber belt that runs the grindstones is overstretched and worn out. Another reason why auto is no good. With regards to the top plate tightening it would be best to check with the manual. My Comoga has 11 screw downs with 11 screws to set the stop points. Main thing is when the blade is in position when you do the front ones up and they put any pressure on the blade when you are hand turning it you back it off just barely and reset the stopper. A piece of paper should be too thick to go between the blade and the upper or lower plates at the front. I try and get all bolts to touch and then back off until I can turn the blade just freely. If it can deflect up or down overly then so can your thicknesses. Getting the blade to show even amounts either side when sharpening is a must and helps to keep the blade in the middle of the gap and therefore the consistency of the split thickness.

Thanks fella. The top blade on mine is only held in place with two countersunk hex-socket screws. I tightened them according to the manual, which was pleasantly simple. No torque ratings, no fannying about, just tighten but not too much that the plate stops rocking on its springs. Then tighten the locking eccentrics so the guide stops rocking and then tighten their locking screws. Those are the sorts of instructions even I can follow. I checked and I can't get a piece of copy paper between the knife and either guide but can turn the knife over by hand. Excellent engineering.

I've solved the mysteries of the auto sharpening feature. In case someone comes across this thread in the future is also trying to fathom it out, the timer appears to be an interval timer that sends out a ~0.5sec 220v pulse between each interval. I.e. if you set it at 10 minutes it'll close the contacts for half a second, then off for 10 minutes, close the contacts for 0.5sec again, ad infinitum. A simple thing to replicate using off-the-shelf parts if you're so inclined.

The timer does not output to a clutch or an electronic control for the grinding motor as I suspected but to a solenoid directly behind the knife advance wheel. For each pulse it receives it advances the knife one notch. I presume that this brings the knife edge heavily into contact with the emery wheels and the edge is ground back by the same amount. I've hooked it up to a temporary toggle switch inside the electrical panel but I doubt I'll get into the habit of using it for all the reasons Rocky said.

derusted_gibs.jpg.2f3abe510f3c6970926cdb782b0dd225.jpgsolenoid.jpg.2c6d993051c430ec404538e5ece2f606.jpg

On 3/8/2019 at 1:04 AM, Danne said:

My experience with splitting machines is "I have seen a machine one time" :) But I have worked a lot with old machines with high tolerances, and also worked as a CNC-programmer. And I hope to find an old Fortuna splitting machine. Preferably something broken that needs repair.  (I don't need one, since this is my hobby, and I'm looking for a bell knife skiving machine too, which is a lot less complicated and would work as a splitter for my smaller projects (Wallets, watch straps)

So the time it would take me to repair it and "figure out" the machine doesn't matter. When I read your answer to Matt, it's clear you have good knowledge of these machines. Your machine work because you understand HOW it works. 

If you have a user manual and/or parts list/exploded view of any band knife splitting machine it would be very interesting to look through them if you want to share.

This was about the limit of my knowledge of band-knife machines too until I bought this one, though I don't have nearly your engineering skill. I was fortunate enough to be in the right place at the right time and had to jump on the chance, though I spent the money I had budgeted for some cutting dies I sorely needed (and still need). Apart from the labour (which was mostly days off and evenings) I've spent about 5-6% the cost of a new machine on this one.

Bell-knife skivers are real handy machines. You can do some small splitting with one (and I do... or did...) but I've never got it setup so I'm happy with the finish if I have to do multiple passes. The largest roller-foot I have is 40mm and it has sharp edges so if the leather's any wider than that I end up with tram lines. The error is probably between the seat and the machine in my case, but that's my experience.

I've got a few PDF manuals I can send along if you're curious but I don't think there's many/any exploded diagrams. Mostly line drawings of sub-assemblies if their function is not immediately clear.

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