The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: kiwipom on 18.01. 2011 07:57

Title: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 18.01. 2011 07:57
Hi guys, I have a Triumph 4 spring clutch to fit to my A10, the alignment is out by 5mm. I have investigated having the taper recut to make it line up and have been told it can be done, I would be interested to know if any anyone on the forum has done this and also are there any problems that might arise once it has been done, cheers, bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: pato08 on 18.01. 2011 08:11
Hi KiwiPom

There has been some discussion about Triumph & Suzuki clutch's on the forum. Try typing in "Clutch" in the search engine in the right hand corner of the Home Page.   *smile*

Pato
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: bsa-bill on 18.01. 2011 13:49
Hi KiwiPom
Not sure if I've got this right so forgive me if I'm barking up the wrong tree

If you mean the clutch wheel is 5mm out of alignment with the engine sprocket then you need to shift the engine sprocket, shims are used for this so maybe you need to add or remove shims to get alignment correct.
If you need to remove shims and there are none to remove I would look at removing metal from the spacer or somewhere else at the engine end.

Now I'm probably reading your mail wrong - right
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: chaterlea25 on 18.01. 2011 13:52
Hi kiwipom,
This is another of the problems with either retrofitting a 4 spring clutch or building a bike from parts
I was active on this topic previoulsy,
Points to note:
Make sure you do not have one of the clutch adaptors with the scroll cut the wrong way  *eek*
1 )The scroll should engage a fair bit into the sliding plate
2) The inner primary case should not be strained, there should be a spacer and 2 gaskets between it and the  crankcase and a spacer or washers between it and the frame mounting at the rear
3) "Normally" a heavy duty chain cannot be fitted, as they foul the inner case!
4) There are 2 different sleeves that fit on the crankshaft with different thickness shoulders
5) There are different shaft adaptors for twins and single cyl models, the patten ones can be bored reasonably easily
the originals are much much tougher and I would think have to be ground internally, this makes it harder to match the taper, which Must be a perfect fit on the shaft

HTH
John O R
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 18.01. 2011 20:29
hi guys, thanks for the feedback but am still confused. if the engine sprocket was moved 5mm/3/16" would that not impact on the engine cush operation? i will take a couple of pics and post later,cheers, bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: BSA_54A10 on 18.01. 2011 21:14
Yes it will make it a little tighter to compensate for 60 years of wear and loss of temper in the spring.
Fit the spacer and the entire cush drive minus the spring.
If the 2 sides can slide over each other is all is fine.
If not yon can remove some meat from the back of the inner.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 19.01. 2011 04:15
hi guys, i hear what you are saying, a 5mm spacer behind the sprocket will only leave 3mm for the sprocket to bear on, the best that i think that i could do would be to space the sproket carrier out 2.5mm on the crank shaft and 2.5mm behind the sprocket, what do you think? do you not like the idea of recutting the taper to move it 5mm or has it not been done before what would be the out come? thanks for all the input i have incuded a few pics,cheers, bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: trevinoz on 19.01. 2011 06:14
Kiwipom,
              Have you actually got the spacer that fits between the bearing and the cush drive?
Trev.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 19.01. 2011 06:22
hi trev, no, it was originaly fitted with a 6 spring unit so had no spacers,cheers,
bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: bsa-bill on 19.01. 2011 09:20
Well spotted Trev, I had similar thought
Bob - spacer needs to be there with or without six spring clutch, it's got an internal taper on one side
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: chaterlea25 on 19.01. 2011 12:31
HI Bob and All,
Another thing is that you have a 4 lobe cush drive assembly???
I have only seen this fitted to early plunger framed B models??? Open to correction here?????
I am now of the opinion that you do not have the correct cush drive inner sleeve, As I said in my previous reply there are 2 different thickness shoulders on the inside,
your crank sprocket looks too close to the crankcase???
Do you have crankshaft spacer 67-1138 fitted?
Any minor shimming required should be between this part and the cush drive sleeve 42-0069?? there is a separate pt no. for the other type

The clutch adaptor looks correctly placed, if it was any further inboard the taper would appear at the front

BSA_54A10 is not correct in saying that the cush drive should be able to slip!!! It should lock solidly before the cams ride over each other,
If the cush drive can ride over and does when the engine is under load damage to the bottom end will quickly happen
This is why it is ESSENTIAL to keep the cush drive nut FULLY TIGHT  *ex* *ex*

HTH
JOhn O R
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: trevinoz on 19.01. 2011 19:55
John,
             I think that the very first swinging arm A10s had a four lobe cush drive. Also the B series.
Trev.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 20.01. 2011 06:11
Good work guys, found some info and so am posting some pics of it. Trev/bsa-bill you were exactly right, thanks for pointing me in the right direction, the info clearly shows the spacer and shim as you noted. All you guys know your stuff and is great to be able to tap into it from the other side of the world, certainly saved me from floundering in the dark. It seems that the plunger and early swinging arm machines had the four lobe set up and later changed to the two lobe system, i am going to try to source a complete two lobe set up so won`t have to think about moving that taper although i think it needs a clean up as it is not in top condition. I had wondered why the large spacer behind the timing cover was never there probably left out to compensate for no cush spacer, there are a few things that i could show you that would make you wonder about one or more of the previous owners,anyway guys once again thanks for the help it was great,cheers,
Bob 
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: A10Boy on 20.01. 2011 13:51
Dont forget the oil seal, it doesn't appear to be shown in the diagram [unless I need another visit to specsavers]. The cush spacer pushes onto the crankshaft with the internal chamfer towards the crank. The oil seal taps into the crankcase and the lip runs on the cush spacer. Early semi unit engines didnt have this seal, but I'm sure all pre unit models did.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 20.01. 2011 19:34
hi guys, yes A10 boy the seal is there thanks for the concern i think that i am on the right track now this site is great, my biggist worry at the moment are the earthquakes that we are having here, the first thing that i do after a shock is check that the bike is still upright, have put a couple of tie-downs on it to make sure, cheers
Bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: trevinoz on 20.01. 2011 20:33
Bob,
            Nothing that some previous butchers do surprises me now.
Trev.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: Mosin on 23.01. 2011 23:56
Hi Kiwipom,

You might want to take a look at this thread: http://www.a7a10.net/forum/index.php/topic,2689.40.html (http://www.a7a10.net/forum/index.php/topic,2689.40.html)

I had almost exactly the same problem when fitting a four spring clutch. Go straight to the last couple of posts for the solution!

Good Luck

Simon
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 24.01. 2011 09:41
hi simon, thanks for your input and i have looked at the similar problem that you had, your solution will not fix my problem strange though it may seem as you will see from the pics my bearing has an 11.5mm built in to take the place of a spacer. i need to find 4-5mm from somewhere, apparently the spacers are 10-12mm wide but i cannot source one from here so may have to have one made. if i leave the clutch in the position that it is in at the moment that means that i will have to move the engine sproket out 4-5mm, to do that i believe that i will have to have a spacer 10mm wide so as to engage the oil seal and then take 5mm off of the origonal bearing piece that will put the middle of the sprockets about 18-20mm out from the primary casing, any other solutions would be welcome,cheers,
Bob.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: Brian on 24.01. 2011 10:14
Bob looking at your bottom photo (clutch centre) it looks like the clutch centre is the problem. It should sit further into the sliding plate than it does. You can see quite a lot of the scroll, most of it should be in the sliding plate bush. Do you have any other centres to try or get some measurements from someone, maybe someone on the forum has one apart at the moment and could measure how much thread on the mainshaft is sticking out.

If you start spacing the whole assembly out you may run into clearance problems with the outer cover.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: bsa-bill on 24.01. 2011 11:33
Interesting Bob - looks like a fair bit of thread out through the centre, maybe not as much in http://www.a7a10.net/forum/index.php?action=dlattach;topic=2689.0;attach=7121;image (http://www.a7a10.net/forum/index.php?action=dlattach;topic=2689.0;attach=7121;image) but not far off, worth giving yours a measure as in the photo.
Your primary case looks to be where it should be also.
Possibilities left are
Gearbox not where it should be (engine plate?) unlikely and you can punch me for suggesting it, if you ever meet me
Wrong mainshaft - unlikely but given the funny set at the engine end !!
Key holding the centre from tightening up onto the taper
Wrong centre - could be a duff one

Keep us posted
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: jjbsa on 24.01. 2011 11:50
What an interesting thread is this!  I have been to somewhere quite close to this place myself very recently.  BTW I call the thing that fits on the taper the clutch sleeve and the inner part of the clutch that fits on it I call the clutch centre.

I feel that Brian (reply number 18) has hit the nail on the head with your problem kiwipom.  The photos do suggest that the clutch sleeve is sitting too far out.

My problem initially was that when the clutch centre was tightened down then the clutch chain wheel would not spin freely.  This turned out to be because the clutch sleeve had been driven up the taper when the clutch centre nut was tightened and it had stretched where the internal keyway is cut into it.  This meant that the race the rollers run on had become oval, about half a thou oversize at 90° to the keyway ( and explained why the rollers didn?t want to go in).  The rollers were pinching on this part of the clutch centre.  

Also, because the sleeve was too far up the taper, the chain wheel was inboard of the engine sprocket (a situation I had never seen before).  I ended up deciding to buy a new sleeve, which also ended up giving me good sprocket-chain wheel alignment.  

An interesting difference that I noticed between the new and the old sleeves was that the clutch centre nut tightened up against the clutch centre when the new clutch sleeve was being used, but with the old clutch sleeve the nut tightened up instead against the clutch sleeve, with the clutch centre remaining about a half millimetre below the sleeve, which meant that the clutch centre was free to chafe around (I hope that all makes sense[pls also note I've edited this after my initial post as I'd used the word "centre" in a few places where I meant to say "sleeve"]!).  I presume that the new clutch sleeve has things tightening up the right way?
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: trevinoz on 24.01. 2011 20:42
JJ,
         The washer under the nut has a recess which ensures that the centre is tight regardless of the sleeve height.
Trev.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: bsa-bill on 24.01. 2011 21:05
Quote
An interesting difference that I noticed between the new and the old centres was that the clutch centre nut tightened up against the clutch centre when the new clutch sleeve was being used, but with the old clutch sleeve the nut tightened up instead against the clutch sleeve, with the clutch centre remaining about a half millimetre below the sleeve, which meant that the clutch centre was free to chafe around (I hope that all makes sense!).

JJ - this is even more interesting, I had exactly that happen to me, the old centre was the cush type, I had all sorts of configuration of nuts and washers but it still always had a just discernible bit of play, I bought a new (nos) non cush centre and the problem was cured.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: chaterlea25 on 24.01. 2011 23:35
Hi Bob and All,
From your photos, I'm almost certain that the cush assembly you have is the Wrong one *ex*
The inner sleeve looks to be from an earlier semi unit engine????
As pointed out it also looks as if the clutch adaptor is not sitting in far enough????
Do you have the spacer and 2 gaskets fitted between the crank and primary cases, these make up near enough 1/8in.
I can see from the pics that no spacer is fitted between the lower rear mount and frame??? usually theres need for some washer or spacer here?? DO not force the primary outwards by omitting any spacers needed

I can take some photos tomorrow of different centres on a mainshaft, must set a reminder to myself *ex*

HTH
John O R
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 25.01. 2011 00:03
hi guys thanks for all the input. what i would really like is the distance that the primary chain is away from the case then i should be able to work on the bit that is not right, it seems to me that the engine sprocket is too close to the case so if anyone could supply centre of chain to back of case measurment i would be gratefull. I am sure that some of the parts must be wrong but they came with the bike so i am not sure which ones, as a matter of interest i have one quite thick gasget for the primary case/crank case (fitted) ,that was in the kit so don`t know about two, can`t see the point of two anyway but if i have to i will make one, thanks guys
Bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 25.01. 2011 03:37
hi guys me again, just a couple of pics of the clutch centre with measurments,cheers
Bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: BSA_54A10 on 25.01. 2011 09:35
Quote
What an interesting thread is this!  I have been to somewhere quite close to this place myself very recently.  BTW I call the thing that fits on the taper the clutch sleeve and the inner part of the clutch that fits on it I call the clutch centre.
I feel that Brian (reply number 18) has hit the nail on the head with your problem kiwipom.  The photos do suggest that the clutch sleeve is sitting too far out.

BSA used the same tapper on every box ( that had one ) it ever made and these include ones for cars, stationary engines ( reduction & right angle drive boxes), invalid chairs , farm equipment ,,,, the list goes on.
They all look very similar but they differ in the size of the hole.
As it is a tapper, the bigger the hole, the closer it sits to the gear box.
AFAIK there are 4 commonly used on bikes, 2 long ( for big clutches ) & 2 short ( for small clutches ), one with a big hole for tin primaries and one with a slightly smaller hole for alloy primaries. The difference in hole size has the clutch sitting between 1/2" & 1/4" out of alignment.
Oddly enough there only seems to be big & small listed in the parts books but I have a box  of them dating from the early days when I did not know any better and shoved all of the sleeves from all of the clutchs together in an oily box for storeage.
It took weeks to find the correct combination of sleeve & center to replace the single spring clutch for a 6 spring on the M20
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: Mosin on 25.01. 2011 20:32
hi guys thanks for all the input. what i would really like is the distance that the primary chain is away from the case then i should be able to work on the bit that is not right, it seems to me that the engine sprocket is too close to the case so if anyone could supply centre of chain to back of case measurment i would be gratefull. I am sure that some of the parts must be wrong but they came with the bike so i am not sure which ones, as a matter of interest i have one quite thick gasget for the primary case/crank case (fitted) ,that was in the kit so don`t know about two, can`t see the point of two anyway but if i have to i will make one, thanks guys
Bob

A lot of my problems stemmed from measuring the distance things were from the Primary Inner case and assuming that this was a fixed point. This can be extremely misleading as it's easy for the case to become slightly twisted one way or the other and creating the optical illusion that other things are either in line or out of alignment. I know it's a hassle, but I would really recommend removing the inner case altogether so it can't act as a confusing distraction. You can then take the time to get everything nicely lined up with all your spacers and shims and what-not in the right places, your sprocket and clutch aligned and your chain running smoothly. Once you are totally happy with it, it's not too difficult job to whip the whole lot off again, replace the case and then put it all back together.

As regards the two gaskets, these sit one either side of a quite thick spacer (I don't have the part number to hand sorry) between the primary inner and the crankcase, and the three together serve an essential job in ensuring the inner case lines up correctly. (A washer or two may be needed at the other end as has already been mentioned just to keep things true). Apart from anything else, without the spacer in place there is the very real danger that the three large bolts at the front end of the primary outer case will reach too far through the crankcase and actually foul the crank itself!

Good Luck!

Simon
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: chaterlea25 on 25.01. 2011 21:34
HI Bob,
Here are a couple of pics of the location of 3 adaptors on the same BSA shaft
The first one is an original BSA part,
second is one of the "Crap" pattern ones with the scroll going the wrong way
third is a NOS 6 spring adaptor
The total length of the adaptors varies a bit, original 38.75mm, pattern 38mm and the 6 spring 37 mm
they all sit within a reasonably tight tolerance on the shaft as seen in the pics
I know Simon has gone through all this when he rebuilt his bike, his advice and description are good

You definitely need the correct cush drive and sprocket  assembly to sort your problems

Regards
John O R
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 13.02. 2011 02:06
Hi guys, back on the four spring clutch again. Received new bits from S.R.M. which included the new clutch centre, the only difference between the one I had and the new one is that S.R.Ms. has a thrust washer but in any case only moved the clutch 1mm closer to the primary case.  I managed to procure a two lobe Cush drive set up for the engine and as you can see in the pic the Cush sleeve has no built in spacer like the 4 lobe, this is what I wanted so I would just get a spacer made to suit the clutch set up, my measurements tell me that I need a spacer that is 13.7mm wide.
O.k. you will note in my second pic that I have the old original Bsa 6 spring clutch (munted) the S.R.M.centre (middle) and the clutch centre that I am replacing (left) my question  is this which way does the oil scroll have to be? To my way of looking at it the S.R.M. centre will scroll the oil outwards where the other two will scroll the oil towards the clutch, I can`t imagine that the Bsa one was the wrong way around.  I am going to e-mail S.R.M. for their opinion, cheers
Bob 
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 13.02. 2011 02:18
hi guys, just comparing the centre that John shows in his pic to my ones, his scroll goes the opposite way to S.R.Ms what do you think? cheers
Bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: MG on 13.02. 2011 08:06
Yes, clearly a wrong one. It will pump the oil OUT of the chaincase, like a spiral conveyor. Just turn it by hand to see, direction CCW when looking at it from the splined side.

Better to send it back and get another one. I seem to remember that SRM has removed the centres from their online shop, saying that the taper wouldn't match the shaft exactly, so you got good chances to have problems there as well if it came from that faulty batch.

Title: Re: Triumph 4 spring clutch (non cush type)
Post by: alanp on 13.02. 2011 11:27
Yes, clearly a wrong one. It will pump the oil OUT of the chaincase, like a spiral conveyor. Just turn it by hand to see, direction CCW when looking at it from the splined side.

Better to send it back and get another one. I seem to remember that SRM has removed the centres from their online shop, saying that the taper wouldn't match the shaft exactly, so you got good chances to have problems there as well if it came from that faulty batch.

Yep, this wrong scroll situation gets me very upset - I bought a very expensive Tony Hayward belt drive for my A10 and it included an adaptor made for Tony by SRM with the wrong scroll, just like the photo. When I complained, SRM said it didn't really matter and supplied their 'Fix' which was a felt ring to fit between the rotating back of the adaptor and the stationary sealing plate on the face of the primary chaincase. Goodness knows how long that would last. Obviously because it would have cost them a lot of money to make another batch!! It's sad to see that they are still selling the adaptors with the wrong scroll even though they know they are wrong.
My expensive belt drive kit is still gathering dust on my garage floor while Tony says he doesn't know much about A10s and is relying on SRM who does!
It has taken the enjoyment out of my rebuild to be treated like this. If it gets replaced with a correct scroll one please let me know.
Alan 
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: chaterlea25 on 13.02. 2011 23:10
Hi Bob, Alan and All,
If you  look at the middle pic of my last post you can see that I said this one had the scroll going the wrong way
I got that one from Cake St Classics cheaply as he knew they were wrong
To the best of my knowledge these were supplied through Wassels (open to correction here)
(I also had problems with pattern 6 spring sleeves as they were undersize where the bearing race fits *eek*)

I have modified the "wrong " ones by machining off the scroll , Then I unrivit the centre from the sliding plate
Turn up a new one and rivit back in, but this time I incorporate a groove for a "Quad ring"
This is an X profile "O" ring used in Hydaulics
I use a cork gasket instead of the felt ring and wind up with a 100% seal  *smile*
The only thing is that it is then necessary to provide a breather for the primary case,
I have attached a brake pipe with banjo fitting to the filler plug on mu own SR but there are several ways of providing a breather hole

HTH
John O R
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 13.02. 2011 23:44
hi guys/John, thanks for the info, yes the only difference is that 55 quid+8quid post is not a cheap item. I have e-mailed S.R.M. and asked nicely for their advice but unless they offer to send a new one i will be making my own suggestions. I can`t understand how this problem can happen, no scroll at all would be better that one that works opposite to intended action. I thought that turning off the scroll and making a better seal that the origonal would be the way to go but i dont do my own machining and after paying good money i shouldn,t have to.Your fix sounds good and what you seem to be saying is that the primary case breath`s through that sliding seal so when a 100% seal is in place another breather would have to be made.
As a matter of interest being an expat Brit, we often answer the native kiwis who complain about british made goods that they say is useless with the saying of, yes we know it`s useless that`s why we sent it to N.Z. It seams we may have been telling the truth all along, cheers
Bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: chaterlea25 on 14.02. 2011 22:03
Hi Bob,
Yes, When the sliding plate side is "sealed" pressure builds up as the cases heat,
I have the mod done on my own SR for nearly 10 years no probs *smile*

HTH
John O R     (Southern Ireland)
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 15.02. 2011 18:45
hi guys, i sent an e-mail to S.R.M. about the faulty clutch centre asking them to replace it with a good one here is the reply,cheers, Bob.

The BSA A10 clutch centre whether with or without a scroll will not seal, the centres BSA`s and ours are 1.500 inch diameter, the hole in the sliding plates are 1.550 and can vary a fair bit above this.
No way does this constitute a "sealing" fit and will pass oil regardless of what shaft is fitted. Our centres are sent out with a felt washer to sandwich between the flange at the back and the sliding plate, this is the best way to seal up this area without totally redesigning the sliding plate system.
 
We have used our centres on bikes here with the felt seal with great success, please try , if you are not satisfied with the result, please return the item for a refund.
 
Regards Gary
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: wilko on 15.02. 2011 20:04
They do have a good point.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: kiwipom on 16.02. 2011 03:36
hi guys, so why do they put the scroll on backwards?
Bob
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: Hubie on 16.02. 2011 07:33
I had some trouble making this area oil tight as well.  In the end, I took the primary apart, had the scroll/worm/thread bit machined off the clutch centre and took the sliding plate and centre to a bearing place and they found an oil seal to suit.  I pressed this into the sliding plate and the problem is now solved.

Cheers,
Dave.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: alanp on 16.02. 2011 11:53
hi guys, so why do they put the scroll on backwards?
Bob
It's because when they have the part in a lathe with the top of the part rotating towards you as usual, it is easy to run the tool from right to left. It saves them having a more difficult job running the tool from left to right starting close to the flange. Laziness.
I see that SRM came up with the same excuse I got which is complete bulls**t.
Alan 
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: alanp on 21.03. 2011 11:41
Attached are photos of the incorrectly threaded and my corrected clutch adapter. It now has a LH thread. The machinist used a diamond tipped tool to remove the hardened surface and fitted an interference fit stainless sleeve with the LH thread.
Title: Re: Triumph 4 spring clutch (non cush type)
Post by: MG on 21.03. 2011 12:41
 *clap*
Good man!

If it was laziness that made them cut it the wrong way 'round, why did they bother to cut one at all? Better to have no grooves than incorrect ones I reckon. Some people....