Been sailing my Mach One 6.2 for over a season, and love it but always struggled to get the cams to rotate. Kills gybe exits every time. Rigged on recommended Severne 430 at about 2 cm under spec downhaul (at full spec the leech seems too flappy). I'm pretty much on spec for outhaul depending on conditions.
On a gybe exit I have to give an almighty snap to pop them around. Only really works when there's heaps of wind, and is very tiring late session. If that doesn't work, I try to really get it loaded downwind to pop, but most often end up pushing it by hand.
I've taken out all spacers, and tried more/less outhaul/downhaul but can't crack it. I'd prefer a fuller belly, but the cam issue makes me down/out haul harder than I want. I'm resigning myself that it's just how race sails can be, but eager to hear if anyone else out there has similar experiences or advice for me.
Trousers save the heartache and move it on . I've had new gear and done just that in the past when after 3 sails you just know it's not for you.
rotation is a tricky thing, have you tried it with spec downhaul? 2cm is a lot. Some sails are designed to have a very floppy leach, you may find it both sails and rotates better, but there again you may not.
I've improved sail rotation on some of my koncepts by reducing the cam spacers a mm or so. Not much difference but decreases the luff tube friction a fair bit, if they've been very tight.
For max low wind pressure draft, the cams are set up tight. You can't grab any slack in the luff tube, but I prefer easy rotation, so I can grab about a mm of slack in the luff tube.
If the Severne mast you are using is not an Apex it can cause rotation problems even without spacers. The diameter of the Apex is smaller.
My 6.2 M1 rotates perfectly with the 430 ARC mast. I upgraded my 400 and 430 when I went to the R8s and the smaller sizes pretty much demanded the newer mast shape and diameter. At the time, my R8 7.8 rigged perfectly on the older 460 (Severne 75%) mast so there was no need to change.
I have recently purchased the 7.8 M1 and an 8.6 M2. Both of those I'm rigging on the older Severne 75% mast (460 & 490) and I'm noting a very poor rotation. Haven't used them properly yet (only rigged on the grass) and have removed all spacers. Really hoping that I don't need to purchase new masts but I guess if it's the difference between rotation or none, it will be an easy decision. I bet Mrs Polony will be wrapped!!!! 
Take out the metal plates on the end of the battens too (they sit between spacers & end of batten in luff).
Select to expand quoteTony Wills said..
My 6.2 M1 rotates perfectly with the 430 ARC mast. I upgraded my 400 and 430 when I went to the R8s and the smaller sizes pretty much demanded the newer mast shape and diameter. At the time, my R8 7.8 rigged perfectly on the older 460 (Severne 75%) mast so there was no need to change.
I have recently purchased the 7.8 M1 and an 8.6 M2. Both of those I'm rigging on the older Severne 75% mast (460 & 490) and I'm noting a very poor rotation. Haven't used them properly yet (only rigged on the grass) and have removed all spacers. Really hoping that I don't need to purchase new masts but I guess if it's the difference between rotation or none, it will be an easy decision. I bet Mrs Polony will be wrapped!!!!
I concur. Im running a 7.8 M2 on an older 75% Severne Mast and the rotation on the middle cam is not great, even with the packers removed. It is workable but certainly doesn't rotate as easily as my M1's 7.0 & 6.2 on the recommend RDM. Their awesome, but the 7.8 on the older (4 yr old) mast takes quite a bit of pump to turn her pulling out of a jibe.
Select to expand quoteKazza said..
Take out the metal plates on the end of the battens too (they sit between spacers & end of batten in luff).
Thanks buddy! I wasn't sure whether removing the metal plate would damage the sail at the cam / batten pocket. Will give that a go if the rotation is ordinary.
Mach 1s won't rotate well on the older thicker masts, put a Apex mast in and downhaul to spec. Less downhaul loads the cams up onto the mast, also try running negative 2 on outhaul to get more power if you need it.
Apex100 430/ Downhaul to spec/ Outhaul minus 2 from spec.
Okay, I'll try taking the metal bits out, otherwise it seems I'm in the market for an new mast, cause yes - I do have the previous gen mast.
And I'll revisit full downhaul again, thanks for the replies, most helpful!
Select to expand quoteKazza said..
Take out the metal plates on the end of the battens too (they sit between spacers & end of batten in luff).
Have the same problem with 7.0 M1. (460 90% severne SDM, a model just before the arc). I had thought of doing that, but what about the wear that the these are protecting against? Have you noticed any yet? I had though of taking a dremel to back of the cam and making it shorter. Though more downhaul has so far has made the sail useable. I have a spare somewhere.
A bit disappointing when you purchase all the "correct" gear and it doesn't work properly!
Used the sails (without the metal plates) at GI this year and they had a lot of rotations and don't seem to have any wear & tear.
Select to expand quoteTrousers said..
Been sailing my Mach One 6.2 for over a season, and love it but always struggled to get the cams to rotate. Kills gybe exits every time. Rigged on recommended Severne 430 at about 2 cm under spec downhaul (at full spec the leech seems too flappy). I'm pretty much on spec for outhaul depending on conditions.
On a gybe exit I have to give an almighty snap to pop them around. Only really works when there's heaps of wind, and is very tiring late session. If that doesn't work, I try to really get it loaded downwind to pop, but most often end up pushing it by hand.
I've taken out all spacers, and tried more/less outhaul/downhaul but can't crack it. I'd prefer a fuller belly, but the cam issue makes me down/out haul harder than I want. I'm resigning myself that it's just how race sails can be, but eager to hear if anyone else out there has similar experiences or advice for me.
I've noticed my M2 ODs are very downhaul specific. I need to downhaul to specs,right down or the rotation is lousy. It does make them floppy all the way to the boom .
My Mach 2 's rotate better than my Overdrives.
I have the 'newer apex and Apex pro masts.2017.
With the overdrives when your using the correct mast and setting the extension as it says on the sail are you downhauling till the pulleys are almost touching? I find about a 2inch gap between pulleys works best, the very bottom of the sail lines up with the bottom of the extension and if you took I line from the center of the sails pulleys it would line up with the 3rd hole up the extension. Almost as if you could drop the extension down a couple more holes
I have an 6.2 Overdrive M2 and 430 Arc mast. I removed the spacers but left the metal pieces on. I sanded the 2 bottom cams shorter by a few mil and dremeled small notches in the centre. I went for a foil today in light 13 knots and the cams rotated a lot better. In stronger winds the rotation shouldnt be a problem. The profile of the sail is still quite deep which is a plus.
So today I rigged the M2 8.6 on the 75% Severne 490 mast. I removed the stainless plates between the cam and the batten. DH was set to spec and it rotated perfectly. Will keep an eye out for any any undue wear...
Select to expand quoteTony Wills said..
So today I rigged the M2 8.6 on the 75% Severne 490 mast. I removed the stainless plates between the cam and the batten. DH was set to spec and it rotated perfectly. Will keep an eye out for any any undue wear...
Are they like the loft sails metallic cam interface? if so I would leave them on, some of my previous race sails didn't have these and the inner sleeve/luff material basically got destroyed by the cam
Yeah they are pretty much the same. Thanks for the info.
Will put them back on and see how it goes with just the cam interface (no spacers). The last thing I want to do is damage a brand new sail...
