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kwilliams
09-23-2009, 07:27 PM
I'm new to archery this year and picked up a Scepter 3 elite, Nitrous X cams in shoot-through configuration.

According to the sticker on my bow, the max draw weight is supposedly 50 pounds, but the archery shop I went to checked it and it was at 53 pounds. The bolts are nowhere near all the way in, and in fact may be out almost as far as they should safely go (according to a shop tech).

The original draw length was 27" but it's now at 30", the maximum length for the A cam on it.

I measured the brace height at 8" from the string to the grip, which appears a little short (should be 8-3/8" according to specs). Measuring from a string stretched tightly axle-to-axle I get a brace height of 7".

I checked the tiller, and it appears virtually identical top and bottom, within my measuring error limits.

Now the curious part, which may be by design or not. The distance along my shooting string from the nock point to the bottom cam is 3-1/4" longer than the distance from the nock point to the top cam.

Is it by design to have the nock point be that dramatically higher? As a completely uninformed archer, I would have expected the nock point to be somewhere near the center of the string, not 3 inches above the center point.

With my brace height being a little shorter than spec and my draw weight higher than is supposed to be possible with the bolts tightened all the way, is there a problem with my bow that would merit having it carefully examined by a Martin tech?

Opinions? Advice? I'm completely green to all this stuff, so any advice would be extremely helpful!

Thanks!

bfisher
09-23-2009, 08:33 PM
Let me answer a couple things and I'm going to bed.

Nocking point. It is not 3+ inches above square. The rest mounts that high, too so the nocking point has to be roughly perpendicular to where the rest mounts. Measure to the rest mounting holes and you find they are approximately the same height as the nocking point. The vertical center of the bow is approximately through the arrow shelf, but this means nothing anyway. Don't worry about it.

To check the weight range of the limb we need to know what the limb deflection is. This is a number/letter written at the base of the limbs. It'll say something like 5H or some other number.

You can check the tech info section on Martin's website and it might tell you what limbs give what weight ranges.

OK, before I fall dead in my tracks there's a guy on these forums, goes my the name Scepterman30. He can answer almost any question you have about a Scepter.

kwilliams
09-24-2009, 04:11 PM
It looks like I have 4H limbs on my bow. With an A cam at 30 inches draw length, what should the weight range be?

I'm considering switching to B cams if I can locate some. Anyone know where I can find some Nitrous X B cam modules?

bfisher
09-24-2009, 06:12 PM
From what I can get from the Tech Info your bow should be a 40-55. Might even go to 58#. The cams are good from 27" to 30" draw.

With B cams the weight range drops to 35-50.

By the way, I prefer B cams over A cams. Better overall performance. Now, all you gotta do is find some.

Robert58
09-24-2009, 08:22 PM
Are you sure you have Elite recurve limbs on the bow. This is the webpage for the 2004 Scepter III. Look and see if your bows limbs look like the ones pictured. There is no way you could have 4H recurve Elite limbs at that poundage if you have the correct string and cables.

http://martinarchery.com/bows2004/sce.htm

I set up my Scepter II using the Scepter III spec's. Limb angles are the same on both bows. I have 6L Elite limbs with Nitrous A cams and my bow max's out at just under 60 lbs. You should have 44 3/4" cables and a 55 1/2" shooting string. ATA 43 3/8" to 43 1/2" with 8 3/8 bracehight.

Martin says not to shoot their bows with the limb bolts backed out more than 5 turns. (45 to 60 lbs. @ 3 lbs. per turn)

If your bow is drawing 53 lbs. with the limb bolts backed out almost 5 turns something is seriously wrong. The previous owner has changed the string and cable lenghts. You need to find a Martin Dealer that knows about Nitrous cams and have him completely check everything out.

Robert

kwilliams
09-25-2009, 09:46 AM
My bow looks exactly like the 2004 Scepter III Elite on the Martin 2004 website (if you click the link to see bigger images), including the Procat red color.

I do indeed have A cams, with the standard modules, in X configuration. I have Elite limbs, size 4H.

So, if my bow's draw weight is off, what's the most likely culprit- string or cables? What would be the problems introduced by such errors?

By the way, thanks very much for the advice - good advice is hard to come by, especially where I live!

Robert58
09-25-2009, 10:12 AM
Look at this Link and see if your cams are rotated correctly.

http://www.archerytalk.com/vb/showthread.php?t=104090

I am not a Pro when it comes to setting up a compound. I have searched this site and Archery Talk enough to finally get my bow set up where it shoots the most forgiving for me. I don't know if you bought the bow from the original owner or not. People change so many things to get their bow to perform the way they want that it is hard to tell exactly what you have got.

In the link above the first picture is the correct cam position. If you have a portable bow press I would take the string and cables off and measure them to see if they are correct. Then resinstall them going by the pictures in the link I gave you in the previous post.

Hopfully someone with alot more knowledge than me will post a reply over the weekend or Monday.

Robert

Montalaar
09-25-2009, 11:08 AM
I recommend you to use the first picture in Roberts link as a point to start. If you cannot see this pictures i can measure the distance from string to cam at the end of the groove.

Picture two is also possible but it preloads the cam and the limbs a tad more. This will result in a shorter draw length with a higher poundage.

kwilliams
09-25-2009, 01:14 PM
My cams are positioned very similar to the first photo.

I'm going to attempt to measure my string and measure my cables to see what's up.

Would it be advisable to tighten my bolts all the way, then back them out exactly 5 turns and get a measurement of the peak draw weight?

Obviously, if the cables and string aren't the right lengths then I'm hosed anyway - get to buy new ones.

kwilliams
09-25-2009, 04:31 PM
Ok, so the axle to axle distance is about 1/2" too long if you go by the Martin specs for my Scepter III. Having difficulty getting a good measurement on my cables and string though - I don't have a bow press.

I would have expected the axle-to-axle length being too long would have an impact on the draw weight, but I would have thought the draw weight would be reduced as a result.

I'm going to visit the archery shop tomorrow to see what the draw weight on this thing really is.

Robert58
09-25-2009, 07:06 PM
One of the best investments you will ever make, is to buy one of those portable cable bow presses. Then you wont need to go to the Bow Shop every time you want to install a different peep or change strings and cables.

Robert

kwilliams
09-26-2009, 09:18 AM
Looks like I'm all set. The cables and string look like they're about the right length. The brace height is still 8", but the draw weight is now 44 pounds with the 4H limbs and A cams, with the bolts 3 turns out from all the way in. That means my bow, with 4H limbs will peak out at around 50 pounds with the bolts all the way in, right?

The problem was with the previous shop's scale - it wasn't reading right.

Robert58
09-26-2009, 10:52 AM
Glad to hear everything is alright. I knew there was no way your bow could be pulling 53 lbs. with the limb bolts backed out that far.

Robert

RogerSr
09-26-2009, 11:18 AM
Looks like I'm all set. The cables and string look like they're about the right length. The brace height is still 8", but the draw weight is now 44 pounds with the 4H limbs and A cams, with the bolts 3 turns out from all the way in. That means my bow, with 4H limbs will peak out at around 50 pounds with the bolts all the way in, right?

The problem was with the previous shop's scale - it wasn't reading right.

On Martin bow's for every full turn of the limb bolt it is 3lbs of weight, so if you are 3 turns out at 44lbs add 9lbs to that, and they will max out at about 53lbs, and that is what i get from most of my 50lbs bow's.