Sorry but Stu has a lot of people overspined by 20-25#s even when entered correctly. Do yourself a favor and get your arrpw selection from him and go at least one spine lower and add 50 grains more weight up front and than you may be close. Shawn

 

Thanks Shawn but I would still like to know what some of the recommendations are and how to enter the appropriate information. It should at least give me a starting point and some tuning will do the rest.

 

Chad, did you download the PDF instructions as well?

 

I emailed Stu about the centreshot issue. This is the answer I got:


The topic of selecting the right arrow while using a plunger has come up already twice this week so it seems to be a popular issue. The benifit of a plunger is its ability to be adjusted infinitely which is also what makes it really difficult to select the correct arrow. For me, I make some basic assumptions which I believe will get one into the middle of the "tunable envelope" and then suggest the plunger be fine tuned from there. That said, here is what I recommend:

Start with the plunger depth set to "0" or -1/16" with a medium spring. This is the resting position of the plunger tip relative to the string/limb centerline. To decide whether to set it at true centercut (0) or -1/16 is basically made depending on the shafts that you have available. If they are on the stiff side then go with the -1/16".
Enter the position chosen in step 1 into the centercut position and input the other bow setup numbers into the DSC as usual to see the bow's required dynamic.
Add 10# to the dynamic shown. This is the "nominal" arrow dynamic that should be matched. I have found this will get you into a good tunable middle ground.
Enter the appropriate arrow inputs as usual to get a good match.
Shoot a few groups of bare and fletched shafts. Compare the point of impact of each. For a right handed shooter, I like the bare shafts to hit slightly low and right of the fletched group. Make sure not to cant while shooting and try to shoot at a distance of at least 20 yards.
If the initial results show weak then move the plunger rest position out while keeping the medium spring.
If stiff, keep the plunger position but go to a softer spring. Re-shoot and then fine tune with plunger position or brace height.

 

I understand the footing now. I did not see the illustration first time I looked at the instructions. Thanks Greysides.

Still confused on this:

Using a BB warf what do I enter for strike plate position (center shot)? I am using a hoyt stick on rest so what do I enter for strike plate thickness under the strike plate position (center shot)?

 

I'm unsure of it as well. I think the relevant line, from above, is this one:

Start with the plunger depth set to "0" or -1/16" with a medium spring. This is the resting position of the plunger tip relative to the string/limb centerline.

To me this means the location of the 'plate' of the stick on rest relative to the centreline of the riser- half the riser by looking past the string from the belly side and note the position of the plate of the rest compared to the string when it's central.

I'm quite prepared to be corrected but that's what I'd start with.

As regards using a plunger, here's what Stu has to say:

The plunger basically acts like a dynamic stike plate and dampens the arrow paradox significantly. In my experience an "average" plunger sping will drive the arrow spine needed up by about 10#. Of course a stiffer spring will cause you to use less, perhaps only an increase of 5#. A softer sping may drive an additional 15#. In any case, a plunger makes tuning very flexible so just follow the specific manufacturers instructions and use an arrow that is ~10# to stiff on the DSC.

 

Using a BB warf what do I enter for strike plate position (center shot)? I am using a hoyt stick on rest so what do I enter for strike plate thickness under the strike plate position (center shot)?

Thanks for the help. I appreciate it.

Chad, I do shoot BB WARFs but I don't have Hoyt rests on them. so I don't know the exact answer to your question. However, here is an explination of how I measure center shot when I am using Stu's calculator.
It is relatively difficult to measure actual center shot at the riser but I find it pretty easy to place an arrow on the string. Hold the bow out in front of you so the string appear to line up with the center of the limbs (this is easier if you place the bow on some type of hanger, rather than holding with your hand). Now with out moving the relative position of your head, sight down the arrow and estimate the distance the arrow point is outside (or inside) of the string. Most peoples arrows are approximately 30 inches long and brace height around 8 inches (you can use your exact measurements) or approximately a 4 to 1 ratio. If the arrow point appears to be 1/2" outside the string. Your strike plate is +1/8" (or 1/4th of 1/2). Remember this measure measurement is for the center of the arrow, so now take 1/2 the diameter of your arrow (approx 1/8") and subtract it. For the above example the actual strike plate position will be 0.
At first it would seem that if the strike plate were at 0 the string would go down the middle of the arrow, but not so. Think about it, if the strike plate is at exact center shot then the center of the arrow is outside center shot approximetely 1/8". and the point being multiplied 4 times will appear 1/2" out.
For those that tune their bows so that the edge of the point is lined up with the string, the numbers are 1/4 (ratio) times 1/8 (one half diameter of arrow), or +1/32.
This method gets me close when using Stu's calculator.
I have found the most mistakes folks enter with Stu's calculator is strike plate positon and draw length. Many people draw alittle further when measuring draw length than they do when actually shooting and not thinking about draw length.
I also think Form Factor is a very under utilized feature of Stu's Calculator. If you have a bow that already shoots very well. just plug the numbers into the Calculator and see what it says, chances are it will be off some. Just play with the Form Factor until it says what you are shooting is right, then use the same Form Factor on future calculations. While most people are not perfect in their form or measurements, they are usually consistent in their mistakes, that is what Form Factor is for.

 

Thanks for all the help guys. This is what I have come up with and it seems to shoot very well although I have not done any bareshaft tuning. I have a 27 inch draw and it comes out to 43#. I was using a 29 inch Beman MFX Classic .600 with a 125 grain field point, 75 grain brass HIT insert (footed .6) with 3 five inch shield feathers LW helical.

Seems to fly very well. It hits hard and flys fairly fast for a 43# recurve. It comes in right at 10.5 grains per pound so it should work well for deer hunting. Does this setup sound right to you guys?

I look forward to shooting this through a chrono. I am guessing it shoots in the low to mid 170's which is not too bad in my opinion. My BB warf shoots very quiet with TT Blackmax short limb (wood/glass), 12 stand D-97 string with beaver puff silencers and truglo stab. I love the added mass and weight of a warf riser.

 

Ttt

 

ttt

 

Chad, you should email Stu directly. He usually answers reasonably promptly. A real gentleman. His email address is on the dowmload site.