# Tuning..."The Thunder Child"



## sidekick (Feb 10, 2006)

I don't question your results, but my 44#, 56" TC needs 29" GT 1535's with standard inserts with 145 gr. points to work. I've found my GT 3555's 30" with 50 grain inserts and 175 grain points to be stiff. I was trying to shoot 3555's out of the TC until Jim told me I needed to be shooting 1535's, and the big man was right. I agree on the quiet THOOMP.


----------



## JINKSTER (Mar 19, 2011)

*"IN WORKING WITH OTHER ARROWS":*

Today I was made very much aware of why there's been many times I'd read of other archers getting very unexpected results regarding the 75gr H.I.T. inserts in their 9/32ndths Easton/Beman Shafting as I began attempting to tune in some 3rd Gen .400 spine Axis shafting.

At 9GPI?....This shafting was destined to become my "EFOC/Heavy Hunter" arrows...I have a dozen where (9) are still at their 32" full length with no inserts installed yet but I have (3) which I had cut too 29 3/4" (to cut JUST past the first epoxied in inserts) in an attempt to facilitate 250-300grs worth of insert/broadhead weight and in my tuning and testing of these 3 shorter shafts I wound up dang close but still just a touch stiff using the 16gr alum. H.I.T. inserts (cling wrap bound in the shaft for ease of removal) and 250gr points for a total of 266grs up front...well?...easy fix right?...just toss in the 75gr Brass H.I.T. inserts and drop down too 200gr points...(nice selection of broadheads in that weight)...but here I was nearly 10grs heavier up front and got a waaaay stiffer bare shaft reaction and here's why...










see that 25gr break-away to turn the 75gr insert into a 50gr insert?...well including the break notch?....it's a full 1/2" longer than the 16gr alum insert which means that extra 25grs of weight?...just came at the cost of the equivalent of chopping 1/2" off you arrow length because it turns an additional 1/2" of your shaft into solid rod....so I snapped it off and tried again...










looks like they might pan out with the brass inserts at 50grs with 300gr broadheads...hello Big Jim?...got some 300gr VPA's?...and?....300gr field points to practice with? LOL!


----------



## JINKSTER (Mar 19, 2011)

sidekick said:


> I don't question your results, but my 44#, 56" TC needs 29" GT 1535's with standard inserts with 145 gr. points to work. I've found my GT 3555's 30" with 50 grain inserts and 175 grain points to be stiff. I was trying to shoot 3555's out of the TC until Jim told me I needed to be shooting 1535's, and the big man was right. I agree on the quiet THOOMP.


No offense but...a 1" longer CF shaft makes a world of difference between your set up and mine.


----------



## Homey88 (Dec 10, 2013)

That is quiet jinks! Wow!


----------



## JINKSTER (Mar 19, 2011)

Homey88 said:


> That is quiet jinks! Wow!


Thanks Homey! 

and yeah....I'm blown away with this little lotta bow! :laugh:

I think it's the limbs....CF/Boo cores sandwiched between the lams of....

*"Verawood"....AKA....."Argentine Lignum Vitae"*

one of the hardest, heaviest, highest density woods known to man...the navy actually made "submersible bearings" (for ships) out of this stuff and it don't play! :laugh:

Then take into consideration that the riser those limbs are mounted too is about 90% solid clear glass?...capped with moose antler and wrapped (damped?) with a beaver tail skin grip with puffs on the string?

and you got one dang quiet bow...even with lightweight screaming arrows!....I'm loving life with the Thunder Child!


----------



## BarneySlayer (Feb 28, 2009)

glad it's still got your interest jinks!


----------



## JINKSTER (Mar 19, 2011)

BarneySlayer said:


> glad it's still got your interest jinks!


Funny man...glad I still have yours! :laugh: 

So now that the chop busting is out of the way?....on with the normally scheduled tuning of "The Thunder Child"

back to our normally scheduled tuning of the Thunder Child.

Taking into consideration that elsewhere Big Jim commented that what I don't know is that all the TC line are extremely quiet due too their grip forward design and limb profile (and of course he's correct..he's the bowyer) so?...with me now understanding that the reason it's not expressing any audible dismay with very light arrows...I now know why...thanks to Big Jim straightening me out on that so I've reconsidered and dropped the "just under" 8GPP arrows for three reasons....

1. To take heed of Big Jim's recommendation to stay above 8GPP and?...

2. Those GT35/55's of mine are like 4 years old and kind of beat up anyways and?...

3. Why tune and use those when I have a dozen brand new 32" long, .400 spine Axis arrows laying here?

So it was the full length, 32" long Axis .400's that got worked with this evening and I struck paydirt there using the 16gr alum. H.I.T. inserts w/ 125gr screw-ins and man was it easy to get those dialed in.

I spent the last hour of two hours roving the backyard with that (1) bare shaft...and as long as I did my part and stayed strong steady and smooth?...bullets. 

Here's how the numbers played out...

"The Arrow"

Total Arrow Weight: 429grs (bare/no feathers)

GPP: 9.3 

F.O.C.: 14.45%

"The Bow"

BH: 8 1/8th"

Strung Length: 53"s N2N

And it was sweet...very predictable with consistently clean flight (as long as I didn't screw it up) and plenty enough speed to keep the subconscious gaps in check.

Now here's the thing...the tech spec's above don't mean squat too me as I'm snap shooting...so I'm not tuning by form...I'm tuning by feel and actual results and with the rig set up as described above?...if my loose came a little early?...the bare shaft would be a couple degrees nock right...a little long?...a couple degrees nock left...but the bulk of the "just right shots"?...bullets...that's how I tune when I'm snapping and this is going to be one extremely accurate rig when I get feathers on these sticks. 

Thanks for keeping up and L8R, Bill


----------



## JINKSTER (Mar 19, 2011)

So..several days have past...decisions have been made...all other bows are for sale...and arrow configuration has been selected after 3 days of testing all different point and insert weight combinations working with full length (32") easton axis .400 spine shafting...and one combination kept out-shining and out performing all the rest...(just what was stated above)....32"/.400Spine/16gr Alum. H.I.T. Insert w/ 125gr points...flying like bullets (bare shaft) whether I snap or form shoot them off this 56"/46#@28" Thunder Child.

But the only problem was that...

Every arrow chart I read and even 3Rivers Spine Calculator (which is extremely comprehensive even listing both this specific bow and shafting) ALL SAID....I'm like a notch or two "Stiff"...with the 3R spine calculator infering I'd be very near spot-on with 175gr points rather than the 125gr points that perform so well and I tried 175's...and they were weak as all get out flying at about a 30deg angle nock left...so this disturbed me...and before finalizing the decision of whether to epoxy in 16gr inserts or 50gr inserts or 75gr inserts and ruining 2 dozen axis arrows?....I decided to take a closer look at things...the cool part was when I lined the string up down the bows centerline?...the 32" shaft had the point "exactly" (by eyeball) just left of the string (as it should be)...but what I didn't know for certain was how far before center the arrow was positioned when meeting calf hair strike plate...so I drew it up....

The points too the left represent my nock/shaft centered too the string...8"s too the right? (my BH with the wall center just above the grips throat) you'll see a short vertical C/L....that's where the shaft contacts the center of the riser wall...24"s too the right from there?....is the inside of my point meeting the strings C/L path.










Next I created (2) yellow points at the vertical intersection of the shafts O.D....deleted the short yellow line and drafted in the point locations....










where .183 - .105 ='ed...

*".078" Before Center"*










so the bow is shooting a notch stiffer arrow configuration than what most charts and calculators recommend.

Other decisions?...where to go with 4" Parabolic (instead of shield cut) as I hear tell they fly quieter and MR. Barbee says my bow is very quiet but my arrows are screaming like they been hit with boiling water! LOL!

I also invested in a RW clamp for my bitz as most places I go for feathers only carry right wind and/or a better selection of them...and yes...the feathers are RW.










I think they are going to look purdy and as easy to find as they are on the eyes of the creatures in the woods. 

Thanks for keeping up and L8R, Bill.


----------



## JINKSTER (Mar 19, 2011)

Meanwhile back in the looney bin that is my mind...I made a mistake on the cut-before center deal folks as it appears I forgot to divide by two...which should cut that .078" dimension in 1/2 too .039" which is most likely very close too the thickness of that calf hair strike plate which in turn means my TC's window is most likely..."Cut-Too-Center".

and while i was thinking math?...this thought also occurred to me while epoxying in my 16gr H.I.T. inserts today and that thought was...

Many folks make a great argument for using low temp hot melt to install the inserts with a great debate point of....

*"If you epoxy them in?....how do you orientate your Broadheads?"*

well?...I gave that some thought as well and while not quite as quick and convenient?....it can still very easily be done and here's how....

That "Piloted Squaring Stone" they give you in every pack of H.I.T. inserts?...well...the 8/32 thread means .031" travel per turn...so worst case scenario with a 3 Blade BH?....stone .010" off the end of the shaft and you're there...two blade?...

.015" and your there.

and those are "worse case" scenarios.

Just figured I'd mention that....cause I like epoxy...the 24hr slow cure stuff easton supplies with the H.I.T. inserts.


----------



## JINKSTER (Mar 19, 2011)

Meanwhile elsewhere?...here is how Big Jim addressed the question of minimum/optimum GPP off his Thunder Childs...

*"I express that 8gpp is the bottom end but what I think is ideal is 9-10 gpp.

I build hunting bows that can be taken to any range. If you suck than at least you have a decent looking bow to draw attention away from your shooting. If you shoot well, then there is a nice companion to join you for pictures at the end.

These aren't high tech, squeeze out every little foot per second bows (not that they are slow) with infinite adjustments. They are feel good bows that make you happy to be an archer and not an engineer.

Set it up with a nice 9-10...or more gpp arrow and it will be super smooth and quiet and bury deeply into the earth covered in blood followed by a very loud and resounding smile."*

And too me?...the above statement and demeanor embodies the spirit and mentality of what old school archery is all about...that said?...here's how my actual numbers played out on 3Rivers Online Spine Calculator....(and huge thanks too 3Rivers for making such available)....

*********************************
Arrow Total Weight (grains):441.9 
Arrow Specific Weight (GPP):9.9 
Front Of Center (FOC) %:14.6 
Arrow Speed (feet per second):179.9 
Arrow Energy (ft-lbs):31.7
*********************************

This is with bow input numbers of 46#@28"s being drawn too 27 1/2"s with a strike-plate thickness of .039" on a cut too center bow.

The calculator is also telling me that my dynamic arrow spine is about 10#s higher/stiffer than the bows dynamic spine yet I'm getting bullets for bare shaft flight so what's that say about this bow? 

180fps from nearly 10GPP off a 46#@28 bow being drawn too 27 1/2"s and pumping out nearly 32KE from a 56" short longbow?

and look great doing it? :lol:

I'll take that all day long.


----------



## JINKSTER (Mar 19, 2011)

Well Folks?...I'm proud of myself today and Glory be too God as this makes 7 days since I was admitted into the hospital with a stroke (or two) and 5 days since I got out...exactly 1 week from the start of that event and this afternoon?...I grabbed my Thunder Child and quiver of 2 Bare/3 Fletched Axis arrow and began my final phase of tuning...Bare-Shaft Testing...and I was apprehensive about doing this after just having a stroke but to my surprise?...the fletched arrows showed the bare shafts (that looked like they were flying decent and within reason) to be (without question) on the weak side and after several confirmation groups?....(just to be sure I was warmed up and broke in)...I dropped point weight from 125gr screw-ins too 100gr screw-ins and got darts of'em all with real nice flight characteristics and this Thunder Child is no slouch...this isn't my greatest shooting but for having a stroke a week ago and tuning in and getting used to a new shorty longbow?...

I'll take it! 





















Thanks for looking and L8R, Bill.


----------



## Bwhntr247 (Nov 9, 2014)

Glad to hear your doing better, Big Jim does make some nice bows. Been loving my Bighorn #47 @ 28 with cx/boo limbs very quiet and hard hitting also. Still working on the best arrow.


----------



## JINKSTER (Mar 19, 2011)

Bwhntr247 said:


> Glad to hear your doing better, Big Jim does make some nice bows. Been loving my Bighorn #47 @ 28 with cx/boo limbs very quiet and hard hitting also. Still working on the best arrow.


My guess is you are going to have to go "Stiffer" than what the charts suggest...3 rivers spine calculator shows my model bow and these very arrows playing out about right with 175gr points...but I wound up down at 100gr points after all was said and done.

Ironically?...Big Jim says he doesn't build his bows to wring out every last FPS because he wants the folks who own them to feel more like an archer rather than an engineer however?...you could've fooled me...this TC is extremely zippy for what it is.


----------



## JINKSTER (Mar 19, 2011)

No Pix today...Just an Update:

Because it was a very interesting afternoon with the Thunder Child and still recovering from a recent stroke?...I'm questioning and double checking everything from it's current state of tune too...how I shoot it.

Today my focus was on "Grip" and since I've just been doing the..."Grip it & Rip It"...thing?...I couldn't really explain (even to myself) what the heck I was doing with the grip outside of letting the web of my hand naturally seat the throat...but through execution of my shot with my eyes closed and doing the slo-motion record thing with my mind?...I could feel what I was doing and what was happening is I would start out with the web of my hand in the grips throat but as I raised a drew?...my hand was rolling down into more of a low wrist position using up a rather large contact portion of the grip...to me?...it felt more stable that way however my arrows told a different story as I identified bow hand torque as the gremlin that was giving me sideways fliers as I thought...

"Here I am in a world where everyone states that consistency is key and what am I doing?...even my bow hand is in an ever changing state throughout my draw."

So I decided that needed addressing first as I began to compare low wrist and high wrist results which were as follows...

Low Wrist: Even when held in/at a consistent pressure point throughout the shot?...this little lotta bow didn't seem to respond well too such and by far preferred...

High Wrist: Where the small of the grips throat nestled neatly in the "OK" sign web of my rather high wristed hand position...the up side of this?...the left/right fliers left the building and moving my nocking points as little as a wrap or two was immediately and consistently reflected in the flight of my bare shafts proving to me that this Thunder Child preferred minimal hand contact with the grip...The downside?..(which could really be an upside pending how you view it)...was...

With that little grip contact?...I needed to cut the tempo of my shot in 1/2...and very slowly with extreme smoothness execute my shots...which I guess isn't a bad thing and my group sizes reflected such as they nearly got cut in 1/2.

and that's it...and that was enough for today...still haven't super glued my nocking points in place but I'm taking my time in both tuning and?...

getting to know this bow. L8R, Bill.


----------



## BarneySlayer (Feb 28, 2009)

Selling everything else? I don't believe it!


----------



## JINKSTER (Mar 19, 2011)

Tricky, Tricky....everything I thought I discovered about the grip and having to shoot the TC high wristed yesterday?...flew out the window tonight cause the tricky part wasn't tuning the bow...it was tuning my form...explanation follows here and now...

The reason I was getting left/right fliers wasn't because of bow hand torque due to a low wrist grip and a huge contact patch...(which BTW feels great on my bow hand)...it was due to my lack of shoulder alignment unto the bow and why do I claim this you ask?...because...

Tonight I was wanting to move back...I had 10-12 yards down pat and 15yds was decent but I really wasn't shooting "consistently" tight enough yet to venture back to 18 & 20yds so in desperation?...I started trying to "Form Shoot" my TC and the first big differences there was...

"Posture" (standing bolt upright): and this brought the TC inward much closer too my body which resulted in much better alignment with my bow arm and what this did was...

Cleaned up my Release: Like house=keeping at the Hilton! LOL!..and got my Anchor & Loose in far better alignment with my now extremely more comfortable low wrist grip and?..

Schwaaaak!..Schwaaaaack!....Schwaaack!

Started banging them in there in nice tiny clusters at 15yds....but alas?...the sun was going down and the wife was hollering "Billllll!!!...Dinners Ready!"...but tomorrows another day and it sure is fun getting to know this little lotta bow!


----------



## JINKSTER (Mar 19, 2011)

Sight & Sound vid...


----------



## JINKSTER (Mar 19, 2011)

Here's a couple pix to give you folks some perspective of just how "Limby" this 56" Thunder Child is...

Excuse the shaky camera hands and grainy blown up pic but here's the best I could do lining up "The Fades" of the limb bases...










and here's what a set of "Medium Length" ILF Recurve limbs look like up against the 56" Thunder Child....










and it's draw is mind-blowing smooth for a 56" bow but the draw is just the first 1/2 of the show...the other 1/2 is how comically fast and powerful this little pocket rocket whips out an arrow.


----------



## JINKSTER (Mar 19, 2011)

Well?...I guess this thread "IS" my *"Comprehensive Review"* of my Big Jim's Thunder Child...cause after the stroke?...I just don't have the energy to put together anything else anytime soon.

That said?...Member fatzboys came over this morning with his gorgeous blacked out and fine shooting Omega Imperial...he also wanted to check on me and see how I was doing and?...also check out my new Thunder Child...I was happy to have the company and put on the coffee! 

I filled him in about my stroke...then told him all about how after I test shot it?...I knew I wasn't leaving Ocala without that Thunder Child and the good spirited comedy scene that was Big Jim and I haggling it out to close the deal where we both had a blast LOL!

With that?...I explained to him that when Big Jim saw me draw checking this bow?...at a glance he knew what I was doing and asked me..."What's your Draw Length?" (while I still had the string back..and I guess he saw it was a touch past my natural anchor) as I informed him 271/2"s!...to which he responded...that bow is a 56"er and it will draw stack free too 30"s...then he claimed..."My personal Thunder Child is a 58" Model and I draw 32"s."...so I told fatzboys all this as a precursor to telling him...

"So...if you start feeling any stacking going on at your 31" DL?...please let down so we don't break my new bow! LOL!"

He agreed...that axis arrow of mine is a full length .400 spine which measures 31 1/2"s from con-eoc....fatzboys claimed he felt no perceivable stacking unless he tried to pull it beyond his 31" draw...and he said he really liked the bow...as it truly is a short fast longbow that draws and shoots like a full scale longbow....and here's the frightening sight of what it looked like at his 31" full draw position...










Me?...I wasn't to worried about it as this 56" Thunder Child has a...well?...I can't even call it "a riser" as it's simply nothing more than a mostly solid clear glass handle with a small window to facilitate a shelf WELL?...HERE...you can clearly see that the riser (if ya want to call it that and I think Europeans would refer to this as "A Handle") is only about 8"s in length...and only about 12"s from end of fade too end of fade yet?...Big Jim managed to bless it with a full featured hand filling grip...and i don't know if the weight of the solid clear glass in the riser/handle is why or if it's the comprehensive design of the bow with it's dramatically reflexed limbs but...well tuned?...it exhibits like zero hand shock at the shot...










and the only reasons I felt extremely comfy allowing fatzboys to attempt stretching it out to his full 31" length of draw is because...

A. I trusted him and knew he would back off and let down if he felt he was over-stressing the bow and?...

B. This 56" short longbow has pretty much what I would call "LONGS" for limbs...as here's how my "Medium" ILF Sky Recurve Limbs compared...










and last but definitely not least?...the other real cool feature (of many) about this bow?...is that in it's 2pc TD configuration?...both pieces are actually shorter than my full length arrows so...talk about compact pack-ability?......










all I got today folks but figured I better get it done as my Two Tracks Longwalker is scheduled to arrive tomorrow!


----------



## Homey88 (Dec 10, 2013)

Awesome review and great bow jinks!


----------

