AdamTill

Hi Jon, You can thin West if that would be helpful...I think I've used xylene in the past, or even pure alcohol in a pinch (just don't use a plastic mixing container...tends to melt <sigh>). When you say vacuum infusion, do you mean that you're adding/drawing the resin under vaccum, or using a vacuum bagging system to hold the cloth against the tree? Cheers, Adam

If I may...West System is a laminating resin, so different then a pre-preg setup. Pre-preg comes with the epoxy added already, at about the best ratio of resin to fabric available. Laminating resins are added to fabric afterwards, meaning that you end up with more resin for a given mass of fabric, and thus a heavier product. Resin doesn't add strength, and thus the trick is to use enough to bond the fabric, but not so much so as to add excess weight or "float" the fabric. West System resin is decent, and I've personally used it quite a bit on aviation projects, but there are better alternatives (MGS, for example). I tend to use West for plugs or anything not needing much heat resistance.

Thanks for all the leads folks...most appreciated! Blake - especially appreciate your offer, but I need a couple of other bits of hardware as well, and I'm not in a rush.

Hi folks, Anyone have any good leads for replacement stirrup bars for english saddles (available in North America)? Thanks, Adam

Okay, gotcha on the above. I did a few tracings a couple of years back as I was working through some conformation excercizes, and I'll add one to this post for the horse above. The dots in the cervical region were indicating joint spaces, and you seem to be going from the middle of C6, so I'll guesstimate that position. Then, ignoring all but the pink lines, I think this particular horse is built relatively level. Makes sense. Well, before I bought him this particular horse was used hard and unappologetically as a lesson horse even after foundering, so he has his fair share of issues (which we're working on). Taking your example and translating it onto the topline, it's interesting to see that the topline and "balance lines" are offset and showing those "issues". I guess in essence this is a continuous state of ventroflexion, for all intents and purposes. Very interesting - thanks for this. Thanks for the article...I'll study that one to see what you mean. Wow, that's exactly what I needed to get started...thanks tons. I'll play around with that ROM data and see if I can't come up with something interesting. Cheers, and thanks again. Adam

Well, that bit of the decision making process is easy - I make a decent enough living at the moment otherwise, and have no interest in the horse world from a business perspective. I worked in the hoofcare side of things part time for two years, and got a real eye opening lesson in how a lot of horse owners see their critters. The only thing that would prevent me from providing the best care for my horse that I can is the need to keep food on my own table and a roof over my head, but a lot of other horse owners seem to try to find the absolute cheapest way to do things (even while driving BMWs). I respect those willing to try to make a living from horsepeople, but have no interest in joining them So anything I make would be for my own use. My first project will hopefully be an english-styled saddle with "western" style bars and seat like the one you made for the endurance saddle...possibly with the pommel, cantle, seat and bars molded from carbon fibre as a single unit. I'd like to learn what would be involved in making the flaps and seat using leather, but my first concern is shaping the underside of the bars. I've been working with Alexandra Kurland (who studied with Bettina Drummond, Mr Oliviera's student) for a few years, and have also started clinicing with Josh Nichol on Dr. Deb's recommendation, so I'm happy that my horsemanship instructors are leading me in the right direction. I'm also hoping that Dr. Deb's schedule allows for a skeleton assembly class up here this year, since the dissection class was so good last year. I've done a bunch of anatomy study via Equinology's courses (and am taking Dr. Ridgeway's saddle fit course this year), but being able to actually see and feel a psoas muscle vs learning "function, form and innervation" from a textbook, for example, was very helpful. So, net result, I know enough anatomy to know how much anatomy I don't know. I'm just pretty new to thinking of it terms of saddle fit. That would be because of a desire to get the rider's "center of motion" (or the average thereof) as close as possible to the horse's center of motion, correct? (and thus the sadde sits further forward) I didn't really read the other discussion regarding the low point of the back, but is placing the saddle on the horse's back so that the entire tree sits behind the scapula a brida concept? I had thought that the brida/jineta line was more to do with how the rider sits in the saddle (I have a copy of Conqueror's on order as well...just waiting for it to arrive). I'll have to study those photos carefully...thanks for the link. Could you give a quick summary of a few of the points which you look at in seeing whether a back is healthy enough to accurately determine what it's proper shape might be? I've heard statistics like that before...scary, but not overly surprising considering what's winning medals in just about every discpline (western or english) nowadays. I don't know all the differences between the two camps, but as a baseline I'd like to end up with a saddle that sits as close to the horse's "center of motion" as possible with without compromising shoulder movement but maintains sufficient support area under the bars, a rigging system that cradles the saddle evenly, and with a seating/stirrup arrangement that lets me sit in a balanced position (the "won't fall over backwards if the horse disappears" sort of balance). One of biggest concepts I'm struggling with the most is the degree of flexibility in the spin/rib cage that would factor into the bar design (ie the designing for movement part). I understand the mechanics of collection, but horses don't always operate in a collected fashion if that describes a spinal shape with a "suppporting arch" (ie, highpoint in the middle, rather then lowpoint in the middle for a hollow back). I learned from Dr. Deb, for example, that in a true extended gait extension is actually defined by the spine oscillating between "arched" and "hollow" (to some degree), as opposed to standard gait which oscillates between arched and flat, or a collected gait which largely maintains the arched profile. That would still mean (in my mind) that some allowance has to be made for a "hollow" back...(ie) a bit more rock then a baseline, stationary back might otherwise show a need for. Is that how you think of things? Thanks much! Adam

Hi again David, Thanks much for the welcome - very nice board thus far. No such thing as dumb questions...probably just a terminology thing. A "fired" muscle in my world is just slang for a contracting muscle. So a fired topline would be when the muscles of the back contact, and the spine drops. So my thinking is asking that was to say that when the back drops, there would be the greatest degree of downward curve to it, and thus the greatest need for rock in the bar. Cheers, Adam

Hi David, Less then it seems, actually...I did the back tracings for David G when I ordered a couple of saddles from him a couple of years ago. I'm an AutoCAD user myself, for the same reasons (I'm an engineer as well by day...used to do mechanical design, though I'm now in land development). I've had a copy of Rhino3D for about 3 years from when I vowed to get into 3D modelling for some personal CNC milling projects (molded model sailplane wings), but haven't had time to learn how to do much with that. I noticed it myself, and didn't know if it was a true profile or just a legacy of transfering flexible rulers to paper, scanning those, and tracing them in CAD. I tried to be careful and did the tracings twice to verify, but who knows what creeps in. I'd need to go back out and check on Marshall's back to see what the actual case...coud be the spring of the ribs locally, could have been a stance thing...who knows... I actually used a line of best fit on the other sketch, FYI. Not sure...it would seem to depend on whether that bump is a result of a skeletal/structural shape or a muscle/stance shape. Not sure what "a bar with a lot of ball" is referring to, sorry...new to this area. I noticed that it seemed oddly rearward, but I think it's just a weird photo angle. That's one of David G's excellent endurance saddles, and he wouldn't design the low point of the seat to be back too far based on what I know of his design philosphy. This is a link to David's website of the same sort of saddle: http://www.aboutthehorse.com/secure-web/html/ls2d.htm I don't want to speak for something I didn't design, but it seems to me that the low point of the seat is about in the middle of the section of bar that contacts the horse most often. Happy to stand corrected if I'm misreading that, however. These sorts of conversations are why I'm here - happy to participate. Cheers, Adam

Hi David, Okay, that helps, but I guess my next thoughts concern where the flex "points" of those hinges would be. For example, from Dr. Deb's writings and the dissection course I attended, I don't really recall there being much flexibility to the spine along the ribcage. But that said, "much" is relative. Can the area from around T12 back to the last rib be fitted with a rock that roughly equals what the back would allow when dropped (spinous process gaps limiting that)? Then, when the horse rounds up and releases the muscles of the topline, do those relaxed long back muscles "absorb" and conform to the rock that isn't technically ideal for the rounded condition? As a result, is the rock at the back of the bar mainly designed to keep the skirt of a "western" saddle off the horse's back? (and by extension, would an "english" saddle with bars like a western saddle need any rock at the back end of the bar, given no skirt). Is rock at the front of the bar in excess of what the dropped back requires designed to account for scapula movement? Lots of questions, sorry, but any help would be appreciated. Adam

Sorry, the last graphic had an error on it (rock was being measured past the end of where the bar ended)...should be as follows.

Hi Rod and Denise, Thanks very much for the reply. I look forward to doing a bunch of reading - my workshop is packed up in preparation for putting the house on the market, and it's killing me to not be able to go down there and putter. Okay, I'm with you on all points there. By saying saucer rather then bowl, do you mean that it should be a more gentle curve, or do you mean that the rock curves at the bar tips are more upswept then the curves in the middle? My thought process in saying that the low point was in the center of the seat was that the seat (in my mind) should ideally be centered in the middle of the span of the bar which contacts the horse in most cases (ie, the section that isn't flared to clear the shoulder). That way the center of pressure (from the rider's weight) is centered over the center of support (middle of that span of bar). Equally ideally, the support center of the rigging on the tree should designed to straddle the center of pressure, so the saddle doesn't rock or shift. Not sure if that's true, but it makes sense from over here. I don't know Mr. Lane's system, but I think I can picture what he's doing. I'll attach a few files to this message with my interpretation of that, though I'll pull off a profile 4" from the midline instead (assuming the midpoint of a 5" wide bar positioned 1.5" off centerline). The dark blue line is the midline profile, and the light blue line is the profile at the offset distance. Now, in the photographs I've overlaid the profile lines onto the actual horse (the profile was done two years ago, though it still seems close enough today). The angled red lines are just an attempt to get a feel for the boundaries of the saddle fit region (saddle might be a scotch forward in the photos), and the angled green line is the center of the seat (or close to). The taped bits on the horse are meant to show the scapular spine, the rear edge of the scapula, the shelf of the ribs, the (very defined) edge of the spinalis muscle, and the edge of the last rib. So, taking all that, if you go to the attachment that shows only the line drawing with the two profiles and the saddle fitting range, I'm picturing the line of rock being something like the pink line in relation to the back profile underneath the bar (standing, at rest) as the light blue line. Thus the rock measurements I'm trying to get an appreciation for are the ones marked forward (considering rock ahead of the scapular seems pointless, as flare would dominate), and rear (at the end of the bar). Does all that make any sort of sense? (tough concept to show in drawings I'm finding). Absolutely…midline profile along the tops of the spinous processes would seem to be almost but not quite independent of the profile in the region where fit occurs. The files I've attached back that up (in this case, anyway). I guess I had taken micro-fitting to refer to customizing a tree for a specific horse (as opposed to using a "standard" tree from a given range that comes close enough), but I take it the term actually more specifically refers to fitting a horse "as-is" with no consideration for whether that's where you actually want them to be in the future. I'll remember that for the future, and I'll also heed your warnings against doing so.

Hi folks, I'm new to the board (and to saddle design), but have really enjoyed reading everything so far. I gather that there were previously a lot more threads that were lost in a server crash, so please excuse me if this topic has been discussed before, but I would really appreciate learning more about rock in saddle trees. I can understand flare and twist pretty easily, and the concept of rock itself is straightforward, but the details of rock are eluding me a bit. I also understand that every tree blends these concepts to a large degree, but for purposes of discussion, splitting rock out for now would benefit me immensely. So, in no particular order: 1) If rock can be visualized as a curve, is the "low point of the bowl" under the low point of the riders seat (assuming jineta design)? In the middle of the bar? (assuming that point isn't one and the same) 2) If one were to micro-fit a tree to a particular horse, how does one determine the amount of rock? Is that designed for the case where the topline is fired, and the back dropped, or a worse case then that? 3) If looking at the horse from behind, is the "plane of rock" perpendicular to long muscles of the back, or parallel to the midline? So in the attached photo, if turquoise is the rough plane of the back, red would be perpendicular to that, and dark blue parallel to the midline. That may be overthinking things since the difference would seem to be small on most horses, but I'm curious. Thanks tons...really appreciate any help anyone could offer. Cheers, Adam