Plate-Loaded Machines

[KBKB]

I assume no closing is necessary either (????)

Right - no closing is needed either.

Something else worth mentioning is that when you're replying to a specific point - as I did above - you can trim all of the extraneous stuff out of the quoted material so that it's really clear about which point you're responding to. I.e. when I wrote this reply, I trimmed away all of your message except for the "I assume no closing..." portion.

[SomeDudeAtHome]

I assume no closing is necessary either (????)

A proper closing on these forums is "smell ya later MOTHERF*CKERS!!!"

[HenryMaag]

Merry Christmas, ...to all who will receive it.

[LarryPendur]

I hope I am not repeating some comments or questions, but:
You machines look quite nice, particularly the glute press. But is the target market commercial gyms or home gyms ?
For commercial gyms, the price is probably secondary to how bullet-proof and solid they are, and how easily they adjust to a wide range of users.
But for home gyms, price is going to be a big factor.
I just sole a Body Solid Vertical leg press and bought a powertec leg sled. I would probably have considered spending a little more money for something that was obviously sturdier and heavier duty, but for home use $1K seems like a psychological barrier for any single piece of equipment.

What are your prices like ?

[HenryMaag]

The prices are all in the $2000-3000 range.


Thank you for the complement.

[HenryMaag]

Well, it has taken nearly 6 months of observations to come to a conclusion of what angle of inclination to make my Incline Press offering for Cross Axes Tech. I started out with a 35° angle of inclination for my Incline Press machine, but after some conversation with members on this forum I came to the conclusion that this was not only not an ideal angle for developing either the pectorals minor or the frontal deltoids, but it was also so common as to place me in a position where I was competing with many other manufacturers. For this reason I decided to offer two different versions of the Cross Axes Incline Press, one for more effectively targeting the pectorals minor muscles of the upper chest and the other for more effectively targeting the frontal deltoid muscles of the frontal shoulders.

After getting input from HealthNut MD, a doctor on the forum, I decided to build a 25° incline press (seen earlier on this thread) for better targeting the pectorals minor muscles of the upper chest than the 35° angle that I started with. So I built and tested it, but found that even at this relatively shallow angle of inclination, operator's were still significantly arching their backs at 1-5 rep max. So I went down a notch in inclination and have just built this new very shallow 20° Cross Axes Incline Press (shown to the left side in these pictures), which, along with end users (here at local gyms in southern California), I intend to test for its effects on pectorals minor stimulation and growth. I figure, at the very minimum, I will have little competition for a very shallow angle incline press machine (I can think of no one who offers one at 20°). I believe that this shallow of an angle will allow relatively heavy weights and will have a significantly different feel and effect on an operator's upper chest muscles than the standard 30-35° options (which are common in the industry).



At the other end of the incline press spectrum, I have built this new 45° Cross Axes Incline Press (shown to the right side in these pictures) to more effectively target the frontal deltoid muscles than the standard 30-35° options offered by others, which, I feel, are a 'one option' compromise for upper chest / frontal deltoid development (after all, this is the reason I started with this angle).

[KBKB]

Well, it has taken nearly 6 months of observations to come to a conclusion of what angle of inclination to make my Incline Press offering for Cross Axes Tech. I started out with a 35° angle of inclination for my Incline Press machine, but after some conversation with members on this forum I came to the conclusion that this was not only not an ideal angle for developing either the pectorals minor or the frontal deltoids, but it was also so common as to place me in a position where I was competing with many other manufacturers. For this reason I decided to offer two different versions of the Cross Axes Incline Press, one for more effectively targeting the pectorals minor muscles of the upper chest and the other for more effectively targeting the frontal deltoid muscles of the frontal shoulders.

After getting input from HealthNut MD, a doctor on the forum, I decided to build a 25° incline press (seen earlier on this thread) for better targeting the pectorals minor muscles of the upper chest than the 35° angle that I started with. So I built and tested it, but found that even at this relatively shallow angle of inclination, operator's were still significantly arching their backs at 1-5 rep max. So I went down a notch in inclination and have just built this new very shallow 20° Cross Axes Incline Press (shown to the left side in these pictures), which, along with end users (here at local gyms in southern California), I intend to test for its effects on pectorals minor stimulation and growth. I figure, at the very minimum, I will have little competition for a very shallow angle incline press machine (I can think of no one who offers one at 20°). I believe that this shallow of an angle will allow relatively heavy weights and will have a significantly different feel and effect on an operator's upper chest muscles than the standard 30-35° options (which are common in the industry).



At the other end of the incline press spectrum, I have built this new 45° Cross Axes Incline Press (shown to the right side in these pictures) to more effectively target the frontal deltoid muscles than the standard 30-35° options offered by others, which, I feel, are a 'one option' compromise for upper chest / frontal deltoid development (after all, this is the reason I started with this angle).

Pics embedded.

[nnclark11]

They would be interesting to demo. The foot print looks very reasonable

[HenryMaag]

Reunion picture of the two 'classic' Lamb back building machines - the B-1000 'Pumpjack' Pulldown, and the B-3000 Vertical Row.

Just a note for those who may be interested, the B-3000 Vertical Row and the L-3000 Glute Press were the only two machines built by Lamb Bodybuilding Machines which did not utilize a four-bar linkage as the force varying mechanism*. (*While the L-3000 Glute Press utilized a four-bar linkage as a foot plate 'tracking mechanism', it did not effect the force output at the foot plate which was applied simply by the rotating effort-weight arm assembly, making its variable resistance come through a simple 'lever type' mechanism like those used by Hammer Strength.)

[dparty82]

You make some nice equipment. Look great and beefy.

[HenryMaag]

Because I both love Him and appreciate what He has done for me (on this day), I am compelled to remind all who will receive it, that it is 'Good Friday' and the only 'body' (this being a 'bodybuilding forum', and assuming that we all worship our bodies to some degree - myself included) which really counts was put on a cross just outside of Jerusalem, Israel (some two thousand years ago, now) for our sakes, where He made provision (the only provision) for us to come to Him some day.


I will not turn this forum into a religious forum and have placed this post only in this thread started by me, and while I have agreed to stop using closings in my posts, after this post I must add the word 'sincerely'.

[HenryMaag]

The two (relatively) new cross-axes back building machines built by Cross Axes Tech (on the right side of the picture) meet the two rebuilt versions of the two old 'classic' back building machines build originally by Lamb Bodybuilding Machines (on the left side of the picture).



Regarding the 'feel' and 'function' of the Cross Axes Tech cross-axes back-building machines and the classic Lamb Bodybuilding Machines original back-building machines, make no mistake about it, they feel and function differently. The cross-axes pulldown machine (built by Cross Axes Tech) on the right side rear and the "pumpjack"* pulldown machine (built originally by Lamb Bodybuilding Machines, back in the 90's) on the left side rear, have completely different feels. (* The work 'pumpjack' was affectionately attached to Lamb's B-1000 pulldown machine by end users who compared its appearance and construction to oil field pumpjacks. It was the first actual 1000lb capacity plate-loaded pulldown machine ever built.)

Regarding the differences in 'feel' of these two versions of pulldown machines; the handles on the 'effort arms' on the cross-axes pulldown move through arcs traced through the frontal plane of the body, making the latissimus dorsi muscles, that they develop, tend to fan out to the sides of the body while performing the exercise; while the handles on the 'effort arm' of the standard 'pumpjack' pulldown trace arcs which pass through parasagittal planes symmetrically offset from the centerline of the body, causing a greater stimulation to the deeper (more medial) aspects of the latissimus dorsi muscle bellies.


Once again, the cross-axes vertical row machine (built by Cross Axes Tech), pictured on the right side front, and the classic vertical row machine (built originally by Lamb Bodybuilding Machines back in the 90's), on the left front, have completely different feels. The handles on the 'effort arms' on the cross-axes vertical row move through arcs traced through the transverse plane of the body, making the mid-back muscles and rear deltoids that they develop tend to fan out to the sides of the body upon contraction; while the handles on the 'effort arm' of the standard vertical row move through offset parallel arcs traced through parasagittal planes offset from the centerline of the body, causing a greater stimulation to the deeper (more medial) aspects of the mid-back muscle bellies.


So the two different pulldown movements and the two different rowing movements actually stimulate the same targeted musculatures in significantly different ways, and actually end up complementing each other. Unlike other manufacturers, I have never built two machines which I feel are duplicating, in essence, the same movement.

[KBKB]

The two (relatively) new cross-axes back building machines built by Cross Axes Tech (on the right side of the picture) meet the two rebuilt versions of the two old 'classic' back building machines build originally by Lamb Bodybuilding Machines (on the left side of the picture).



Regarding the 'feel' and 'function' of the Cross Axes Tech cross-axes back-building machines and the classic Lamb Bodybuilding Machines original back-building machines, make no mistake about it, they feel and function differently. The cross-axes pulldown machine (built by Cross Axes Tech) on the right side rear and the "pumpjack"* pulldown machine (built originally by Lamb Bodybuilding Machines, back in the 90's) on the left side rear, have completely different feels. (* The work 'pumpjack' was affectionately attached to Lamb's B-1000 pulldown machine by end users who compared its appearance and construction to oil field pumpjacks. It was the first actual 1000lb capacity plate-loaded pulldown machine ever built.)

Regarding the differences in 'feel' of these two versions of pulldown machines; the handles on the 'effort arms' on the cross-axes pulldown move through arcs traced through the frontal plane of the body, making the latissimus dorsi muscles, that they develop, tend to fan out to the sides of the body while performing the exercise; while the handles on the 'effort arm' of the standard 'pumpjack' pulldown trace arcs which pass through parasagittal planes symmetrically offset from the centerline of the body, causing a greater stimulation to the deeper (more medial) aspects of the latissimus dorsi muscle bellies.


Once again, the cross-axes vertical row machine (built by Cross Axes Tech), pictured on the right side front, and the classic vertical row machine (built originally by Lamb Bodybuilding Machines back in the 90's), on the left front, have completely different feels. The handles on the 'effort arms' on the cross-axes vertical row move through arcs traced through the transverse plane of the body, making the mid-back muscles and rear deltoids that they develop tend to fan out to the sides of the body upon contraction; while the handles on the 'effort arm' of the standard vertical row move through offset parallel arcs traced through parasagittal planes offset from the centerline of the body, causing a greater stimulation to the deeper (more medial) aspects of the mid-back muscle bellies.


So the two different pulldown movements and the two different rowing movements actually stimulate the same targeted musculatures in significantly different ways, and actually end up complementing each other. Unlike other manufacturers, I have never built two machines which I feel are duplicating, in essence, the same movement.

Pic embedded.

Just looking at the machines, without seeing them in motion, I would not have guessed that there'd be a significant difference in the arcs traced by the handles.

Since you say that the old & new generations complement each other, I gather that you don't think one is "better" than the other?

[HenryMaag]

First off KBKB, thank you for the help with the embed.



If you can identify the pivotal axes of the 'effort arms' on the two different machines (and I appreciate that not all people can without, like you said, seeing the machine in motion), then you will see that the traditional machines (on the left side of the picture), both utilize a single rotational axis which lies in front of the operator's body and is perpendicular to the plane looking straight forward, to which a single 'effort arm' (the moving part which contains the handgrips which the operator engages to apply 'effort') rotates about. This configuration causes the handgrips to move through arcs in the plane looking straight forward (the sagittal plane of the body), which, in turn, tend to cause more stimulation to the targeted musculature closer to the centerline of the body. On the other hand, the cross-axes configurations utilize two parallel sets of rotational axes which are parallel with the plane looking straight forward; so their 'effort arms' rotate through planes which are perpendicular to the plane looking straight forward (the 'frontal' plane of the body), tending to cause more stimulation to the lateral part of the targeted musculature.

After reading this attempt to describe the movements of these two types of machines differently, I can appreciate if any reader is still confused. Perhaps, end users will simply have to experience both types of machines to realize that they are, indeed, significantly different in both 'feel' and 'function'.



Regarding whether I think one configuration is better than the other; No, I don't personally think that one is better than the other, just that they are different. I can say that for end users looking for the so called "V taper" that the cross-axes machines are a 'theoretically' better choice. And for those looking for 'theoretically' more durability, that the traditional machines are a better choice. I only say this because the most vulnerable parts on any of my machines for wear are, without a doubt, the rod-end-ball-joints on the cross-axes machines. That being said (and before anyone goes into a panic regarding machine durability), I have had some of these cross-axes machines in some heavy-lifting bodybuilding gyms for close to a year now with no ill effects; and you only need to look at some of the videos on 'you tube' to see the kind of pounding that they are taking 'day in and day out'.



Here are a few additional pictures of the 'pulldowns' and 'rows', if they can be of any help in identifying the rotational axes of the machines.

[TASOSCHATZ]

John Meadows likes your chest press machine, he actually performs two excersises within one workout session
https://www.youtube.com/watch?v=OkZj7Zrfcpc

[TASOSCHATZ]

And your shoulder press machine is also used by Meadows in this video https://www.youtube.com/watch?v=md5w8lwyhVA

[HenryMaag]

And your shoulder press machine is also used by Meadows in this video https://www.youtube.com/watch?v=md5w8lwyhVA

Wow, thank you TASOSCHATZ for placing the links to the two videos, its nice to see some big guys working out on the machines, and it makes me wonder if they will discover the back or leg building machines in that gym.


Henry

[HenryMaag]

The equipment looks good and appears to function well. You should change the colors of the pads tho, it makes your stuff look dated. I'd get rid of the banding or piping too. Maybe all black pads with the silver frames. For black frames use black or bright bold colors not the muted shades you have currently. I'd also make all grips black, they are going to get nasty looking quick and you don't want people to skip by your equipment because the handles are stained - if you cant' see it it's not an issue. Also alter your name...it doesn't flow very well. Use acronym CAT and get a simple identifiable logo it will look much better. Pick a good bold legible font and keep it one color vinyl sticker or cnc burn it thru a plate and have it as a gusset on the machine. Don't put your tagline on your equipment either, just your name. You can have the full name on your website / IG page and consider using Cross Axes Technologies vs Cross Axes Tech. Use the tagline in advertising to highlight construction and heavy duty nature you want to convey but not on the actual equipment itself. I'm not a huge fan of the tagline but I see what you are doing with it and it #tags ok. People love heavy duty (but usually don't want to pay for it.) Your customer will determine if the plate loading arms are going to cause you headaches if they aren't chrome plated and capped. It's weight lifting equipment - it scratches and chips which might not bother most but there are enough people who will complain and about the finish wearing or chipping off on something with metal to metal contact points...if your market is commercial you might be ok if it's consumer they will want it to look new forever. Expand your line to include accessories, cages, stands, plate trees, power tower, benches etc and you're the next Rogue!

Good luck with your return.

How do these new colors I just recently added look?

[EricAtl]

How do these new colors I just recently added look?

They look good.

Can you put end caps in which I think would give a more finished look.

[jessedemasi]

They look good.
Can you put end caps in which I think would give a more finished look.

I think maybe those ends are open to be able to secure the machines to the ground by studs? A piece of flat stock welded onto the end would allow you to close those holes and still bolt them down. I like the look of vertical leg press and the chest press a lot. Would love to try them out next time im in CA.

[HenryMaag]

I think maybe those ends are open to be able to secure the machines to the ground by studs? A piece of flat stock welded onto the end would allow you to close those holes and still bolt them down. I like the look of vertical leg press and the chest press a lot. Would love to try them out next time im in CA.

World Gym in San Diego has the full set. Many of the machines can be seen (in use) on their instagram site.

Thank you for the complements, and, yes, they (World Gym) bolted them all to the floor. I have designed the entire line to remain stable, irregardless of the weight loaded on them, without being bolted to the floor.

[HenryMaag]

They look good.

Can you put end caps in which I think would give a more finished look.

Yes, I suppose I could add 'end caps'. Thank you for the suggestion. They would have to be plastic, and removable, because there are mounting holes in the transverse cross pipes which can be used to secure the machines to the floor.

[HenryMaag]

Any forum members in the Torrance, CA area can try out either a cross axes chest press or a cross axes vertical row at Dave Fisher's Powerhouse Gym in Torrance, CA.

[HenryMaag]

Forum members:


Just to demonstrate that Arthur Jones, and Nautilus, and all of its offshoots (Hammer Strength, Medx, etc.) have nothing on me when it comes to machine design capabilities; I intend to build a machine which addresses the latissimus dorsi isolation movement: just so that athletes can compare my interpretations of what this machine should be, compared with Arthur's. Arthur called his version of this machine the "Nautilus Behind-Neck Torso Machine".


Arthur's vintage "Nautilus Behind-Neck Torso Machine" (which Nautilus sold approximately between 1974 and 1982) utilized independent 'effort arms', which were engaged and articulated simultaneously through roller pads of approximately 5" diameter, which engaged the back sides of the operator's upper arms while performing a humeral adduction movement with the latissimus dorsi being the primary movers. While his 'effort arms' could move independently, his machine was configured (and meant to be used) primarily as a 'bilateral' machine (both sides of the body moving concurrently).


Because the latissimus dorsi muscles of the back cross many vertebral joints between their insertions at the backs of the humorous bones and their origins down the spine, I believe that such a movement should be performed one arm at a time, so that the spine can actually bend in the direction opposite to the arm being exercised, in order to both further increase the range of motion and to further isolate the latissimus dorsi muscles (incidentally, the second largest muscle grouping in the human body) through working only one side of the body at a time.


I intend to design a machine which will utilize a fixed pad (unlike Arthur's 'roller pad') which will rotate about an axis common with the operator's rotating shoulder joint (much like Arthur's), but at a distance farther offset from the axis of the operator's rotating shoulder joint, causing the pad to engage the back of the operator's upper arm much closer to the 'sweet spot' just short of the operator's elbow joint. I will be able to implement this better configuration because my machine is working one side of the body at a time. Shoulder joint stabilization (necessary for performing the exercise) will be obtained through the use of an adjustable shoulder engaging pad which will engage the operator's opposite shoulder while performing the exercise.


The fixed pad on my machine's 'effort arm' will spread the body-machine contact forces out over a much larger area of the back of the operator's upper arm than the Nautilus model's small diameter 'roller pad'. Additionally, because my pad will engage the operator's upper arm at a greater distance out from the shoulder joint (closer to the elbow joint) the amount of force applied at the body-machine contact surface will be much less, in order to obtain the same amount of rotational torque applied to the operator's shoulder joint. All of these factors, acting together, will greatly reduce the body-machine contact surface discomfort (associated with the Nautilus machine - for anyone who is honest with themselves).


In my own opinion, while Arthur and Nautilus managed to theoretically isolate the lat muscles by taking the much weaker bicep muscles out of the movement; they, through their use of their roller pad, which engaged the backs of the average operator's upper arms in a position substantially between the shoulder and elbow joints, in effect, substituted body-machine contact pain tolerance for the relative weakness of the bicep muscles in this latissimus dorsi building machine. You may reflect on your own experience of Arthur's machine (if you have used one) regarding the amount of pain you could bear, while having your tricep muscles pinched laterally between the machine's relatively small body-machine contact bearing area and your humorous bones (courtesy of their small diameter 'roller pad').

Actually, given their bilateral configuration for this machine, they really had no choice but to provide a shorter than necessary 'effort arm' length (the distance from the center of their 'roller pads' to the axes of rotation of those pads on the machine) if they were going to make their machine universal enough to cover shorter operator's (5'8" or shorter). While it is possible that they could have designed in 'adjustable roller pads' (that could move radially in or out from the axis of rotation of the shoulder joint) - this would add complexity to their machine; and complexity and adjustability are always opposed to durability and reliability.


A final fault with the Nautilus design (which they addressed with a seat belt), is the fact that it is only the weight of the operator's torso (while in a seated position) that holds the operator down while adducting the arms; and the lat muscles, acting at the distance of their 'roller pads' offsets are far stronger than this. This is an added benefit of my configuration; because my configuration will exercise one side of the body at a time only half the amount of uplifting force will occur while performing the exercise.


I have obtained materials, and am going to begin construction on my version of a true 'lat isolation' machine.

I intend to design my configuration of this machine to exercise one side of the operator's body at a time, resulting in a greater and more effective range of motion than the Nautilus Behind-Neck Torso Machine. My configuration will provide for adjustment of the position of the operator's rotating shoulder joint along two axes ('up and down' and 'side to side') instead of the single axis of the Nautilus machine (just 'up and down'); making it possible for a large range of operators to position their arms to engage the 'sweet spot' and put the 'pain' of this particular exercise movement back in the latissimus dorsi muscle bellies (where it belongs), and not at the body-machine contact surfaces (where it does not belong).



Oh: and in addition, I intend to use a four-bar linkage to make the force-curve on this machine fit the average operator's ability to apply force in this particular body movement. In addition, unlike Arthur Jones and Nautilus, who had their own understanding of proper machine load patterns, I will fit my machine with a force-applying load pattern that peaks in the middle of the movement (as dictated by the body-mechanics of this movement) instead of the end (typical of Arthur's load patterns).



Historically, it might be noted that the 'Nautilus Behind-Neck Torso Machine' is no longer around. You may reflect on its past use and effectiveness as a latissimus dorsi developing machine for yourself, if you have experience it over the years.

As for my configuration, I will keep you posted. It is coming, and I do intend to get feedback from serious bodybuilders and strength athletes on its effectiveness versus Arthur's version, and will pass this information on to whoever will hear it.

[HenryMaag]

Just an update on the new prototype Lat Isolation Machine which I am building (for those who may be interested).



Regarding the design process: and all manufacturers (except, of course, those copying others) must undergo it: you never know what you will get until a prototype real-world model is built and is taken to the market (the kind of people who may use it), and evaluated by them.

I market candidly, by bringing my prototype machines to real world users and getting their feedback on how they really feel about the machine (most of the time I simply leave the machine with them so that I will not interfere with their evaluation). I believe that this was a fault of Nautilus, who would test their machines with a group of Nautilus salesmen standing around while the tests were being conducted (imagine how you might respond with 3 or 4 people standing around waiting for your feedback).




Anyway, I have finished the frame.

The frame is the assembly that will journal the rotating assemblies (things like 'effort arms', 'weight arms', 'body positioning arms', racking mechanisms, body engaging pads, .....and for some manufacturers, things like cup holders, computer boards, lights, bells, and other fun stuff).
You will note (in the pictures) that the frame basically employs a 4.5" diameter heavy-walled transverse member that sits on the floor to give the machine its lateral stability (to keep it from falling over from side to side).

Like many manufacturers that use a common theme in their frame construction (Hammer Strength, Pendulum, David, etc.), this transverse cross member is common to all of my machines (both the old LAMB product line and the new Cross Axes Tech product line), although the LAMB line utilized a 4.0" diameter tube, while I am now using a 4.5" diameter tube (purely for aesthetic purposes - both are overkill from a structural standpoint).

Rising perpendicularly from this transverse member are two parallel sets of triangularly arranged frame assemblies which hold the flanges which will, in turn, journal the rotating assemblies, and mount operator back-support pads.

This is a two-sided machine (right and left). Incidentally, the only two-sided machine I have built (except for a one-arm pulldown machine which I built under the LAMB label). Being two-sided, you will note that the machine is symmetrical-about-centerline, with right and left sides being mirror images of each other (actually, just like all of my machines). The operator will perform the exercise in a seated position, looking laterally away from centerline (this will become more evident as progress on the machine continues.....).

[ironforgedgym]

Cant wait to see where you are going with this Henry!

[Greybird2]

I remember using the Nautilus back machine you are referring to. I remember (used to work at Nautilus as a kid) Many people using that machine wrong. They would wrap their elbows around it and do a movement like a cable crossover for chest. Maybe somehow you could design in a way to prevent that?

[TASOSCHATZ]

I remember using the Nautilus back machine you are referring to. I remember (used to work at Nautilus as a kid) Many people using that machine wrong. They would wrap their elbows around it and do a movement like a cable crossover for chest. Maybe somehow you could design in a way to prevent that?

I still use a Panatta version of the Nautilus machine, an old model that they do not produce today. It is a larger / heavier piece than the nautilus one but the major difference I see is that the seat is at a slight incline, from photos I think the original is vertical. The way to better isolate the lats is to place your arms looking either in front, like a double biceps pose, or even better facing up. Also I sit facing the back of the seat, the normal way works more my pecs while this way is 100% back.

[HenryMaag]

After making 'educated' ('educated' by years of experience designing muscle-building machines) guesses as to where to place the machine's 'effort arm' assembly, relative to the operator, while in the determined operating position: I have finished the 'effort arm' assembly, the 'weight arm' assembly, and the 'connecting link' that mechanically joins the two of them.

These three assemblies, along with the machine's frame, constitute the four members of this machine's four-bar linkage. By investigating and specifying the distances and orientations between the pivotal axes of these four components, I can specify a particular force-output profile to be applied at the body-machine contact surfaces on the machine's 'effort arm' (an applied force that will vary throughout the movement).



The machine's 'effort arm' is journaled in the frame in the frame's upper bearing flanges (placed near the 'peak' of the frame's two parallel triangular sections). This is a position which approximates shoulder joint height while in a seated position for most people. The 'effort arm' consists of a bearing tube (if you can consider a section with a 1/2" wall thickness to be a 'tube') with a couple of flanges running radially off of it which engage the 'connecting link'. Also running off of this bearing tube are a pair of symmetrically oriented 'L shaped' solid bars which join to a pair of 'cupped' steel plates which, in turn, will engage the back sides of the operator's upper arms while performing the exercise.

While I typically use built up pads (plywood backing with foam glued on and covered with fitted vinyl upholstery - like everyone else), I have decided to experiment with these 'cupped' plates for two reasons. The first reason is that the 'cupped' surface will further spread the body-machine contact load out over an even greater area when engaging the operator's basically round arm sections. The second reason is that the 'cupped' section will more securely engage the operator's arms to prevent slipping off the pad, which will, as an added benefit ensure proper 'tracking' while performing the exercise.


The machine's 'weight arm' is journaled in the frame in a pair of flanges placed below the pair which journals the 'effort arm'. This location allows for the weights to be loaded on the machine's weight bar at a low (stable and safe) location where the plates (up to 45lb) can be loaded without getting in the way of the operator.


The 'effort arm' and 'weight arm' are joined to each other by the 'connecting link', which is simply two parallel bearing tubes joined to each other by a steel bar.



Now that the basic force-applying mechanism for the machine is built, I will move on to the operator body constraint. My plan is to utilize two different body-machine constraint surfaces: one (an adjustable seat) to move the operator's body (and therefore his shoulder joints) up and down, and the other (an adjustable 'opposite' shoulder engaging pad) to move the operator's shoulder joints right and left. Between the two adjustments, it should be possible for a wide range of operators to adjust the position of their exercising shoulder joint to comfortably correspond with the path of the machine's 'effort arm' engaging pads.



To be continued......






.

[HenryMaag]

I remember using the Nautilus back machine you are referring to. I remember (used to work at Nautilus as a kid) Many people using that machine wrong. They would wrap their elbows around it and do a movement like a cable crossover for chest. Maybe somehow you could design in a way to prevent that?

Greybird2:


Just like TASOSCHATZ has suggested, the most efficient way to hit the lats in this movement would be to have the forearms rotated upward 'like a double biceps pose'. This is the way I envision my machine being used. I can see that if the machine were used like a 'cable crossover for chest' it would end up significantly transferring load to the pectoral muscles just like you suggested. I don't think this will be a problem on my machine because the force transmitting 'cups' are placed too far out to 'wrap one's elbow joints around'.

I will admit that your observation has given me some 'food for thought' because it would be possible on my machine to rotate the forearms forward to some degree which would, in turn, lessen lat isolation. Perhaps I may have to add some kind of handles placed in a position that would ensure proper arm orientation.

Thank you for the observation.



.