cost of production

[Beeman]

I was under the impression that chain was pretty good at energy transfer. (http://www.gates.com/facts/documents/Gf000202.pdf).

[jerseybigfoot]

mudN, I have made the calculations and the hydro option has serious displacement to gear ratio problems especially if your are looking for a machine under 900 lbs and limiting the HP to 25 hp. It works out different when if you look at a 1500 lb machine and 40 hp. Simply stated the calculated torque for your wheel motors is not the available pump pressure but 1/3 or 1/4 the pressure as you drive the motors in series. so actual motor differential pressure of 1000 psi on 3000 psi pump for a 6 wheel drive machine. What you end up on the pump side is to oversize the pump displacement to give you the ground speed. But wait, at the higher ground speed we have to decrease the pressure or we overload and slow the prime mover. Once we have selected this high volume pump and matched it to our25 hp engine we cant start it as the starter now has to also spin the charge pump and (2)feathered main pumps along with the engine. Not Ok but we can add a clutch or belt drive for the pump (been done) an on, and on and on. So for 25 hp and 800 lb machine that can climb a 45 deg incline the top speed is 10 mph.

[azz7772]

mudN, I have made the calculations and the hydro option has serious displacement to gear ratio problems especially if your are looking for a machine under 900 lbs and limiting the HP to 25 hp. It works out different when if you look at a 1500 lb machine and 40 hp. Simply stated the calculated torque for your wheel motors is not the available pump pressure but 1/3 or 1/4 the pressure as you drive the motors in series. so actual motor differential pressure of 1000 psi on 3000 psi pump for a 6 wheel drive machine. What you end up on the pump side is to oversize the pump displacement to give you the ground speed. But wait, at the higher ground speed we have to decrease the pressure or we overload and slow the prime mover. Once we have selected this high volume pump and matched it to our25 hp engine we cant start it as the starter now has to also spin the charge pump and (2)feathered main pumps along with the engine. Not Ok but we can add a clutch or belt drive for the pump (been done) an on, and on and on. So for 25 hp and 800 lb machine that can climb a 45 deg incline the top speed is 10 mph.

that is a good argument.......... to consider my design I thought of having just one drive motor on each side driving a sprocket/track over free wheeling balloon tires picture a bombardier bombi but with a different track that incorporates the balloon tires. You would have a strong but simplified frame, two drive motors, two hydro pumps in tandem and choice of motor the wheel axles would just have to mount on the outside of the tub bolted through to the frame. t but there would be no bearings in the tub for water to penetrate.you can see in the pic where the sprocket is located that would be what I was thinking.

[mudbug3]

The main problem I see with this concept is the high cost of admission for a recreational vehicle. With the higher cost you then limit the potential customers that you're trying to reach. Another thing is the weight. The heavier an amphib becomes the less amphibious it becomes. This is the problem that I had with the Mudd-Ox 8x8 that I used to own. It weighed over 1,800 pounds with out a driver and it used only two wheel motors at the front of the machine and powered the axles with double 60 chain. If I drove slowly down a steep embankment and then into the water , water would come pouring into the tub. This happened because the heavier Mudd-Ox that I used to own would,nt float up as fast in the water as the much lighter Max and Argo that I have now. If I tried to drive up a creek bank with an angle of 25-30 degrees, water would then pour into the rear of the tub. This is another problem you have with a heavy amphib. The Mudd-Ox 8x8 uses a 40 hp motor to run all of the hydraulics and still have some performance left over. The special order Mudd-Ox 8x8 with a hydraulic wheel motor on each wheel and uses a turbo charged 44hp Kubota turbo diesel engine to power all of the hydraulics. This machine cost high $48,000 I think.

[mudNmallards]

mudN, I have made the calculations and the hydro option has serious displacement to gear ratio problems especially if your are looking for a machine under 900 lbs and limiting the HP to 25 hp. It works out different when if you look at a 1500 lb machine and 40 hp. Simply stated the calculated torque for your wheel motors is not the available pump pressure but 1/3 or 1/4 the pressure as you drive the motors in series. so actual motor differential pressure of 1000 psi on 3000 psi pump for a 6 wheel drive machine. What you end up on the pump side is to oversize the pump displacement to give you the ground speed. But wait, at the higher ground speed we have to decrease the pressure or we overload and slow the prime mover. Once we have selected this high volume pump and matched it to our25 hp engine we cant start it as the starter now has to also spin the charge pump and (2)feathered main pumps along with the engine. Not Ok but we can add a clutch or belt drive for the pump (been done) an on, and on and on. So for 25 hp and 800 lb machine that can climb a 45 deg incline the top speed is 10 mph.

I appreciate your post probably more than you will ever realize and at a point in the future I would love to see your math and probably consult with you and a few others who have shown similar expertise in key areas. One of the things I have learned over my career is, just like most maintenance guys I deal with, is that when one is looking for detailed knowledge and especially problem solving and troubleshooting the guy on the ground in his shop who does this as a labor of love has already recognized the problem and designed a solution (even if he doesn’t have the technology or resources to bring it to fruition) rather than the “white coat engineer” who puts something on paper in his ivory tower that looks good and impresses a management team and the CFO ( who are clueless to the technical aspects of anything) then blames the poor maintenance guy because he cannot make a bad design work like the paper says it should.

Like most others I don’t have time to blog because I work for a living and on the rare occasions I have it is on a technical board or product board for either a problem (or other specific purpose) I’m having or something I’m looking to buy. ( which in this particular case- both apply)

When I was “ghosting” here before I officially joined it what impressed me the most was the level of technical knowledge and “experimentation” along with the “field testing” videos. (honestly, if the levels of work that exist here existed in the industrial world- the US would be back on top of the industrial world in production of everything). Seriously, I’m a member of both ASME and SAE and I’m telling you that you cannot buy, borrow or steal the wealth of “in the field” knowledge and data contained in groups like this.

Let me just qualify where I’m at so you get an idea where I’m coming from ( and going) because sometimes I switch gears between the two and it can give a mistaken idea of what my intent is and there are only 3 with no particular order because they all have unique priorities.

My purchase- I’m going to buy one of these things and all the brochures tell me how great and wonderful “X”s product is and how many pretty and useful things I can stick on it. I’m not interested so much in the upfront cost as what it is going to cost me to own it over the life of the vehicle as what they really can do under extreme field conditions. That’s where this board is really worth its weight in gold to me personally.

Industrial/military model- That’s what made me get going on the thought process because that’s where firms contacted various people and assembled a team (me included- I didn’t start this idea nor is it my creation, I was simply invited to the party). If it gets past the marketing analysis there will be a purchase order attached to it with substantial financial benefit. Granted ( based on the preliminary criteria I have been given) this machine will be an AATV in name and concept only compared to what the focus of this board is own. Just based on what I have now, I can see this machine being all steel, having run flats as well as steel treads, weighing 2 tons and costing about 150k easy. That’s hardly a 1:1 with whats here except in operational concept and maybe general appearance.

Our pet project- That was a logical drill down of the above project to see if we could adapt everything we will accomplish and learn and come up with a marketable product in this market ( and maybe laterally extend into a few others). That’s the main reason I’m posting rather than just reading. I’ll figure out what works and what is feasible- what I’m really interested in is what does NOT work or where my ideas are going way off base because given the choice of 2 options I would rather switch gears in the brainstorming phase and select the right path even if it takes more time on the front end than go off “loosey goosey” and find myself waist deep in quicksand over something stupid that a blind man would have seen had he looked beyond his tunnel vision. (particularly when I would be maybe 10 steps along and have expended considerable time, effort and money just to finally prove it didn’t work and have to go back to square 1)

Please keep the critical critiques coming and please if you would ( since you apparently have run some numbers and I have not even started) go into a little more detail as to what you discovered and how you derived them. I’m really interested in seeing that.

[Bw6]

The motors I am considering have an RPM range around 350 on the top end. With a 25” tire @200 RPM is about 30 mph so I don’t see the RPM as a big issue as far as road speed is concerned and if it were to become one a belt/pulley can be installed to increase it. I don’t think I personally would want an AATV driven past 40mph personally but I’m sure there are people who would.

MudN: I think you better reconsider RPM, because a 25" tire @ 200 RPM is more like 15 mph, not about 30 mph.

I agree with Jerseys' calculations, and Mudbugs comments, I think you should start generating some solid numbers.

If the goal is a 900 lbs hydro machine with 25 hp., I don't think that's possible. I'm not just shooting from the hip. I was commissioned last year to design a machine that would weight under 1500 lbs with tracks for a company that operates in Canada's oil sands. The reason for the weight limits was because of coptering it in. They wanted diesel power, hydro, ROPS, half cab, tracks and min. 15 mph. Well I designed it, and did a spreadsheet documenting every component, even down to the weight of the fasteners. But there was no way I could comply. So good luck, and I mean that sincerely.

I did another design with diesel power, not hydo, and came under 1500 lbs., but they wanted hydrostatic.

[azz7772]

[QUOTE=Bw6;115223]MudN: I think you better reconsider RPM, because a 25" tire @ 200 RPM is more like 15 mph, not about 30 mph.

I agree with Jerseys' calculations, and Mudbugs comments, I think you should start generating some solid numbers.

If the goal is a 900 lbs hydro machine with 25 hp., I don't think that's possible. I'm not just shooting from the hip. I was commissioned last year to design a machine that would weight under 1500 lbs with tracks for a company that operates in Canada's oil sands. The reason for the weight limits was because of coptering it in. They wanted diesel power, hydro, ROPS, half cab, tracks and min. 15 mph. Well I designed it, and did a spreadsheet documenting every component, even down to the weight of the fasteners. But there was no way I could comply. So good luck, and I mean that sincerely.


what material did you use for the frame? Was it all hydro or a hydro chain setup? And what material for the tracks? Wheels aluminum or steel?

[mudNmallards]

MudN: I think you better reconsider RPM, because a 25" tire @ 200 RPM is more like 15 mph, not about 30 mph.

I agree with Jerseys' calculations, and Mudbugs comments, I think you should start generating some solid numbers.

If the goal is a 900 lbs hydro machine with 25 hp., I don't think that's possible. I'm not just shooting from the hip. I was commissioned last year to design a machine that would weight under 1500 lbs with tracks for a company that operates in Canada's oil sands. The reason for the weight limits was because of coptering it in. They wanted diesel power, hydro, ROPS, half cab, tracks and min. 15 mph. Well I designed it, and did a spreadsheet documenting every component, even down to the weight of the fasteners. But there was no way I could comply. So good luck, and I mean that sincerely.

I did another design with diesel power, not hydo, and came under 1500 lbs., but they wanted hydrostatic.

Oh no, There is one thing about you and a few other posters here who have specific detail in their posts- there is zero doubt you are not “shooting from the hip” and believe me- you and they have my full and undivided attention when you post and thats why at a point in the future I would like to maybe take this offline in deeper detail with some folks here on the recreational project.

I did run the RPM number on the plane to the meetings and a few other rough ones just to get an idea of how to direct my thoughts.
I used the industry standard formula of RPM= 168 X MPH (30 is what I plugged in) X G ( gear reduction so I figured direct couple so plugged in 1) /R (rolling radius of a tire) which is one of my baseline formulae I have on my quickie calculation spreadsheet.

At 30mph that comes out to 201.6 on the RPM. Now granted I have yet to factor in rolling resistance calcs, grade, acceleration and all that simply because I don’t have a conceptual vehicle weight/payload etc to estimate those calculations because nobody has yet reached a consensus on what exactly we want the end product to be and be able to do. ( that’s also driven by the fact that I’m not doing anything on the body design and really cant until I’m given something as a baseline to say “I can power it to meet the specs with this or that” or either say “it wont work”)

Judging from your post you did it all turn key ( or at least in close proximity with your team with a lot of interaction) and had a high degree of ownership in your process. I’m dealing with a group contacted individually by a manufacturing company through a marketing firm to provide technical input for a “potential” product (at this point). I only know 3 of these guys personally and this group is spread out over 6-7 different countries and time zones and this is not anyone’s sole or priority project. Also, I’m not the captain of this ship neither is this my sole idea or “my” (as in individual) project. As a result, I have some constraints that you probably didn’t have and I wouldn’t have if this was a one man show. I know what needs to be done to design a machine but I’m in the “hurry up and wait” mode so whatever other expert in their respective area gives us whatever he/she comes up with and a decision is made as to whether we go with it or not. I’m not a big fan of working remotely on things like this but it’s the nature of the beast in the modern world. I’m giving you that info so you can see where I’m coming from and when I say I “can’t” go further you can see why so you don’t think I need to be drug tested or just sitting on my thumb.

That said, if in the future the decision on the recreational AATV becomes “do not proceed” with this group- I can easily see coming to people on this board any trying it that way and I would finance a chunk of it.

Given that you went all the way through the process, maybe your end number is the “final” result? Could you give me a sample of how you derived your speed because I know my “raw” number is going to come down because no vehicle weighs in at zero and likewise no tractive force is zero either.

Its funny you mention Oil Sands, I spent most of 10 and part of 11 there doing another reliability project and that environment was one of the ones we are to plan against. It appears to me based on the requirements you were given that we are doing a substantially different vehicle. (especially on the military application we have to consider)
Ours appears to be a multi purpose light construction/utility vehicle with AATV characteristics rather than a vehicle for pure human conveyance. Except for the weight I have been given the same basic desired qualities you listed and to run on JP-8 exclusively but I think the capabilities they want must be radically different because some of the attachments they would like to put on it weigh a lot more than 1500lbs.

Just FYI, I’m not “married to” hydrostatic drive only. I can do them all equally well. I just started there because it’s a parameter in the big project. I think I’m like you in this one aspect. I made it clear when I was tapped on the shoulder and accepted this project that theres no doubt I can build a hydrostatic system and drive to give them any performance they want. The question on the table is: “can the system that delivers what they want fit in the box they want to put it in”. I’m personally open to any type of drive system.

[azz7772]

here is a page for some inspiration it even has the max track that was mentioned also the poncin vp 2800 is also interesting 35hp 60km/hr amphibious with tracks

http://www.unusuallocomotion.com/pag...les-light.html

[North Country Tough]

MudNmallards question,if I where to Cryro my new axles for my Argo just how much tougher would they get,how much more resistant to bending or shear force,if you could give me a idea like by a factor of 2,3,at the moment I do not have the specs on the steel being used or what process if any they have been treated,I have requested that info from ODG but as of yet have not had a response.And do you feel it beneficial to Mr Freezee the chain and sprockets while I have it down.NCT

[Bw6]

[QUOTE=azz7772;115225]

what material did you use for the frame? Was it all hydro or a hydro chain setup? And what material for the tracks? Wheels aluminum or steel?

All hydrostatic, no chains (I hate chains), Alum. body, with HRS frame. The tracks are a proprietary design of mine (lighter than Argo), steel wheels.

[mudNmallards]

MudNmallards question,if I where to Cryro my new axles for my Argo just how much tougher would they get,how much more resistant to bending or shear force,if you could give me a idea like by a factor of 2,3,at the moment I do not have the specs on the steel being used or what process if any they have been treated,I have requested that info from ODG but as of yet have not had a response.And do you feel it beneficial to Mr Freezee the chain and sprockets while I have it down.NCT

I’ll give you the best approximation I can with the absence of specifics on your shafts. If you get me the information I’ll send it to some of the companies I use and try to get you a better answer. (I “use” cryo I don’t actually do it so I don’t know all of their calculations and secrets. I do do heat treating but cryo is a totally different world)

Chains/sprockets- Other than the normal alignment/lubrication, cryo is the only thing you can do to enhance them. Based on my own experience you can realistically expect a 2-300% extension of the life expectancy especially in the chain stretch. The only caveat I have experienced is that the chains must be totally stripped prior to treatment and before you put them back in service you need to really soak them in oil or thinned grease to get under the rollers to the pins and recoat them to get them back to OEM.

Shafts- on bending, maybe taking your current shaft to about 125% of stock property. It’s not much. Cryo will NOT keep any shaft from bending/flexing or sagging much more than when it was originally turned but what it will do when treated is make the whole shaft uniform so when it flexes to load it will return to its relaxed state and not accept the bend or deform. (unless the modulus of elasticity of the base metal is exceeded- then its gonna bend)

Shearing- If you are talking about lateral shearing then I would say there will be zero improvement. If you are talking about torsional shearing then I would say based on my experience that you will realize benefits literally in orders of magnitude. I don’t want to stick my neck out too far but from my own experience I have NEVER had a treated shaft break from torsional stress that was cut to be “fit for purpose”. This is what finally made a “believer” out of me was conveyor shafts with overhung gearboxes and motors on them at mines, lumber mills and steel mills and shock loads out the wazookie.

[Robinhood02]

200 rpm on a 25" tire is about 15 mph
mudNmallards your calculation went south when you used the rolling radius ,you should have used the circumfrence of the inflated tire

[azz7772]

here is a vid of a hydrostatic driven front sprocket drive vehicle

[mudNmallards]

200 rpm on a 25" tire is about 15 mph
mudNmallards your calculation went south when you used the rolling radius ,you should have used the circumfrence of the inflated tire

Well, when I read your post I went back and checked what I put in my running spreadsheet for quick calculations and it was correct. I didn’t write this formula, I got it and a few others out of a Parker manual before I left for the meetings this week to play with.

I got nervous when I read your post last night ( it aint the first time I’ve plugged in a wrong calc when I was in the initial stages on the fly and probably wont be the last) so I emailed one of our Eaton reps and the char-lynn application manual he sent me this morning specifies that exact parameter for use in sizing for a vehicle and roller speed application at the wheel. ( rolling radius and not circumference)

Since I’m not a certified mathamatologist, not the author of the formula, never tested it and honestly never used it before (for a vehicle application) and my only “claim to fame” is its in 2 different pubs where I got it and verified it from- I’m in no position to say yea or nay, right or wrong or defend/prosecute it with any degree of accuracy so I’m not even going to try while I’m at meetings and doing facility tours this week.

However when I get back to oz and the site, I’m going to check Marks Mechanical Engineering Handbook and a few others to see what types of formulae there are and what any differences are.

When I get back to work, I am in a position to go to safety and borrow one of their radar guns and get my tachs and photostrobes and go to the wheeled vehicle shop, grab a vehicle and test it for accuracy. I’ll let you know one way or the other when I do that.

Thank you for pointing that out and please don’t hesitate to put the brakes on anything I post you feel might be in error or off base or offer any new or different ideas from your own vast experiences. I would much rather switch gears in the thought stage than further into the process.