Ground Speed Indication Options ?
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URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=110062
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Topic: Ground Speed Indication Options ?
Posted By: Macon Rounds
Subject: Ground Speed Indication Options ?
Date Posted: 07 Aug 2015 at 4:08pm
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Ground Speed indicator / speedometer .....
Looking for acurate 2 MPH to 10 MPH indication system.
I have seen speedometers attached to bicycle wheels and GPS systems.
Looking for other options for true ground speed under pulling conditions.
All genuine and sarcastic replies welcome !!!!
------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Replies:
Posted By: ToddnwIl
Date Posted: 07 Aug 2015 at 6:52pm
| I'd try an older corn planter monitor with a radar gun that is properly calibrated. There is a couple ways it could monitor speed. You could use an actual radar gun or they make some that look like a hockey puck. This way as traction went away it wood show your true speed. I have never tryed this but thought about it. |
Posted By: cwhit
Date Posted: 08 Aug 2015 at 7:26am
| There is usually a speed lag if using a monitor-radar- puck system. Bike tire units seem to be a little more exact, at least the ones I've seen at slower speeds. |
Posted By: DaveKamp
Date Posted: 08 Aug 2015 at 9:04am
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Bicycle wheel and electronic bicycle computer. It has the ability to be calibrated to substantial precision, and includes time, distance, average and max speed. Use a 20" front wheel with knobby tire, mount a bicycle front fork on a swingarm to contact the ground just in front of your drive wheels. Mount the bicycle speedometer per instructions, but use TEN wheel magnets instead of one... this will give TEN pulses each wheel rotation, so 10 times the signal clarity. When you pull at 4.05mph, it will read 40.5. MANY bicycle computers have a secondary input feature for second magnet sensor that measures cadence (crank speed)... and some record it as well. I don't believe any 'log' the cadence, but one can compare cadence input to ground speed to measure SLIP. These bicycle computers are inexpensive... $25 bucks... runs on a coin battery, and lasts well over a year. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
Posted By: Macon Rounds
Date Posted: 08 Aug 2015 at 1:58pm
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Thanks for the suggestions fellas. You have given me some real good info to chew on ! ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: DanWi
Date Posted: 08 Aug 2015 at 9:42pm
| Wanted to see what speed I was actually cutting hay at with the 190 and discbine just took a garmin with me. Are you looking for something for you on your tractor or for something to monitor others at a pull? |
Posted By: timmypuller
Date Posted: 09 Aug 2015 at 7:49pm
| go on ebay and look for a marine speedometer. they run off of gps and are very accurate. it will take about 2 weeks to get it because it ships from australia. costs around 175 to 200 with a magnet mount antenna |
Posted By: PeaRidge180
Date Posted: 09 Aug 2015 at 9:16pm
| Why not use a cell phone app? Some of them are supposed to be accurat |
Posted By: PeaRidge180
Date Posted: 09 Aug 2015 at 9:17pm
| Why don't you use a cell phone app? |
Posted By: DaveKamp
Date Posted: 09 Aug 2015 at 9:42pm
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GPS really has no accuracy at this level- you're talking a distance of 300 feet at walking speed. Because of Selective Availablility, a guy with a GPS in his car, or his phone, or his tractor can be SITTING STILL and get a 7mph indication sideways. This occurs ON PURPOSE, at RANDOM, so that 'bad guys' can't use it against 'good guys'. Best thing to use for a ground speed indicator, is a sensor that reads ground speed. When you use the bicycle tire as I noted above, you'll have accurate indications of a hundredth of a mph, because you're triggering it at 10x resolution. The tire will NOT slip, and you can very precisely calibrate it using a tape measure. I highly doubt you'll find a better solution, and you certainly will not find it at a lower cost or easier build. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
Posted By: SHAMELESS
Date Posted: 09 Aug 2015 at 10:22pm
| monitor outta a combine work? they show RPM, MPH, |
Posted By: wayneIA
Date Posted: 10 Aug 2015 at 12:04am
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I use two older micro trak systems on my tractors for field work, they use magnets on the front wheel to determine ground speed, but they now have a GPS option. I know if your front wheel comes off the ground it wouldn't tell you your speed, but when I pull it is usually in the last 10-20 feet where speed doesn't make much of a difference. the address for the speed unit is: http://www.micro-trak.com/granular-seeders/spreaders/calc-an-acre-ii" rel="nofollow - http://www.micro-trak.com/granular-seeders/spreaders/calc-an-acre-ii
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Posted By: Macon Rounds
Date Posted: 10 Aug 2015 at 3:02pm
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GPS and phone apps will have lag for sure and marine speedometer will probably be simular. I like bicycle wheel with the 10 magnets..... for improved accuracy. ..... I will look into micro trak but I believe it w I'll not be cost effective. I do like the large display though ! ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: timmypuller
Date Posted: 13 Aug 2015 at 4:22pm
Posted By: timmypuller
Date Posted: 13 Aug 2015 at 4:43pm
actually a gps works just like the bicycle equipment. the more input it gets the more accurate it is. i use a calcu acre monitor and it is faster than the wheel setup on the sled which sounds a whole lot like the bicycle wheel deal you are talking about. the only drawback on the calcu acre is cost $800. the marine speedometer is only $200 with shipping and gets the same amount of signals that the calcu acre does . if you farm the extra cost of the calcu acre is worth it because it does a great job when spreading fertilizer or seed. the marine speedometer is the way to go for just pulling. it will defininatly be the lightest and easiest to install and you will look a lot cooler without that extra wheel hanging under your tractor. plus since its made for a boat you can just leave it on all the time since its waterproof and because its on your dash you won`t have to remove it when loading or unloading like those silly looking wheels 
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Posted By: DaveKamp
Date Posted: 13 Aug 2015 at 11:25pm
Tim... I cannot, for the life of me understand how anyone could ever make that claim. A field monitor, using a local DGPS beacon will do a much better job than standard GPS, or a cellphone, but very few GPS receivers have a DGPS receiver, and where they do, there's rarely a DGPS transponder anywhere nearby to relay GPS timing data correction. (A DGPS transmitter listens to satellite timecoding from a FIXED location, and then calculates the amount of 'skew' in the timing signals {mostly generated either by atmospheric conditions or selective availability}, and then transmits the CORRECTION FACTOR for each timing signal for any dGPS-equipped systems within radio earshot (a mile or so). My cellphone, my Garmin, my TomTom, and my Faria Chesapeake SS will all indicate different speeds, varying from 2mph to 12mph, while TIED TO THE DOCK. To get an accurate indication on my boats, I use a doppler radar, and drive towards a bouy... and it's really, really obvious when the GPS signals have been skewed by 'selective availability'... not only does my speed indication go berzerk, my course indicated on the GPS plotter goes way out-of-the-channel, and my elevation indication changes. Now, I'll admit that the river does flow downhill, but from a macro perspective, it's typically pretty close to flat. I'll gain a few feet from one end of a 26-mile pool in the river, I WON"T gain 35 feet going from the gas dock to the transient overnight slip. A 20" bicycle wheel, triggered 10 times per revolution, will turn 62.8" in one revolution, so it's trigger distance is 6.28"... or 100*12/6.28 = 191 points of measurement over that 100' pull. The bicycle computer's chronograph measures in sub-hundreths of a second, so if the pull runs 3mph, that's 4.4ft/sec, you're seeing 52.8 inches per second, and seeing over 8 pulses in one second, the end result is a speed calculation integration error easily two orders-of-magnitude more accurate than a GPS indication, especially at walking speed in course-over-ground. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
timmypuller wrote:Posted By: Charlie175
Date Posted: 14 Aug 2015 at 5:37am
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I tried Cell phone apps, they are not close at our speeds. Now if I am going 55, then they seem to read closer to the right speed. ------------- Charlie '48 B, '51 CA, '56 WD45 '61 D17, '63 D12, '65 D10 , '68 One-Ninety XTD |
Posted By: timmypuller
Date Posted: 14 Aug 2015 at 1:52pm
| I don't know about all those numbers but I do know what works. We've been running GPS for 3 years now and never once has it said I've been moving when I'm not. Also we've never been disqualified for speed since using gps. As far as how it works on a boat I wouldn't know but I've been on boats on the water and have never seen one sit completely still so it may be reading the movement from the waves or current. A gps will not distinguish whether movement is forward ,backwards or sideways it just knows it's moving. I also use a gps in the semi I drive and never had one say I'm moving when I'm not,maybe I have a better product. As far as cell phone apps there are some that are fairly accurate but most of the free ones are not that great. My final word on this is a gps such as a marine speedometer or a calcu acre works great and I still look cooler than some one with a bicycle wheel on their tractor running down the track. If you saw my orange junk running down the track you would have to say he needs all the cool he can get. |
Posted By: Dan73
Date Posted: 14 Aug 2015 at 2:06pm
| Just mark your rear tire and count how many times it goes around in a fixed amount of time then find the circumference of the tire and you have distance and time. A little math and you will know. Cheaper then rigging up a bike spedo but it might not be as accurate depending on how well you do at monitoring the wheel mark and with the time. |
Posted By: jaybmiller
Date Posted: 14 Aug 2015 at 7:23pm
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don't come to this often but am I to believe you can't go fast in a pull or you'll lose ? I thought the idea was to pull a big honking weight down the track, the furthest on wins ?? Jay ------------- 3 D-14s,A-C forklift, B-112 Kubota BX23S lil' TOOT( The Other Orange Tractor) Never burn your bridges, unless you can walk on water |
Posted By: DrAllis
Date Posted: 15 Aug 2015 at 7:33am
| Many Antique Pulls put a maximum speed of 3 1/2 or 4 MPH on their classes. You are correct, usually speed is the solution, but not in antique classes. |
Posted By: DaveKamp
Date Posted: 15 Aug 2015 at 2:48pm
The GPS knows that your moving, because it knows your position and vector, the latter being direction. The GPS system works on a network of satellites that have stratum-2 precision clocks that are synchronized to an atomic clock on earth. Each satellite broadcasts this time at a fixed radio frequency, and the time clock is phase-locked-loop synchronized to the frequency that the transmitter operates on. This means, the GPS bird is little more than a clock in orbit, with a radio beacon that transmit's the bird's ID and a time code. It 'knows' it's orbit path based on ground transmitters placed at regular intervals, and as it passes, it 'hear's the ground transmitter, and determines the frequency shift that occurs by Doppler Effect. It maintains it's orbit, and transmits frequency. Terrestrial receivers hear the GPS signal, read the time, bird's ID, and then calculate doppler shift. It does this to several other birds, and from that, the receiver can determine it's own position in 3 dimensions. Change in position equates to movement in a vector, and the time in which that change occurs, equates to velocity. That means, going straight up, is moving just like going north, south, east, or west. The GPS's position determination circle in 'standard' (non Mil-precision), is about 300 feet. That means, when you get a 'fix', you will most likely be within a 100 foot SPHERE of the identified position. Anywhere in that sphere (including below ground, or on an overpass, when you're really on the service road), is considered accurate. Mil-spec puts you within 15 feet or so- close enough to get a missle in a large doorway or window, or fly an aircraft under a high-tension wire. Selective Availability, is when the Department of Defense decides to alter the time code signal to cause the GPS to be less accurate 'for defense purposes'... i.e. some adversary decides to use an off-the-shelf GPS to remotely guide a home-made road-vehicle with an IED, or some other antic. Getting good data isn't about how you 'look' doing it, it's how the performance numbers look after you've completed the pull. ------------- Ten Amendments, Ten Commandments, and one Golden Rule solve most every problem. Citrus hand-cleaner with Pumice does the rest. |
Posted By: timmypuller
Date Posted: 19 Aug 2015 at 2:43pm
| Once again all I know is what works. This past Saturday nite I pulled in 3 classes, 7500 lb,8500 lb and 10500 lb. These are our open classes with a speed limit of 8 mph. In the 7500 lb class my gps said I was going 8 mph matching the sleds wheel version exactly. In the 8500 lb class my gps said I was going 7.7 mph once again matching the sled exactly. In the 10500 lb class my gps said I was traveling at 7.9 mph an exact match with the sled. GPS WORKS!!! I got 1st in the 7500,3rd in the 8500 (operator error 6th gear is way too fast when I get that much traction),and 1st in the 10500. Numbers are great but it's hard to argue with the facts. As far As far as the looking cool not being important you're wrong. 2 young fellers came up after the pull and congratulated me on having such a good nite. The last thing they said was "You need to paint your tractor because then it would be the coolest one here". These boys were 8-9 yrs old and I don't think you could get one more jd article of clothing on them. If I had a paint job I might have converted them |
Posted By: Larry(OH)
Date Posted: 21 Aug 2015 at 5:09am
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Set your GPS unit to walking to bike for the lower speeds. Both my Garmins have it. Now I did talk to a guy that had a radar set up on his tractor. said 800.00 to put it on, but since he had 25K in the engine, whats another 800.00 ------------- '40 WC puller,'50 WD puller,'50 M puller '65 770 Ollie *ALLIS EXPRESS contact* I can explain it to you, BUT I cannot understand it for you!! |
Posted By: Macon Rounds
Date Posted: 21 Aug 2015 at 10:05am
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Information and application..... That's what I LOVE about this forum ! You get all that and more here on our Allis site !!! ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: Macon Rounds
Date Posted: 21 Aug 2015 at 4:04pm
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Tim ........... I sent you a PM....
What type GPS reciever are you using ?
Also are you looking at GPS "real time" or after you are finished with your run ?????
Thanks in advance. ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |
Posted By: timmypuller
Date Posted: 24 Aug 2015 at 12:07pm
| Looking at realtime.the best by is the boat speedometer. On ebay for $ 162 |
Posted By: timmypuller
Date Posted: 24 Aug 2015 at 12:19pm
| When running a speedometer we find its very hard to get exactly on the speed you want. I run 8 &10 mph classes.10 mph in the 8500 and 10500 open is simple to hit and hold with my 21 in 6th. Not so hard to do in 8 mph 7500 in 6th. Have enough tire slippage to keep from setting off alarm. Very hard to do 8 mph in 8500 in 6th usually drop to 5th need to put a 5 and a half in for 8 mph 8500 and 10500 . What I usually do is get it as close as I can and crank it open when I feel the weight hit. |
Posted By: Macon Rounds
Date Posted: 01 Sep 2015 at 6:36pm
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Thanks for Your help and information. ------------- The Allis "D" Series Tractors, Gravely Walk behind Tractors, Cowboy Action Shooting !!!!!!! And Checkmate |