| Author |
Message |
Scott Whitney (66.82.9.14)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, February 20, 2003 - 10:57 pm: | |
Hi Guys,
This question is for a friend who does not have Net access at the moment.
He has an MCI speedometer made by Dixson Inc. It is model #7L-8-859 and operates at 500-1100Hz. It is currently set at 346/revs per mile. He wants to install this on his MCI coach, but needs to know how to set the dip switches.
He has removed the old gauge which is a MCI model S401 made by Sigmanetics and set at 480 revs./mile. Will the sender/pick-up from this speedo work with the new speedo?
So far I have downloaded and printed several documents from: http://www.ametekdixson.com/ which is the Dixson web site. But I am not sure if I even have the correct documents. They list formulas and pages of dip switch settings, but I am not sure that this info is for the 7L-8-859 gauge. Their literature section mentions 500 series and 700 series, but not sure which series his falls into.
Any ideas? Dixson does have an 800 number. Might need to call them and see if they can shed some light on the mystery gauge.
Thanks,
Scott |
Gary Stadler (Boogiethecat) (68.7.217.217)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 21, 2003 - 3:32 am: | |
Scott, if you can't find the Dixon specs that simply tell you what the settings are, you can do the math and figure out how many hertz the bus would be putting out at say 60 miles per hour, then set the speedo up on a bench with variable frequency oscillator and a frequency counter. Basically just set the frequency to the correct hx for 60 and flip switches until it reads the right MPH.I did a bunch of speedos like that for Ronthbusnut...it works fine. If all else fails he could send it to me and I could do it for ya...
Cheers
Gary |
Jack Perry (Jpwinks) (68.71.200.180)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 21, 2003 - 7:28 am: | |
Scott, is the model S401 working? what was the reason for replacement? If the model S401 is working I know someone that could use it (me)LOL. Please advise. jpwinks. |
Chuck Harris - PD4104 (207.172.11.147)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, February 21, 2003 - 10:18 am: | |
Scott,
The pub you want is on the web site, marked something or other 51536B It is the second to last pub in the specs listing.
This is a high frequency speedometer. Not all systems are compatible. If you use this speedo on a bus with a front wheel magnetic sensor, you need more than 100 slots on the rotor. eg. at least 100 pulses per revolution of the tire.
I have 30 or so of these Dixon speedometers. I haven't found an application for them yet. I plan to put one on my 4104, with a suitable sensor.
-Chuck |
Scott Whitney (66.82.9.16)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, February 24, 2003 - 12:22 pm: | |
Thanks guys! I have printed everything out. Will see if he can have a go at installation now.
Jack: I don't know if the S401 is working. I presume it is. He is replacing it because he came across a very good deal (free!) on a whole set of new gauges. He also has a new dashboard. So the new gauges, just go with the look of the new dash. I'll find out about the S401 for you.
Scott |
Scott Whitney (66.82.9.19)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 02, 2003 - 10:30 pm: | |
One more question about this speedo. . . He has two bolts that are on the wheel hub that apparently act as the senders for his MCI 8. I printed all the charts and forumlas etc., but the math to figure out RPMs, Hz, dip switches, etc. is all a bit confusing. Would anyone here be willing to give him a call and help explain the hook-up of one of these speedos? I know nothing about them and can only help by posting his questions here.
His name is Sam and is very friendly and helpful (we spent today replacing an air-bag on my bus). Anyone who might be able to help, please call him at (918) 247-6150. Thanks! (I am sure he'd call you back on his dime)
Scott
P.S. Jack, I asked him about his plans for the old speedo. Unfortunately, he already promised it to a guy that is buying another old MC8 from him. (was the engine doner for his conversion project) |
Chuck Harris - PD4104 (207.172.11.147)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 03, 2003 - 11:11 am: | |
The dip switches on the Dixon speedometers set the frequency (pulses per second) that will result in a full scale reading on the speedometer. The speedometer in question has an 80MPH full scale, if I recall correctly. So here is the math:
(80miles/1hour) x (1hour/3600secs) x (480revs/mile) = 10.67 revs/sec
That means that the tire makes 10.67 complete revolutions every second when traveling 80 mph.
The speedometer is adjustable to accomodate anywhere between 450 and 1450pulses/sec to indicate 80 mph. However, your tire rotates 10.67 times per second at that speed. So, you need between:
450/10.67 = 42.19 and 1450/10.67 = 135.9
pulses out of your wheel rotation sensor for each revolution of the wheel. You only have 2 pulses per rotation of your wheel. This speedometer will NOT work in your application.
To make this speedometer work on your MCI, you would have to have between 43 and 135 bolts evenly spaced on your hub. This is why I said 100 in an earlier post. Probably the easiest number to comeup with would be 64.
-Chuck |
Stephen Fessenden (Sffess) (65.130.11.248)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 03, 2003 - 10:05 pm: | |
I bought a VDO speedometer on Ebay that has a, much, much wider pulse range than you are describing. It has a trip odometer too. 12 or 24 volt. |