Ohming out arms and stuff
#1
Posted 17 March 2009 - 12:59 PM
Some of the offending junk:
Joe Lupo
#2
Posted 17 March 2009 - 02:03 PM
Set the multi-meter on the highest ohm setting. Touch either probe to any of the copper comm plates, then the other probe to either of the other 2 plates. The reading on the m/m will be ohm reading. Continue to different plates, or segments, till you check the arm a couple times.
The original T-jet arms measure from 16 ( yea, sixteen!) to 18.5. The Magna Traction average 14 to 15. Most all the rest are in the 6 range except the famous quad lam Super II arm that is around 4.5.
Try to find Neil's Wheels tech tips if it's still on the web. That gives a detailed rundown on each Aurora arm.
Neil had so many e-mails that he had to take the tips off the web when he quit selling HO parts. I'll see if I can find my link to the tips but I doubt it.
Ohming is very easy on a clean comm and very important! About 20% of the arms will be bad and about 1 in a 100 will be "racing quality"!
11/6/54-2/13/18
Requiescat in Pace
#3
Posted 17 March 2009 - 04:17 PM
Joe Lupo
#4
Posted 17 March 2009 - 05:54 PM
Agh, more or less just take the average. A typical early T-jet arm with gray stacks and green wire will likely read 16.8, 16.9, and then 16.8 on each different segment of the comm.
I don't remember exactly but Aurora used something like 400 turns of close to 40 gage wire on their first arms. It's not at all unusal to find an arm with 15 more turns on one stack, thus the varying ohm readings.
If the arm is "dead" there will be NO ohms at all. Meters vary but the meter will either remain blank or read zero.
I checked my favorites and google but couldn't find Neil's Wheels nice tips, printed it's about 10 pages and covers all the early Aurora chassis. HO cars aren't real popular here, you may try Yahoo Groups for HO World. There are close to a 1000 members. Also try HO World. net (I think it's net). Check the archivies section. Someone has the tech tips on their site, I just can't remember who. There's a lot of HO sites!
11/6/54-2/13/18
Requiescat in Pace
#5
Posted 17 March 2009 - 06:44 PM
"Everything you love, everything meaningful with depth and history, all passionate authentic experiences will be appropriated, mishandled, watered down, cheapened, repackaged, marketed, and sold to people you hate." Von Dutch [Kenneth R. Howard] 1929-1992
."If there is, in fact, a Heaven and a Hell, all we know for sure is that Hell will be a viciously overcrowded version of Pheonix." Dr Hunter S Thompson 1937-2005
"Whither goest thou, America, in thy shiny car in the night?" - Jack Kerouac 1927-1969
"Hold my stones". Keith Stone
My link
#6
Posted 17 March 2009 - 07:27 PM
Joe, I believe you are the same person that was looking for springs last week. While looking for Neil's store on ebay, I ran across this:
http://cgi.ebay.com/...O...A1|240:1318
Might be a good sourse for springs and the prices look better.
11/6/54-2/13/18
Requiescat in Pace
#7
Posted 18 March 2009 - 07:14 AM
I scanned the Front Range site and it did look good.
Joe, I believe you are the same person that was looking for springs last week. While looking for Neil's store on ebay, I ran across this:
http://cgi.ebay.com/...O...A1|240:1318
Might be a good sourse for springs and the prices look better.
GO TO SLOTCARMONSTER.COM TONY V. POSTED A STEP BY STEP, ON ARMS AND BUILDING TJETS,ARMS ETC. HE DOES BUILD SOME VERY FAST ONES
#8
Posted 15 June 2012 - 05:07 PM
Joe,Can someone tell me how to ohm out a T-jet or A/FX arm with a DVOM ? Also, in values, what is a good arm? And one more thing, I see lots of ebay listings stating green tip , green wire arm etc. What is the best and does it really matter? I am just starting to sort out 35 years of collecting H.O. stuff and I think I have my work cut out for me Thanks in advance for the info.
Some of the offending junk:
Now i see when you say it will take some time. WOW your collection is endless.
Keep photos coming
Thanks John F