What's new
What's new

Tram - definition?

Anymouse

Aluminum
Joined
Oct 11, 2008
Location
South Texas, USA
The word "tram" that is used to describe the squaring process of a mill spindle and table, is it a truncation or derivation of another word?

Where/how did this word get into machining speak?

Wally
 
Tram came from "trammel", as in using two trammel points to scribe a circle. When tramming a mill spindle, those two points are the spindle center and tip of the indicator.

-Sol
Glacern Machine Tools
www.glacern.com
 
I had read before, but I can't find a reference to this, that it's Italian slang. I can't remember the exact verb (and my wife's phone is busy), but it's something like "trama" or "tramare". The meaning is fairly loose...scheming, designing, planning.

That goes back to trade school days and I didn't keep the stone tablets that we used back then.
JR
 
tram 2 (tr
abreve.gif
m)n.1. An instrument for gauging and adjusting machine parts; a trammel.
2. Accurate mechanical adjustment: The device is in tram.

tr.v. trammed, tram·ming, trams To adjust or align (mechanical parts) with a trammel.
 
In the Louisville area indicating the turret head in is called sweeping the head. The first time I heard tramming is here. I always thought of a tram as a subway or electric tracked vehicle.
 
Last edited:
Railroad mechanical engineering from the last century makes extensive use of the term; a four wheel truck (wheel assembly) is said to be "in tram" when the axles are parallel and 90 deg. to the rails. There were extensive texts on the art of "tramming" the running gear of a steam locomotive; first steel wires were stretched through the cylinder bores and centered, then the frame was adjusted to be parallel with the wires, next a cross wire was established at 90 deg. to the cylinder bores, and the axle bearing wedges carefully adjusted to bring all the axles into line. On modern day engine restorations this is all done optically, but the result is the same.

Dennis
 
Anymouse --

Back when I started hanging around in machine shops -- after school, in San Francisco, in the late 1960s -- the old-timers used the words "square" or "align" to describe the adjustment of a vise, fixture, or part relative to a non-moving machine feature (such as the face of a machine column or the edge of a machine table). These guys reserved the words "tram" and "tramming" to describe the adjustment of a vise, fixture, or part relative to a movement along or around a machine's axis.

John
 








 
Back
Top