<snip> <snip> Don't forget that your MAST is going to expand 12*100 ppm too, so it'll be a bit less than that Nylatron 66 is at 80ppm, go with MD grade it is 50ppm ___________________________________
I have much less mast inside the tower but I concur that there is no reason to have three bearings on the mast (two thrust plus the rotator). John KK9A Jorge, If this question is directed at me, no,
The coefficient of UHMW linear expansion of 11e-5 in/in/deg F means 0.011"/in/in for 100 deg F temperature change, which changes the 0.030" gap I machined at 3" nominal bore at 65 deg F to about 0.01
UHMW PE is about 100 <snip> SO let's take an example of a 2" diameter mast. going from -40C to 60C is 100 degrees, and probably wider than the range most ham towers will see. So that's a change in di
Here is an interesting thrust bearing video from DXE https://www.youtube.com/watch?v=EuewFM15Py4 73 Tim K3LR Those .375 inch st bolts, that are spaced every 120 degs. Mine all rusted and seized up re
I have much less mast inside the tower but I concur that there is no reason to have three bearings on the mast (two thrust plus the rotator). John KK9A middle thrust bearing was adjustable..so I coul
I was fortunate to have a 12" dia X 10 " tall Teflon solid ROD machined to fit the Rohn AG45 top plate hole 8 inched inserted snugly in the hole with a 2" tall collar. An 11" in dia. 1/4 thick SS pla
<anip> I guess your science teacher "Back when" didn't do what mine did. He had a steel ball (on a handle, and a steel ring (ditto). At room temp, the ball would NOT fit through the ring - maybe 1/32
Absolutely. The circumferential expansion far exceeds the tiny inward radial expansion. Thomas W Noel KF7RSF _______________________________________________ __________________________________________
There's no radial inward expansion at all. everything moves "out" the outer edge moves out "more" than the inner edge. Thomas W Noel KF7RSF <anip> I don't agree. If the hole is large enough to just
Sure. But since most machining isn't done at -40 deg C, the hole does get smaller when the temperature is lower than when the hole was bored. I think my calc was correct from a 65 deg F machining tem
Author: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Tue, 13 Dec 2016 03:44:36 -0500
Except when tho OD is constrained from expanding by a metal with less expansion 73 Roger (K8RI). On 12/9/2016 11:10 PM, Grant Saviers wrote: Sure. But since most machining isn't done at -40 deg C, th