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Elevator tab jack screw nut http://t18.net/thorpforum/viewtopic.php?f=2&t=8300 |
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Author: | Jeff J [ Mon Dec 24, 2018 8:26 am ] |
Post subject: | Elevator tab jack screw nut |
I noticed I have quite a bit of play between the jack screw and the nut. The assembly the builder used does not match the drawings. I have the tools to fabricate the nut and could use some practice using them so I figure I will give fabrication a shot. The drawing calls out aluminum plate for the nut but mine appears to be made from brass. What is the most popular metal being used to make the nut? |
Author: | bfinney [ Mon Dec 24, 2018 1:43 pm ] |
Post subject: | Re: Elevator tab jack screw nut |
Mine is made from aluminium bar stock as called out on the plans. How do I know this you ask? I recently made a new one cause I had what I thought was excessive play in my trim system. Merry Christmas to all and to all good night. ![]() |
Author: | James Grahn [ Mon Dec 24, 2018 9:27 pm ] |
Post subject: | Re: Elevator tab jack screw nut |
Per Plans...in stock. Cubes |
Author: | fytrplt [ Tue Dec 25, 2018 7:45 am ] |
Post subject: | Re: Elevator tab jack screw nut |
An old newsletter talks about putting a thrust washer in the bearing block to take out the end play in the jackscrew. |
Author: | jrevens [ Tue Dec 25, 2018 11:47 pm ] |
Post subject: | Re: Elevator tab jack screw nut |
Jeff, As I believe John Thorp himself pointed out, aluminum and steel actually make a pretty good bearing pair, with proper lubrication of course. I don't remember what alloy is called out on the print for that "nut", but I believe it is 2024-T3. That's what you should use, IMHO. You also should have the proper thread type. Like you said though, your assembly is obviously not built to plans, based on the picture. |
Author: | Jeff J [ Wed Dec 26, 2018 6:44 am ] |
Post subject: | Re: Elevator tab jack screw nut |
I don’t have the drawings handy but I remember thinking the thread called out was a standard bolt thread. If it isn’t, then I cannot fabricate as I don’t have what I need to turn an internal thread. All I have for cutting threads is a standard tap and die set. |
Author: | jrevens [ Wed Dec 26, 2018 12:06 pm ] |
Post subject: | Re: Elevator tab jack screw nut |
It’s been so many years since I built my T-18... I was building in the 70’s and 80’s, and I no longer have the prints to check, but a jack screw like that is frequently an acme thread. Anyway, Cubes has the right part I’m sure. I didn’t mean to muddy the waters, Jeff. That thread may indeed be a “standard” thread, but I believe I may have borrowed an acme tap to make mine. I could be wrong. |
Author: | bfinney [ Wed Dec 26, 2018 3:35 pm ] |
Post subject: | Re: Elevator tab jack screw nut |
Per plans, drill 5/16" tap 3/8-16 NC, this is how mine is made works fine, so far. ![]() |
Author: | James Grahn [ Thu Dec 27, 2018 3:44 am ] |
Post subject: | Re: Elevator tab jack screw nut |
Look at the 694 drawing. It is 2024t3. It’s made from .500 bar. Cubes |
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