• We want to encourage those of you who ENJOY our site and find it USEFUL to DONATE and UPGRADE your membership from active member to donating or premium membership. If you want to know the differences in membership benefits, please visit THIS PAGE:

    https://www.hobby-machinist.com/premium/

    Donating memberships start at just $10 per year. These memberships are in fact donations that help pay our costs, and keep our site running!
    Thank you for your donation, God Bless You

[4]

EDUCATED ACME NUT

[3]
[10] Like what you see?
Click here to donate to this forum and upgrade your account!

RIMSPOKE

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jan 16, 2016
Messages
258
Likes
800
#1
A FRIEND WHO OUTFITS PEOPLE FOR PROSTHETIC LIMBS HAS SOME SPECIALIZED EQUIPMENT .

ONE OF THE TOOLS HE USES IS A SUPPORT THAT ALLOWS HIS PATIENTS TO STAND ON ONE LEG
WHILE HE WORKS ON THE OTHER .

THIS HAS A NARROW BICYCLE SEAT MOUNTED ON A STAND . IT NEEDS TO BE HEIGHT ADJUSTABLE
FOR DIFFERENT SIZE PEOPLE .SO IT HAS A 1" ACME THREADED SHAFT .

THE PROFESSIONALLY AVAILABLE DEVICE THEY SOLD HIM HAD A NUT WITH WINGS ,
THIS WAS NICELY MADE BUT REQUIRED HIM TO SPIN IT UP AN DOWN THE SHAFT
WHILE THE WINGS WOULD HIT THE PATIENT's LEGS .

MY TAKE ON THIS WAS TO MAKE A LARGE SIDE EDUCATED NUT LIKE WE USE FOR A QUILL STOP
ON OUR MILLING MACHINES .

HE GAVE ME THE NUT AND SHAFT TO PLAY WITH AND THIS IS WHAT I CAME UP WITH .

PRESS THE BUTTON AND THE THREADS DISENGAGE . THE KNURLS MAKE IT EASY TO
FINE ADJUST UNDER A LOAD . I ALSO HAVE A THRUST BEARING UNDER IT .

SO HERE GOES , HE WILL BE TAKING IT TO THE LEG SHOP TOMORROW FOR A TEST DRIVE .

DSC_1109.JPG DSC_1122.JPG DSC_1131.JPG DSC_1133.JPG DSC_1135.JPG
 

Asm109

Registered
Registered
Joined
Aug 29, 2017
Messages
187
Likes
204
#3
Beautiful work and a very clever idea. Did you test it to see how much load the nut can take? Probably not a problem but you are making something for human use where they are trusting it not to fail.
 

RIMSPOKE

H-M Supporter - Silver Member
H-M Supporter - Silver Member ($10)
Joined
Jan 16, 2016
Messages
258
Likes
800
#4
Beautiful work and a very clever idea. Did you test it to see how much load the nut can take?

THE INTERNAL TENSION IS ADJUSTABLE .

THE NUT STARTED OUT AS AN ACME HEX NUT .
I TURNED THE OD DOWN TO 1.500" . I THEN CHUCKED IT ON MY ECCENTRIC CHUCK AND BORED A 1" HOLE .200 OFF CENTER .
THIS CLEANED UP THE THREADS COMPLETELY ON ONE SIDE BU LEFT THEM INTACT ON THE OTHER .

A 1/4" SLOT WAS MILLED ON THE REMAINING THREAD SIDE SO WHEN IT IS ASSEMBLED , I CAN COMPRESS
1 , 2 OR 3 SPRINGS INTO THE SLOT . THIS GIVES THE THREAD ENGAGEMENT A PRETTY HEFTY PUSH
AND WILL CERTAINLY HOLD HUNDREDS OF POUNDS BUT STILL SPINS FREELY ON THE SHAFT .

IF FRANK DECIDES THE EFFORT TO DISENGAGE THE THREADS IS TOO GREAT , HE CAN TAKE IT APART
AND REMOVE ONE OR TWO SPRINGS . HE CAN ALSO INSTALL SOME STIFFER SPRINGS .
THAT BEING SAID , I THINK HE WILL PROBABLY USE IT LIKE IT IS .

HE PICKED IT UP THIS MORNING AND WILL BE TRYING IT OUT THIS WEEK .

DSC_1134.JPG
 
[6]
[5] [7]
Top