• This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn more.
  • Guest,  We want to wish You and Your Family a Healthy, Happy Thanksgiving! Click the "X" at the top right corner to remove this notice)
  • PLEASE: Read the FORUM RULES BEFORE registering!

4

Repairing A Keyway Question.

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

savarin

Active User
H-M Supporter-Premium Member
Joined
Aug 22, 2012
Messages
1,566
Likes
1,979
#1
I am re-visiting some earlier rough work on my telescope in an effort to improve things.
I originally cut a 3mm keyway in a 12mm shaft that skewed slightly so I want to recut it straight.
Also making new tight fitting keys.
What would be the better method?
Using the original 3mm end mill and make two cuts in the old keyway widening it by .5mm each side producing a 4mm keyway
or
using a 4mm end mill and cutting over the original keyway cutting both sides at the same time also producing a 4mm keyway.
Unfortunately without a mill I cant use a woodruff cutter.
 

David S

Active User
H-M Supporter-Premium Member
Joined
Nov 18, 2012
Messages
1,042
Likes
684
#2
I am not an expert, but I think your first suggestion would be best.

David
 

Bob Korves

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Jul 2, 2014
Messages
4,036
Likes
4,185
#6
If you go to 4 mm you will also have to make the depth deeper in both pieces if you use a standard square key. You can machine a key to a custom dimension (3 x 4mm) to fit instead.
 

savarin

Active User
H-M Supporter-Premium Member
Joined
Aug 22, 2012
Messages
1,566
Likes
1,979
#7
If you go to 4 mm you will also have to make the depth deeper in both pieces if you use a standard square key. You can machine a key to a custom dimension (3 x 4mm) to fit instead.
Ha Ha Bob, the accuracy of my machining means I have to make everything to fit what I did before.:laughing:
 

12bolts

Global Moderator
Staff member
Active Member
Joined
Apr 23, 2011
Messages
1,929
Likes
368
#8
Charles,
Could you mount a woodruff cutter in your chuck and use your vertical slide to move the shaft. Might be a bit iffy getting in there that close to the chuck?

Cheers Phil
 

savarin

Active User
H-M Supporter-Premium Member
Joined
Aug 22, 2012
Messages
1,566
Likes
1,979
#9
maybe next time Phil.
Its done
keyways-cut.jpg
keyways.jpg
way better that the original but still not perfect. Hopefully good enough.
 

bfd

H-M Supporter - Premium Member
H-M Supporter-Premium Member
Joined
Sep 9, 2016
Messages
351
Likes
190
#11
bob its cut to size beat to fit paint to match ha ha ha bill
 
[6]
5 [7]