Todays Project - What did you do today?

[Pete O]

I think I may have convinced the missus that there are possible uses for all these machines other than making parts for one another.
The transfer case in my Land Rover had sprung a leak (yeah, surprise...), there is an 'O'ring at the rear of the intermediate gear shaft that is very prone to leaking and involves removal of the transfer gearbox to fix it. I have a mate with the same model landy and his was leaking worse than mine, so I offered to do both in my workshop if he would help me, as it's a 2 person job.
The O-ring leaks because the lateral forces on the shaft cause ovality of the bore in the aluminium housing where the head of the shaft sits. I decided on a more permanent repair than just replacing the o-ring.
Enlarged the bore in the case by .600, made a bush from some 4140 with a .001 interference fit in the housing and .001 clearance on the shaft.
   
Heated the case on the BBQ and cooled the bush in the chest freezer, applied some loctite 620 and a simple puller arrangement
   
   
Put all new bearings and seals through the box whilst it was out, lot of work but now it's quiet as a mouse and not peeing oil on the ground. Only downside is that now I have to do it all again on my mates car. Nice to have the gear to do the job properly.

[Mayhem]

Nice job Pete

[dallen]

nice job

[Kennyv]

Nice work Pete exceptional job.
quick Q you mentioned .001 interference fit is that with the new bushing and the case ? Im thinking out loud here but thought should be up to .010 bc of softness of allum no?
now I may be wrong someone correct me if so... cuz if I can rem we used the +.010 tolerance interference but that was cambering's in the journals of an engine again was Long time ago...
all replies welcome TIA
kind regards Kenny v

[Pete O]

G'day Kenny, been wondering where you got to, good to see you back. The reason I went such a small interference was fear of introducing too much stress in the narrow part of the casing where I have bored out toward the opening for the front output housing- on the left in the top pic. I was frightened of cracking it and ruining the housing altogether. Not having the training that yourself and some others on here have, I just pulled the .001 figure out of thin air. The 620 (if I'm remembering the number correctly- it's a long way from the computer to the shed) is supposed to be a permanent bond and can fill up to .003" so hopefully it will stay put.
If someone is going to tell me that the housing will expand and let the bush fall out, please tell me before I do the second one!

[TomG]

I took a mental health day and basically just fooled around in the shop. Against my better judgement, I gave Horror Fright another $19 and replaced the impact wrench on my power drawbar. Maybe when I have more time, I'll do a re-design on it and make it more robust.

Tom

[Roadracer_Al]

In response to Pete O's comment about the pleasures of being equipped to do a job, I'll give that a hearty second.

I ordered receiver hitch -- a class III Curt -- for my wife's RAV4, and when I tried to install it, only 3 out of 4 holes would line up, so I took it into the shop and stuck it in the hydraulic press, and I bent that sucker into shape. The holes lined up right. Took all of 7 minutes "from door to door", as it were.

I love having the right tools.

[johnnyc14]

I really miss the quill DRO that came on my PM932 mill so I wanted to add one to the Ferro knee mill I have now. I bought two 6” digital Accu-Remote scales from KMS tools on sale at $30 each and use one on my lathe and the other for this project. I started by making up a prototype bracket from a couple of pieces of aluminum angle and pop rivets.







I made the permanent versions from a length of 2.5” square 6061 aluminum tubing with 3/16” wall. I marked out the pattern on the tube with a scribe and highlighted it with a sharpie then carved it out on the mill with a ¼” end mill. I painted the final product with engine enamel and baked it at 250 degrees for 2 hours to harden the paint.





I had to reduce the OD of the fine feed wheel to clear the thicker bracket so I put a knurl on it as well.







I also had to make up a plug to fit into the hole in the quill stop. It has a nose machined on it that fits into the hole and on the other end is a 5mm threaded hole to fasten the bracket of the digital scale. I attached it the quill stop with JB Weld epoxy.







It turned out well.

[EdK]

Nice work John!

I was just looking at quill DROs today since I want to put one on my PM935 as one of the first modifications.

Ed

[DaveH]

Nicely done John   
 
DaveH