Harrison L5 lathe service

[Andrew Wildman]

Good evening chaps (and chapettes)
I am a long time lurker on this forum but this is my first post.

A bit of intro first...I am a mechanical engineer by day (calculators and computers, not getting my hands dirty!) who designs bits and pieces for gas turbines.  By night I am a shed dweller who gets a telling off from the wife for putting greasy fingerprints on the wall on a regular basis.

I have recently moved house and was levelling the tools in the new shed when I realised that the L5 lathe had more clearance than I liked between the saddle and the bed.  I took the back 'gib' off and rescraped it and sorted the issue there (the bed is in reasonable shape and most of the wear appeared to be on this plate).  I had a look at the 2 front gib or clamp plates, behind the saddle and it appears that they need work also.

I know it is bad form to ask for help on your first post....but here goes anyway!  It is not clear to me how to get these fron plates off as they appear to be doweled but don't want to shift.  I was hoping one of you (possibly Micktoon? - good work by the way your machine will look great when finished) could help me.

 While I am at it I thought I would open up the saddle gubbins and give it a bit of a clean up.  What is the best way to take the saddle off.  Is it first remove the leadscrew and lower dive shaft by taking the tail stock end bearing block off?  I do not want to bent these shafts.

Here are some pics of the specimen in its natural habitat with a few bits removed:

[micktoon]

Hi Andrew, Welcome to the forum.  Good to see another L5 getting some attention ( lets hope it does not end up in bits as long as mine lol ) To be honest mine has been took apart that long I can not remember how it came apart never mind how it goes back together, I think there should be clues in my earlier posts of the lathe getting stripped but the parts are on the bench so I will look tomorrow and remind myself, I think those front plates were dowelled , I did take the saddle off by removing the tail stock bearing block and the lower shaft pulled out of the safety clutch type collar coming out the Norton gearbox on mine.
  Hope this helps , Let me know if you want photos of any particular part and I will post them.
  Cheers Mick.

[Jonny]

Bit of  pain to get lead screw back in Mick with Norton box. Just feel for the spline in the clutch shear.
Cant look at my 140 scrapped it over two years ago many features are better than current M300.

Andrew you can get some access by taking the top of the carriage off, same with M300.
Once its out it becomes clear for next time.

I couldn't get no where near enough reduction on mine, needed a recess approx. 1.5mm where it clamps up to top of carriage so it clamps further.
Look carefully see if theres grooves appearing in the V sides close to the chuck. A few thou here off either 55 degree V face will drop carriage loads!
May look ok but beds worn, tension up at tightest point by tailstock.

[Andrew Wildman]

Thanks both.  I sorted out the back plate and I can't measure any clearance or movement at the 'worn' end and it is not excessively tight at the tail stock end.  I hope the triangular way is the same when I flatten the plate.  No sign of any steps in the front way.

Does the leads crew also just pull out of the gearbox? (mine is the non Norton version)

Just been on a business trip looking at 10 t gearboxes being manufactured.  Makes our kit look a little light!

[Jonny]

Yes the lead screw just pulls out of the clutch/shear thing you may need to stress it to clear the carriage, it will spring back.

Try lifting the carriage or if reasonably close watch for dispersing lubricant on the slides when rigorously moved.