Results 1 to 15 of 146
Thread: Homemade lathe in the making?
-
4th Apr 2020, 03:46 PM #1Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
Homemade lathe in the making?
Possibly a light duty homemade metal lathe C channel is 6mm back wall 10mm top and bottom
Looking to use cnc linear rails but they are really hard to find on aus atm
Will pick up a couple new old stock prescision taper bearings from the USA or UK but unsure on shipping at this time
The lathe will have a 160mm or 200mm chuck just for the extra jaw length
I can use my small lathe to machine a spindle plan will be to have the shaft push thru the chuck side and out the belt side, there will be a correct size for the id of bearing left hand nyloc nut to keep correct bearing tension
Anything i've missed?
-
4th Apr 2020, 09:15 PM #2Golden Member
- Join Date
- Sep 2008
- Location
- Riddells Creek, Vic.
- Posts
- 831
Oh dear.
-
4th Apr 2020, 09:19 PM #3Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
Lol its not welded or tacked if your emo is about that
-
4th Apr 2020, 09:33 PM #4Most Valued Member
- Join Date
- Nov 2008
- Location
- North Brisbane. Qld. Australia
- Age
- 70
- Posts
- 1,511
That piece of channel will not be flat, not square and probably twisted.
Nev.
-
4th Apr 2020, 09:59 PM #5Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
Your right Nev its bowed across the 150mm section up about 1mm i put a strait edge/1m metal ruler and a 500mm metal square along it tonight and used a torch on the other side shes bowed about 1mm but i am going to use round bar for the slides so only the rear and front L angle touches the bed the round bar will be welded into the angle iron
Have to check if its warped if it is i will use shims before welding in the rods
Tried drawing on my picture but computer isnt coperating atm
I ditched the idea of using the cnc rails i'll fab them out of steel 25-30mm
-
4th Apr 2020, 11:38 PM #6Most Valued Member
- Join Date
- May 2011
- Location
- Murray Bridge S Aust.
- Age
- 71
- Posts
- 5,945
There's quite a bit missing, how will the toolpost be attached? How will it be moved, consistently to give a smooth finish, gear driven/gearbox or stepper motor type of thing?
I did find one at random, it only goes for about 5 mins, about half way you can see the slide flexing as it's being wound in,
https://www.youtube.com/watch?v=6H4lT5E6KqA
What you're proposing is I feel, totally unsatisfactory for your aim.
KrynTo grow old is mandatory, growing up is optional.
-
4th Apr 2020, 11:44 PM #7Gear expert in training
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 1,075
Pretty much everything. Lets see...
- A cylindrical grinder for the spindle bearing journals (you might be able to get away with turning the spindle between centres, but grinding is really the way to go)
- A mill big enough to machine the bed after it's built (it WILL NOT be square or flat after welding) and preferably a big ass surface grinder as well.
- The spindle housing shouldn't be welded to the bed because there will be no adjustment to square it up
- Rack, pinion and intermediate gear for the carriage travel
- A carriage
- Acme threaded rod (preferably ground) and nut for the cross slide
- A cross slide
- A top slide/compound (optional)
- A tailstock
- Toolpost mount
And that's just a start... You really sure you want to do this?
Yes, it's going to be spectacular and not in a good way
-
5th Apr 2020, 12:01 AM #8Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
Hey Kryn i'll likely buy a tool post and mount that, it will be motor driven with 2 of those 5 slot pulleys
I havent built the slide yet i was thinking of using heavy round rod for the slide to slide on i did look at 39mm round bar just so it doesnt flex over the 800-900mm bed length, there will be 4 sleeves machined from a heavy round lathing stock if i go with 30-39mm rod for the slides i will make the sleeves about 10mm wall thickness the cross slide will be welded to these sleeves the sleeves will be machined id for a nice no slop fit may need wd40 to lube them
I will repeat the same for the tool post slide but may use 16-20mm round rod
-
5th Apr 2020, 12:06 AM #9Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
I found the correct bearings for a lathe, both bearings have a inner bearing race so finish of the shaft should be ok on a lathe, im not sure if welding will distort this steel it weighs atlease 60kg its BHP 150MM industrial beam it came from a new house being built that was wrongly ordered
I think i can lay the bed on the foot path and shim the underside so its level (foot path is not level) than use a spirit level to check the bed, the head stock and the horizontal and cross way of the slides to make sure its all ok
-
5th Apr 2020, 12:19 AM #10Gear expert in training
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 1,075
Mate, it's not even going to be flat or square enough BEFORE welding.
If you want to be boring cylinders, you can't just hack something together. Precision work needs a precision machine; the spindle bearings need to run concentric to each other within microns, the ways need to be ground flat and parallel, the cross slide needs to be square to the bed within a fraction of a degree.
This is not a back yard project.
-
5th Apr 2020, 12:25 AM #11Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
Elan the chucks holder will be machined by this very lathe as its spun up for the first time so the chuck should be square to the slide
-
5th Apr 2020, 12:30 AM #12Gear expert in training
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 1,075
Only if the bed rails are perfectly parallel to the axis of the spindle and the cross slide is perfectly square to it.
A machine can't square up itself if it's not built square to start with.
-
5th Apr 2020, 12:43 AM #13Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
-
5th Apr 2020, 12:49 AM #14Gear expert in training
- Join Date
- Aug 2008
- Location
- Melbourne
- Age
- 34
- Posts
- 1,075
Ohhh a spirit level, square and magnets. Yeah...that'll hold micron tolerances...
There's no point trying to explain this any more. Good luck and all that.
-
5th Apr 2020, 01:17 AM #15Most Valued Member
- Join Date
- Aug 2009
- Location
- Sydney, NSW, Australia
- Posts
- 1,836
Thanks for your concern Elan
Similar Threads
-
Making a lathe compound slide for the mill
By KBs PensNmore in forum METALWORK GENERALReplies: 0Last Post: 17th Jan 2020, 02:14 PM -
Recipe for homemade Way Oil
By KBs PensNmore in forum METALWORK GENERALReplies: 6Last Post: 6th Jun 2019, 10:43 AM -
Making gear blanks in the lathe - workholding suggestions
By OxxAndBert in forum METALWORK GENERALReplies: 13Last Post: 1st Aug 2018, 12:26 AM -
Homemade Boring Bars
By Oldneweng in forum METALWORK GENERALReplies: 19Last Post: 6th Sep 2011, 08:11 PM -
making square stock round on a metal lathe
By 19brendan81 in forum METALWORK GENERALReplies: 17Last Post: 19th Apr 2010, 09:20 PM