Headstock installation + alignment - DIY metal mini lathe part 7
ฝัง
- เผยแพร่เมื่อ 8 ก.ย. 2024
- Headstock alignment is a critical point in every lathe, in this video I show how I've done it for my home made benchtop precision mini lathe.
Before going through the actual installation I've performed some simulations of the whole process. The headstock is installed using leveling paste that allows only small corrections once it is set. The headstock is equipped with compressing and expanding screws to let adjustments over the vertical plane and lateral screws to let adjustments over the horizontal plane.
DISCLAIMER: In the video some items show their brand because due to limitations of my editing skills I was unable to remove them. So I clarify here that there are NO SPONSORSHIPS, I DO NOT ENDORSE NOR DISAPPROVE THOSE BRANDS THAT ARE INCIDENTALLY VISIBLE IN THE VIDEO. Products are visible in the video because they are necessary for the purpose of the work shown and because I found them fitting my personal purposes, not because sponsorship or paid placement. In future videos I will try to overlay a message that clarify this point when brands appear too prominently.
Video is composed by the following sections:
0:00 Intro; 1:00 simulations; 1:42 the problem of test bar deflection; 3:40 ball-tip dial indicator may lead to erroneous readings; 4:54 counterweighting; 6:20 preparing leveling paste; 7:28 headstock installation; 8:02 alignment operations; 12:30 double check with a square and final considerations.
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That kind of alignment accuracy is obviously very good. Except as a general rule both the lathe head stock and tail stock are purposely misaligned by roughly .001" in 10"-12" over the length of the bed both up and towards the operator. That slight misalignment is done in an effort to build in a compensation factor for both work piece weight and cutting tool pressures. It's obviously not a perfect system since both the work piece weight and cutting tool deflection can have large changes depending on what's being done or even the cutting tool material used. So it's a best case average that helps the lathe deflect towards being more accurate instead of less in most cases. And that was very clever thinking to use a weight counter balance to remove the test bars sag due to gravity.
Good point, you re right about the slight misalignment. Indeed I forgot to mention this point in the video but I've actually kept the unavoidable error (about .0004") up. Thank you for your comment.
You are going to enjoy this project for years to come!
Liked before watching 😁
In the home made mill I am making, the base is epoxy granite with steel plates that I bolt the linear rails to.
For alignment, I’m epoxy on bronze sheet between the linear rails and base, and i am hand scraping in the bronze sheet to achieve flatness.
I’m using a home made autocolimator with 300mm focal length to measure flatness.
Nice.
I hope this series is still going!
Nice to see you're back. Great job can't wait to see some chips
Simply amazing!
Thank you for such videos and keep up the good work!
Greetz from Austria
Vielen danke!
Thank you for posting this. Very helpful.
It’s looking great!
very interesting
Glad you think so!
I believe if you had of worked on the space shuttle challenger they wouldn't of had any issues.👍👌
How about chucking a laser pointer to the chuck and a optical sensor on the tailstock.
Nice idea ...I have no tailstock yet.
I like the counter weight at the end, but do we not now have a steel bar supported at both ends, with resulting sag in the middle? Your solution clearly improves the situation, but I wonder if you ever calculated the deflection of the new situation, with an eye toward increasing the number of points of support as needed until desired accuracy is reached.
Counterweights compensate the sag.
in order to use this method to align the headstock, the test bar has to have close to zero run out first, not sure how you did that
Your lathe is better than a Chinese made one.
Hopefully 😊
You should not use 3 jaw chuck as a base for alligment because these kind of chucks are not precise in nature.
Aren't they imprecise because of the run out?
@@AccidentalScience They are not precise becouse of their design. Usualy you buy a alligment bar, that have Morse taper on one side, same as in a spindel and some cylindrical part on the other. It cost somethin about 50 euros. Your approach to lathe building is in few places unorthodox ( welding after machinning , using glue, using cold rolled stock that is not annealed) but at the end of a day , what is importent is that, are you happy with your machine? Is it precise enouth for you? BTW I also thing that Whitworth 3 plate method is somehow amazing and enlightening. Love your work!
@@kundeleczek1 thank you. I actually like to experiment new things ...sometimes boldly going where no man dared to go before 😃
I wish you were my next door neighbour. I Got problems aligning my lathe. I have problems with irregular facing and bell shaped cutting.
🖒🖒🖒🖒🖒🖒🖒👏👏👏👏👏👏👏👏👏
homemade+precision are incompatible.
The mistake you are doing is that you're building on a Flexible wooden bench . . if your goal is precision (which I am not against at all) . . it is better that you start by building a concrete work bench with a flat granite on top or a buy a big flat granite rock if you can afford it. Of course building your machine is more fun and exciting than buying one . . stone is hard and less flexible than any other material and glass can't handle weight . . so stone is the best
Thank you for commenting. That bench is actually made of steel, has just a covering made of wood and melamine. But yes, it is not adequate and I've already planned to change it with a stronger steel-concrete bench. To do this I have to build a new tool, that you'll see in a future video. Cheers.
interminable nous verrons jamais la fin
Le voyage est plus intéressant que la destination ☺