Thread: 7x10 lathe

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  1. #1
    i try to build a small rotary (4th axis) for my router...
    already i got the materials for tailstock... but my little lathe crossed my imaginations...

    the first issue was the gears... for feed and thread cutting... when i tried to change gears, i discovered theres no 127... the reason lack of room for...
    getting on the net i find a few website about this nifty machinery... they talking about the 21 teethed gear

    so first looked for the whole problem what can be done on simple way...
    on the first picture you can see the original part, made of 3.5 mm hotrolled sheetmetal...
    you can see the design ""ignored"" the necessity for gears and modified to the available room for...
    so first i cutted a testpart, which one worked better...

    some more study on this, and find out the part has more room on the front... new design, and it is close what i would like...

    next issue was the gear...
    the inch-mm require the 127/120 ratio... even i moved the part to the front, still the room is not enough for... (due to the maximal teethnumber can be applied)

    the first test of this was a 51 teeth gear... actually it would require about 0.8 mm dia endmill, but i had only 1.23 dia... so toothroot has a little undercut, but it doesnt reach the main circle..

    127/120= 1.0583 the necessary
    21/20=1.05 error 0.0083
    51/48=1.0625 error 0.0042

    might be next week i will get from ebay the right endmill.. already ordered, just it takes time...

    thank you
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  2. #2
    the next issue is the rest... some website sells for, but originally i purchased from harborfreight, and they don't have this time...
    so i gave a try on this weekend for...

    it is made 1 inch thick aluminum billet.. first i cutted a paper template, which one not really worked.. so i just measured the tailstock..
    after dimensions were in hand, i drew it up in cad, andd cutted contur on the router, and slots were made on my mini miill.. a rongfu 45, 29x9inch tablesize...

    it is openable what like really, because the saddle can be leaven on its position and the jaws also not necessary to release...

    it is not ready yet, might be next weekend i have time for again...

    and some picture about the gear i tried... the steelgear is original with the lathe..
    i checked the dimension, on five teeth, but i could compare only with the caddrawing... i can't calculate involute a...


    thank you
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  3. #3
    Hi QS welcome to MYCNC.

    I'm sorry but you have lost me on what you're doing or asking? making gears out of Aluminium is not the way to go as ally is too soft a material for a machine ie lathe orientated,reason being they get chewed easily and chip at the finer points ie the teeth.

    Have you looked at this site for all manner of spares for all models of the mini lathe?

    http://www.littlemachineshop.com/pro...First=H&Last=K

  4. #4
    my post rather informative...
    since all gear made of nylon, or some similar plastic on this lathe, i think aluminum is suitable... i was thinking to cut of corian...
    also the sdpi website has ready gears, but those only 6mm thick and this lathe has 8 mm thick gears...

    thank you for link, in the recent days i discovered many similar site... i found one item i might buy that is the longer bed... theirs longer by 4 inch...

    the gear, i felt no comfortable with the 21... still it is just a very substitutive solution... very possible i have to shift for a larger lathe, which ones are has better solution like this mini lathe...

  5. #5
    I think the C6 has the biggest bed 21.65 between centers.

  6. #6
    Very interesting and practical. Thanks for posting.
    You could get away with a 6mm wide metal gear on these lathes as the loading is very small.

    .
    John S -

  7. #7
    Quicksnail i don't there is anything wrong to use aluminium but a better proposition would be to use tuffnell as this is what the big boys use to make their plastic type gears. hard enough to take the abuse but at the same time very easy to cut. it will mesh with the metal gears and the plastic very well.
    If the nagging gets really bad......Get a bigger shed:naughty:

  8. #8
    Brass isthe better option if steel is out of the question? Ally just gets chewed over time.

  9. #9
    So the original plastic gears are harder than aluminium ?
    John S -

  10. #10
    The point is Plastic and Aluminium gears are not suitable material for machinery and if the shipping wasn't so hefty from the states I'd change them on my own Lathe for metal ones.

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