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_ Home Made: Delrin 120 tooth change gear for 14x40 lathe...

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  • _ Home Made: Delrin 120 tooth change gear for 14x40 lathe...

    Started a thread acouple weeks ago asking peoples opinions on how much quieter a Delrin gear would make the lathe.
    Well i got around to making one and im so happy i did (and didnt screw it up - moving that indexing pin 120 times was a real chore for me).
    Some time down the line im gonna make a recording of the two different gears, but boy it made a pretty big difference.... its not dead quiet, but if you disengage the feed gear box and flip on the spindle and then reengage the gear box theres only a "small" sound (not sure how of word that) of gears spinning.

    I think the gear came out real good (only the second gear ive ever made so i might be alittle biased ) - the tooth profile meshes well with both a 60 tooth and 30 tooth gear and the "flat" on the top of the last tooth cut and first tooth cut are almost perfect (dont have a comparator to check).

    Have not threaded anything with the lathe yet, but it runs smooth and much more quieter then before... it also seams nice that i will not have to get an absolute perfect mesh as before with the metal gears.... Just hope it holds up for a long time to come.

    You can read more and see some more pics of the process i took here:
    http://site.thisisjusthowidoit.com/m...120-idler-gear

    ~ What was once an Opinion, became a Fact, to be later proven Wrong ~
    http://site.thisisjusthowidoit.com
    https://www.youtube.com/user/thisisjusthowidoit

  • #2
    Wow what an excellent idea. I will try the same. Thanks for posting.

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    • #3
      Nice job. It'll hold up. I made a similar gear for my lathe spindle drive a few years ago and it's been holding up just fine, with much greater loads than your changegear will ever see.
      Peter - novice home machinist, modern motorcycle enthusiast.

      Denford Viceroy 280 Synchro (11 x 24)
      Herbert 0V adapted to R8 by 'Sir John'.
      Monarch 10EE 1942

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      • #4
        Very well done. Making gears seems much harder than it really is. It is one of my most favourite machining jobs.
        Free software for calculating bolt circles and similar: Click Here

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        • #5
          Thanks every one...

          Originally posted by Evan View Post
          ... Making gears seems much harder than it really is...
          Making the gear was not bad at all (just need to pay attention ), but understanding how to make a gear, the correct radius for the cutter, tooth height, etc... is a whole nother story for me. For the application im using this for - getting it really close (and not perfect) will fit the bill (i have yet to thread with it tho). I think there is a bit more "science" to gear making then most other parts of machining if you are doing it from scratch/the ground up.

          But boy... does this thing sound good

          _
          ~ What was once an Opinion, became a Fact, to be later proven Wrong ~
          http://site.thisisjusthowidoit.com
          https://www.youtube.com/user/thisisjusthowidoit

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          • #6
            Is there a difference between the white and black delrin?

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            • #7
              Not enough to worry about - the black doesn't show up grubby finger prints. I didn't actually use Delrin I used regular acetal, partly because it was cheaper and partly because they had stock in a size closer to what I wanted.
              Peter - novice home machinist, modern motorcycle enthusiast.

              Denford Viceroy 280 Synchro (11 x 24)
              Herbert 0V adapted to R8 by 'Sir John'.
              Monarch 10EE 1942

              Comment


              • #8
                Originally posted by mikem View Post
                Is there a difference between the white and black delrin?
                I don't know about Delrin, but white acetal turns yellow with exposure to light. Also , I think the black may be more UV resistant.
                Last edited by cameron; 06-11-2013, 02:17 PM.

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                • #9
                  Originally posted by mikem View Post
                  Is there a difference between the white and black delrin?
                  Funny you ask... the other night i email Matt (owner of PM Tools, who i bought the lathe from) and we talked about the color alittle... I dont know much about Delrin, but from what i have read and the info on the McMaster-carr site (which is where i bought the raw from) there are many different kinds, the word 'Delrin' is kind of like saying Stainless Steel (there are different series), again i don't know alot about this. In the past i bought some Delrin whihc was dark brown which i used for making a left handed nut for a lead screw in a X-Y table, the brown stuff was "high wear resistant" but no good for shock, the stuff i made this gear from was high wear resistant and good for shock and they (MasterCarr) said it was used for gear making. I would not take my word for this but if you plan on using Delrin, i would research your use and the correct stuff to get... I choose white over blank cause it was acouple bucks cheaper
                  ~ What was once an Opinion, became a Fact, to be later proven Wrong ~
                  http://site.thisisjusthowidoit.com
                  https://www.youtube.com/user/thisisjusthowidoit

                  Comment


                  • #10
                    As has been pointed out in numerous other posts Delrin and acetal are not the same thing. They have different properties in strength, chemical resistance and casting/extrusion performance. They are similar and for many purposes can be interchanged. They are also used to make plastic alloys with many other plastics and may also be filled with a variety of fillers to produce various enhanced properties. The same is true of most plastics. With acetal/Delrin the colours are just that and make little difference to performance, if any. However, there is black acetal that is carbon filled to produce a static free material as it has low enough internal resistance to discharge static on the surface. "White" acetal is just "natural" with no colourant added. That is what the raw resin looks like.

                    When buying acetal or Delrin ask which you are getting. If they tell you it's all the same thing find another supplier. While it may not make a difference to your application it shows they do not know their plastics or don't care.

                    The name Delrin is a Du Pont trademark for homopolymer acetal resin. Generic "acetal" is a copolymer acetal resin.
                    Free software for calculating bolt circles and similar: Click Here

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                    • #11
                      Delrin and Acetal are exactly the same thing because 'Delrin' is an acetal, as is 'Tecaform', 'Ultraform', 'Celcon', 'Hostaform' and others.

                      The difference - as already pointed out - is that Delrin is a homopolymer acetal whilst the others are co-polymer acetals.

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                      • #12
                        In the flyer that I just got from Enco, it says on page 60, natural -- high natural lubricity, black--normal lubricity. I wonder what that means?

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                        • #13
                          Originally posted by Peter Neill View Post
                          Delrin and Acetal are exactly the same thing because 'Delrin' is an acetal, as is 'Tecaform', 'Ultraform', 'Celcon', 'Hostaform' and others.

                          The difference - as already pointed out - is that Delrin is a homopolymer acetal whilst the others are co-polymer acetals.
                          You mean they're exactly the same thing, but different?

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                          • #14
                            Congrats on the gear! I looked at what you went through to make a gear cutter, and have a suggestion. Since you went to the trouble of grinding an HSS tool to the profile to make a cutter, you could have done the other side of the HSS tool and you would have had a single point cutter to cut the gear with. Plus if you make a single-point holder correctly you don't have to fuss with grinding a relief.

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                            • #15
                              Delrin and Acetal are exactly the same thing because 'Delrin' is an acetal, as is 'Tecaform', 'Ultraform', 'Celcon', 'Hostaform' and others.
                              That's like saying that Hydrogen monoxide and deuterium are the same thing because they are both forms of water.

                              If you are processing tomato juice you really don't want Delrin in the pot. Generic acetal is fine.
                              Free software for calculating bolt circles and similar: Click Here

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