GEARS!!!???? Trying to learn what's in my K&T 2HL
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  1. #1
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    Default GEARS!!!???? Trying to assign values (reverse engineer) what's in my K&T 2HL

    Got my 2HL universal with the vertical attachment. Luckily it came with the drive gear, however, that gear (a non-factory replacement) has no provision for drive dogs. Hence the gorilla torque used on the drawbar. I'm looking to find a good way to incorporate them into this one but decided I would learn about gears while I'm dealing with it.

    What a [email protected]#$_. I have a 24T drive gear and a 23T driven splined shaft. I have no pitch gauges and trying to figure out all of the specs is overwhelming. Are there any "gearheads" that know how to speak this foreign tongue?

    The root diameter of the 24T drive gear is 2.715", the O.D. is 3.208" the face is .986" and the angle of the gear teeth are between 28-29°. Can this be translated into a known value?

    As these gears have a great propensity to go missing. I would like this post to provide information for those unfortunate enough to need a gear made from scratch by a gear company. There is a fair amount of chatter about 24T, 30T and even 32T but the formula for someone without the ability to make their own gears doesn't seem to exist.

    I'll ask in advance if we could please keep the information on point for the specifics about these gears for the K&T 2HL so that it can be a solid reference for others. Other threads have wandered about the larger models and they didn't have much info to help either. Too many people wanted to add unrelated info and they went off the rails.

    Here are a bunch of photos and I can get other measurements if I'm told what to look for.
    Thanks

    Mark

    Sent from my ONEPLUS A6013 using Tapatalk
    Last edited by Crank; 07-24-2019 at 09:27 AM. Reason: Renaming thread for clarity

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    One of the "several" math pages involved. In other words, the angle isn't something you measure - it instead comes from the pair of gears and their features

    A useful text is Manual Of Gear Design - Section Three - Helical And Spiral Gears by Earle Buckingham
    Attached Thumbnails Attached Thumbnails helix-angle-suit-center-distance.jpg  

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    John,
    So to determine that angle, I would plug in the numbers with the differing tooth counts and do the math. Seems straight forward. I won't get a chance to look at the other gear until tomorrow, but I will do my homework.
    Thanks

    Mark

    Sent from my ONEPLUS A6013 using Tapatalk

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    This whole thread is worth the study of in that is directly applicable to the 23/24 gear set. A few revealing posts are 74, 81 and 82

    KT 2HL ,Need gear for vertical head

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    Not a single one of those measurements has any value.

    First get the center distance between the shafts and the numbers of teeth.

    The outside diameters will have some value later on, but only as inputs to find other things.

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    Not a single one of those measurements has any value.

    First get the center distance between the shafts and the numbers of teeth.

    The outside diameters will have some use later on, but only as inputs to find other things.

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    Best way to handle this is to design and make a new set Not a single gear
    Many possible variabeles which are hard to detect

    Peter

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    Okay, to clarify, I don't need gears. That wasn't the purpose of this thread. I was trying to identify the specifications that would allow others to recreate a missing example.

    With what has been said, would those in need of a gear be better to just get a set of gears from a vendor if they fit the dimensions available?

    Mark

    Sent from my ONEPLUS A6013 using Tapatalk

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    Here is the page related to "getting" gears by making them on a Universal Horizontal milling machine equipped with gear driven dividing head

    wathomas thread on making one by such means - with photos

    Helical Lead? 30T drive gear K&T
    Attached Thumbnails Attached Thumbnails helical-math-.jpg  

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    Archie Cheda covered the topic of reverse-engineer an helical gear, in order to make a duplicate as part of the thread on his K&T (if the link does not bring you to the right post, the discussion starts around post 88 of that thread):
    K & T 2 C H -- the mill I have wanted . . .

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    Respectfully to all, this has not gone the way I hoped.

    Okay, so with the info so far, what I am understanding is that this gear does not exist with a set of values that have been, or could be documented as a repeatable standard that can be relayed to a manufacturer. That is sarcasm, for clarity

    I was trying to go on the basis, that there will be people that are not equipped and/or lack the skill/comfort level to produce their own helical gears and would need to provide data in a known format to a manufacturer in order to produce a gear without a pattern to start with.

    In my job, working on ordnance, we have production drawings for every single component of the gun mounts that would allow me to recreate a part from a documented material, with dimensions, data for thread pitches, radii, surface finish/coating, etc... That way said part could be recreated in any capable facility, should the supply chain fail to be able to provide it.

    I guess I had some fantasy idea that K&T had constructed these gears to a repeatable documented standard and that information existed or could be easily identified from an example. I do appreciate the input, but I guess I failed to state my intentions properly. I completely understand the reasoning behind reverse engineering as it was a part of my world as a gunsmith. It was not unusual for a common failure, or routinely lost part which had ceased to become available. Often someone would take the time to dimension an existing component so that it could be reproduced consistently at a future date. Some would share that with the gunsmithing community, others would keep it a jealously guarded secret.

    I wasn't trying to teach myself yet how to make a gear, I just wanted to be able to learn enough to determine values needed in order to provide the information to others for future reference.

    Mark

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    Mark,
    Perhaps, you should try again with a more reasonable title for your thread: how to "reverse-engineer helical gears".
    As far as I understand, there are way too many variations of head designs, with rather limited production each and there is so limited demand that any "mass production approach" would not work.

    Paolo

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    Paolo,
    Thanks for the reply and the suggestion. I guess what I was trying to do is to avoid the premise of reverse engineering (although that may be an accurate description) since I have a functional gear and merely wanted to assign values to it's construction. I guess I had a noble thought to try and share the information, but I lack the knowledge to do that in the language of gears.

    I want to emphasize that I appreciate the responses and links to previous threads, all of which I have previously read, but failed to see the info in a usable format. Again, that would likely be due to my lack of knowledge.

    Mark

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    Tried to change title, but it only affected the sub-title.

    Mark

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    Default Cutting Helical Gears

    Shaft center distance, real pitch, numbers of teeth, are all factors which apply...Been there, done it, but I have slept since then....Ramsay 1
    Attached Thumbnails Attached Thumbnails k-t-gear-cut.jpg  

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