Deckel FP2 acquired (Preliminary) - Page 44
Close
Login to Your Account
Page 44 of 46 FirstFirst ... 344243444546 LastLast
Results 861 to 880 of 910
  1. #861
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    There is some initial flex I have not been able to get rid off despite all the extra stuff I've stuck on, not sure if it's the finger behind the gears or not that bends a little, I've considered welding a rib that spans the length of the pusher on the right side for stiffening it up.

    I cannot be sure it's just the 3rd gear as I have clamped all the gears back together for maximum space for the fingers that go behind the 3rd gear. I am able to push them apart again though using my small M8 spreaders I used before.

    I've gotten some 4mm grinding points and have thought I'd dedicate today to see if I can grind out the broken off drill. Honestly not sure what the reason is it's so stuck. I'm still waiting for the lapping compound I ordered.

    Also I meant to say I started work on it last weekend, been tacking on stuff all week.

  2. Likes ballen liked this post
  3. #862
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    Managed to grind through the broken drill bit piece though there are still pieces left I can see, I made another extension to be able to get it all the way in.



    Ground down to a stub now. I am attaching new pieces using superglue and using heat to make them release when I need to replace one. It has worked well though it takes a while between switches.


  4. #863
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    2,608
    Post Thanks / Like
    Likes (Given)
    1611
    Likes (Received)
    905

    Default

    Dennis, how is it going? We are all rooting for you. Cheers, Bruce

  5. #864
    Join Date
    Dec 2002
    Location
    Benicia California USA
    Posts
    7,994
    Post Thanks / Like
    Likes (Given)
    1778
    Likes (Received)
    2351

    Default

    Quote Originally Posted by DennisCA View Post

    Honestly not sure what the reason is it's so stuck. I
    My educated guess is that when the key failed and the gear spun, the surface of both the gear (ID) and the shaft(OD) got upset at the key slot,so that when the gear rotated it formed circumferential
    ridges and grooves in the mating parts...
    Think of this as having a series of snap rings on the shaft......
    Because there are likely more than one , the holding resistance can be substantial...To move things you have to generate enough force to make the steel move (plastic deformation)

    Don't think you are going to do that with the push "C" clamp tool you made.....
    Got to reduce the height of the ridges or enlarge the space they need to pass through to get the gear to move....this is why i suggested the lapping strategy...
    Its going to be slow, you have to be patient but i believe it will work in the end.

    Might need to refit the end bearings and mesh the offending gear, and use the drive motor to rotate the parts. Don't need to reinstall the cover, just position,by hand, the gears that will drive the problem gear.
    Leave the remaining gears disengaged....Be careful not to mesh more than one ratio at the same time......
    Make up your lapping "mix" , thin at first and load it into a squeeze bottle that you can use to squirt the slurry into the gear/shaft interface .....Use a length of hardwood to lever against the rotating gear and apply pressure
    parallel to the shaft applying pressure forward and rearward to in effect push sideways against the bumps and grooves.

    Cheers Ross

  6. #865
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    I've been working on that, by hand though. But I am otherwise engaged this week, so many other things, and a lot of things I've neglected in my focus on this. I've thought about motorizing the process as you mention.

  7. #866
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    2,608
    Post Thanks / Like
    Likes (Given)
    1611
    Likes (Received)
    905

    Default

    Quote Originally Posted by DennisCA View Post
    I've thought about motorizing the process as you mention.
    Please take care not to get your fingers caught in the gearing. Nasty.

  8. #867
    Join Date
    Feb 2001
    Location
    Redwood City, CA USA
    Posts
    4,941
    Post Thanks / Like
    Likes (Given)
    175
    Likes (Received)
    882

    Default

    Maybe this has already been stated, but it seems to me you would be miles ahead by directing your time and energy to buying, begging, borrowing, building, or burgling a replacement shaft, and then removing the bad one destructively. Forget the "sunk cost" of your press tool, etc.

  9. Likes sneebot liked this post
  10. #868
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    I'm fully prepared for the idea that I have to destroy the shaft. But as I've written earlier, I want to rebuild the shaft in that case. Ideally I'd get it out as completely as possible. I have little to no hope of finding a spare shaft and if I did I believe it would probably cost more than having a replacement made by a shop.

    But I am also in no hurry and I will try to lap it and see if that helps.

    At any rate I think the shaft will need work afterwards even if I get it out in one piece. The key slot needs welding up and machining and probably the whole portion of the shaft needs to be welded and machined down again. The gears will also need some work I am thinking.

    But like I said I am really busy with other things at the moment. I haven't had time since sunday to look at the machine, for instance.

  11. #869
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    Well today I managed to make the 3rd gear move axially, finally (!) I have managed to press it further out than before now but it stops after a while.

    I am pretty sure the reason it's stopping is the 3rd gear key slot is no longer aligned, I mean I was rotating the shaft while keeping the gear standing still while lapping it. So the next step is to use my small spreaders again and visually align the the key slot again on the 3rd shaft before carefully pressing it back together. Then I hope it will come off all the way after that.

    But now for a break to digest this small step forward.

  12. Likes ballen, sigurasg liked this post
  13. #870
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    Got the shaft back far enough that the 1st gear is off the shaft now, but I am not able to get it out. Unfortunately I managed to damage the threaded portion with the pusher so more damage on the shaft when I took it off and put it back on, because I could not see properly. Things are getting difficult again becauyse the shaft is now very free to move radially. I am thinking I need to rebuild the pusher too.

    I hope it's weldable material, definitely gonna need repairs, or I will have to cut it off entirely and make a new part.

  14. Likes ballen, sigurasg liked this post
  15. #871
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    2,608
    Post Thanks / Like
    Likes (Given)
    1611
    Likes (Received)
    905

    Default

    Dear Dennis, you must be very frustrated by this. Hang in there! Cheers, Bruce

  16. Likes DennisCA liked this post
  17. #872
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    Success, the shaft is now out! But the first gear is still inside, as is the big gear in the middle, there is not enough room to get them out without disassembling the lower shaft. I think I will need to do this, just to clean out the gearbox.

    The gears themselves looks almost completely unharmed, there is a burr on one of them but otherwise they all look fine.

    Here are some pictures of the shaft, as you can see it's plenty damaged, the threads on the front are completely obliterated. So now, time to consider repair options? Cut off this part (after measuring) and thread on a new oversize part perhaps, turn to size and machine the slot anew. Maybe I'll just give it to a machine shop and ask them.






  18. Likes jz79, sigurasg, CharlyDE liked this post
  19. #873
    Join Date
    Mar 2017
    Country
    LATVIA
    Posts
    302
    Post Thanks / Like
    Likes (Given)
    76
    Likes (Received)
    163

    Default

    few ideas:
    cut off the thread end, drill and tap for an insert, thread it in with some permanent loctite, machine to diameter, cut the required thread, there is little axial load on the shaft, so as long as the bearing journal is fine, a repair like this should work save the shaft

    that 3rd gear journal doesn't look too bad actually, there are places that do spray welding to build up some material to be machined off later, building it up oversize and machine the gear just as much as to clean up the surface, then turn down the 3rd gear diameter on the shaft to match this new size

    as for the key way, perhaps machine it a little oversize in the shaft, just so the seat is clean and uniform, them make a custom key (if the keyway in the gears is undamaged) with the correct bottom size to fit in the shaft and narrower at the top so the gears fit

    on the other hand, all of this might be about the same amount of work as making a new shaft, so maybe, if the 3rd gear still fits snug enough on the shaft after cleaning up the burrs, you might get away with not spray welding the shaft, so just the keyway, key and the thread to repair

  20. Likes DennisCA liked this post
  21. #874
    Join Date
    Aug 2010
    Location
    Canada
    Posts
    314
    Post Thanks / Like
    Likes (Given)
    4
    Likes (Received)
    98

    Default

    I've been watching the whole time and congratulate you on your perseverance. I know it isn't all great but at least now you know what you have.

  22. #875
    Join Date
    Apr 2015
    Country
    AUSTRALIA
    Posts
    571
    Post Thanks / Like
    Likes (Given)
    33
    Likes (Received)
    134

    Default

    i would just make a new shaft back to spec in regard to keys etc watch out for the gear if the bore is oversize though that needs to be checked also the keyways in the components.
    do a good job and it should last a long time is the way i view it.

  23. #876
    Join Date
    Sep 2011
    Country
    GERMANY
    Posts
    2,608
    Post Thanks / Like
    Likes (Given)
    1611
    Likes (Received)
    905

    Default

    Kudos for your pluck and perseverance. I think the shaft can probably be saved, let's see what others advise. If you can get it built up with some welding material, I can put it on my cylindrical grinder and grind it between centers for you. Will need a clean center mark at both ends for this.

    Cheers,
    Bruce
    Last edited by ballen; 09-28-2019 at 04:39 PM.

  24. Likes DennisCA liked this post
  25. #877
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    Thanks, that would be appreciated! I've taken the dimensions of the shaft and made a basic CAD model, still some features I've not modeled but I got the basic ones:
    16mm (thread) - 25 mm (front bearing) - 27 mm (gears) / 30 mm (bearing) / 35 (sliding gear) 36/39.45mm (splined area) - 30mm (back bearing).

    OAL 325.477mm as I modeled it, probably meant to be 325.50 mm



    BTW CharlyDE, since I got the gears out I was able to count the 2nd and 3rd gears, they are 60 and 65 teeth like in your drawings. I am pretty sure all the rest of the gears are going to be the same.

  26. Likes JHOLLAND1, CharlyDE liked this post
  27. #878
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    Made a drawing with the main dimensions, the relief cuts I did not detail because I believe they are non-critical, mainly for making sure oil gets in there and lubricates the setup I believe, it's a 45 degree cone though that is around 1mm deep and 2mm wide.



    Does anyone know what a suitable replacement material would be for this shaft?

    Repair options I have considered:

    1. Part the shaft where it reduces to 27mm, bore a hole and tap it, say M20x1mm LH thread (LH required for a self-tightening thread). Fit an oversize blank onto the shaft, red loctite and machine new features.

    2. Part the shaft and remove only the M16x1 thread, bore & tap a hole like in option 1 and remake the threaded portion. Turn the shaft only to clean up the burrs, so the gears will fit again. Machine a new slot opposite the old one and use that instead, leaving the old slot as is.

    3. Turn down everything 27mm and below for a clean face and weld on material and machine new features. Perhaps a local shop might do spray welding, though that won't be enough to fill up the old slot, but it might not be required either to do a repair.

  28. Likes JHOLLAND1 liked this post
  29. #879
    Join Date
    Mar 2015
    Country
    GREECE
    Posts
    493
    Post Thanks / Like
    Likes (Given)
    132
    Likes (Received)
    114

    Default

    Well done Dennis, you must be happy with the progress I guess!

    Do you have an idea what caused the shaft to be so stuck? Did you see something that would be an obvious answer to that?

    Regarding the repair, I think making the shaft from scratch would be a nice project and a neater solution than trying to salvage pieces of it. Just turn the shaft, thread it, and have a local machine shop do the splines and the key way. How much would they ask for that?

    But I do understand your desire to keep the splined part.
    In this case, I think I would cut off the damaged part and turn a male spigot on my part, long enough. Fit a long and oversized in OD shaft on it, press fit using heat and Loctite and what not, secure it with a tapered pin and then turn the OD to size. I would like to believe that after turning down the OD including the tapered pin, it would be hard to tel that it was ever there. But haven't tried it....

    BR,
    Thanos

    ps. I would assume that the clearance at the splines aids machining. The machinist wouldn't have to worry about the vertical faces when trying to get the round portions in between the splines as smooth as possible. This is an operation that has always puzzled me...how can one get a nice smooth finish at the valleys of the spline? I would assume that that's where the gear rides, since it's easier to prepare the mating surfaces on the gear. Is it done with special horizontal cutters? Of just by going back and forth along the spline in very small angular steps, so that the surface could be considered smooth enough? (good thing is that the tooling imperfections in this case would be along the direction of movement, gear does not need to rotate, so, it might not really matter that much...)

  30. #880
    Join Date
    Oct 2017
    Country
    FINLAND
    Posts
    505
    Post Thanks / Like
    Likes (Given)
    83
    Likes (Received)
    150

    Default

    I don't know, bur I don't think they could do the same quality job that the original Deckel machinists....

    Based on trying to scratch the parts, I think the 35mm and splines are not only ground but also heat treated / hardened, looking at the splined part that is only turned, it has the pattern of a case hardened rifle receiver. That's a lot of work I would like to not do again.

    P.S.

    As for turning the splines. I believe I would do it like this:

    Mounted the shaft in a dividing head

    Centered it

    Offset the cutter 6mm + cutter radiius

    Cut the side of the spline.

    Then I would rotate 90 degrees and repeat until I have cut 4 of them.

    Once back in the starting position I would offset it 12mm + radius of cutter to the other side and repeat the procedure.

    The splines are now all cut, now I just need to hog out the material between them. Or most of it and done the final work on a grinder.

    Lastly cut the relief.


Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •