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  1. #1
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    Stretched Marzocchi fat fork

    Like many others I really want to try a suspension fork on my Pugsley. I have an older Marzocchi Z3 and a Z1 that I am going to use for this project. I plan to widen the fork to 135mm by making a new arch and crown for the fork.

    I can post a few pics after I get to the minimum 10 posts
    Last edited by Machinist; 01-24-2013 at 10:57 PM.

  2. #2
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    Just wasting a post to get up to ten.

  3. #3
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    The donor forks for the fat bike fork projectThe blue fork has a 135mm spacer to simulate the final width of the fat fork. The green one has standard 100mm spacing. I made the spacer so that I could make a few rough measurements at the 135 mm width.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-10141.jpg  

    Last edited by Machinist; 01-30-2013 at 09:00 PM.

  4. #4
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    Both forks torn apart and ready to be modified. I removed the brake posts on the blue fork for practice. I hacksawed the posts off and then cleaned up the cuts on a lathe.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-10142.jpg  

    Last edited by Machinist; 01-30-2013 at 09:03 PM.

  5. #5
    not FAT free
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    just make it good and people will ask You how much and if You can make one for them !!!
    ...and they will make You rich
    i'm glad that "fat addicted" machinist finally got good idea and is ready to make it happen!
    cheers

  6. #6
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    Wooden prototype arch to test fit over the tire. The final version will need to be wider at the top.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-10144.jpg  

    Last edited by Machinist; 01-30-2013 at 09:01 PM.

  7. #7
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    The final aluminum arch after lots of sanding and some polishing. The arch on the left side is an aluminum dust shadow. I still need to remove some excess material from the back of the arch to save weight.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-10145.jpg  

    Last edited by Machinist; 01-30-2013 at 09:04 PM.

  8. #8
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    Keep up the great work. Cool project
    Still cleaning my Fatback.
    It's a life style.

  9. #9
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    Way to go. I've considered this myself as I have some older Z1 and Z2 forks around with the bolt-on brace. Just remember you're going to have to consider some limit to the full travel. The tires are so tall that they'll approach the bottom of the crown at compression.

    Anxious to see your results, so keep us posted.
    Deceleration Trauma is my middle name

  10. #10
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    The last pic seems to have failed. I will try a different pic.

  11. #11
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    This started out as the green Z1 fork. I found an old can of industrial strength paint stripper at work that removed the paint in about five minutes. The brake posts were also shaved off. The dropouts had been filed at some point in the forks life and they were crooked. I managed to set up the legs in a milling machine and take a skim cut to make them square again. The axle slots were also the old 9mm size and most rear hubs use a 10mm axle now. I cut them to 10mm while the fork was in the mill.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-10146.jpg  

    Last edited by Machinist; 01-30-2013 at 09:06 PM.

  12. #12
    will rant for food
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    Nice.

    FYI there have been issues with the forum displaying images of recent, might not be your fault.
    Disclaimer: I run Regular Cycles (as of 2016). As a profiteer of the bicycle industry, I am not to be taken very seriously.

  13. #13
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    Thanks Drew Diller, I am not super computer savvy so I was blaming myself. I can make just about anything out of metal but computers baffle me.

  14. #14
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    Speed holes in the back of the arch to make it lighter.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-10147.jpg  

    Last edited by Machinist; 01-30-2013 at 09:14 PM.

  15. #15
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    This is a prototype plastic crown so that I can figure out a few more measurements before I jump into a metal crown. I have a very special piece of metal that I have been saving for years, just waiting for the right project.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0645.jpg  

    Last edited by Machinist; 01-30-2013 at 09:18 PM.

  16. #16
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    The grey coloured round bar on the back of the bench in the last pic is a 4 inch diameter 24 inch long piece of solid titanium. I just thought you guys might appreciate that info.

  17. #17
    gone walk about
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    well that asplains it.
    "ORANGE IS THE NEW BLACK"

  18. #18
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    The new wider crown will be cut from a piece of solid titanium. It's not as light as an aluminum crown but I think it will be way cooler. I have sprayed a blue layout dye on the titanium and sketched a few rough measurements on it as I plan out the new crown.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0639.jpg  


  19. #19
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    mmmmm titanium
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0641.jpg  


  20. #20
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    I'm picking up what you're layin' down. Keep it coming...Awesome project !

  21. #21
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    This is definitely looking awesome. I know myself and one other that did a fat conversion on these forks keeping the 100mm spacing (there's a thread on here about it). I can't wait to see the finished 135mm version, should be awesome and not be so limited on tire/rim combos.

  22. #22
    Nemophilist
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    Damnn...

    You're beating me to it. Ahhh... for lack of a DRO. I just don't trust that I could hit the marks without one. I also do not have the process for the super fine tolerance of the bore for the stanchions, let alone the steerer. Boring is such a difficult thing to master on any level, but nice clean high precision stuff is much tougher yet. At least for us garage hacks. If I could only hit 1.259 dead. Maybe I just have not experimented enough....

    Interestingly, there is a real black art to the whole cryo fit thing. They use highly sophisticated equipment to create and then measure all of that stuff. "Tenths" are absolutely critical. And yet, a lot of that high tech knowledge does not necessarily transfer to clamp fitting. I had a pretty in depth discussion with a friend who does this stuff for a living (you ALL know the company), and he really had no idea of how or if the cryo knowledge was useful. The whole idea made him nervous.

    Sit and study a modern cryo fit lightweight fork and you will see lots of subtlety in its design. There are some VERY important things going on there. None of it is by accident.
    Most people ply the Well Trodden Path. A few seek a different way, and leave a Trail behind.
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  23. #23
    All Lefty's, all the time Moderator
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    Quote Originally Posted by Drew Diller View Post
    FYI there have been issues with the forum displaying images of recent, might not be your fault.
    So I'm not the only one with the issues? Seems none of my fellow mods know or heard anything about it, at least those that have gotten back to me on it...

    As for the OP's work? SWEET! Beautiful work, making me jealous over here with all that tooling. Keep it up, you're gonna be so stoked
    This is a Pugs not some carbon wannabee pretzel wagon!!

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  24. #24
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    Regarding the cryo fit, I assume you mean for the steerer (if not simply press fit) and stanchions. Some of these older Marzocchi's have all three bolted in though, so I would assume the tolerance is not nearly as precise - am I wrong on that? I for one had a crown with all three bolted.
    As an aside, I have also press fit steerers in and out of crowns to make the steerer tube longer, it isn't that difficult if you have a simple hydraulic press (I know, everyone has one of those, right?!). The one I used was just welded up with a simple bottle jack and heavy duty iron for the frame - it was originally for AMP forks but I used it on Marzocchi's back in the day as well. I know I wouldn't do it multiple times to the same crown for fear of fatigue, but I never got nervous about a one-time press out and replace with a longer steerer.

  25. #25
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    Love this project. Fits my favorite equation nicely.

    Time + Toys = More and Better Toys
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  26. #26
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    Trailmaker, I don't have a DRO either. We have good old equipment at work and it's all dials for me. The bores on the crown were done by clamping the crown in a 4 jaw chuck on the lathe. I will post a few more pics when I get home from work tonight.

    woodi2259, I think it was your thread where I mentioned my plans to do this. Seeing your thread pop back up motivated me to start posting some pics.

  27. #27
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    Hey;

    Speaking solely of cryo fit, tolerances are ABSOLUTELY CRUCIAL. Clamp fit is not so crucial as to bore tolerance, but it is still very important and not to be minimized. Let's say going from a tenth or two fro cryo to perhaps a half a tenth or a little more. The most critical aspect of clamp fitting is the eveness of the clamping force. It is important to make sure the forces are distributed over the entire area evenly, and that must be considered carefully. The wall thickness of the clamp area, the thickness of the bolt flange, whether that bolt flange will maintain the same position relative to the clamp area, bolt torque, etc. The main focus is to make sure that the bore is round, and that it has at least a light press fit tolerance. If the clamp has any excess tolerance when it begins to compress, it will go ovoid in shape and introduce an uneven load on the stanchions. This is NOT a good situation.

    This is all based on current understanding and materials. Back in the day they just made things heavy and probably didn't sweat it. With all the light weight thin wall stuff, it gets really important.

    Pressing steerers in and put of alloy crowns is fine, I guess, but I would not do it without (the proper amount of) heat. You might get one shot at it cold, as the broaching out of the steerer bore in the crown would loosen the tolerance. Far less so with some heat expansion.

    I would guess if you were working with old clamp fit components, you would have more leeway on all of this.
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  28. #28
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    sick project! Looking forward to seeing this one develop

  29. #29
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    The new titanium crown is slowly starting to look like a crown. The new aluminum steerer tube was a good find on ebay.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0714.jpg  

    Stretched Marzocchi fat fork-cimg0763.jpg  


  30. #30
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    Once again I can't see the last pics so hopefully this one works.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0713.jpg  


  31. #31
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    Awesome.

  32. #32
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    Bwaaaaaaaahhhhhh!

    Awesomness.

  33. #33
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    you guys're awesome!
    not just because you're creative and resourceful, but also because you remind me of stuff I may have in the basement!!
    BLACKSPIRE SHOCK TOWER showing nearly 1/2" over a 3" gazzi on a 321 rim.

    seems to be about 380mm radius form axle to crown, how tall is a 3.8' knard again?
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-crownie.jpg  

    Last edited by byknuts; 01-24-2013 at 09:18 PM.
    If steel is real then aluminium is supercallafragiliniun!

  34. #34
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    I can't see the pics on my computer but i can see them on my wife's laptop so I am going to try a few more.

    The pics so far have been out of date, I have been working on this project for about a month and a half. I have limited time to work on the crown so progress is slow but steady. This set will bring you guys almost up to date.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0798.jpg  

    Stretched Marzocchi fat fork-cimg0799.jpg  

    Stretched Marzocchi fat fork-cimg0800.jpg  

    Stretched Marzocchi fat fork-cimg0803.jpg  

    Stretched Marzocchi fat fork-cimg0805.jpg  


  35. #35
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    Really enjoying following this thread. Amazing work you are doing! I can't imagine how many questions you will get about that fork once you are done.
    By the way, let me know if you want to sell the old crown from that fork. I'm trying to revive an old bomber from my garage to put on my wife's fat bike and am looking for a crown.
    Keep up the great work!

  36. #36
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    byknuts, I remember those Blackspire arches very well. I had the Envy version of that arch on my old Jr T. If I didn't want the extra width I would have tracked down one of those arches.

  37. #37
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    I know you guys like custom made parts so I'm slipping in a pic of my bashguard. It started as quarter inch aluminum plate and I turned down the centre to shave a bit of weight. The rest of the bike is fairly heavy but who wants a heavy bashguard. I also cut a groove into the outer edge of the bashguard and then machined a matching piece of teflon to snap into the groove. The result is a super slippery edge that slides over trees and rocks.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0509.jpg  


  38. #38
    Gumnut Peddler
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    Loving your bike porn! Good to see people doing amazing DIY stuff
    Burning fat, not oil.

  39. #39
    Fat & Single
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    Awesome work there Machinist !!!
    Evil Following
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  40. #40
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    When can I order one?

  41. #41
    How much does it weigh?
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    Try hosting your images on imageshack.us... I love this thread, and it is nothing without the sexy titanium photos.

  42. #42
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    I can see all the pics now but if anyone is still having trouble I have also created an album on my profile, just click my name to find the pics. I have had no trouble uploading the pics there.

  43. #43
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    That is some awesome work.
    Oh noes. I'm going to drink the Kool-Aid.

  44. #44
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    So cool!

    I love seeing DIY machining projects for bikes. I built the upper crown for an old Judy DHO, and while a challenge, it was tons of fun!

    Can't wait to see the finished fork. Looks awesome so far.

    frog

  45. #45
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    It's about time, someone did this.

  46. #46
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    Approaching the problems from perspective of a framebuilder insead of a machinist, I have contemplated making a widened fork crown built much like a segmented tube steel fork (ala fat chance), but with super-short (2") fork blades that pinch-clamp the suspension stanchions to the crown. Someday...

  47. #47
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    Wow, this is awesome! Keep up the good work and keep posting pictures.

  48. #48
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    Thanks to everyone for all the great comments. I can feel my ego growing by the minute.

    I would also like to mention that all my work is done on full manual machines. We have no cnc machines at work and I have actually never used one. I go by the dials on the machines and also some very accurate magnetic backed dial indicators that I stick to the machines. The milling machine does have a digital readout but it can't always be trusted.

    I promise a few more pics later today but I have to go do some trail building right now.

  49. #49
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    The End Mill cutter on the right is brand new with sharp corners. I hand ground a radius on the left cutter so that there will be no sharp corners when I use it to cut the crown. It's not easy to get a nice radius when grinding free hand. 1 1/8 diameter cutter.

    There is always time for one quick pic.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0771.jpg  


  50. #50
    Puro Vida!
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    Very nice! I

  51. #51
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    OMG this is awesome!

  52. #52
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    The more I cut off the crown the harder it is to set up and hold in the vice. I have a couple of one inch blocks and some .025 inch shims added to each end to clamp it securely. It is also raised up on a couple of .875 inch parallels (steel blocks).
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0842.jpg  


  53. #53
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    Shimmed, clamped and ready to cut. I need to cut .225" depth with the crown level and then take the final cuts on an angle.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0843.jpg  


  54. #54
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    I can now angle the crown in the vice and cut down to the scribe marks.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0844.jpg  


  55. #55
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    This is the most recent pic of the crown. I only had time to cut one angle on the front of the crown. Hopefully I will have time on Monday to make the other angle cut. I need to set up a rotary table on the mill for another job next week. If time permits I want to use the rotary table to round off the sharp corners around the ends where the stantions will be clamped.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0855.jpg  


  56. #56
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    Out of curiousity - why are you removing those two extra portions? For weight or aesthetics? Regardless, awesome project - subscribed!

  57. #57
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    The portions on the front? I am just trying to copy the original crown as much as possible and remove as much weight as possible. There are pictures of the original crown in earlier pics.



    The front being the cuts in the last picture.
    The notches on the back place the pinch clamp bolts in the proper position. You can see the holes for these bolts in the side picture of the crown in the vice.

  58. #58
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    Quote Originally Posted by Machinist View Post
    If time permits I want to use the rotary table to round off the sharp corners around the ends where the stantions will be clamped.
    I was wondering about that, as those corners look like they could hurt in a crash.

    Nice work.

  59. #59
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    A machined titanium arch. That is one expensive piece of raw stock. Machine time would be rather significant as well. Want to see finished piece....

  60. #60
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    The crown is slowly taking shape. I finished the angle cuts today and also rounded off the top a little bit to make it look like the stock marzocchi crown. The two notches in the top are there so that a punch can be used to remove the crown race. The felt marks show my next cuts. You can also see the pinch bolt holes on the back which will clamp the stantions.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0904.jpg  

    Stretched Marzocchi fat fork-cimg0909.jpg  

    Stretched Marzocchi fat fork-cimg0912.jpg  


  61. #61
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    Quote Originally Posted by crux View Post
    A machined titanium arch. That is one expensive piece of raw stock. Machine time would be rather significant as well. Want to see finished piece....
    The raw stock used to be a titanium pump shaft that pumped some really nasty chemicals. When I started working at my current machine shop the lead hand hand cut the shaft up and was going to toss it in the scrap bin. He told me to do whatever I wanted with it, just not to put it back on the shelf.

  62. #62
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    Just curious, how long does it take for your machine to make one of the bigger flat cuts?

  63. #63
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    This is what the crown started out looking like. A shaft with a few diameters and threaded.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0846.jpg  


  64. #64
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    Quote Originally Posted by JoeG View Post
    Just curious, how long does it take for your machine to make one of the bigger flat cuts?
    On the larger flat cuts I had the milling machine running at about 400 RPM and 3 inches per minute of feed. The cutter is 4 inches wide, so it's pretty quick. The time is all eaten up in the set-up of the part. Almost every cut on this project required realigning the piece in the vice.

  65. #65
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    Quote Originally Posted by Machinist View Post
    The raw stock used to be a titanium pump shaft that pumped some really nasty chemicals. When I started working at my current machine shop the lead hand hand cut the shaft up and was going to toss it in the scrap bin. He told me to do whatever I wanted with it, just not to put it back on the shelf.
    Wow, and I thought I got cool kick downs as a bike shop employee.
    Beautiful work! Can't wait to see the finished product. Would be cool to have a cnc program designed around the final crown.

  66. #66
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    Thanks again for the compliments. CNC would be really cool, it could have saved me from spending all my lunch breaks working.

    One more comparison picture, just because I like pictures.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0914.jpg  


  67. #67
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    work quicker! I am dying in anticipation of this having just found this thread!
    Try this: HTFU

  68. #68
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    Quote Originally Posted by rockcrusher View Post
    work quicker! I am dying in anticipation of this having just found this thread!
    I'll try, maybe I can explain to my boss how many people are waiting for this to be finished. My Facebook friends have been watching this project for over a month, I think some of them may smack me the next time we see each other. This should be my top priority workpiece for this week.

  69. #69
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    I can see the price of old Marz forks going up as this project nears completion, just as Leftys have. Really nice work. This might be a production thing if you show your boss how nutty we all are!

  70. #70
    How much does it weigh?
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    Really should host your photos somewhere that currently works.

    Seems every time I come on MTBR, there is different photos missing, and different ones showing.

  71. #71
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    Oh sweet. I could see the old Z1s will be in demand here soon if not already, especially if you offer the crowns and arches for sale.

  72. #72
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    I've already been pricing them and enlisted a machinest friend.....

  73. #73
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    I have an old Superfly that would be a good cantidate, except for the lack of a disc caliper mount.

    One thing that wasn't mentioned (or maybe I missed it)- these are not 29er forks, so travel will have to be limited. What sort of travel will you end up with when you're done?

  74. #74
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    Quote Originally Posted by Borgschulze View Post
    Really should host your photos somewhere that currently works.

    Seems every time I come on MTBR, there is different photos missing, and different ones showing.
    Sorry about that, the pictures have all been working for me so I just assumed everyone could see them.

  75. #75
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    Quote Originally Posted by Machinist View Post
    Sorry about that, the pictures have all been working for me so I just assumed everyone could see them.
    Don't apologize, they work randomly. We should be grateful that you are sharing at all. Ungrateful little snots!!

  76. #76
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    Quote Originally Posted by Machinist View Post
    Sorry about that, the pictures have all been working for me so I just assumed everyone could see them.
    Don't you dare post to this thread without pictures!

    I'm drooling in anticipation.
    Oh noes. I'm going to drink the Kool-Aid.

  77. #77
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    I think it's time to crush everyones hopes and dreams and reveal that this will be a one off project. I encourage everyone to find away to create their own fork but this will be the only one I will make. The machine shop I work at is located in a pulp mill and all of our work is for the the mill. We have more than enough work to keep us going and the mill has no interest in taking out side work.

    I had no plans of adding a picture today since I did not make any progress today but I am no longer allowed to post without a picture so here is one more. I mounted the rotary table on the milling machine today for another job so put the crown up there for a picture. Hopefully I will have time tomorrow to round off the front corners with this setup. Machining curves on a manual mill take a lot more setup. A cnc machine just requires a few different codes.

    I am going to post the pic the same old way because I like the excitement of seeing if the pic shows up. Here it is........maybe.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0920.jpg  


  78. #78
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    Wow

    Love these threads, excellent work Machinist, allways nice to watch something unique unfold before our eyes.


    Today i chopped down a Thomson seatpost in a proper liquid cooled chopsaw, i thought it was pretty rad being used to using any old hacksaw and trying to cut with no vice, i de-burred the post on a fine grinder and used a small fine file to de-burr the internal face, then tonight i read this and don't feel so rad anymore, always good to see people with access and the know how to good tooling to get stuck in and have a go and make us all jealous, top work.

  79. #79
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    The crown is finally getting very close to being finished. I found the time last week to round off the outer corners on the rotary table setup. I have also been doing a lot of filing and sanding to blend in the transitions between cuts. Before I was a machinist I liked to see the machining marks on a part but now I just get tired of looking at the machine cut marks. I plan to keep smoothing and polishing the flat areas and rounding over all the edges. I don't have the time to do that on work projects so I am eager to see what kind of surface finish I can achieve. The only cuts I have to do on the crown are the slots to clamp the stantions. I hope to find the time to remove some more material from the bottom of the crown to save some weight and make it look more like the original crown but it will obviously work without those cuts.Stretched Marzocchi fat fork-cimg0947.jpgStretched Marzocchi fat fork-cimg0951.jpgStretched Marzocchi fat fork-cimg0953.jpg

  80. #80
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    As a fellow machinist, nice job!!!!
    "I ride to clear my head, my head is clearer when I'm riding SS. Therefore, I choose to ride SS."~ Fullrange Drew

  81. #81
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    Quote Originally Posted by nitrousjunky View Post
    As a fellow machinist, nice job!!!!
    So Nathan, you gonna knock out a couple of these for our bikes?


  82. #82
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    Quote Originally Posted by nitrousjunky View Post
    As a fellow machinist, nice job!!!!
    Thanks a lot, I do like to get compliments. Even the old machinists at work have been checking out the crown and those guys never care about the bike parts I make.

  83. #83
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    Neat work.

    You realise that you now have to upgrade the rest of the fork to match its pretty crown?
    As little bike as possible, as silent as possible.
    Latitude: 57º36' Highlands, Scotland

  84. #84
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    Great to see your hard(and GREAT) work comming to fruition
    A Fatback'd Lefty for who life IS a Beach

  85. #85
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    Quote Originally Posted by jncarpenter View Post
    So Nathan, you gonna knock out a couple of these for our bikes?
    Might could be arranged.
    "I ride to clear my head, my head is clearer when I'm riding SS. Therefore, I choose to ride SS."~ Fullrange Drew

  86. #86
    Levi Early
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    I love seeing the fabrication going into this project. That crown is a beauty

  87. #87
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    I have been pretty busy with other projects lately so I have not had time to update this thread. There has been slow but steady progress on the fork. In this pic I have bored a few random holes in the bottom of the crown to reduce the weight a little bit.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0957.jpg  


  88. #88
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    I have also been squeezing in the odd ride to keep me busy.Stretched Marzocchi fat fork-cimg0972.jpg

  89. #89
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    The main problem that had been holding up finishing the crown was a slitting saw to cut the slots so that the stantions can be clamped in the crown. We didn't have the right width of saw at work so I had to track down one that was the right thickness. A coworker found one that is 3/32" (.094") cutting width. I was hoping to find a 1/16" (.062") like the original crown but I decided not to be too picky and went with the thicker saw. The setup in the milling machine took a little extra work. I had to convert the mill from vertical operation to horizontal and turn the vice sideways on the mill table. That's not hard to do but it is time consuming when you are in a rush during a lunch break.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg0983.jpg  

    Stretched Marzocchi fat fork-cimg0986.jpg  


  90. #90
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    The slots are now cut and the next step is to press in the steerer tube. I machined a scrap piece of steel plate for the crown to sit flat on and machined a scrap of aluminum to sit on the steerer tube so that I was not pushing directly on the tube. I have pushed a few steerer tubes in and out of old marzocchi forks and it's surprisingly easy. My crown steerer assembly has an interference fit of .003" which is quite a bit for a bore that is only 1.185" diameter. The standard fit on most machinery that we want to be permanent is .001" per inch of diameter.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg1023.jpg  

    Stretched Marzocchi fat fork-cimg1018.jpg  


  91. #91
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    The pressing operation.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg1017.jpg  

    Stretched Marzocchi fat fork-cimg1016.jpg  

    Last edited by Machinist; 02-22-2013 at 04:47 PM.

  92. #92
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    DUde - awesome progress! For those of us not from a machining background - how much force is required to press that crown in?
    Last edited by alexkraemer; 02-23-2013 at 11:10 AM. Reason: typos

  93. #93
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    Stretched Marzocchi fat fork

    Quote Originally Posted by alexkraemer View Post
    DUde - answer progress. For those of us not from a machining background - how much force is required to press that crown in?
    A socket and a baseball bat should get the job done....

  94. #94
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    Quote Originally Posted by alexkraemer View Post
    DUde - awesome progress! For those of us not from a machining background - how much force is required to press that crown in?
    To be honest, I didn't even look at the gauge on the machine to see how much pressure there was. I too busy staring at steerer tube to make sure it was going in nice and straight and smoothly. I do know that when I pressed the steerer out of the stock marzocchi crown the gauge did not even move. Steerer tubes go in and out pretty easily.

  95. #95
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    It has been fascinating to watch your work progress. A incredible job well done. Thanks for sharing.

  96. #96
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    I can't wait to see this on the bike!
    2012 Surly Necro Pugs
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  97. #97
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    This is fascinating, I can't wait to see the fork on the bike.

  98. #98
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    I am currently waiting for a new set of fork seals that are on order and I also need to make some internal spacers to limit the travel but I could not resist test fitting the fork together. So far everything lined up nicely and bolted together without any trouble. Now that I know it goes together I just need to worry about how much it will alter the geometry of the bike.
    Attached Thumbnails Attached Thumbnails Stretched Marzocchi fat fork-cimg1028.jpg  


  99. #99
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    Stretched Marzocchi fat fork

    Looking great. Do you have drawings and numbers of what you've done? Might be worth something.

  100. #100
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    Quote Originally Posted by Schott View Post
    Looking great. Do you have drawings and numbers of what you've done? Might be worth something.
    I had no plans on making any more after this one so I didn't keep track of all the numbers. It wouldn't be too hard to make up a drawing and get some dimensions now that I have a sample piece to measure.

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