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Thread: Multico Mortiser Mystery Madness

  1. #1

    Question Multico Mortiser Mystery Madness

    Good evening all. Something very strange happened over the last week (no, this isn't a Halloween scare story) and I would love to hear your theories.

    Backstory: Back in about 2002, I bought a new Multico PM20 benchtop mortiser. I'm not sure where I got it, but as I understand it Garrett-Wade was a distributor back then so that is a possibility.

    I've used the machine very little for the last few years, but I remember it working smoothly and accurately when I used it to cut mortises for a few small to midsize furniture projects.

    Last year we bought a new house and I emptied my shop and moved all my tools to the house's garage. Everything sat for a year but I finally started selling off items that didn't fit in half a 2-car garage (I'm moving from separates to a combination machine to save space). Among the items I sold at a garage sale last weekend was the Multico, to a young woodworker who (like me) loved the fit, finish, features and funkiness of the British-made machine.

    In the middle of the week I got a call from the buyer who said that he wanted his money back. He explained that the chisel collet didn't seat properly, which left the chisel canted towards the mortiser fence and unable to cut straight.

    I had no idea what he was talking about. I'd never noticed a problem with the mortices I cut — though to be fair I didn't actually cut that many. But then he sent me a picture showing what appeared to be a repair to the machining of the chisel collet boring. It looked very weird, and I agreed to meet him back at my house this morning to evaluate what was going on.

    He showed up this morning, and there is absolutely a problem. Let me pause for a second to explain the structure of the mortiser. If you already know how these machines are laid out, you can skip the next paragraph.

    The mortiser motor is bolted to the top of a hollow casting with open sides. The motor shaft passes through the top of the casting and drives the mortiser bit chuck. The bottom of the casting is bored to take a collet or bushing which holds the hollow chisel. The PM20 has three different bushings for chisels of different diameters. The solid front of the casting has a threaded hole for a set screw which passes through a hole in the bushing and seats against the chisel shank (which is a tight slip fit inside the bushing), pinning both the bushing and chisel in place.

    The buyer showed me that the bushing was a sloppy fit front-to-back inside the boring (side-to-side was tight). As such, when the set screw is tightened, the bushing and chisel both cant, leaving a gap between the bushing face and the bottom of the casting of perhaps 1/40", and angling the chisel towards the body of the mortiser:

    pm20_chisel.jpg

    (Note that the chisel flares at the tip so if the bushing fit correctly, the blade of the square would hit the bottom of the chisel first.)

    Here's where it gets weird.

    I removed the bushing and looked at the boring in the casting into which the bushing should slip. As mentioned, the buyer had already sent a photo, but seeing it in person was ... nuts. The back half of the boring appeared to be smeared with what looked for all the world like Bondo, as if the boring process had been screwed up, and then someone had tried to fix it with filler!

    pm20_bushing.jpg

    Here's another photo, better showing the smear of filler on the inside of the boring:

    pm20_bushing2.jpg

    What THE HECK is going on here? I bought this machine new from a respected dealer, and the manufacturer (when it existed) had a very solid reputation. Has anyone seen anything like this before? Is fixing bad machining with filler an accepted manufacturing practice? Can anyone imagine any other way this could have happened? Damage in transport that was repaired by the importer or dealer?

    And perhaps more importantly: Is there any way that this can be repaired to a normal machine standard? Could the filler could be ground out and a patch welded in, then be reground? The center of the boring has to be colinear with the motor drive shaft, but I can't imagine that usable accuracy would be that hard to achieve. As it is, I can't (and wouldn't) sell the machine, but I can't use it either. I guess in the short term I can attempt to shim the bushing, but other than that am out of ideas.

    I'd be much obliged for any advice or suggestions. Thanks!

    /adam

  2. #2
    I think any repair that involved welding and machining would cost almost as much as a new mortiser. It's way too long since you bought it to recover anything from the manufacturer or dealer, even if you had the sales papers.

    Best to write it off. Especially since you don't want (or need) a mortiser in your shop (since you sold it).

    Mike
    Go into the world and do well. But more importantly, go into the world and do good.

  3. #3
    Mike, you may be right on the economics. But the mystery still stands of how I ended up with a mortiser filled with Bondo.

    I actually do need a mortiser. Originally I had planned to buy the mortising attachment to the combination machine, but for a variety of reasons decided that was not a good option. So my plan was to put the $600 I got for the Multico towards a Domino, but if I can get the Multico functional (and find room for it in the shop), I guess I kind of have to keep it.

  4. #4
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    Drill it out and press in a bronze bushing? I would think a machine shop could do that, or something better.
    Rick Potter

    DIY journeyman,
    FWW wannabe.
    AKA Village Idiot.

  5. #5
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    I have the same machine, but never had a problem. You might contact Multico. They are now headquartered in France. I had to purchase some spare parts and they were very helpful with that, but not sure how they would deal with a problem like yours.

  6. #6
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    Quote Originally Posted by Rick Potter View Post
    Drill it out and press in a bronze bushing? I would think a machine shop could do that, or something better.
    This sounds like a good idea. Short term you could file out the Bondo and replace it with epoxy-steel which would probably wear for years.

  7. #7
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    What is the diameter of the top of the chisels that you have?

  8. #8
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    Looking at those pics makes me wonder if the person you sold it to tried to "fix" some percieved problem, and stuck you with it when he failed. Especially considering that you remember it to be working fine when you used it. I would persue having the casting bored or reamed to the next standard hole size and have a bushing made to replace the existing one.

    Alternatively, is there room to drill and tap for a set screw from the back side? that would push the chisel forward to the good side of the hole. Lots of options, the machine certainly isnt junk but it will take a little time and money to get it right. (If you're going to write it off as some have suggested I'll pay for shipping and your time to crate it and you can send it to me)

  9. #9
    Quote Originally Posted by Tom M King View Post
    What is the diameter of the top of the chisels that you have?
    Do you mean the shank diameter? It's 0.5"; the other two bushings I have are larger but are unmarked and I have not calipered their ID. The ODs are of course the same and they all fit the boring the same way.

  10. #10
    Quote Originally Posted by Bob Falk View Post
    ...not sure how they would deal with a problem like yours.
    Ha ha ha indeed...I can only imagine the Gallic response to my accusation that 15 years ago some Britons made a fabrication error. I'll email them, though, as I have nothing to lose. Thanks for the suggestion.

  11. #11
    Quote Originally Posted by Rick Potter View Post
    Drill it out and press in a bronze bushing?
    Rick, that's a really good idea. I wonder how hard it would be for the machinist to get his hole to be colinear with the motor shaft.

    Thanks!

  12. #12
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    Quote Originally Posted by John Lanciani View Post
    Looking at those pics makes me wonder if the person you sold it to tried to "fix" some percieved problem, and stuck you with it when he failed. Especially considering that you remember it to be working fine when you used it.
    That was my first thought as well. I also think if the dude bought a 10+ year old machine from you, he gets to keep it, and has no right to expect a refund. That is part of the fun of buying used gear.
    Paul

  13. #13
    Quote Originally Posted by John Lanciani View Post
    Looking at those pics makes me wonder if the person you sold it to tried to "fix" some percieved problem, and stuck you with it when he failed.
    John, that is exactly what my first thought was as well. But I see no way that he could have bent the casting so as to stretch out the hole without other visible signs of damage (to the machine or the chisels I sold with it, and that returned unharmed), and it just doesn't make sense that he would have gone at the bottom of the machine with his drill press. Plus he only had it for a few days.

    I did consider that when I rented out my shop for a year to some cabinetmakers that something may have happened, but they were very responsible guys in all visible respects, and the same issues cited above would apply in their case. Plus the mortiser at the time was bolted to a steel table.

    Bottom line is I simply cannot envisage any scenario that could have occurred after I purchased the machine.

    Quote Originally Posted by John Lanciani View Post
    Alternatively, is there room to drill and tap for a set screw from the back side? that would push the chisel forward to the good side of the hole.
    That is a really good idea. This photo suggests that it could be done:

    IMG_2429.jpg

    Quote Originally Posted by John Lanciani View Post
    (If you're going to write it off as some have suggested I'll pay for shipping and your time to crate it and you can send it to me)
    I'll keep that in mind, thanks for your consideration...

    /afb

  14. #14
    Quote Originally Posted by paul cottingham View Post
    I also think if the dude bought a 10+ year old machine from you, he gets to keep it, and has no right to expect a refund.
    Paul: Yeah, I kind of get that. I guess I felt it was my karmic obligation. And I could certainly see how he would think he'd been sold a badly patched-up piece of gear.

    /afb

  15. #15
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    Quote Originally Posted by Adam Block View Post
    Do you mean the shank diameter? It's 0.5"; the other two bushings I have are larger but are unmarked and I have not calipered their ID. The ODs are of course the same and they all fit the boring the same way.
    I was hoping it was 1/2". There are other chisel and bit sets with a larger diameter-for instance 3/4". If you can get it machined correctly to work with larger chisels, that would take care of the problem without having to fiddle with setup every time you put another chisel and bit in it.

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