Help making alu mounts

  1. Nathan

    Nathan Tea anyone?

    Messages:
    160
    Loughborough
    Hi im currently building a cr500 hybrid and the original frame mounts need to be removed and new ones welded in. You can buy machined mounts but this is over 300 quid which i just dont have the money for.

    What im looking to do is get some 5mm thick alu and make some myself. What im planing to do is make a mount out of 2 pieces of alu and weld them together and then weld to the frame. They need to be strong, as its a dirt bike.

    Look at the pic or this wont make sence (might not make sence with the pic LOL)
    [​IMG]

    So my thought was to have two pieces of 5mm alu and cut them to shape. then cut a slot then slot in and weld together. The mount needs to be a 90degree angle. i will try get some pics of the old frame mounts tomorrow so you get an idea of what im trying to make.

    Can you think of a better way or ways to improve the design?
    Oh and does anyone knwo where i can get 6061 alu? only need about 125mm square.

    And this is what im makeing them for. cr250 frame with a cr500 motor. 2stroke:D
    [​IMG]

    thanks nathan
     
    Last edited: Jan 9, 2009
  2. hareng Member

    Messages:
    1,465
    Location:
    Wolverhampton
    250 and 500 used to be the same frame.

    May be better or easier to use two new flat brackets with holes drilled, line engine up and tack in place. Beef it up with another plate to spread the load at right angles, no need to mill in unless machined out on one side, negating the idea and therefore weaker.

    ASC over your way will have off cuts knocking about.

    Too much, low and mid power for me.
     
  3. wyn

    wyn Member

    Messages:
    2,976
    Location:
    Cardiff
    6061 is more of an American material, over here the similar material is 6082.
    From what i remember the aluminium Honda frames are a 7xxx series aluminium, not much help i'm afraid.

    The motor is looking nice in that frame.
     
  4. hotrodder Member

    Messages:
    4,587
    SE England
    I wouldn't bother milling a slot but i would lose all the sharp corners if you weren't already planning to (ease of drawing i suspect).

    What about using a T section extrusion? Available cheaply everywhere in 6082 and 6063-T6, upto 1/4" thick and 3" leg length IIRC. Only downside is that a lot of commercial extrusions have little to no radii at the section changes
     
  5. Nathan

    Nathan Tea anyone?

    Messages:
    160
    Loughborough
    So i should do away with the slot? and just butt weld it?

    Yeah the shar corners where just for the drawing they will be rounded when i make them.
    You can see on that pic the lower engine mount thats the kind of thing im aiming for
     
  6. aametalmaster Member

    Messages:
    763
    Location:
    Salem Ohio USA
    One thing nice about alum is you can work with it with wood working tools like a router and table saw. I get 1/2" thick sheets in all the time and cut them in my table saw like it was wood. A carbide blade is all that is needed. The same with the routher it cuts alum great and fast so slots become easy...Bob
     
  7. Nathan

    Nathan Tea anyone?

    Messages:
    160
    Loughborough
    Yeah i think some T section alu would be perfect. its just finding some to the specs i need. ive had a look on ebay but carnt find any though.
     
  8. wyn

    wyn Member

    Messages:
    2,976
    Location:
    Cardiff
    You could try here for small amounts of T section.
     
  9. hotrodder Member

    Messages:
    4,587
    SE England
    :o How much!!! Don't usually have much use for T section but i checked their prices for full sheets- almost 3 times the going rate! Tube by the metre is more than i pay for a 5 metre length!! Doesn't really help much though as stockists like http://www.aalco.co.uk/ will only sell complete lengths. No prices on line but there's a comprehensive PDF catalogue available

    The only place i know of that splits lengths/sheets has a £50 min order (£75 for carriage paid) so that doesn't help much either. Sorry.
     
  10. wyn

    wyn Member

    Messages:
    2,976
    Location:
    Cardiff
    That's where they make their money i suppose.

    It's tricky if you only want a small amount.....i usually go the 5/6m route and whoever the job is for, is paying for it anyway with plenty left over for other uses.:laughing:
     
  11. hareng Member

    Messages:
    1,465
    Location:
    Wolverhampton
    Looks like 1 1/2 x 1 1/2 x 1/4" T is the smallest available so would have to cut down any way.
    Angle 1 x 1 x 1/4"

    Pop along in person to local ASC and have a rumage through the bins.
    Worst case you will come away with some flat.

    Reckon 3/16" thick will be strong enough, worst case could send you some angle.
    Theres a place based in Leicester that sells small off cuts on ebay inc titanium, pricing ok but you can collect.
     
  12. Nathan

    Nathan Tea anyone?

    Messages:
    160
    Loughborough
    I think 2 pieces tigged together should do the job just nicely. Yeah i use metal direct and metal off cuts for most of my metal. il order some monday and get on with making them if they dont turn out well il try the T.

    Cheers for the info anyway ;)
     
  13. Nathan

    Nathan Tea anyone?

    Messages:
    160
    Loughborough
    Ok got some 5mm thick 6082 today and made a couple of mounts. When i cut them out and tried them against the motor there wasnt as much space i was hoping for. as i was going to weld to flat pieces together now i found out this will not work.

    So my idea now is to still use the mounts a made but get rid of the second flat piece and get some solid alu bar and create a flat side which will sit on the frame. This will be welded to the mount i made today. Also this gives room to get a bolt in too.

    Here are the pics of the mount up against the frame and engine, mounts i made and what im hoping to make. Please dont laugh at my butchered old engine mounts. thats what you get if you try use an angle grinder in a tight space hahaha I need to buy a reciprocating saw. And yes the engine was out while i tried this;):laughing:

    I hope you can understand what im doing as its quite hard to say what im tying to do :P

    [​IMG]

    The width of these are a little over the top at the moment so they will be trimmed down some more.
    [​IMG]
    [​IMG]
    [​IMG]
    As you can see there is no room to put another piece in or even to weld and then put a bolt in lol The new mount will just hang over the frame so it gives room for the bolt.

    [​IMG]
     
  14. Cal Member

    Messages:
    307
    Bristol, UK
  15. Nathan

    Nathan Tea anyone?

    Messages:
    160
    Loughborough
    yeah ive heard of Gix. on cr500riders i think :]
     
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