Australia Designing new Router called Maximus - Page 7


Page 7 of 13 FirstFirst ... 45678910 ... LastLast
Results 73 to 84 of 148

Thread: Designing new Router called Maximus

  1. #73
    Member
    Join Date
    Jan 2005
    Location
    USA
    Posts
    9766
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Quote Originally Posted by davida1234 View Post
    Thank you Peter.

    I did look up Crestomer. It looks like it is not available/can't be shipped to where I live. Your Scotchweld is interesting. It is a widely available manufacturer here. Do you happen to remember which type/number you used for the melamine plugs? Because I tried a few and the bond would come apart when a bit force was applied.
    This is about as good as it gets for HDPE don't expect it to have a great bond this is not a material that bonds well, the best process for this material is fusion

    Attached Files Attached Files
    Mactec54


  2. #74
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi Zorbit - Green and smelly says its a PMMA adhesive. Yep its acrid stuff!! But good...Crestomer is a brand name and covers several adhesive systems. The one I've used on boat structures is a hybrid urethane/acrylic stuff that is moisture tolerant. Urethanes use moisture as a curing agent so the surface moisture that is on everything is not a detrimental thing. It is with epoxies as they do not like water. We did several destructive tests with Crestomer 1152 and found it to outperform epoxy. No need for taping either and these were survey boats that we had to jump through lots of hoops to get it to the water. Surveyors and DOTs don't like new solutions.

    For routers in metal or timber simple epoxy with good prep is all that's needed. Use a hot air gun on metals or a flame before application... roughen surface with some grit paper, follow manufacturers instructions and all's good. Peter



  3. #75
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All - I've borrowed the bench and stand from Boxi a prior plywood router design to get Maximus grounded. Boxi used pocket screws and glue to hold it together. I'm now going through plywood supplies to decide on the biggest sheet I can get to create the the machine bed and get the 2400mmx700mm plus edge allowances or so bed size in one sheet. This will finalise the machine size. Once the machining size and footprint is frozen I can move along to Round 2. I know I've been talking about R2 for a while now.... I'm also still thinking about a metal bench, stiffness is king here...Peter

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-max-2-jpg   Designing new Router called Maximus-maximus-1-jpg  


  4. #76
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All - I've done a bit more stressing and adjusting parts. Simsolid only displays values to 0.00 so I've been using 10,000N as the design load so I can see the differences to the third place so to speak. 10,000N is 1019kgf or 1.1 US tons. The structure would survive this with 314MPa being the highest stress in a small corner if we used G350 steel for the gantry front. But being a light router I doubt we will get past 100kgf tool load in reality. So we are now deflecting at 30% more than our 10N/um target with over 10X safety factor on stress. So you guys out there that keep saying its got to be "stronger" need to say it's got to be stiffer (there must be a joke in there somewhere) I have to widen the gantry and get the proper bench into the structural model. So I'll get the bench size frozen then can start the rebuild.

    I'll modify the comment about deflection. The force is being applied at the bottom clamp for consistency purposes. At the clamp its deflecting 0.95mm which is under the target stiffness ie 10,000N <1.0mm (10N/um) Happy Days...

    Currently in the simulation all faying surfaces are "bonded" which means they are more efficient than when we come to bolt them (maybe if we use the right bolts in the right places it will be equivalent) So the simulation is more like the structure is welded together at the moment. Ultimately I have to decide if the design is too expensive for the market that I target. But until we get to the design resolution that's a mystery. Peter

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-maximus-1t-deflection-jpg   Designing new Router called Maximus-maximus-1t-stress-jpg   Designing new Router called Maximus-max-front-jpg   Designing new Router called Maximus-max-jpg  

    Designing new Router called Maximus-clamp-deflection-jpg  
    Last edited by peteeng; 04-18-2019 at 02:19 AM.


  5. #77
    Member
    Join Date
    Aug 2014
    Posts
    94
    Downloads
    4
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Quote Originally Posted by peteeng View Post
    Hi Zorbit - Green and smelly says its a PMMA adhesive. Yep its acrid stuff!! But good...Crestomer is a brand name and covers several adhesive systems. The one I've used on boat structures is a hybrid urethane/acrylic stuff that is moisture tolerant. Urethanes use moisture as a curing agent so the surface moisture that is on everything is not a detrimental thing. It is with epoxies as they do not like water. We did several destructive tests with Crestomer 1152 and found it to outperform epoxy. No need for taping either and these were survey boats that we had to jump through lots of hoops to get it to the water. Surveyors and DOTs don't like new solutions.

    For routers in metal or timber simple epoxy with good prep is all that's needed. Use a hot air gun on metals or a flame before application... roughen surface with some grit paper, follow manufacturers instructions and all's good. Peter
    Our destructive tests included chaining test pieces to a mooring buoy at low tide and leaving them there for several years. As far as I know, they're still there, checked yearly.

    More recently, I had to glue some 7075-T6 aluminium reinforcements into a hardwood frame and consulted the West Systems bible for advice. They recommend sanding the aluminium through the wet epoxy, to prevent the near-instant oxide layer from forming.



  6. #78
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi Zorbit - the wet sanding method is tried and true. But immediately before you start, a waft with a flame or a heat gun to remove surface moisture is best. If you ever tig weld you will see the water leaving the surface of the metal ahead of where your are welding. We are on a water planet and water is everywhere. I also learnt about this when I was vacuum bagging various things and found that epoxy stuck to things like the polished surface of an extrusion like the proverbial. But if I had done this in atmosphere it would not have stuck. Under vacuum all the free water boils off so epoxy sticks to things exceptional well. When I was welding hovercraft parts we had hydroflouric acid to clean aluminium before we welded things. A very large tank of dangerous stuff. Anyways the oxide took about 4 hours to recover so it doesn't happen quite instantly.

    The aircraft industry does most of its secondary bonding hot, partially because of the epoxies used but also to boil off the water...

    To bring the day to an end I have turned the Z axis into a tube design. The back piece and front piece will be identical. I did have it as a shoebox fit but making such a fit in sheet metal is tough. So I shall use side straps and lots of bolts. Plus the spindle clamp can bridge across giving it the correct load distribution at the end. This one has 6mm thick bits vs the 8mm thick before and its same stiffness and weight. 0.98mm deflection at the clamp with 10,000N applied. Now the major deflection is in the gantry so need to tidy that up.

    I'm off for the weekend to do some towing launch tests on a flying trimaran, should be exciting.... Peter

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-z-axis-jpg  
    Last edited by peteeng; 04-18-2019 at 07:32 AM.


  7. #79
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All - A brief summary of where the design is at. By the way the transverse rigidity is 4x the longitudinal rigidity. Peter

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-max-transverse-jpg  
    Attached Files Attached Files
    Last edited by peteeng; 04-18-2019 at 08:13 PM.


  8. #80
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All - I'm back and the trimaran flew successfully and nothing broke!! Yeh, that's a 2 year project off my list. The 10 hour return driving time gave me lots of time to think about Maximus. I have been thinking how to evaluate and optimise the structure. With a stress domain object that is quit easy as you can work through the machine part by part, look at its stress state and do things to reduce the stress to the allowable limits. In fact several FEA systems can do this for you automatically. But with a stiffness domain structure no-one has given me a part by part deflection limit only a global limit. So reading Bamberg's thesis again he discusses stiffness or structural loops. I shall work it a similar way. He does the vector maths, I use simulation. I break the machine into its sub assemblies. The Z axis, the bearing plate, the gantry and the columns. I have isolated each assembly and calculated its individual Z deflection. Then I rank these against the global deflection as a %. This tells me the compliance contribution of each bit and therefore which bits to work on. Results:

    Global deflection 0.13mm in the Z direction from a 1000N load. This is at the collet by the way not the load application point.

    Z Axis 0.03mm or 23.1%
    Bearing Plate 0.01mm or 7.7%
    Gantry 0.08mm or 61.6%
    columns 0.01mm or 7.7%

    A bit glaring on what to work on!!

    The gantry contributes 62% of the deflection so need to work on this. I'm considering using a single SHS or RHS for this but need to talk to the laser people to find out if they can cut the size I want. (nope 150mm max so have to sheet metal the gantry )Plus I'm going to weld a full flange on the end vs the partial bolt up at present. I'm generally agin welding due to distortion but if they plug weld the flange on, distortion will be minimal (fingers crossed) I'd prefer to braze it but they don't braze so I'd have to pick the parts up, braze them myself and take them back and that's a 3 hour turn around so they can then paint the parts, too far to be economical... I also think the current column/gantry integration is poor. The other negative is that the Maker will have to tap all the holes if I use an SHS but then their time is considered to be free. The picture is becoming clearer... Peter

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-3-z-axis-exagerated-jpg   Designing new Router called Maximus-2-max-z-axis-jpg   Designing new Router called Maximus-1-max-z-axis-global-jpg  
    Last edited by peteeng; 04-21-2019 at 07:52 PM.


  9. #81
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All- Been mucking around trying to improve the gantry. I haven't been able to do it in RHS or SHS because the laser cutters tube laser can only go to 150mm square. Seems the gantry will be about 250x250mm or rectangular but at least 230mm high. So I've added an internal diagonal brace to the gantry that stops it lozenging. I didn't like the shear webs because the gantry response will be different in between them. The brace provides consistent stiffness along the gantry. The brace has dropped the deflection from 0.13mm to 0.10mm which is a start.

    In regard to machine width I can get 1525mm wide x 3050mm long plywood. This will make a board that has 100mm margin for clamping etc around a std sheet. Makes the machine 1600mm wide which is a bit too big for the space its in. So working backwards if I make it 100mm wider than current then the working envelope will be 1000mm by 2500mm. and the machine footprint will be 1400mmx2600mm maybe longer. cheers Peter S

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-brace-jpg   Designing new Router called Maximus-ss-brace-jpg   Designing new Router called Maximus-gantry-brace-jpg  


  10. #82
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All - I've added a triangulated brace inside the gantry and the deflection ha been reduced to 0.06mm from 0.13mm. This is half the prior deflection so I'm happy to proceed. I've started working on the bench.

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-max-bench-jpg   Designing new Router called Maximus-push-jpg  


  11. #83
    Activation process peteeng's Avatar
    Join Date
    Jul 2018
    Posts
    304
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Hi All- I've started building the Round 2 model. It will include all the bolts and nuts. Here's a test run on the tool tube. The bolts down its side are torqued to the proof load of class 12 M6 screws (11kN) and the surfaces are speced at friction co-efficient of 0.1. The software prints out the load in the bolts and shows how the connection will slid, gap or not. The tool tube model also has the compliant bearings in it so I'll look back and compare to the prior steel versions.

    I've change the shape of the tool tube as I don't think the bender can bend the close bends to create the gutter. I have sent model's to the bender for comment. It is bendable but it maybe wider than I like so I'm looking at this square version which can be narrow. This also brings me back to using maybe 20mm bearings! I converted another video to wmf. Cheers Peter

    Attached Thumbnails Attached Thumbnails Designing new Router called Maximus-tool-tube-2-jpg   Designing new Router called Maximus-tool-tube-bolts-jpg  
    Attached Files Attached Files
    Last edited by peteeng; 04-22-2019 at 11:47 PM.


  12. #84
    Member
    Join Date
    Jan 2005
    Location
    USA
    Posts
    9766
    Downloads
    0
    Uploads
    0

    Default Re: Designing new Router called Maximus

    Quote Originally Posted by peteeng View Post
    Hi All- Been mucking around trying to improve the gantry. I haven't been able to do it in RHS or SHS because the laser cutters tube laser can only go to 150mm square. Seems the gantry will be about 250x250mm or rectangular but at least 230mm high. So I've added an internal diagonal brace to the gantry that stops it lozenging. I didn't like the shear webs because the gantry response will be different in between them. The brace provides consistent stiffness along the gantry. The brace has dropped the deflection from 0.13mm to 0.10mm which is a start.

    In regard to machine width I can get 1525mm wide x 3050mm long plywood. This will make a board that has 100mm margin for clamping etc around a std sheet. Makes the machine 1600mm wide which is a bit too big for the space its in. So working backwards if I make it 100mm wider than current then the working envelope will be 1000mm by 2500mm. and the machine footprint will be 1400mmx2600mm maybe longer. cheers Peter S
    How is 1000mm going to be ideal if a standard sheet is 1200mm and up to1220mm in the usa

    You also appear to be missing something with your Zaxes, a way for it to move up and down, normally a Ball screw is used for moving it up and down this puts you back to the start as this will need more room for the ballscrew and that means more leverage at the tool

    You said you are testing from the collet, you need to test with a tool 50mm out from the bottom of the collet this is what a normal router would be doing and where the loading is taking place

    Mactec54


Page 7 of 13 FirstFirst ... 45678910 ... LastLast

Tags for this Thread

Posting Permissions

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


About CNCzone.com

    We are the largest and most active discussion forum for manufacturing industry. The site is 100% free to join and use, so join today!

Follow us on


Our Brands

Designing new Router called Maximus

Designing new Router called Maximus