1. Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.
    Dismiss Notice

Connecting motor to wheel

Discussion in 'General Electronics Chat' started by transatlantic, Mar 3, 2018.

  1. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    I'm looking for ideas on how I could connect the following wheel, to the motor shaft below? Ideally, I would like to connect it directly, without a belt.

    Wheel : Bore size 13mm
    Motor : 8mm shaft diam, 25mm shaft length, M4 thread.

    Any ideas?

    Untitled.png
     
  2. tcmtech

    tcmtech Well-Known Member Most Helpful Member

    Joined:
    Feb 22, 2009
    Messages:
    7,317
    Likes:
    511
    Location:
    Upper midwest USA
    Adapter bushing and set screw.
     
  3. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    wouldn't that be something I would need to get specially made? did a quick search and couldn't see anything off the shelf that was 13mm to 8mm?
     
  4. dave miyares

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    2
    Likes:
    -10


     
  5. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

    Joined:
    Apr 17, 2007
    Messages:
    7,983
    Likes:
    1,079
    Location:
    Loveland, CO USA
    Last edited: Mar 3, 2018
  6. dknguyen

    dknguyen Well-Known Member

    Joined:
    May 6, 2006
    Messages:
    7,549
    Likes:
    162
    If you can find the space, drill a hole into the side of the wheel (use a hand drill!) and use a setscrew. Every other solution includes buying or machining a hub. that the shaft slides into that bolts to the wheel.

    In your case, it sounds like the shaft is smaller than the bore, so maybe use some material to close that gap...like epoxy fill or wood. If you use epoxy you can use a 8mm rod wrapped in wax paper as a plug to keep the hole clear as the epoxy cures so you can twist it out and insert the motor shaft.

    If it's not very high torque then you might be able to get away with all of this and just JB-weld or epoxy the motor shaft right into the wheel but it may not be as durable or as removable as you want.

    Honestly, I've always found attaching shafts to random wheels a major PITA. I wish more motors had square shafts and I had a square drill.
     
    Last edited: Mar 3, 2018
  7. hyedenny

    hyedenny Member

    Joined:
    Jan 17, 2009
    Messages:
    151
    Likes:
    9
    If the bore in the wheel is smaller than the shaft, then get a small round file and a small flat file and carefully file away until it fits! Hopefully, it won't have to be exactly concentric.
    Depending on what type of plastic it is, you may be able to heat it up locally until it's pliable enough to force the shaft through, position it, then let it cool in place.
     
  8. dave miyares

    Dave New Member

    Joined:
    Jan 12, 1997
    Messages:
    2
    Likes:
    -10


     
  9. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    Not sure what you mean with that. Those are for connecting two shafts. I have an 8mm shaft on the motor and a 13mm hole on the wheel.
     
  10. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    Thanks for the idea, I may try that if nothing simpler crops up.

    As mentioned, the wheel bore is 13mm and the motor shaft is 8mm
     
  11. alec_t

    alec_t Well-Known Member Most Helpful Member

    Joined:
    Jul 10, 2011
    Messages:
    9,730
    Likes:
    1,277
    Location:
    Cardiff, Wales
    What is the depth of the 13mm hole (i.e. the wheel thickness)?
     
  12. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    About 35mm
     
  13. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

    Joined:
    Apr 17, 2007
    Messages:
    7,983
    Likes:
    1,079
    Location:
    Loveland, CO USA
    I have connected one of these to the motor shaft and then used 4 screws to connect to a wheel.
    upload_2018-3-3_14-30-47.jpeg
    upload_2018-3-3_14-32-8.png
    This next item; you can get with a 8mm hole for the motor and on the other end with a 13mm hole for a short 13 shaft that fits into the wheel.
    upload_2018-3-3_14-32-56.jpeg
     
  14. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    Ive only seen the couplers with up to 10mm bore unfortunatley. Have you actually seen an 8 to 13mm?
     
  15. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

    Joined:
    Apr 17, 2007
    Messages:
    7,983
    Likes:
    1,079
    Location:
    Loveland, CO USA
    I have some that are 0.25 inch. They are used to extend the length of a radio volume knob.
    I know I have used a drill press to enlarge the whole size.

    I found a number of brass tubes that are 8mm inside and 13mm outside. They are meant to be a bearing, not a coupler.
    I think you need a splined shaft for the wheel. Some way so the wheel and the shaft connect.
     
  16. Mickster

    Mickster Well-Known Member

    Joined:
    Feb 24, 2008
    Messages:
    1,291
    Likes:
    104
    Location:
    BDA
    The initial post leaves out quite a bit of information, which could be particularly relevant to what is actually required.
    If the task at hand is to simply attach the wheel to the motor shaft, then something like the circular flange Ron shows in post #11 should easily do the job.
    Place the flange on the wheel, mark some holes and drill the wheel, attach the flange to the motor shaft and then secure the wheel to the flange.

    If more precision than that simple process is required, we need to know.

    Are you looking purely for an off-the-shelf solution?
    Do you require concentric alignment and a minimal amount of run-out?
    What tools are at your disposal, to perform any small mods which may be necessary?

    If you have a drill press and a 16mm bit, something like this would do the job, as long as you don't require absolute precision:
    https://www.banggood.com/8mm-Flange...aring-Fitting-p-1206973.html?cur_warehouse=CN
    Drill the wheel center hole out to 16mm, at a depth > 10mm, mark and drill holes for the mounting fasteners, mount the flange to the motor, then the wheel to the flange.

    If you have a lathe, you may be able to take successive cuts up to 1.5mm DOC off the flange 16mm boss and turn it down to 13mm, to fit the wheel bore. Mark and drill the mounting holes as required, blah blah.

    You may wonder why you are being asked to field a load of questions, but we don't know what you know.

    Please state your requirements, otherwise we are just left to guess and offer opinions/ideas/search results which may be way off the mark for what fits your problem.

    Regards.
     
  17. ronsimpson

    ronsimpson Well-Known Member Most Helpful Member

    Joined:
    Apr 17, 2007
    Messages:
    7,983
    Likes:
    1,079
    Location:
    Loveland, CO USA
    Expanding on post #14;
    It looks like the motor shaft has a place for a screw on the end. Show in light blue.
    I found bushing with 8/13mm size.
    Using the item form Post #14.
    The wheel, not shown, sits on the bushing and is pinched between the washer and the flange coupling part.

    upload_2018-3-3_18-44-36.png
     
  18. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    Thankyou for the further suggestions!

    Unfortunately, there isn't enough meat to drill a 16mm hole, or to mount the flange. If you have a look a the image I posted, there is only about 2mm around the 13mm bore. Although I guess I could attach some kind of hubt


    As to your questions. It doesn't need to be super accurate, as long it is running visibly true then that should be fine. It's running at a very low RPM (~60), so any vibration caused by run-out probably won't be noticeable. As for tools, I do have access to a drill press, but not a lathe.
     
  19. Mickster

    Mickster Well-Known Member

    Joined:
    Feb 24, 2008
    Messages:
    1,291
    Likes:
    104
    Location:
    BDA
    Going a little bit further with TCM's suggestion from post #2..

    Unless there is going to be a lot of load on the wheel, this could be made with a drill press, but you would also need a washer welding on the end and a tap to make holes for set screws. I left the length at 36mm to allow for a washer with an ID of 13mm to be slid over and tack-welded in position.
    The wheel would be sandwiched between the welded washer and another washer, secured with an M4 bolt going through to the motor shaft.
    You could use set screws which protrude slightly and file a key-way into the wheel, to prevent the load on the wheel from unscrewing the M4 bolt, depending upon direction of course. If the motor turns clockwise when looking at the shaft end, this is something you will need to consider.

    Drill 4mm and 8mm holes as shown, in a length of 13mm rod, drill & tap holes for the set-screws.
    Measure the depth of the 13mm hole in the wheel and position the washer so that the shaft will be a couple of mm short of being flush with the outside of the wheel.
    Weld the washer from the back and clean up as required.
    Secure the bushing to the motor shaft, mount and secure the wheel with another washer and M4 bolt.

    Bush.png

    Just an idea, I hope you can use it for your application.
    Regards.
     
  20. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    Hmm. very good! .. but I would need to drill exacty on center for all that to line up! ... gonna do a little research to see how I can accuratly drill holes in rod section
     
  21. Mickster

    Mickster Well-Known Member

    Joined:
    Feb 24, 2008
    Messages:
    1,291
    Likes:
    104
    Location:
    BDA
    Check this out:

     
  22. transatlantic

    transatlantic New Member

    Joined:
    Sep 16, 2017
    Messages:
    15
    Likes:
    1
    I like this technique

     
    • Like Like x 1

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice