Page 3 of 4 FirstFirst 1234 LastLast
Results 31 to 45 of 54
  1. #31
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    Some of my reduction drive parts arrived today and I’m hoping they’re going to be sturdy enough. I’m not overly worried yet and feel I can add in a ramp up and ramp down time to ensure they don’t stretch or break, but only time will tell.




    I did know before hand that the smaller pulleys only had a 12mm bore (the largest I could get and keep the reduction ratios correct). My original plan was to make a reduction bush for the motor but now I have a problem, the motor sticks out too far and this would mean not enough room for the larger pulley above.




    My options are a little limited given the available space but I’m seriously contemplating pulling the motor apart, putting the spindle in the lathe and turning down the end to 12mm.

    Anyone think that’s a bad idea?

    If I find any issues with the belt being able to manage the load, I can simply upgrade the pulleys which would likely still need a 12mm spindle on the motor to accomodate the smaller pulleys.

  2. #32
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default Rockwell Bandsaw Identification, Help and Conversion

    Nearly have all my reduction drive jack shaft parts. This weekend will try and reduce the motor spindle to accept the 12mm bore of the small pulley, plus make the frame for the jackshaft out of some leftover 50mm x 25mm tube.

    The plan is going to be to make a rectangular frame, drill holes in the pivot end to mount to a 12mm shaft (smaller rod in the picture) and make oversized bushes (top hat bushes out of the larger rod) for that shaft so it’s not riding on the thin wall of the tube directly.

    The pillow bearings will mount to the other end and I’ve bought (but not picked up yet) some 17mm silver steel rod for the main axle. I’ll need to drill and bore out the larger pulleys to able to mount them on the axle (17mm) and also the main bandsaw drive wheel (24mm I believe).



    I’m also planning on keying the pulleys to the motor and bandsaw shafts, is have some key stock on order for that too.

    The only thing to do after that is order the belts once I have all the final pulley placements.

  3. #33
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default Rockwell Bandsaw Identification, Help and Conversion

    Interesting day today. I started off doing the shaft and collars for the reduction drive mount and then got distracted half way through with another project before returning to the original one.

    Step 1 was to shorten the shaft to 303mm, then drill the ends and tap to M8. These will take a bolt on the ends to secure them to the lower cast iron base, same as the motor mount pivot. All went well.

    However as I was doing it I noticed some air bubbles in my water cooled DC motor (another DIY job). It’s bugged me for a while and I suspect the copper coils around the motor are the problem as they keep getting blocked every few months.

    Rather than bleed it again and blow out the cooling coils with compressed air, I thought I’d see if the original bandsaw motor would fit the lathe. It has been sitting on my bench ever since I pulled it out of the bandsaw and pulled the star point out with the help of BobL. I hadn’t even tested it!

    I made up a new pulley for the 3PH motor and then set about pulling all the DC motor bits out:



    And in went the 3PH motor after some fine tuning of the mount holes:



    It’s tight, but it fits. There’s good news and bad. The good news is that not only did my dual voltage conversion work but the lathe now chews through work like never before. The difference between the DC motor and this 0.75HP motor/VFD is night and day.

    The bad is unfortunately the motor has a vibration. Sometimes it goes away but most of the time it’s there and has a rhythm to it. I suspect 2 things could be the cause:

    1) There is axial play in the motor because it didn’t have a spring washer in it. I suspect it should and whilst I bought one, it was too large and bound the motor up, so I left it out.
    2) I had some issues putting the bearings in and put them in too far at one point and had to pull them out again. I’m wondering if I buggered the bearings. Whilst it’s very smooth under hand power I’m not sure if this offers any clues to how it would run under power/load. I may remove the bearing that was the problem and replace as a cautionary step.

    The other thing I noticed was the fan in the motor doesn’t move much air Rockwell Bandsaw Identification, Help and Conversion. The one I’ve put in the bandsaw on the other hand does push a lot of air over the fins on the outside of the motor, but this one has a gentle flow from the cutouts. Not sure if that’s a problem. Whilst I was taking some heavy cuts today it got warm but nothing I would consider anything to worry about at this stage.

    With the motor replaced and a new ability to remove material I set about taking some nice cuts off some 30mm steel bar to make my axle bushes. The lathe would easily hold a 400mm length of bar, turn it at 500 rpm on a dead centre whilst taking 25 thousandths DOC. Not something it would ever do before and I couldn’t even hear the motor bogging, the rattle however was still there. I’m hopeful I can get the motor super smooth as it will transform the lathe!

    Turned down a 17mm section and then left a 24mm collar for me to tack weld the the tube. Gave me a chance to also use my new (to me) Mitutoyo micrometer!

    The inside was drilled and bored out to accept the rod. Originally I thought it was 12mm (because I forgot to measure it and I thought I was using the 12mm hot rolled), but it was actually the axle from the original treadmill I bought and used the motor from for the lathe (since went pop). Some careful boring and I got the middle to accept the rod and whilst the wall is relatively thin, it’s more than enough for what I need.

    I left a slightly loose fit (so the collar just started to rock on the shaft) as I plan on greasing it and felt this would allow the grease to really get in to the collar:







    I didn’t really bother with finishing passes to get a smooth finish. The outside will be inside the tube and not visible and the inside I thought would hold the grease better if it had some texture.

    The shaft is 14mm in the end. So the wall thickness is 1.5mm each side roughly.

    I’m not overly worried as I will be drilling the rectangular tube out to 17mm (the largest drill but I have), hence the smaller diameter of the bushes, and these will be supported by both sides of the tube. I will tack weld them in place with my TIG:





    Hopefully tomorrow I can get the tube lengths cut and welded and then drill the holes in the base of the saw for a test fit.

  4. #34
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    I’m sure the motor vibration is because of the axial play. So before pulling the bearings off, I’ll find a suitable spring washer and install that. I also have a pulley here that I’ll also swap in as the one I have on it at the moment has a very slight wobble.

    Today’s job was to cut the reduction drive frame, weld it up and install the pivot rod stuff.

    This is the general plan:



    Step 1 was to get all the tube lengths to the same dimensions. I trammed in the mill vice and set about roughing the lengths to exactly the same dimensions and nice and square at the ends. I’ve done this before on a few projects and it makes welding them up so much easier as I’m guaranteed a perfect fit up:



    Next I had to drill the 17mm holes on each of the tubes. I did this by marking them with the calipers, punching a mark and drilling them out to 4mm. I then went straight to 17mm and turned the mill down to 280 RPM and slowly chewed through the tube. I didn’t go all the way through but set another stop on the mill and flipped them and drilled each side separately:



    Welding was uneventful. I’m not the best welder but I really enjoy it! Thankfully the frame didn’t move on me much and the rod/axle still moves freely with the same level of fit:





    I’m happy to report my plan worked. I’m not going to drill the holes to mount the pillow bearings yet as I want the 17mm silver steel on hand to keep the alignment perfect. The placement will actually be a little closer to the middle than the edge here. I’ve deliberately kept the frame longer as I plan on mounting some additional parts later for a gearbox (hopefully):



    I spent a bit of time getting the pilot holes drilled on the saw base but unfortunately cannot mount it as I need a 15mm drill.

    Final step of the day was to start making the bolts to ensure the pivot rod doesn’t walk itself out. Turned the same material as the rod down to 8mm, then threaded the end. Parted them off and will mill a hex on the end of each but not all the way through as I want a round on the bottom to leave a flanged bolt. Will also make some thick washers.




  5. #35
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default Rockwell Bandsaw Identification, Help and Conversion

    Change of plan on the drive system. I’m not
    Comfortable turning down the motor shaft, so I was looking at chain and sprocket setups on eBay and actually sound something that I think could work around the 428 chain system. I hadn’t bother before as I couldn’t find anything with a good enough ratio but I’m going to try and get around that by adding in another shaft to have a 3 step reduction.

    To get to the 100 and 1000 SFPM required for steel and Alu with my 1420 RPM motor I need 51:1 (102 SFPM) and 5:1 (1040 SFPM) reduction.

    The extra shaft allows me to get those reductions and keep the final bandsaw ratio at 5:1 which then means all I need to do to swap the speed is change the chain from the motor to their second shaft, not the first.

    The other benefit of chain and sprockets is they are made of steel and I can weld and/or attach them to other steel bushes.

    I also suspect the motor noise is because of the axial play. When I push on the end of the shaft it gets very smooth and quiet. I will try and find a place to get some spring washers today and see if that works before replacing the bearing.

  6. #36
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    428 chain and sprockets seems to be the best solution. Checking online I found a calculator to get the diameter of the 32T sprockets (the ones that need to fit under the saw). I get 5.1” as the diameter or 130mm

    These will fit and I also can package them neatly next to each other to get the additional reduction shaft in there too. Looks like a good option.

    I will space the shafts around 90-100mm apart like this:



    It will be a tight package but I’m confident it will work. Then to get the required high/low speed change all I need to do is switch the motor drive to the other shaft and run a 1:1 ratio. I’d like a gear change system for that, but haven’t got that bit worked out yet.

  7. #37
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    Lunch time pop out to see my local motor rewinders. 2 washers later and a very quick motor change... it’s completely cured the vibration. In fact it’s a wonderfully smooth motor and really smooths out at full pace.

    I was always uncomfortable running the DC motor at full power not only because it made me think it was going to explode but also because it got really hot fast.

    Now I have the VFD set to 70HZ max, so can wind her up and know it’s still within a reasonable limit. With a new 3” drive pulley instead of the 2.5” I suspect that will get me 750 RPM at max speed on the middle belt.

    I never bother with the fast belt before because the motor wouldn’t handle it. This new motor may open up that possibility a little more.

  8. #38
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    Replacing the pulley with one straight from the original motor has yielded another benefit. There was a wobble at 40% freq with the old one that I attributed to a slight wobble and the use of a bolt instead of a set screw (adding mass to one point). It’s singing now with the original pulley and is a 3” vs a 2.5” so I need a new belt.

    I also have to tweak the mounting holes as they’re marginal and you have to really pull the motor to get the pulley straight. Will shave a bit off them all to get it right and allow for enough adjustment.

  9. #39
    Join Date
    Dec 2007
    Location
    Sydney
    Posts
    395

    Default

    Have your bandsaw tyres arrived from the US ok?
    I need to buy 2 for a Jet 18” wood bandsaw, could you give me the name of the mob you’re getting yours from.

    Did you get your welding problem with the cover sorted?
    I’ve a couple of tigs here in my shed.
    An ancient Ideal arc and a mates modern one from Total Tools.
    I’m in Concord and although I’m very out of touch with Tig myself you’re welcome to come over if you can weld it yourself.
    H.
    Jimcracks for the rich and/or wealthy. (aka GKB '88)

  10. #40
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    No tyres just yet. I ordered these ones off eBay:

    https://www.ebay.com.au/itm/352316321214

    They seemed like a legit offering.

    Thanks for the TIG offer too, very kind. I’ll see if I can find someone locally to braze or TIG them first, but if I get stuck I may take you up on that offer.

  11. #41
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    Some of my parts for the reduction gear came in too.

    17mm Silver Steel rod
    Chains and links
    Additional pillow bearings.




    I went with 428 chains as a complete guess and I’m glad I did, they look really heavy duty and should work perfectly. They’re maybe a little too heavy duty, but I’d rather that than the other way around:




    I’ll make steel mounts to attach the sprockets to the motor and the shafts. I have the old pulley from the bandsaw that will get turned down on the lathe for the bandsaw sprocket.



    I also need to get around to making some thick washers for the ends of the pivot rod and also add the hex on the ends of the bolts:


  12. #42
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    Managed to almost get the reduction drive frame in the saw base tonight. The rod is a bit too tight at one end and I’ll need to gently die grind it out to keep a nice fit.

    7D4B67F7-7A37-4A7D-872B-B227AA913FAC.jpg

    The frame is perfectly flat once it’s lifted and fingers crossed it’s all got enough clearance once the sprockets go on!!

    Next up I was able to mill the hex heads on the rod bolts and turn some thick washers on the lathe:

    349FCFF2-AAE7-4675-8927-E49DEB03CBF9.jpg

    They’ll look good once on the saw. I still need to knock the corners off the bolts in the lathe, a bit too sharp at the moment and a nice beveled corner always looks finished on home made bolts I think:

    240EF4B0-C83E-4655-B0BF-B039C9D04CBA.jpg

    I’m going to match these bolts and washers for the motor mount rod too. Not only so they match but because one of the ones I got with the saw is actually the wrong thread.

  13. #43
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    Popped the ER32 collet holder in the lathe and took the edges off the bolts.

    8ED43DE6-19C3-49AC-ABA8-1ED614E43693.jpg

    Much better:

    9E1B890A-6DA8-45E9-B872-E48F3877DF35.jpg

    Annoyingly my shoulder on each of the bolts is not exactly the same, but can’t be bothered to set the mill up again considering they will be on different sides of the machine.

  14. #44
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default Rockwell Bandsaw Identification, Help and Conversion

    It works. A little hole fettling and I now have a working reduction drive mount. I’m actually pretty pleased with how minimal and neat it looks, plus the action is tight and smooth:

    9CC87A59-2138-4389-B1B4-6213DDA318B2.jpg

    77E94C26-7E3A-487B-8617-637AF67DAD58.jpg

    So I can now concentrate on getting the gearing in once the sprockets arrive. Then I’ll be ready for a test fire.

  15. #45
    Join Date
    Sep 2009
    Location
    Sydney
    Posts
    666

    Default

    So some progress, getting me one more step closer to having a working bandsaw. Today my tyres came in. They’re bloody tight to get on but years of installing mousse tubes in to dirt bikes made it relatively simple. Some warm water, clamped the tyre to one section with a bit of soft wood to stop any damage and I was able to walk the tyre on with some effort.

    F6E57254-27AC-4816-AEC2-C18737A30352.jpg
    Attached Images Attached Images

Page 3 of 4 FirstFirst 1234 LastLast

Similar Threads

  1. Lathe identification help
    By Chris1985 in forum METALWORK GENERAL
    Replies: 8
    Last Post: 1st Sep 2017, 06:13 PM
  2. Help with old lathe identification
    By mañana in forum METALWORK GENERAL
    Replies: 8
    Last Post: 28th Jan 2012, 08:00 PM
  3. Rockwell C Hardness Tester
    By RayG in forum METALWORK GENERAL
    Replies: 9
    Last Post: 26th Jun 2011, 01:43 PM
  4. Cutting and drilling rockwell 60
    By Fossil in forum METALWORK GENERAL
    Replies: 10
    Last Post: 27th Oct 2009, 10:07 AM
  5. Identification problem
    By Ralphie in forum THE HERCUS AREA
    Replies: 5
    Last Post: 3rd Jan 2009, 10:19 PM

Posting Permissions

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