Page 31 of 31 FirstFirst ... 21262728293031
Results 451 to 465 of 465
  1. #451
    Join Date
    Apr 2012
    Location
    Healesville
    Posts
    1,770

    Default

    You might have a couple of bugs to sort out yet but a very nice machine John....well done m8

  2. #452
    Join Date
    Dec 2007
    Location
    Adelaide
    Posts
    357

    Default

    I've got a 1.6 cut off wheel mounted on an arbour, so once the sharpening is done I can swap over to the cut off wheel and gash the end if I need to, on really small cutters (I've done 1/8") I hold the cutter in the vice and use the dremmel under a large magnifying glass.

  3. #453
    Join Date
    Aug 2010
    Location
    Near Bendigo, Victoria, AUS
    Age
    70
    Posts
    2,893

    Default

    @ familyguy: you can also get 1.0 and 0.8mm cut-off wheels in some sizes (100mm dia I think). I was surprised to see that and thought I might make a special arbor for a thin blade like that for my T&C grinder.
    Cheers, Joe
    retired - less energy, more time to contemplate projects and more shed time....

  4. #454
    Join Date
    Dec 2007
    Location
    Adelaide
    Posts
    357

    Default

    Quote Originally Posted by jhovel View Post
    @ familyguy: you can also get 1.0 and 0.8mm cut-off wheels in some sizes (100mm dia I think). I was surprised to see that and thought I might make a special arbor for a thin blade like that for my T&C grinder.
    I saw a youtube video where a guy put the gash in by hand with an angle grinder, so I thought why not use one of my spare arbors, what I really need though is to make an air bearing indexing cutter holder so I can also do the flutes, it is fine to sharpen just the teeth and I've found that usually this is ok, but the flutes also do some of the cutting so they will eventually need attention.

  5. #455
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Thumbs up Collet Indexing !

    Hi Guys,

    Today is the first chance that I have had to be able to do anything on the Brooks TCG for a little while.
    Sorry for the delay in getting on with it !

    I was having problems with the index finger not having the rigidity to accurately repeat the position of the tool when grinding the ends of the flutes. I had already made a stop ring that clamped to the collet shaft, so rather than make another ring I used it to index the collet in four places by drilling holes that would take a peg and provide four positively located positions.

    Unfortunately I didn't have any brass bar stock that was of a suitable size, but I do have several "Yale" Lock barrels that are made from brass. A little time with the bandsaw produced a suitable piece.

    22-06-2021-005.jpg

    The piece on the right is the original "Yale barrel, the piece on the left is the bit of brass that it contained. The holes down its length are convenient since I need two of them for screws to fasten it to the collet holder body.

    22-06-2021-002.jpg

    This picture shows the collet holder along with the indexing ring. The cap screw securing the pin guide block is M4. A second cap screw will be fitted where the red dot is. The silver thumb screw is going to be replaced by a grub screw because the thumb screw will not clear the surface that the collet holder is fitted to. In the picture I've used a short length of 20 mm precision ground bar instead of the collet for the purpose of setting up the pin guide block for position and marking the holes for the screws.

    22-06-2021-001.jpg 22-06-2021-004.jpg 22-06-2021-003.jpg

    These three pictures show how the pin guide locates into the index ring. Also note the gap between the ring and the face of the collet holder. This is to allow the tool in the collet to be withdrawn enough for it to be rotated without catching the next tool face to catch the grinding wheel. The index ring already had the recess in it when made, since it fits over the collet head it doesn't cause any problem. The threaded hole was where the original stop adjuster was fitted.

    I'll take some more pictures when I've got this ready to use.

    Thanks for looking Guys, your support is very much appreciated.
    Best Regards:
    Baron J.

  6. #456
    Join Date
    Dec 2007
    Location
    Adelaide
    Posts
    357

    Default

    Nice job, just wondering why you would use a finger rest if you have a method of indexing the tool holder, if the cutter teeth are evenly spaced then once the first tooth is set up for grinding the others just follow when you index the tool holder via the indexing holes, I was under the impression that a finger rest was used for shell type cutters and slit saws etc that have multiple teeth.

  7. #457
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Default

    Hi FamilyGuy,

    Thank you for your post !

    Quote Originally Posted by familyguy View Post
    Nice job, just wondering why you would use a finger rest if you have a method of indexing the tool holder, if the cutter teeth are evenly spaced then once the first tooth is set up for grinding the others just follow when you index the tool holder via the indexing holes, I was under the impression that a finger rest was used for shell type cutters and slit saws etc that have multiple teeth.
    I made and fitted a finger rest but found it too flimsy to accurately repeat on each tooth. That is why I made the index pin arrangement shown in the pictures. Once the first tooth is set up then the others will follow. This accuracy is needed so that when grinding the primary facet its square to the secondary one.

    The finger rest will be OK for grinding the flutes since there will not be any force on it, all it will have to do is follow the flute as the cutter is moved back.
    Best Regards:
    Baron J.

  8. #458
    Join Date
    Dec 2007
    Location
    Adelaide
    Posts
    357

    Default

    It seems to me that the general consensus seems to be that an air bearing spindle is the way to go when it comes to sharpening flutes - the spiral flutes on milling cutters are actually a very coarse thread, and when trying to keep the flute in contact with the tooth rest and at the same time pushing it forward, friction is the enemy - I have tried it, my Quorn casting kit came with some castings that when setup could produce ground threads and also sharpen flutes, reamers, taps etc. it is doable but not that easy. After seeing an air bearing setup in action on a youtube video I decided that I would wait until I made such a setup myself before trying to sharpen flutes.

  9. #459
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Default

    Hi Familyguy,

    Whilst an air bearing is preferable and a very nice thing to have, the cutter being ground is not pushed towards the wheel but pulled back away from the wheel. The last thing you want is to crash the end of the cutter into the wheel.

    Remember that you are only taking tenths of a thou off in order to touch up the blunt edge ! The same with a hand tap, though you could do those with a round stone by hand unless they are badly chipped in which case grinding them with a wheel might be better.
    Best Regards:
    Baron J.

  10. #460
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Thumbs up Tool holder !

    Hi Guys,

    I've just got around to finishing off the indexing parts for the tool holder. The next job is putting it all back together on the table mount. Then I will have another go at grinding a slot drill.

    06-07-2021-006.jpg 06-07-2021-005.jpg

    These are close up pictures of the holder for the index pin.

    06-07-2021-004.JPG 06-07-2021-003.jpg 06-07-2021-002.jpg

    These three pictures are of the completed assembly with the index pin inserted into the ring that is secured to the collet holder using a grub screw.

    In use the index ring is loosened with the pin in place so that the collet holder can rotate without the ring moving. The cutting lips of the slot drill are then aligned horizontally and the index ring locked to the collet holder shaft. This enables the collet to be rotated ready for grinding the next tooth.

    Of course the large brass thumbscrew secures the collet in place preventing any vibration from moving the collet.

    06-07-2021-001.jpg

    The completed unit along with the new locking pin.

    Thanks for looking Guys.
    Best Regards:
    Baron J.

  11. #461
    Join Date
    Dec 2007
    Location
    Adelaide
    Posts
    357

    Default

    When sharpening endmills I found getting the first cutting edge aligned to be the trickiest part - once the first edge is aligned the others follow, but it is not always obvious if the cutting edge is horizontal just by eyeballing it, I made up a device to assist - which helps but is not fool proof - how do you plan to get cutting aligned, maybe your idea is better than mine ?

  12. #462
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Default

    Hi Familyguy,

    Thank you for your post ! You haven't said how you would do it !

    Actually I don't think its critical, at least not like sharpening a four facet drill !

    This is a method that I've used, however if you are taking a lot of material off as in the case where I've chopped the end off the cutter, as its sharpened you are moving further down the flute. Obviously the helix angle will determine how much adjustment you might need to correct it.

    07-07-2021-010.JPG 07-07-2021-009.JPG

    This is just a piece of bar with flat parallel ends. The tool holder is tilted down until the edge at the end of the cutter rests on the top of the bar. At this point the cutter rotation angle can be set and locked in position.
    After this the grinding angle can be set. I am trying 15 degrees for the secondary angle and 5 degrees for the primary one.

    As far as this cutter is concerned the gash angle is completely wrong ! far too much clockwise. But as they say practice, practice and learn.
    Best Regards:
    Baron J.

  13. #463
    Join Date
    Dec 2007
    Location
    Adelaide
    Posts
    357

    Default

    The gadget I made is very similar - it is spring loaded - I have found that the height of the cutting edge can vary from cutter to cutter, in practice I set the index ring to 0 deg - loosen the collet holding the tool holder to the index ring and rotate the tool holder until the cutting edge is resting on the top flat of the gadget and then tighten the collet to lock the tool holder to the index ring. I use around 5-6 deg for the primary angle and having tried secondary angles from 15 to 25 deg have more or less settled on just over 20 deg, the end cutting edge concavity (if that is what is called) I set at around 3 deg - no less, the angles don't seem to be critical.


    I've done some 4 facet drills and find they work well - I don't though have a full set of collets so I can only do certain sizes, I made up a drill chuck to fit in the tool holder and this works ok for holding smaller drills for 4 facets but larger drills once combined with the drill chuck length are just too long - one of these days I'll make a set of sleeves - one for each drill - 16mm OD and ID bored to suit a particular drill, held in the sleeve with a brass thumb screw, but as you know the list of things to do only gets bigger - never smaller.

    20210707_230356.jpg20210707_230418.jpg

  14. #464
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Thumbs up

    Hi Familyguy,

    Great minds think alike !

    Thank you for taking the time to take pictures, I like the spring loaded Idea.

    As far as the four facet drill grinding is concerned, I can only go upto 10 mm (ER16 Collets) and I had to drill out the collet bore to get to that. I did try to sharpen 2.5 mm drills but that is as small as I can go without either breaking the drill or the collet nut catching the wheel. 3 mm is probably the smallest convenient size.

    But I did make a holder that I can go down to 0.5 mm drills with that works well. I might publish that design one day.
    Best Regards:
    Baron J.

  15. #465
    Join Date
    Sep 2012
    Location
    York, North Yorkshire UK
    Posts
    4,859

    Thumbs up Re-assembly pictures !

    Hi Guys,

    I've now re-assembled the tool holder and parts back onto the grinder body. I thought some pictures of the assembly would be of interest whilst I've got it in bits.

    07-07-2021-001.jpg 07-07-2021-002.jpg

    This is the support disc that is used to angle the work holder. The centre screw is supported in a pair of bearings ensuring smooth free movement. The slot is for the clamping screw to lock things in place once the tool grinding angle is set.

    07-07-2021-003.JPG 07-07-2021-008.jpg 07-07-2021-004.jpg

    These three pictures show the fixed mounting upon which the rotatable plate is mounted along with the leadscrew and worm cut into the edge, used to set the angle of the work holder. The shim under the left hand leadscrew bearing is to compensate for the slight run out of the thread cut into the rotating part.

    07-07-2021-007.jpg

    This is a picture of the assembled unit ready for placing into its mounting shown below.

    07-07-2021-005.jpg 07-07-2021-006.jpg

    The mounting is bolted onto an adjustable base and consists of a slot into which the work holder assembly is fitted then secured by two M6 Allen grub screws.

    You can see the "Y" leadscrew in the first picture. This drives the table via a moulded plastic nut giving zero backlash. Its also supported at both ends by bearings.

    Now to grind some cutters !

    Thanks for looking Guys.
    Best Regards:
    Baron J.

Page 31 of 31 FirstFirst ... 21262728293031

Similar Threads

  1. Hercus tool and cutter grinder & cylindrical grinder.
    By stix012 in forum EBAY, GUMTREE, and other off forum sales sites
    Replies: 1
    Last Post: 23rd Aug 2018, 05:31 PM
  2. Heald internal grinder & Heald Planetary grinder
    By achjimmy in forum METALWORK - Machinery, Equipment, MARKET
    Replies: 2
    Last Post: 11th Oct 2017, 09:22 PM
  3. New to me old grinder.
    By DSEL74 in forum ANTIQUE AND VINTAGE MACHINERY
    Replies: 12
    Last Post: 30th Sep 2016, 08:35 PM
  4. Roller grinder ways/ plain grinder ways
    By Michael G in forum METALWORK GENERAL
    Replies: 11
    Last Post: 6th May 2012, 12:37 AM
  5. Anyone used this Grinder?
    By bwal74 in forum METALWORK GENERAL
    Replies: 6
    Last Post: 10th Apr 2012, 07:47 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
  •