When I was training in mid 70's, instructor always made a real big deal about working out helix angle. As usual, we 'kids' (18-20) didn't pay enough attention. I had to make a 1" Whitworth thread, helix angle suddenly became 'quite important' as thread depth allowed tool to interfere with sides. Was almost finished when half nuts disengaged, destroyed thread when it took 0.100" cut. (it was a very old worn machine, mainly kept to force people to pay attention, I had previously made 'hundreds' of 0.060"dai, 0.300" long stainless steel rivets for Vic's hobby of clock making ) Vic would go a bit crazy if we ran machine backwards instead of disengaging half nuts, had to use thread dial on all Imperial threads. I've always had a problem with compound angles so trial and error for me as well.😉
Given the Hercus brand catered mainly to the education sector, that poor old Hercus grinder has probably spent it's entire life making threading tools. I recall making a square threading tool when I was an apprentice on the same machine. What ever happened to Hercus? There used to be a Chinese company making machines and the local importer had them branded as Herless. No doubt trading on the similar name.
Thanks for sharing, you useless information but it makes perfect sense when you see it in the video. Steve summers just showed a grinding fixture that may be easily made.
Thanks for the informative video on how valuable it is to know about basic tool grinding and Using it in real world matching jobs. Most people want to buy the most correct tool they can find and when it needs touching up they throw it away and get another. You always have very informative and interesting projects keep it up I know it is a lot of work for you to put these out but thanks again ed
Gday Max, definitely learnt a lot and definitely no useless information, compound angles can sneak in everywhere and my brain don’t have any mathematical components that’s for sure, great video mate, cheers
When he said Compound Angle back on the Gib strip video, I started looking up how to do compound angles. I wasn't getting anywhere, so I took a piece of paper & drew the gib strip very large. Then I marked the 0.065 measurement across the top.That is when I noticed I needed a right angle from the inside face of the strip to the 0.065. As soon as I did that, I realised the 0.065 was the hypotenuse of a 30,60,90 triangle. I got all of the numbers Max did w/just regular trig. Now what he showed us on today's video is truly compound angles. I have my Machinery's Handbook marked at that section & plan on trying to learn how it works. Notice I said TRY.
Max is Back, and has interred into The Swan Valley Machine Shop as a first class toolmaker machinist. I like those shields that you are making for the grinder, and although the wheels very seldom fly apart and put out both of your eyes you are taking all the necessary precautions not only for your own safety but showing the world the right way to do the job, thanks. Thanks for showing how to make a precision thread cutter the right way. And getting your lawn mowed for free, no snakes, no problems, I did see the HBM standing at attention waiting patiently for the year 2024 to come rolling in, so the master can start addressing those ways, and all the broken and bent and missing bits and pieces.
100 % agree on grinding wheel guarding, doesn't take much for then to explode, even when used properly, many don't realise the portable hand tool discs are flexible, not so on machine tools, though some slitting wheels can be. 10 & 14" metallurgical sectioning wheels are certainly not flexible . Great job Max, brilliant design of that cupped wheel. Thanks for sharing
Good info on the grinding Max. You may want the check with your electrician and see if you can wire up a drum switch so you can change the rotation of the grinder motor. On some this can be done. Cheers
My little KO Lee grinder has a reversing switch, and the washer to hold the wheels has a tab fitting into a keyway on the shaft, I assume that prevents wheel friction from backing out the nut. Reversing the wheel definitely helps with different setups, such as getting to both sides of a cutter in one setup... @@swanvalleymachineshop
Nice trick of angling the tool up in the vice to grind the relief. I use a multi axis vice on mine (home made) so I can set all the angles independently. I never put top rake or back rake on because as far as I understand it changes the geometry of the groove it cuts. I guess you could, but you'd have to do a bunch of 3D trigonometry to get all the angles right.
Could put this vise on a small tilt table, if you had something handy... Also, using a single lip cutter grinder, I had to do the other side of the tool rotated upside down, but better than freehand.. and the workhead gives you the relief angle (although I needed to add another index mark to measure negative - upside down - relief angles). Great to see things coming together! @@swanvalleymachineshop
Not sure if the tool grinder spindle rotates fast enough for those cutoff disks Max. They tend to like to run over 9,000rpm; I think (with no proof I admit), that if they are running faster, there are internal stresses built up that help the disk to maintain its shape.
Those reinforced cut off disks can run up to 12000 rpm , my spindle runs at 4000 rpm . The lower revs are not the problem but over heating them is . That is why alot of companies have banned the 1mm ones . People push too hard , the wheel gets hot & goes into a saucer shape & breaks apart . 👍
Great info on tool grinding. If you use a universal grinding fixture and set all the relief and cutting angles at once, would it eliminate the need for the secondary grinding you have done? Thanks again.
I recently bought the 5.16” Diamond holder from Eccentric Engineering. I haven’t got a chance to try it yet. Reminds me of my old Williams and Armstrong holders. But while I bought sone ETM Super Cobalt pieces, I’d really rather use carbide. But no matter where I go I can’t find 5/16” square carbide. Nice job. But I’m wondering why you needed to make that rather than to use carbide thread inserts? I haven’t ground a threading tool in maybe two decades.
Can you even buy 5/16 square carbide , never come across it . My insert threading tool is too small for a 3.5 mm pitch thread , still have to tool up the larger lathes . 👍
Great video, I’ve a new to me TOS tool & cutter grinder, and this is very helpful for a beginner like me! Thanks. Out of interest could you say what stones you used to deburr and finish the tool? I’m missing those finishing bits and would like to know what to buy..
@@swanvalleymachineshop I am not quite sure that we are on the same page or machine here for that matter. I'm a little challenged most of the time, so you need to think about it a little more. Good Work! Mike
Just used the guard to mount the mag base , clocking the vice to the table travel axis . The wheel retainer is also clocked to the table axis . The grinder has multiple swivelling parts that have to be aligned . 👍
Agree. You are taught grinding tools by hand but if you have some equipment that allows you to do it more accurately, why not use it. Max has more skills than most of us have in our left toe. However, if you have skills that Max and most of us don't have, show us how to do it in your videos. Retired mechanic/machinist.
Hi Max I don't know how you do it, i have a small machine shop in Adelaide with all the with all the day to day running i don't have time to scratch myself . And you have a day job and a RU-vid channel as well trying to fix machines and make some parts your unreal you would have to be the hardest worker on RU-vid great work mate👍
@@1967kap Being a hermit helps ! Later it will ease up as i plan to work full time from my shop one day , then i can have some of my social life back & the wife will see me for more than 10 minutes a day !!!
@@swanvalleymachineshopI remember learning a lot about files in metalwork at school in the early ‘70s. Nowhere near as much as you Max, but handy none the less. Do kids learn stuff like that anymore? A file is a handy thing. I wasn’t and am still not anywhere near good enough at maths to get to your level. Jeff
You’re in Swan Valley, I was in Geraldton, I did laser alignment, some local but every 3 months we went to Telfer to change out a mill motor,long time ago now
Hi Max, I have an Ifanger threading tool with 55 and 60 degree HSS inserts, certainly a handy tool for finer threads. I use mainly carbide threading inserts now. Offhand grinding HSS is becoming a lost art with the multitude of inserts available I think. Back in the late sixties used to watch the machinists offhand grind HSS toolforms, true craftsmanship. They wouldnt let anyone near their grinders!
I do not have a good enough off hand grinder with a proper tool rest table . When i find one , one day i will pick one up . Your right , there are inserts for just about everything now , but expensive ! 👍
Hi Max, I was offered same T&C some 40 years ago when our Instrument Maker retired, grinder was made redundant, I declined as had no room in my garage and didn't want the grinding dust on my machines. Kicking myself now.
