Hey Dave! Carbides are 'officially' ground with so called 'Green wheels' ( a very soft (friable) silicon carbide grinding wheel formulated for grinding tungsten carbide.) They can be ground with diamond wheels but those are best used wet. The diamond wheels, from China have something to offer, but it may pay to invest in a proper one. The Chinese ones, is a bit of diamond dust, no good for anything else, mixed with the ashes of dead Chinese babies, I am sure... They often have the 'weeble-wobbles' and there is little to be done about that .... it does make them pretty useless though. Carbide lathe tools or milling inserts/cutters, should NOT be ground freehand... it really is too hard a material for doing that. Because the Green silicon carbide frays fast the wheel will need very frequent truing. (this is another reason why freehand grinding is just a silly thing to do) Nice sine bar ! She is pretty! She is flat and parallel within 4/1000 mm, that is nice, very nice.(but your granite slab may only be shop-grade, so it could be even a bit better) Another small remark is this : if the equipment allows, put a bit more preload on your 10 000 nds clock ( one full revolution is standard practice) And cleanliness is next to godliness, even for a heathen like me.... you really need to take the oil and dust off of your surface plate with something such as Windex (works as good as any 'special cleaner for surface plates, at 10 times the cost) and clean your gauge block, sine plate and angle block with alcohol. When you are measuring in the realm of 4/1000 mm, you also should avoid touching the surfaces involved in the measurement (the surface it rests on and the surface you are probing) or use lint free lab-gloves. I noticed your surface plate lives on a wooden table or bench. It should be supported on three points. You may discard this, but it DOES make a difference when you want to measure to this sort of of tolerances. ( depending on your climate, try the same measurement early in the morning and a second time when the sun is at its highest and take the dial indicator in the house where there is airco for the duration between measurements) you will most likely see a surprising difference (subject to the precision of the indicator) All in all...great video ! Cheers Paddy
True, as much literature there is out there on lathes and milling machines, as few documents are to be found on grinding practice. There are some pdf docs out there, mainly copies of commercial literature (such as by Norton and the like) I have one book (from my late father) which is rather comprehensive on the subject, but that is written in German. The main thing to keep in mind is, that when intending to grind very hard materials, you need softer wheels... it may be counter-intuitive, but that is pretty much a standard rule. Of course you can always go the opposite, but then you get into a bit of a bind when there are no or few harder materials, or they prohibitively expensive for a decent quality wheel. I have bought the odd Chinese diamond wheel, and some have a usable grinding in them, but I found all of them, so far, too flimsy and light in construction. You can, in some cases remedy this by truing them up in the lathe (the aluminium parts!) and making a mild steel flange which can be bolted or loctited on or against the flange parts of the wheel. This gives them a bit more mass and allows them to run a bit more stable. That said, most of the Chinese diamond wheels that darkened my doorstep ended up in the bin rather fast. Cheers Paddy
Did you multiply X 5 for the 5” sine bar?
Yep..
If you don't have gauge blocks you can use an adjustable parallel and adjust it to the size you need.
Did finally get a set!
Hey dear... Will u please tell me how measure the centre distance betwwen rollers of sine bar without unclamped the roller .
Measure the distance to the outside of both rollers and subtract the diameter of one roller.
precision ground flat stones will be next!
Hey Dave!
Carbides are 'officially' ground with so called 'Green wheels' ( a very soft (friable) silicon carbide grinding wheel formulated for grinding tungsten carbide.) They can be ground with diamond wheels but those are best used wet.
The diamond wheels, from China have something to offer, but it may pay to invest in a proper one. The Chinese ones, is a bit of diamond dust, no good for anything else, mixed with the ashes of dead Chinese babies, I am sure...
They often have the 'weeble-wobbles' and there is little to be done about that .... it does make them pretty useless though.
Carbide lathe tools or milling inserts/cutters, should NOT be ground freehand... it really is too hard a material for doing that.
Because the Green silicon carbide frays fast the wheel will need very frequent truing. (this is another reason why freehand grinding is just a silly thing to do)
Nice sine bar ! She is pretty! She is flat and parallel within 4/1000 mm, that is nice, very nice.(but your granite slab may only be shop-grade, so it could be even a bit better)
Another small remark is this : if the equipment allows, put a bit more preload on your 10 000 nds clock ( one full revolution is standard practice)
And cleanliness is next to godliness, even for a heathen like me.... you really need to take the oil and dust off of your surface plate with something such as Windex (works as good as any 'special cleaner for surface plates, at 10 times the cost) and clean your gauge block, sine plate and angle block with alcohol.
When you are measuring in the realm of 4/1000 mm, you also should avoid touching the surfaces involved in the measurement (the surface it rests on and the surface you are probing) or use lint free lab-gloves.
I noticed your surface plate lives on a wooden table or bench. It should be supported on three points. You may discard this, but it DOES make a difference when you want to measure to this sort of of tolerances. ( depending on your climate, try the same measurement early in the morning and a second time when the sun is at its highest and take the dial indicator in the house where there is airco for the duration between measurements) you will most likely see a surprising difference (subject to the precision of the indicator)
All in all...great video !
Cheers
Paddy
Still learning on this one. For some reason there isn't much on the subject of wheels and what they're for...
True, as much literature there is out there on lathes and milling machines, as few documents are to be found on grinding practice.
There are some pdf docs out there, mainly copies of commercial literature (such as by Norton and the like)
I have one book (from my late father) which is rather comprehensive on the subject, but that is written in German.
The main thing to keep in mind is, that when intending to grind very hard materials, you need softer wheels... it may be counter-intuitive, but that is pretty much a standard rule.
Of course you can always go the opposite, but then you get into a bit of a bind when there are no or few harder materials, or they prohibitively expensive for a decent quality wheel.
I have bought the odd Chinese diamond wheel, and some have a usable grinding in them, but I found all of them, so far, too flimsy and light in construction. You can, in some cases remedy this by truing them up in the lathe (the aluminium parts!) and making a mild steel flange which can be bolted or loctited on or against the flange parts of the wheel.
This gives them a bit more mass and allows them to run a bit more stable.
That said, most of the Chinese diamond wheels that darkened my doorstep ended up in the bin rather fast.
Cheers
Paddy