Thread: Truing a diamond wheel - how do you do yours?

Seasons greetings all,

How do y'all true up your el cheapo alu body / resin based diamond wheels?

Not looking to buy or make a brake dresser, more looking for handy bloke-in-shed method. Ive seen some references/vids on grinding steel as a way.

Is that how you do it without specific equipment?

Comments welcome.

Greg.

I have heard of using an old diamond/stone cutting wheel as a dressing tool but not tried that myself.
Before you go that route I found there are two other aspects ie runout and vibe, that are worth addressing address.

The way I true (minimise runout) on my CBN wheel is to use "wobble washers"
see https://www.woodworkforums.com/f155/.../2#post2146795 and the follow up post.

Truing the wheel will get you so far but then some reduction in vibe can be obtained by rotating the washers together with the wheel relative to the spindle
I found it impossible to assess improvements in vibe by just looking or feeling so I measure vibe using a mobile phone vibe app.
It turns into a bit of an iterative process.
If you are lucky you can even find a suitable position that minimises runout and reduces the vibe from the motor spindle.

Very interesting Bob, thanks. I did not know of such things. Im actually intending on mounting the wheel on the surface grinder to have a crack at making some 'precision' ground stones. To help me make some tooling, to help refurb the grinder.

Interesting idea though, but im guessing ill still need to true it up in some way. The washers / vibe thing will finesse it i suppose.

The vibe app thing might be cool to try. What app do you use?

I just use a piece of bright mild steel square bar held upright in a small vice and run the wheel over the end of the bar a few times until the run out is removed. I made dedicated wheel adaptors to suit the bore of each diamond wheel so that they are always mounted and true to the spindle.
After trueing to remove run out, a quick rub over the fresh surface with a very soft abrasive stick will remove some of the bonding material to expose the diamond grit.

Rob Renzetti has a you tube video showing a simple attachment that you can make for a DTI to measure run out before and after trueing, I had about .003" initially and virtually zero afterwards.

Originally Posted by StrayAlien

Very interesting Bob, thanks. I did not know of such things. Im actually intending on mounting the wheel on the surface grinder to have a crack at making some 'precision' ground stones. To help me make some tooling, to help refurb the grinder.

Interesting idea though, but im guessing ill still need to true it up in some way. The washers / vibe thing will finesse it i suppose.
The vibe app thing might be cool to try. What app do you use?

I use the "Vibration" App by Diffraction Ltd. It's only for iPhone/ipad etc.
There are plenty of others out there.
Some only measure the frequencies but you need ones that measure the accerlations (usually in g's)
They can be a bit frustrating and slow to use but if you find a sweet spot you will be very pleased about it

I'd definitely bet truing up before any dressing.

Are you talking about your standard $20 aluminium diamond cup wheel?

I never attempted to true it up BUT, I did have to bore out the mounting hole to fit my Hercus no.3 so in doing so, maybe I also improved its concentricity?

Simon

Sent from my SM-G970F using Tapatalk

Hi Simon, yep. One of those, except flat. Not a cup. Ill also have to bore it out to suit the grinder.

I've had a cheap diamond wheel with run out. I elected to measure the runout, then scrape the bore on the high side and shim on the low (inside the hole) until it was running true. That fixed it AND reduced the vibrations. I've also successfully done this with a plated diamond wheel - which can;t true at all....