Member postings for Sonic Escape

I don't plan to use this steel to anything important. Actually nothing that I do is important

I thought it was interesting because it looks different from what I usually see in stores. And the fact that I paid only 4 euro for the whole bag was also a factor here. I don't have a way to heat it red hot. I doubt a barbeque fire would be enough. I started to read about different hardening methods and various types of steels. But it is a huge domain! It's interesting but I'll let it for later.

To make things more complicated now I realized that HSS is not a single type of steel. I have one HSS tool, the left one in the video that has a silver color. The file slides on it without scratching it. I have also HSS tools that are black. Not on the cutting edge. I guess they oxidized or something. They can be scratched a little.

They are about 10" long. But there are small differences both in length and thickness.

Sounds like an interesting stuff. Can I use it to make lathe tools? In the past weeks I was thinking to make a boring bar that would fit in a 7-8mm hole but I couldn't decide to waste a new HSS bar for this. I'm not sure about the result and they are not cheap. Now with all these bars I can try something.

Edited By Sonic Escape on 16/05/2023 22:32:36

Last Sunday I found these steel bars at the local flea market. The price was very good and I bought them. I had no expectation about the quality, I wanted use them for welding. But then I noticed that the edges are sharp. Like on HSS bars. I tried to scratch them with a file and it is quite hard. Not as hard as a silver HSS tools but for sure it is not mild steel.

I read somewhere that the sparks created when you grind it can give some clues about the material. Here I compared one bar with mild steel (right) and the best HSS tool I have (left).

What should be the thickness of the bandsaw wheel for a 13mm wide blade? I suppose 20mm should be enough?

Yes, this is true. But these days I have a stainless steel bar and a mild steel bar that I keep swapping. I'm trying different tools. Or sharpen them to see the difference on both materials. Yesterday for example I did a 32 to 12mm plastic adapter for a diamond grinding wheel. And again I had to remove the bar from the chuck. And tomorrow I will put it back because I want to see how is the finish after I hone the tool with the diamond wheel. And so on ...

How about making the wheels from PVC? I found some 19mm thick PVC plates. A 30cm diameter disc would be strong enough?

I couldn't wait and I bought a diamond cup from the local Sunday bazar. It is unused. The only drawback is that I don't know what grit value it has. It could be 100. But the word in front of it translates into "concentration" ... so who knows.

Thank you for all suggestions. I'll leave those screws alone. Now I'm looking for a C spanner. In the end I want to be able to remove the working piece and put it back without loosing the concentricity. I find this to be very annoying with the current 3 jaw chuck.

I would like to use an ER40 collet rather than a C5 type. I read that ER is more tolerant to the diameter of the workpiece. A 4 jaw chuck would be the second option. It is more time consuming to adjust.

I use Way Oil also as cutting oil. It has the advantage that being sticky it doesn't decorate my walls due to centrifugal force.

Thank you! So I have a back plate like this.

Now I found also a video where I could see it better

I want to remove the chuck from my lathe. I want to see if it is possible to add a collet holder or a 4 jaw chuck. I think I have to remove 3 screws with an Allen key. But they are stuck. Also somebody forced them before, they don't look good. I'm afraid that if I try harder I might destroy the screw top and then I don't see how I could remove it. Is is barely enough space for the Allen key. What would be the best method?

Also why this thing looks like a giant screw? Is it really threaded in the head stock?

Yes, in the end the results matter. But still is interesting to have a look.

Very nice! How critical is the temperature?

A diamond cup wheel costs around 20€. So the advantage with the diamond stone is only that you have more grits. Tomorrow I'll check the local flea market, I saw last Sunday a few wheels. If it is a good price I will not wait one month to get one from China.

Meanwhile I had a look with a microscope on what is going on in the cutting edge of tools. I have an unused old communist HSS 20x20mm tool that has some rust. It doesn't look too bad:

Until you put it under the microscope:

It reminds me of underwater stones. I tried first to polish it with a felt disc:

But the rust has made small holes and the surface is not even anymore. Then I used a slow turning wet stone, with maybe 120 or more grit, and it looks better:

And finally I polished it with the same felt disc + a blue paste:

Here I draw the first interesting conclusion. Polishing does nothing to improve the surface. It make it mirror like, but those vertical lines from the grinding wheel are too deep. You can see that the top side is polished better but the surface is still not smooth.

The second conclusion is that those cheap USB microscopes are toys. They are just 2Mpixel web cameras with a different lens. I think I can make better pictures with my phone.

Next is a P30 20x20mm brazed carbide parting toll. I used it to make a stainless steel handle for my tail stock locking bar. The first picture is with a new one. It cut a 20mm bar with it. The only thing that I discovered here is that re-sharpening was not necessary. And that I used a wrong angle anyway.

I don't know much about Myfords or lathes in general but I think there are many variants of Super 7. I saw one here that has a gear box that is missing on that model. Or can be attached later maybe?

I'll buy only one. They are not cheap and it is not a necessity, more a curiosity. I have one of those small USB microscopes and I'm curious how the edge of the tool will look after honing.

I have a few carbide brazed tools. The carbide type is P30. I can make them very sharp with a special green grinding wheel. But I was thinking to improve the cutting edge with a diamond wheel. What would be the best value for grit?

I'm thinking on a cup grinding wheel like this one.

Hmm ... that could be an issue. Today I read more about 3 or 4 wheels bandsaws and there are a number of reasons why almost no manufacturer builds them.

I was rethinking what requirements I want. What I fell is missing is the ability to precisely cut small parts. Plates up to 250mm, tubes up to the same length or any other things more or less in the same dimension interval.

If I want to cut long pieces I'll just use the angle grinder like I do now. I just finished a large metal workbench and there was no problem in cutting everything with abrasive tools. And to cut a larger plate will be quite a rare event. I can order it to a laser cutting shop.

There is a Youtube video where somebody is comparing a Mitutoyo caliper with a few low cost brands or Mitutoyo clones. This are some of the conclusions that I remember:

• Mitutoyo consume less power
• It has absolute sensor
• Some cheaper models don't shut down when battery is low but give wrong readings instead. This could be a serious issue.
• Mitutoyo has specified accuracy

I'm trying to find a serious flaw to my no name >10 years old caliper to have a justification to buy a more expensive one but no luck so far. The battery life (biggest issue of cheap models) is not that bad. You can also use SR batteries instead of LR.

These days should arrive a Shahe micrometer. From my research it is one of the best low cost options available now.

Edited By Sonic Escape on 26/04/2023 18:20:53

Yes, I didn't think of that! It is a very good idea