Member postings for AdrianR

I have recently got addicted to watching Engles Coach Shop videos. Seeing the first video of how to turn something which seems too big for a lathe, I thought I had to share this play list.

**LINK**

I have learnt so much about things I have never considered before, very interesting.

Adrian

I have just ordered one of those, I would be interested in any advise too.

Adrian

Myfordboy on youtube uses ZL12 to cast his flywheels. Its casting temp is about 500C so is not so hard to do casting. Artisan Foundry sell 1KG ingots for £7.99. Maybe near you could cast you a blank.

I think there may be one of those kicking about in my dads old stuff, I am sure I saw one when I was a kid.

You can still buy them too **LINK**

Making one of those could make an interesting project too.

Adrian

This is something I have been meaning to look up, especially after my most recent attempts.To small, too small, HUGE! I also found that the two M4 CSK screws I had, have different dimensions.

I have looked it up, for metric this seems to be the closest data to the original ISO i can find without paying.

**LINK**

I also found this site that has simplified data for a whole range of screws, BA, Metric Whitworth etc. **LINK**

The problem is we now know how far to push the cutter in, but we don't know what the starting position is. If we had a hole with the nominal diameter, we could lower the cutter till it's cone just touched the hole lip. Then we just have to cut to the depth of k. e.g. M5 hole diameter 5mm k=2.5mm.

The problem is we rarely have a hole nominal diameter, ie it is tapped or clearance.

With a pointed cutter and a bit of trigonometry we can calculate the depth of cut.

The depth for a pointed cutter to reach the nominal size Ns (d) with a countersink angle A

d = (Ns/2) / tan(A/2)

So the total depth to cut is d + k e.g. for M4 with a 90 degree cutter, Ns=4 A=45, k=2.2

d = 2 / tan(45) = 2 ( I know tan(45) = 1, I included this for other angles)

depth of cut = d + k = 4.4mm

So we should be able to zero with the cutter just touching the work, then cutting to 4.4mm should give a perfect countersink.

If like me you have a counter sink which is a truncated cone, then you have to work out what the offset would be due to the missing part.

I think it is probably easier to counter sink a hole in a piece of scrap that is too deep, but note the depth. Drop in a screw and measure how too deep it is. Subtract that from the depth you cut and that is the depth you should use.

If you are using a mill you could zero the cutter, cut a too shallow countersink, drop in the screw and touch the tool to find how much the screw is proud. That is how much more you need to cut.

Adrian

This thread will help you.

**LINK**

I had a long discussion about these problems with Graham Meek and others in this thread **LINK**

Incidentally I cut two 8mm slots in 1/2" thick steel today. I used the method described in the previous thread. Chain drill, plunge each end, rough slot out small, then finish at size. I did one with the quill and the z axis locked, the other with the Z axis and the quill locked. No bad nasties happened, but the finish is poor.

Yes I have searched through the forum and found enough to put me off buying a variable speed brushed motor mill. I was hoping to hear from people who had more positive experiences.

To expand on my concerns. If I try to use a 2 flute cutter to do a plunge cut without a pilot hole, the mill head shakes violently. I end up with a hole that is around 2mm to larger, and defiantly not round. This is even if I try and creep the cutter in. The issue with slot width is due to the tool moving about 1mm towards the column when the quill is locked.

Having a round column with a single guide I expect that alignment is not that great. With a dovetail I expect it to be better. Good enough that I could bore a hole that is deeper than the quill travel.

On my mill when I cut a dovetail it ends up being quite wobbly due to the lack of rigidity. At the moment I do not feel confident I could even make Howard Halls advanced grinding rest.

I understand these mills are built down to the price, but I would like to feel confident that if I buy one of these mills I will end up with something better than I have now.

Hi

I would like to ask some questions about Warco WM16 and Chester 20V mills.

My Emco FB2 clone has some issues that I am not happy about and I don't want to buy a new machine and have the same issues.

My first questions are;

• Can you do a plunge cut with a 2 flute slot drill without a pilot hole?
• Can you cut slots that have a reliable width?
• Can you use a dovetail cutter?
• When raising/lowering the head is alignment preserved?
• Do you think the column is rigid enough?
• Have you had any issues with the motor or gears?
• Anything you are not happy about with your mill?

Thanks

Adrian

Ah the age old question, what will I do with it all.

So far I seem to spend my time making tools to make tools to make things. I have just completed my first wobbler. I would like to make some more complicated engines, hence the thought of small cutters for steam ports. I don't think I will make large models at most I would guess 1" bore.

It seems unless I want to spend many thousands I cant get a mill that runs at the speeds that the size of mill would infer. Ie a small mill for small things but they all run too slow.

I was wondering how others deal with it, what do owners of Sieg SX2.7, Seig SX3, Warco WM 16, Chester Champion 20v handle the low speeds.

Adrian

I am thinking of buying a new mill. My current mill has six speeds from 110 - 1600 RPM. My current candidates are all have variable speed motors, and the top ends are between 1750 on a larger mill and 2250 on the smaller mills.

At some point I will want to use small cutters e.g. 2mm, how important is the spindle speed. Should I go for a smaller mill with the possible loss of rigidity but faster spindle, or the larger more solld mill with a slower spindle.

Adrian

Dave

In the paper I too thought it was saying adding Hydrogen Peroxide made dezincification worse. Then I spotted the table about temperature. It shows that Zinc and Copper loss are the same between 60C and 80C. So if you heat the solution up to 60C-80C it will etch real fast, but the rate of Copper increases faster than Zinc with temperature.

I have asked my son ( A Chemist) so sort out what recipe I would need to try it. From what I can tell so far the Sulphuric Acid and Hydrogen Peroxide strengths are well bellow the legal limit.

Incidentally it may be possible use electrolysis instead of Hydrogen Peroxide as it is possible to produce it using electrolysis. But that would take quite a bit more testing.

Adrian

I would say it is a T shaped parting blade, the odd thing is someone has ground the top. It should be held in an angled cutter to give the top rake.

See **LINK**

Stelite is a really hard alloy, it is sometimes used instead of carbide. I know it most from welding rods that are used to build up the teeth on digger buckets.

Or in my case, It was put on the worn out chines on my canal boat to protect the corner from wearing out.

You have hit my concern exactly on the head. I have not been in this game long enough to know all the suppliers, and can't tell if it is a new company or just new to me.

On the face of it, the spec of the machine seems just right form me, and the price seems low. Could be a bargain or ...

I have looked at the Weiss site and can see similar machines, but not all the details are the same ie knobs and switches. So I don't know if it is a Weiss or a clone.

Hi,

I am thinking of getting a new mill and EMVIO Engineering EMV-25BB mill popped up in a search.

I have never heard of them before, does anyone know of EMVIO or have one of the mills. Or recognise the mill and what else it might be called?

Thanks

Adrian

MEW issue 43 page 22 A simple number/letter punch jig

I am no Chemist, just A level many many moons ago.

I have been looking at the Sodium Bisulphate (Sodium Hydrogen Sulphate) Hydrogen Peroxide mix and what effect it has on brass and scale.

After much searching I found this paper

It looks at the dezincification of brass using various concentrations and temperature. However they do acidify the solution with sulphuric acid.

On page 62, Table 2 shows the effect of temperature on the dezincification factor of brass treated for 6 h in acidified sodium sulfate solution (1 M Na2SO4 and 0.1 M H2SO4) in the presence of 0.5% H2O2.

It shows that if the solution is between 60C and 80C the rate coper and zinc are dissolved are equal. Perhaps this could be the answer to not getting the pink skin.

I have not found any information on the relative rates of reaction between zinc/copper oxides, zinc/copper and sodium bisulphate. So I cant say if the oxides or brass will react faster.

Adrian

I understand why a foundry would need to know about cores and hence have black colour. But why do they need do they need to know which surfaces need to be machined or not, yellow and red?

Do they do something special for them?

Adrian

The spec says it should take 5 to 10 mins to cure, is it going off quicker than that?

I used Bondloc B638, it too has a <10mins cure time and it did take about 10mins. It was quite cold then, about 15C. You could try putting the Superfit and parts in the fridge for a while. That might slow it down.

Adrian

Over the last few decades we have seen the campaign for real ale and the campaign for real bread. The desire to reject mass produced items and to get back to artisan produced items is spreading.

I think now is the time for model engineers to take up the challenge and start making real steal.

Here are two videos to introduce you to the topic.

https://www.youtube.com/watch?v=q-BVuQZSm08&t=322s

Incidentally, anyone who mocks artisan steel makers gets a not so friendly visit from the crucible maker in the above video.

https://www.youtube.com/watch?v=OP8PCkcBZU4&t=1441s

Adrian