Member postings for Skarven

Machine DRO have a Real English manual for the Sino DRO that is worth quite a lot! If you have seen the original Sino manual with its very pronounced Chinglis language, you will know what I mean.

I have several magnetic scales from Machine DRO, and they are a lot easier to fit and take up less space than the glass scales. They are also much less sensitive to oil etc.

Kai

Andrew

I completely agree, but the back emf is generated by the magnetic field from the rotor rotating in the stator winding.

The back emf will depend on the number of turns in the winding, and the inductance. A motor made for 50Hz will have more turns in the windings than a 60Hz one.

Kai

Hi

It is the inductance of the motor that limits the current. A 60Hz motor will at 50Hz draw as much current as it can handle even with very little load. My US 60Hz bandsaw is run with a transformer at 190V 50Hz and gives about 80% of its rated power. At 240V 50Hz this motor run very hot even with no load.

As the frequency increases, you vould have to increase the Voltage to keep the current constant, but this is not possible with an inverter giving only 240V. You will have to live with the fact that increasing the frequency will limit the current, and with it, the torque. The motors construction will be the limiting factor for the current and of course the torque. Of course, as the RPM increases, this will give an increase in power.

That said, if you are running a 50Hz motor at 60Hz, the current is still limited by the inductance, but this will decrease with load, so you might still be able to run the motor at full torque, and 20% higher RPM, ie. 20% more power.

Kai

Hi Neil

I'm sorry for no response as I have had a 2000km roundtrip to buy a shaper I just came home.

I have probably wasted a lot of time in my HSS grinding then. No wonder I mostly use carbide tips.

I will try out the angle grider for the shaper tool bits which are 5/8".

Kai

Jason. I thought that you should keep the hss steel from colouring when grinding. Isn't that neccesary?

Kai

I also saw a video like that. The grinding of a shaper tool was very fast. (I'm on a 2000km roundtrip to buy a Swedish 12.5 Inch shaper from about 1960 , so I was very interested). My thought was that the tool bit would heat up a lot, but it didn't seem like it in the video. Maybe the fact that the tool bit was held in a vice helped to keep it cool?

A pair of 1/4" copper plates between the Vice and the bit, and a short stick-out would help to keep it even cooler?

This is a tedious job and there is no harm in shortening it.

Kai

Many of the problems I have with Windows is that even if I have administrator rights, I am not allowed to do a lot of things on my own computers. Anybody else on the whole internet seems to have every right to my computers.

The following commands let me at least activate/deactivate the hidden REAL administrator. Strangely enough there is no password involved. Use with causion!

start c:\Windows\system32\cmd with administrator rights
net user administrator /active:yes

Now you can switch user to the real administrator!

You should probably deactivate it afterwords with:
net user administrator /active:no

Hope that helps some.

Kai

A word of caution when heating Zinc.

I did just a few minutes TIG-welding a joint in 1" Zinc-plated steel tube. (I did not know it was plated!)

About 10 hours later I got a serious blood pressure fall. I was outside, and had to hold on to a tree, even when laying flat on the ground. My balance was non-existing, and the world was spinning madly. This lasted for 2 days. It took a week before I could walk with confidence on a flat floor. Zinc-poisoning is no joke!

Cool is good! Now I wonder how you identify proper useless junk. Every time I try that, the item is needed very soon, often within hours. Kai.

This link **LINK** has a lot of useful information on slitting saws on page 13. I think the important thing is that each tooth should be allowed to cut. If the feed is to slow, the teeth will rub and be blunted. If you run a low rpm, the feed should be adjusted for that.

I think I have all the books by Nevil Shute (Norway) and he has been my favorit writer since I was a boy and read Pastoral and The Rainbow and the Rose. Many of them, even Trustee from the Toolroom, is about flying, and it started my interest in that. I must say that even if his novels have different subjects as politics, model engineering, flying... he is very good at describing people and relationships between people, as in Trusty from the Toolroom. My favorit writer!

I do not need all the things that I have in my workshop, but I must admit that it gives me great pleasure to own so much butiful metal and equipment! Lathe, mill, Rotary table, mill tramming thing, micrometers, calipers, QCTP, toolholders, DRO's, tachometers, VFD's...

For many years I made it without these things. Even if I , due to lack of time, have used my workshop mostly for different repair jobs, I still like to go in there to have a LOOK just for the pleasure it brings me!

An expencive car or anything else would not please me as much.

Kai

To me, this sounds as if it could also be a problem with the bearing for the leadscrew.

I have no Super 7 experience, so take that for what it is worth.

I would check it, though.

Kai

I completely agree with this!

On the other hand I have followed this forum for a couple of years, and noticed a deteriorating level of friendliness and helfulness. Sometimes, and more and more often, posts are met with comments not compiled to be friendly, but rather unfriendly!

- you don't have to ask that here, go google it...!

- This post should not go here, there is another thread for that....

- Your language is some kind of bad English... (hits me bad because i'm not English )

- Spelling is way off......

All these things could easily have been answered in a helpful, friendly way and...if not....then these things are soley the job of the MODERATOR. If anybody feel the need to post like that, they should do like Isac Asimov did when he got critic for something he wrote - write an angry letter/post, then angrily and sermoniously throw it in the bin!

I would have to do that now, wouldn't I? or is it to late

If anything, I would critisize David for beeing to kind in his moderation, but I still say he has done a great job.

Kai

How about an accumulator for a small hydraulic model?

Hi cris,

In IE, try

Tools/Internet Options/Advanced/Browsing/Automatically recover from page layout errors with compatibility mode Ouch!

You can also add model-engineer.co.uk to the list under

Tools/ompatibility view settings/

Or for a test, set compatibility mode from Tools/ompatibility View:

Hope that helps.

Kai

Hi

I have noticed a marked reduction in this problem, so somebody is probably trying to fix it.

I am now running W7, IE9 and automatic compatibility mode, while I earlier used XP, Firefox and had a lot of problems with that, so I do not think this is soley a problem with IE or Firefox.

If somebody is trying to fix it, and David is interested enough to ask where the problem is occuring, I think we should help him with that process. That is, in my opinion, the friendly-forum-way of doing things.

English is not my native language, so I hope the intensions behind this post is not misunderstood. I really want to thank for this friendly, and to me very interesting forum.

Kai

The safest and easiest way to heat it is to put it in the oven and set the thermostate to the temperature you want. After 20 minutes, depending on your oven, you are ready to remove the bushes. I would suggest starting at 100 C. This will normally do the trick, but I do not think the casting will be harmed by 200C if that is neccesary. Most ovens go up til 250C.

(You will have to ask your wife first)

With this method there is virtually no risk of overheating. I have often done this with aluminum castings.

You should also clean it well first. Othervice it will change the taste of your food for years.

This method is also useful for curing high temperature epoxy, which need controlled temperature increasing in steps over long time.

Kai

Hi, I'm sorry I assumed this were aluminum castings.

I really do not know if a cast iron casting expands more than a bronze bush when heated.

I'm quite shure that someone on this forum knows, though. What kind is it?

Kai

Hi,

Aluminum expands so much that you can easily heat it in the kitchen, given permission. Outer bearing rings in model airplane engines more or less fall out of the crankcase casting when heated to 150-180 deg Celcius. That is even if very difficult to remove when cold. As for the fit, I would try to make them as large as the ones you remove. They were good enough!

Good luck

Kai