Petr from Czech saying Hi to all!

[pettra]

Greetings to all. I am Petr from the Czech Republic and I am interested in mechanical engineering, machines and everything around production. I'm graduated as a engineer on ČVUT. I worked for many years under the well -known brand TOS Čelákovice, where machine tools, lathes, toothed mills and other were produced. I own a small workshop and I am interested in all information around the mechanical engineering. I also like to contribute with some of your own ideas and discussion to this forum. On the photo it is me in the work

 

[Deva]

Ahoj Sused !
Nice to see neibour from Bohemia !

 

[pettra]

Ahoj Sused !
Nice to see neibour from Bohemia !

Hello Deva, where are you from? According to your "Ahoj sused" I would say from Slovakia

 

[GreenTwin]

Welcome Petr, glad to have you here.
There are lots of talented folks here who like to share information.

Have you done any engine building yet ?
What do you do in your shop ?

Pat J
.

 

[Roadhawg]

Hello Petr and welcome!

 

[awake]

Welcome to the forum!

 

[pettra]

Welcome Petr, glad to have you here.
There are lots of talented folks here who like to share information.

Have you done any engine building yet ?
What do you do in your shop ?

Pat J
.

Thank Pat,
We are repairing old machines such as lathes, milling machines, grinders, but also various others as well as special spare parts. I am a specialist in scraping guide surfaces of various shapes and lengths. And also including scraping the engine block Only a lot of people know and do this job but I really like it very much. And at this point we are working on the development of a controlled rotating table for our milling machine.

I will be very happy to inform this forum using posts on individual activities in the near future. Maybe these projects will be interesting here for some members.

 

[GreenTwin]

Petr-

I watched a video a few years ago of the scraping process, to restore the way on some sort of machine.
At first it seemed counterintuitive to start gouging into the surface, seemly randomly, but as the video progressed, with the bluing process to repeatedly check progress, it became apparent what was happening, and why.

Seems like a mix between science and art in some respects.

I guess my question is how do you start the process?
ie: what datum points do you acquire before you start, and how do you keep track of the progress from the datum points?
Seems like you could scrape off into a tangent direction, and no longer be parallel with what you want to be parallel with, even though the surfaces would mate as intended.

My city had an extensive electric trolley system in the early/mid 1900's, and it was all removed and scrapped in the 1950's.
Then in the 1980's, it was determined that it would be cool to put that trolley system back in place, and so many millions of our tax dollars were spent doing that.
The trolleys we have were purchased from South America, and renovated to some unknown extent.
Then we had two trolleys burn to the ground in one week.

They hired a consulting firm, and that firm discovered that many/most of the trolley maintenance proceedures were undocumented, and sometimes only a single individual could perform certain tasks.
The firm documented all proceedures, and set up a maintenance schedule.
No more burndowns, so far.

I highly value anyone who retains our technological skills.
It is critical for a functional society that we have that knowledge base.

Good to have you here.

Pat J

.

 

[Richard Hed]

Thank Pat,
We are repairing old machines such as lathes, milling machines, grinders, but also various others as well as special spare parts. I am a specialist in scraping guide surfaces of various shapes and lengths. And also including scraping the engine block Only a lot of people know and do this job but I really like it very much. And at this point we are working on the development of a controlled rotating table for our milling machine.

I will be very happy to inform this forum using posts on individual activities in the near future. Maybe these projects will be interesting here for some members.

Is it possible to get a video of you doing some scraping? I would very much like to see that.

 

[pettra]

Is it possible to get a video of you doing some scraping? I would very much like to see that.

Richard yes it is possible. But I think that I will start a new thread "My scraping" where I could take a photos, videos and some experience.

 

[pettra]

Petr-

I watched a video a few years ago of the scraping process, to restore the way on some sort of machine.
At first it seemed counterintuitive to start gouging into the surface, seemly randomly, but as the video progressed, with the bluing process to repeatedly check progress, it became apparent what was happening, and why.

Seems like a mix between science and art in some respects.

I guess my question is how do you start the process?
ie: what datum points do you acquire before you start, and how do you keep track of the progress from the datum points?
Seems like you could scrape off into a tangent direction, and no longer be parallel with what you want to be parallel with, even though the surfaces would mate as intended.

My city had an extensive electric trolley system in the early/mid 1900's, and it was all removed and scrapped in the 1950's.
Then in the 1980's, it was determined that it would be cool to put that trolley system back in place, and so many millions of our tax dollars were spent doing that.
The trolleys we have were purchased from South America, and renovated to some unknown extent.
Then we had two trolleys burn to the ground in one week.

They hired a consulting firm, and that firm discovered that many/most of the trolley maintenance proceedures were undocumented, and sometimes only a single individual could perform certain tasks.
The firm documented all proceedures, and set up a maintenance schedule.
No more burndowns, so far.

I highly value anyone who retains our technological skills.
It is critical for a functional society that we have that knowledge base.

Good to have you here.

Pat J

.

Pat
Yes this is a really strong topic for a long time. What you wrote in our country we say, "Carved into the rock". Absolute truth. And for Your: Seems Like and Mix Between Science and Art in Some Respects I say: Exactly! I wouldn't say it better.
And for all here who do not have exactly all details about scratching I would like to add this: Scratch technology has never been replaced and overcome.
Nowadays robots, computers, CNC systems and UI are still manual scratching irreplaceable And also it should be noted that the scraping is really very heavy hand and dirty work.

Thank you very much for your really strong post. I am really pleased to be here.
In the photo I am working on scraping the engine.

P.S. Very sorry that my English is not good. I had to learn this language myself for my money, because at that time it was not allowed to speak English in our country . At school we had to learn only Russian. But fortunately, this is a very long history. I am 60 but still full of life and work.

 

[GreenTwin]

Not a hobby for those with carpal tunnel syndrome, I can just tell from the photo.

.

 

[Richard Hed]

I'm surprised that you are scraping an engine.

 

[SmithDoor]

Greetings to all. I am Petr from the Czech Republic and I am interested in mechanical engineering, machines and everything around production. I'm graduated as a engineer on ČVUT. I worked for many years under the well -known brand TOS Čelákovice, where machine tools, lathes, toothed mills and other were produced. I own a small workshop and I am interested in all information around the mechanical engineering. I also like to contribute with some of your own ideas and discussion to this forum. On the photo it is me in the work

Welcome to the group

Dave

 

[TonyM]

Hi Petr and welcome. Nice to meet a local on here.

 

[pettra]

Not a hobby for those with carpal tunnel syndrome, I can just tell from the photo.

.

Yes, I absolutely confirm this. I myself already have carpal tunnel surgery on my left hand No wonder, I've been holding a scraper in my hands for 40 years! The convalescence after surgery lasted only 15 days - nice. And today without any problems I scrape away.

The carpal tunnel problem is the standard problem of any scraper.

 

[pettra]

I'm surprised that you are scraping an engine.

I understand you are surprised.
It is one of my specializations and my known how in the scraping process. I would like to discuss this in my new thread. Here I answer briefly.

This is a key repair of the engine block and the only way to get a fully functioning engine from a completely dead engine. Only the scraping of the upper contact surface guarantees precise flatness and the certainty that the seal between the block and the head will never break again. Compared to a milled or gritted surface that does not guarantee such quality.
I correct the blocks that have a twisted upper surface of more than 0.06 mm or more. Otherwise, many damaged engines could not work in this state.