Scraping in a dovetail - detailed

Here, I show in detail -upon request- how to scrape inside a dovetail. And you see what crap is coming out of the "happy elefant fart, tractor and fortune cookies factory" in China.

Category:

Science & Technology

Tags:

• metal
• scraping
• biax
• dovetail
• dove
• tail
• refurbishing
• machine
• tool
• guide

[Tombfyre80]

One of the best for details. Just one request, do you cover reading the layout or image in one of your other videos? My boss/instructor is from East Germany, and I'm not sure I'm understanding the process right for using the layout medium.

[MuellerNick]

@Tombfyre80

No sorry, there is no detailed (or any) description how to read the blue. I thought about making a video about that for several times. But it would require some animation tools I don't have. I tried to collect shots of clear readings, but that also failed.

Maybe once I'll come up with a description. As soon as you understand what the blue does, it's easy to draw your own conclusions. I never found a clear explanation. Maybe, I'll try it with some sketches.

[princeigorash]

Hello.

If I may ask...where I can find detailed information about scraping.It may sound stupid...but why not to machine on grinding machine?Wich is the difference between a scrapped surface and a polished surface? The scraped surfaces are they mating together during operation or there is an oil film between them?Can this be done on larger machines (lathes wich can machine pieces 1-2 m length )?

Thank You.

P.S.: I don't know nothing about scrapping.

[MuellerNick]

@princeigorash

Forums like HomeShopMachinist of PracticalMachinist talk about scraping. You'll find information there.

Two polished surfaces adhere to each other, they don't glide very well. Oil pockets at one side are essential for good tribology.

[phibieb]

I am interested to learn basic scraping. what model manual scrapper is that? where can they be purchased.

[MuellerNick]

@phibieb What country are you from? I mean, if I tell you that I bought it at Hoffman Munich, is that of any help?

Any Sandvik dealer should have them. But there are other manufacturers.

[The87wing]

thanks for making this video- its been very helpful- great job!

[FueShuN]

at 8:43 the chief engineer gave approval lol

[billgator2005]

hello; had to laugh on your comments. bulls eye! IMHO. i have a chinese built lathe labelled for marketing by a tool company in 1 of 2 north american countries(do not know the legalities of commenting here but rather not be sued). this video gives me hope i can rectify my carriage, crossslide, issues . my tailstock and carrige have been scraped to the ways with a mini grinder. please continue with the videos. your knowledge can save us from the fate of this junk from china.

[ardvarkkkkk]

I would be willing to bet a lot of the distortion in Chinese machine ways is do to not stress relieving the casting before machining. Hopefully it has moved as much as it's going to before you do all that work to it.