Myford 7x7 bed flats scraping and measurement

[@sblack48]

Im here by Richard’s recommendation. So happy to find this 👍👍👍

[@jansverrehaugjord9934]

Thnks! Yes, we are lucky to have this kind of teaching from him

[@spamspammesen5970]

When finished I'm sure these lathes will be considerably more accurate than when new. The amount of work you put in to these should make them collectors items!

[@jansverrehaugjord9934]

Thanks! But I assume the Myfords came out of the factory as good as these. But, it may also be true that they couldn't devote as much time as I on something that was a "sales item".. as long as it answered to their internal standards, good enough is the point where you shall stop.. otherwise it is just extra work for no more income. I am nonetheless sure that their standard was very high. A side step.. I plan to experiment a little also towards different setups for individual longitudenal feed and threading, also with an ELS

[@somebodyelse6673]

I would like to think that your rebuilt Myfords will find homes with model makers or jewelers, who are more inclined to treat their tools with care than professions which make their money by working fast instead of carefully.

[@jansverrehaugjord9934]

Agreed.. it is not a productipn tool.. far from it I guess. I will experiment however.. for example fitting one machine with an ELS2 on the Z axis. Also some other ideas for "modernization"

[@spewgw8417]

​@jansverrehaugjord9934 hi Jan, actually your lathes will be considerably more accurate and 'tight' in comparison to myfords brand new lathes. They ground the beds, and the scraping marks you see on the brand new machines are questionable. I have a brand new myford , scraping marks are present but as you say, you never know until you test it. Tested with straightedge and results were a bit disappointing. Cross slide as an example, seems to be milled and 'flaked' for appearance, missing the crucial part you do which is scraping for points per inch. Which all makes sense from myford as they are a business, and can't spend all day scraping one machine. In simple terms, your myfords are considerably better than a brand new myford.

[@9neil]

Astounding accuracy Jan.

[@jansverrehaugjord9934]

Thanks Neil, Not bad, I guess.. but it is easy to become a victim of yourself and get caught up in improving on something that is good enough..

[@neil1058]

Thats not a bad thing jan. We do this stuff for our own pleasure, not to make money or impress others or save the world. As others have pointed out, the end result is probably well over the top when considering what the thing is worth - so what. The satisfaction of doing something well is what its all about. Why else would I collect & fix old electric master clocks, that don't keep good time, are old and ugly, often complicated, but fascinating and irresistable (to me!) .

[@jansverrehaugjord9934]

Well said Neil!!

[@woozhi9218]

Do i have to use level to check for twist or printing on the surface plate is good enough

[@jansverrehaugjord9934]

Well, I would say that you need to check twist AFTER mounting the lathe also, so should do both

[@stanholmes4293]

Can you use a 6x6 inch surface plate when scraping a lathe bed? Lathe bed is 18".

[@jansverrehaugjord9934]

Use what you have, but a plate that is 1/3 of the length of the lathe bed isn't ideal. You could put the bed diagonally, ie. to have apprx. 1.4x longer surface, but still short. The problem is that it is harder to interpret the readings you get.

[@stanholmes4293]

@@jansverrehaugjord9934 Thank you for your prompt response. I will give it a try .

[@paulac2311]

What is that blue stuff called please? I am new to this and want to try scraping myself on a myford bed I have.. Any help would be appreciated :)

[@jansverrehaugjord9934]

The marking coumpund I use most is a water soluble product called Canode. It is obtainable from various sources, eg. www.artcotools.com/Canode-Blue-Die-Spotting-Ink.html Then I also have used some oil based compounds, best in my opinion being the Diamant brand, as linked here kuerschner.ch/epages/176212.mobile/?ObjectPath=/Shops/176212/Products/%22020%20-%20ZTB%22&ClassicView=1

[@pintofkimberley]

I use micrometer blue. Does the same job.

[@mclam5623]

I am a novice machine operator. I still need to learn a lot I have a question: why does the bed has to be scraped, if the bed is very flat after grinding? (I have no flat surface to bleu and measure) Do you scrape for inbedding oil or to get a flatter sutface?

[@jansverrehaugjord9934]

You scrape for both alignment and oil retention qualities. A bed is of course normally ground, but as long as you have a soft bed (ie. not hardened) you can also scrape it . Given it's a small bed it is not such a big deal one way or the other. The flat Myford beds are also very easy to measure. There can be many arguments to what "surface quality" you should try to achieve on the "exposed surface", which in this case the bed represents, but I like to scrape it a bit shallower/smoother than for example the underside of the carriage, which is supposed to have oil pockets.

[@jansverrehaugjord9934]

Add commets: Pardon the music during the level measurements. The editing of this video went a little "overboard". Not sure what happened, but blame the editor.. the part where I showed/try to show use alternative shorter/other straightedges/surface plate, I also meant to show the short plate in combination with a narrow straightedge , explaining how to overlap with 2 or 3 measurements with the plate, a "cross" reading, ie. SE across both flats, which will detect wind/twist in the bed, and then a couple of straight end- to- end measurement with the SE (each flat separately)

[@EuclidesFRezende]

What the name of this músic? At 4:27.

[@paulac2311]

So is the bed surface all bumpy?

[@jansverrehaugjord9934]

Sorry for the delayed response.. this comment/question somehow didn't surface in the header of my YT channel or in my gmail, to which I usually get a copy. Anyhow, a scraped surface will be straight and flat and have deviations ie. surface variations within allowable limits, usually mine are +/- half a hundreds of a millimeter. The mating component to the exposed surface, ie. in this case the bed, wold be the underside of the saddle and this could have deeper scrape marks and/or what we call flake marks. The purpose of such being for oil retention and thereby keeping the thin oil film onto which the parts float. Not deep enough/correct scraping marks leads to the possibility of the oil being squished out, parts sticking together and/or rubs .. which will produce premature wear, scoring and generally bad things..

[@paulac2311]

@@jansverrehaugjord9934 ah right I see now thank you for that its much appreciated and keep up the good work 👍

[@remajaberkarya7871]

Menamba pengalaman masalah bubut a

[@vadimturov7808]

that surface plate should cost a fortune

[@jansverrehaugjord9934]

Not new.. I think I paid around 5000 NOK. You can get them new though from this source www.microbas.se/surface-plates-2/ I think it is the article: 8070.17110, Grade 0, size1200 x 800 x 120mm, listed at SEK 24 120 plus VAT