2A637 Horizontal Boring Machine Retrofit

[digitalmg]

Hi all
I'm started to retrofit a 35 years old CNC 2A637F3 Horizontal Boring Machine made by Russia.
I try to post photos and videos from my inspections and corrections here.
For the beginning, there is a question that how to inspect flatness and straightness of Y axis guideway which is about 4 meters long and consisted of 4 sets of 110mm ways.
I tried dismantle the column from the base and lay it down on the ground, then by the aid of jack screws and precision level, I tried to level the guide ways horizontally at about 0.03mm/m
I have a granite 00 grade straight edge with the length of 500mm in my work shop.
Is it possible to inspect 4000mm length by dividing into more than 8 sections and check it with bluing the 500mm granite edge and rub it on the guideway along the total length? (for example 10 segments of 400mm with 100mm overlap to each other)
Any how the largest camel type straight edge available on DIN 876 with 0 grade is 3000mm which is 1 meter short for my application. So what is the practical solution for this issue ?

Thanks

 

[Richard King]

If I were you I would look for a granite surface plate and use it. The short parallel would be a real nightmare. I bet there are more granite surface plates then even long straight-edges.* I would look for unworn area's of the ways to use as a guide. If you had a 457 mm x 610 mm granite plate so you can scrape both of the ways at the same time. Before scraping use a micrometer and measure from the underside of the ways. In 90% of those types of machines the underside hold down ways are not worn. You could also make a L shaped sled that you glue plastic turcite to so you can slide it on the top ways. Then use a magnetic base on the outside edge of the sled magnetized to and put a dial indicator on the underside of the ways.

Find the lowest or most worn area of the base and saddle and start there and scrape it flat and co-planer to the undersides. Make both sides of the base and saddle ways the same thickness.

* a good source of granite straight edges is an old obsolete CMM (coordinate measuring machine) Check with used machinery dealers if there are any in your area as the software on many of those old CMM's can't be updated and many times they scrape them.

 

[Richard King]

You have to assume it was right when new and use area to measure from like the clearance side of the box ways, measure the ends of the feed screw, hold down ways, the ends of the ways where the machine seldom travels. Have to play detective. :-)

 

[Tyrone Shoelaces]

What makes you think the column ways need re-working ? In my experience - on relatively modern machine tools where the spindle frame ways are usually lined with some sort of anti friction material the column ways are usually in pretty good condition. Normally that’s the least of your problems. I take it you’ve already scrapped the 35 year old CNC system. CNC years are like dog years.

It’s too late now but I used to do the tests whilst the machine was still under power. You’d normally check the coluin ways with a big square and a DTI on the spindle frame.

Regards Tyrone.

 

[Garwood]

I take it you’ve already scrapped the 35 year old CNC system. CNC years are like dog years.

You must not have spent much time around Fanuc machines. 1988 would be Fanuc 10/11/15A time period. Digital AC servos, Around 600IPM rapids and 300IPM feeds. Those are damn good controls. Some of the best ever made.

2019 I scrapped out a 1979 Mazak with a Fanuc 5T control. Nothing whatsoever wrong with it. Just got a 2008 machine with more gizmos. In 40 years it needed a $10 5V power supply for the optional position display and it blew 3 fuses everytime you hooked the phase rotation backwards. 40 years old and it never had a real issue in it's lifetime.

 

[Tyrone Shoelaces]

You must not have spent much time around Fanuc machines. 1988 would be Fanuc 10/11/15A time period. Digital AC servos, Around 600IPM rapids and 300IPM feeds. Those are damn good controls. Some of the best ever made.

2019 I scrapped out a 1979 Mazak with a Fanuc 5T control. Nothing whatsoever wrong with it. Just got a 2008 machine with more gizmos. In 40 years it needed a $10 5V power supply for the optional position display and it blew 3 fuses everytime you hooked the phase rotation backwards. 40 years old and it never had a real issue in it's lifetime.

I agree Fanuc are pretty reliable however it’s unlikely that a Russian machine would have a Fanuc control.

Regards Tyrone

 

[digitalmg]

This is the real photo from the machine. The former photo was from a similar model.
As you may see Y axis guideways are scraped from the factory and I have not touched it yet. the total length is about 4 meters. I will discuss about the quality of surfaces in the next post.
The first question rises here is why the factory scraped this surface at all? I though normally these surfaces are grinded only. I have seen many machines with grinding ways only. The counter surface that you see in the second photo has coating like Turcite from the factory but it was damaged and I replaced it. before replacement I saw a few remaining scraping signs on it. Now I'm trying to do a rough primary scraping on the new Turcite and then rub it to the guideways which are blued before.
I will post the guideway inspections later.

 

[Tyrone Shoelaces]

This is the real photo from the machine. The former photo was from a similar model.
As you may see Y axis guideways are scraped from the factory and I have not touched it yet. the total length is about 4 meters. I will discuss about the quality of surfaces in the next post.
The first question rises here is why the factory scraped this surface at all? I though normally these surfaces are grinded only. I have seen many machines with grinding ways only. The counter surface that you see in the second photo has coating like Turcite from the factory but it was damaged and I replaced it. before replacement I saw a few remaining scraping signs on it. Now I'm trying to do a rough primary scraping on the new Turcite and then rub it to the guideways which are blued before.
I will post the guideway inspections later.

“ Kearns-Richards “ used to go over their column ways with a “ Biax ‘ half moon flaker after slideways grinding. I don’t know wether it did anything practical but it certainly looked nice.

Regards Tyrone.

 

[digitalmg]

“ Kearns-Richards “ used to go over their column ways with a “ Biax ‘ half moon flaker after slideways grinding. I don’t know wether it did anything practical but it certainly looked nice.

Regards Tyrone.

Hi.
The pattern I see is not the half-moon and also Richard King strictly told that it should not be applied on exposed surfaces.
More over half-moon could not be applied on Turcite as he told.
So there might be another reason behind this.

 

[Tyrone Shoelaces]

Hi.
The pattern I see is not the half-moon and also Richard King strictly told that it should not be applied on exposed surfaces.
More over half-moon could not be applied on Turcite as he told.
So there might be another reason behind this.

I could see that it wasn’t the usual half moon flaking. I’ve worked on lots of Hor bores over the last 50 years and I can’t recall another one were the vertical ways have been scraped like the one you have. It’s hard to see what the reason was behind it. Once modern anti-friction materials became easily available so the moving elements could be lined with it most ways were just slide-ways ground and left like that.
As I said early “ Kearns Richards “ went over the column ways with a “ Biax “ flaker but that was probably for purely decorative reasons.

Regards Tyrone.

 

[digitalmg]

Dear Tyrone
All guideways X, Z, Y are like the same and hand-scraped in this machine.
Could you please tell me how much is the accuracy for the straightness and the flatness of way grinders in 4 meters length?

 

[Tyrone Shoelaces]

Dear Tyrone
All guideways X, Z, Y are like the same and hand-scraped in this machine.
Could you please tell me how much is the accuracy for the straightness and the flatness of way grinders in 4 meters length?

Bang on. Within 0.0005“ if the operator knows what he’s doing.

Regards Tyrone.

 

[Richard King]

I just saw this. I am teaching a class today and have been all week. I have to be there in 1 hour. I am in a hotel room and I have a 20 minute drive. I will comment tonight. I prefer not to flake the exposed surfaces, but many machine builders do because it serves the purpose of oil lubrication and it looks good. Bridgeport is a typical Machine builder that does it. Talk to you tonight.

 

[Richard King]

If the ways are soft then and not flame hardened then machines in the states were normally scraped. The soft ways needed oil pockets or low scraping spots to hold the oil. I wonder when that machine was made? Why even think about it. You have soft ways and Turcite now, so no reason to wonder why...lol Possibly the factory could not harden the ways or Turcite was a new product and they started to put it on soft ways or maybe the machine was rebuilt before and they put Turcite on to bring the ways back to the original height because the ways were scored. Who knows??. I was telling Digital in private messages that I celebrated my 21st birthday in Masjed Soleyman when my Dad had a contract to assemble several BIG Machine tools for BMY a company in York, Pennsylvania. They build a factory there to rebuild vehicles they made and our government gave them to the Shaw of Iran after WW2.

It's a shame of the relationships our countries now have as I met several wonderful people in Iran back in 1971. The last couple of days I have heard some terrible news.
I am finding it difficult to help Digital now. So I am going to step back from this thread. Sorry.

 

[digitalmg]

Here is the inspection result by my granite straight edge.
As you may see, cross checking shows hot spots are in the outer area and low spots are in the middle expect non-working areas that has better surface.
The same result is in the entire 4 meter length and opposite slide-way.
I have checked with 0.02mm filler gauge and there is no gap between the straight edge and guideway just like the photo.
Running a dial indicator base on the top of granite and traveling the indicator on the way shows less than 0.01 mm deviation.

For longitudinal checking, I have checked what Mr. King recommended at the beginning and observed maximum 0.02mm wear in the mid-length.
I have read that precision camel type cast iron straight edge with length of 3000mm in DIN876/0 has accuracy of 0.016 mm
As total straightness tolerance for this axis is 0.02mm/m based on ISO 3070-1 and I can see scraping signs on the guideway more or less every where (From the factory release), Do you guys believe the surface accuracy is good enough to be used as reference for the mating Turcite surface scraping? or I should see uniform blued pattern every where on the guideway before going to Turcite scraping ?

 

[Tyrone Shoelaces]

Here is the inspection result by my granite straight edge.
As you may see, cross checking shows hot spots are in the outer area and low spots are in the middle expect non-working areas that has better surface.
The same result is in the entire 4 meter length and opposite slide-way.
I have checked with 0.02mm filler gauge and there is no gap between the straight edge and guideway just like the photo.
Running a dial indicator base on the top of granite and traveling the indicator on the way shows less than 0.01 mm deviation.

For longitudinal checking, I have checked what Mr. King recommended at the beginning and observed maximum 0.02mm wear in the mid-length.
I have read that precision camel type cast iron straight edge with length of 3000mm in DIN876/0 has accuracy of 0.016 mm
As total straightness tolerance for this axis is 0.02mm/m based on ISO 3070-1 and I can see scraping signs on the guideway more or less every where (From the factory release), Do you guys believe the surface accuracy is good enough to be used as reference for the mating Turcite surface scraping? or I should see uniform blued pattern every where on the guideway before going to Turcite scraping ?

I’d need a bigger straight edge than that. Just one tip - I never bothered using feelers on jobs like that I cut strips of paper say 1” by 6” . Place them under your straight edge about 12” apart and see if you can move any of them.

Regards Tyrone

 

[TGTool]

Ha. My teacher used strips of cigarette paper - much thinner. But that doesn't mean it's any better for checking since you're really using the "feel" of different friction among the strips. Unless (really stretching here) you could theorize that PUSHING the strip gave you any better reading where the thinner paper would buckle with less force. It's a good test in the range of less-than-feeler-gauge thickness.

 

[digitalmg]

I make progress slowly on Slideway scraping!
I have no milling or grinding machine for rough machining of applied Turcite and it takes alot of time form me to achieve a flat plane.

 

[digitalmg]

Could any one suggest how to scrape main V in the middle ?
V angle is 45 Degree to the horizontal reference, and they both make 90 Degree angle together. Length is about 3.5 meters
My idea is to make a reference shape like the attached photo, but I cannot make it larger than 600mm due to the limitation of granite surface plate for scraping and machine tools available around.
Is there any trick to use 600mm reference to scrape 3500mm length ?

Thanks

 

[Harri89]

Can you add a picture of the mating part of the V-way, where the ways are visible