Author Topic: Surface grinder restoration and scraping  (Read 2051 times)

Offline Andrew Wildman

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Surface grinder restoration and scraping
« on: June 21, 2017, 04:08:43 PM »
Hi all.
I have posted the first in a series of videos documenting the restoration and scraping of a Herbert junior surface grinder.
<a href="http://www.youtube.com/watch?v=dYJYqqWhyxM" target="_blank">http://www.youtube.com/watch?v=dYJYqqWhyxM</a>

This will be the first of I don't know how many videos charting the success or otherwise of my restoration.

I hope you enjoy! :D


Offline mattinker

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Re: Surface grinder restoration and scraping
« Reply #1 on: June 21, 2017, 04:49:34 PM »
I'm looking forward to following this thread!! Off to a good start!

Regards, Matthew

Offline Pete W.

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Re: Surface grinder restoration and scraping
« Reply #2 on: June 22, 2017, 04:48:18 AM »
I've just updated Adobe Flash Player but I still get a post with a big blank space! 

   :worthless:

When I right click in the big blank space, I get a window saying 'Movie not loaded'!

   :bang:   :bang:   :bang:   :bang:   :bang:   :bang:   :bang:   :bang: 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Online philf

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Re: Surface grinder restoration and scraping
« Reply #3 on: June 22, 2017, 05:07:40 AM »
Hi Andrew,

Thanks for sharing this.

I have a similar job to do on a Capco surface grinder so I'll be watching with great interest.

Cheers.

Phil.
Phil Fern
Location: Marple, Cheshire

Offline Mike E.

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Re: Surface grinder restoration and scraping
« Reply #4 on: June 22, 2017, 05:54:44 AM »
Hi Andrew,

I've seen a couple of Alfred Herbert Jr. machines in the past and liked the simple design. A couple of months ago in April I found a later model unit with the larger knee & oiler for sale. It appeared to be in very good condition, so I bought it. There won't be a chance to try it until my new garage / workshop is built, and a rotary phase converter installed. Thank you for posting this topic, I am looking forward to your rebuild with great interest !

Here is a photo of the machine I acquired.
Mike

California & Wales  - Home, & Home Away

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #5 on: June 22, 2017, 07:55:54 AM »
Mike,
Mine is the same model with the oiler.  the rest of the ways seem in ok condition.  I think the bellows failed on the column and grit go in.

Pete,
I am not sure if the problem is just with you or others also can't see.  anyway, here is the link:

https://www.youtube.com/watch?v=dYJYqqWhyxM

Phil,
I was looking out for a capco when I spotted this.  they seem to be very similar machines, I think the capco has a slightly bigger capacity

Online philf

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Re: Surface grinder restoration and scraping
« Reply #6 on: June 22, 2017, 08:14:40 AM »

I was looking out for a capco when I spotted this.  they seem to be very similar machines, I think the capco has a slightly bigger capacity


Andrew,

My Capco is a mighty heavy lump. The table is 640mm long. It's all in bits at the moment but the stroke must be about 550mm. If I had a big mill I'd remachine the dovetails on the table - but I haven't (mine only has a 300mm travel) so scraping is my only option.

Cheers.

Phil.

Phil Fern
Location: Marple, Cheshire

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #7 on: July 02, 2017, 04:00:59 PM »
hi all,
Please find the next in the series below.  BTW I am looking for an old (ideally a bit beaten up - save wasting a good plate) 18" surface plate to cut up to make a straight edge.  Does anybody have anything that they would not mind selling for a fairly low sum?

<a href="http://www.youtube.com/watch?v=5sOd_VIj4Bo" target="_blank">http://www.youtube.com/watch?v=5sOd_VIj4Bo</a>

Offline Pete W.

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Re: Surface grinder restoration and scraping
« Reply #8 on: July 08, 2017, 03:31:18 PM »
Hi there, Andrew,

I've sent you a PM. 
Best regards,

Pete W.

If you can keep your head when all about you are losing theirs, you haven't seen the latest change-note!

Offline Biggles

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Re: Surface grinder restoration and scraping
« Reply #9 on: July 11, 2017, 11:58:21 AM »
Great work Andrew, enjoying the videos.  :clap:

Online Pete.

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Re: Surface grinder restoration and scraping
« Reply #10 on: July 11, 2017, 12:07:41 PM »
Great project Andrew, I have a Herbert milling machine of similar size, they are quite chunky for a small machine. I also have an identical 48" camelback to yours and they are really heavy to pull about - 33kg I think. The other style 48" with just the round holes are about 33% lighter.

What do you need a 18" straight edge for? I have a 24" you could borrow but it is not a dovetail type.

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #11 on: July 11, 2017, 05:03:58 PM »
thanks all for the offers to borrow straight edges or for various bits of cast iron that people have.  I appreciate the thoughts and may take some of you up on the offers, however I think I may have sourced a suitable plate nearby (Lincoln area).  If I get it I will post a video on machining up and scraping the straight edge.

I think I may be developing scrapers elbow!

Offline stvy

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Re: Surface grinder restoration and scraping
« Reply #12 on: July 12, 2017, 09:20:21 AM »
Andrew,

Please do continue posting about this interesting rebuild. Also if you don't mind please take some shots of the tooling you have made. How I wish I had such a large surface plate!

Thanks,
Steve

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #13 on: July 12, 2017, 04:36:23 PM »
hi stvy,
I will probably focus on some of the tooling as part of some of the future videos.  There are plenty of widgets required to check alignment.  I am hoping that I can do most of them by re using the same parts.  If you search 'kingway' tool you can see some lengths people go to create tooling to achieve correct alignment.  While people enjoy making these tools, often they are more fancy than they need to be to do the basic job.  I just want to get the thing grinding true! :ddb: :ddb:

Offline Biggles

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Re: Surface grinder restoration and scraping
« Reply #14 on: July 19, 2017, 02:34:05 PM »
Re scrapers elbow; :coffee:  I have pondered on whether a standard off the shelf oscillating grinder can be adapted to scrape with the plane blade and some hard steel welded onto the end. I realize this may be a little hard on the work piece but it possibly would take care of any large amounts that need whittling down. Any ideas?  :lol:

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #15 on: July 24, 2017, 04:43:38 PM »
there seem to be a fair number of people made a cheap biax type powered scraper using reciprocating saws, that would probably be the easiest route?

Offline Biggles

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Re: Surface grinder restoration and scraping
« Reply #16 on: July 27, 2017, 01:26:56 AM »
thanks Andrew, sounds good.  :)

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #17 on: August 11, 2017, 05:51:35 PM »
Latest episode below...

<a href="http://www.youtube.com/watch?v=MwCrmCDCxG4" target="_blank">http://www.youtube.com/watch?v=MwCrmCDCxG4</a>

Offline Mike E.

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Re: Surface grinder restoration and scraping
« Reply #18 on: August 12, 2017, 10:58:56 AM »
Hi Andrew,

Gosh, you have done a lot of work to restore the machine. Thanks for recording the process on video. I'm sure others, like myself will also be grateful when meeting the challenge to rebuilding our Herbert surface grinder's.

Cheers  :thumbup:
Mike

California & Wales  - Home, & Home Away

Offline Biggles

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Re: Surface grinder restoration and scraping
« Reply #19 on: August 12, 2017, 12:18:49 PM »
Thatís a lot of hard work Andrew, well done; I hope a have the energy to do the same when I come around to doing my machines. Keep going mate, brilliant. :clap:

Offline PekkaNF

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Re: Surface grinder restoration and scraping
« Reply #20 on: August 12, 2017, 01:13:50 PM »
Really like this thread and YT videos. Very educational and nicely edited.

I am building up tooling to start some scraping projects too. I have some questions.

1: How do you hold down the parts when you scrape dovetails?

2: I think I saw a dove tail scraper (Sandvik handle? Dapra scraper?) in some picures. Any pictires and advice on dovetail scrapers?

Thank you,
Pekka

Online philf

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Re: Surface grinder restoration and scraping
« Reply #21 on: August 12, 2017, 03:28:20 PM »
Hi Andrew,

This is quite inspiring but I don't know if I have the patience!

My Capco is all stripped down, 5 layers of paint removed and in grey primer.

I have the knee sat on my milling table and with an 8" square I can see 0.3mm wear in the Z-axis!

Too much to scrape I think so I'm wondering how I can machine it on my mill which is really too small. I'm currently thinking I can clamp the knee flat to the table and spin the head through 90 degrees.

I'm not sure how much the dovetail is worn or if it's just the face. Looking at your method I would need to get the face perpendicular again before testing the dovetail. I have a 55 degree dovetail cutter but the face width isn't enough to re-machine the dovetail in one go - it's about 21 mm.

I have a good reference face to the lhs where the 4 tapped holes are. This is for a block gib so sees no wear. You can almost see the shadow created by the 0.3mm step at the top. (Very little wear at the bottom.)





Phil.

Phil Fern
Location: Marple, Cheshire

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #22 on: August 14, 2017, 04:36:55 PM »

Pekka,
I just stood the table on the 'workmate' (this is a diy type trestle table that has a clamp action top) and clamped it lightly.  this was more than sufficient for the light loads from scraping a dovetail.

I have a sandvik scraper and the standard sandvik blade for roughing.  For finishing and dovetails I clamp a carbide paint scraper blade that i have dressed the end up of.  This holds up as well as the sandvik blade and cost me about £1 rather than the £15 for a proper sandvik one. :D

Really like this thread and YT videos. Very educational and nicely edited.

I am building up tooling to start some scraping projects too. I have some questions.

1: How do you hold down the parts when you scrape dovetails?

2: I think I saw a dove tail scraper (Sandvik handle? Dapra scraper?) in some picures. Any pictires and advice on dovetail scrapers?

Thank you,
Pekka

Offline Andrew Wildman

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Re: Surface grinder restoration and scraping
« Reply #23 on: August 14, 2017, 04:49:50 PM »
Phil
I suspect if you have that amount of wear on the knee then the column face and definitely the column dovetails also have some serious wear, as obviously they are both made of the same material.

If you set the gibs to allow free movement along the whole length of the knee is the knee loose at the most work point?  Would give you an indication if you column needed work to make the grinder serviceable.

You could scrape the column in a similar manner to me, even if your plate was not as big, but you had a precision level to ensure that each of the smaller scraped sections were in the same plane.  This would then allow you to scrape the knee too it.  You might want to take most of the material off in the mill to save your time and your mind! :bang:  your solution looks the best way to do this.  BTW your knee is a bit different to mine as mine has a oiler and double vee ways for the carriage (aligning these is a headache that I am now solving!)



Hi Andrew,

This is quite inspiring but I don't know if I have the patience!

My Capco is all stripped down, 5 layers of paint removed and in grey primer.

I have the knee sat on my milling table and with an 8" square I can see 0.3mm wear in the Z-axis!

Too much to scrape I think so I'm wondering how I can machine it on my mill which is really too small. I'm currently thinking I can clamp the knee flat to the table and spin the head through 90 degrees.

I'm not sure how much the dovetail is worn or if it's just the face. Looking at your method I would need to get the face perpendicular again before testing the dovetail. I have a 55 degree dovetail cutter but the face width isn't enough to re-machine the dovetail in one go - it's about 21 mm.

I have a good reference face to the lhs where the 4 tapped holes are. This is for a block gib so sees no wear. You can almost see the shadow created by the 0.3mm step at the top. (Very little wear at the bottom.)





Phil.

Online philf

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Re: Surface grinder restoration and scraping
« Reply #24 on: August 14, 2017, 05:09:41 PM »
Hi Andrew,

I thought I'd fix the knee first before testing the column. The dovetail currently flat on the mill table might be OK as there isn't a cantilever effect like on the knee. Having said that the z leadscrew is in the centre so it's hard to imagine why there's so much wear. All the oiling points on the machine were clogged with grease which probably couldn't reach where it needed to be. Rather than trying to clean the nipples out I ordered a batch of new ones. There doesn't appear to be any provision for lubing the z-axis!

I think the most critical axis is the x-axis which needs to travel in a straight line. It doesn't matter if it's not perpendicular to the z axis. Similarly the Y axis - if it's a touch out of perpendicular to the Z axis then when the wheel is dressed it will be parallel with this axis.

The grinder doesn't owe me much and I'm in no great hurry.

Like Pekka I was going to ask what sort of tool you used to scrape the dovetails - a photo would be nice.

Cheers.

Phil.
Phil Fern
Location: Marple, Cheshire