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Author Topic: Highland Park B12 rebuild, suggestions please  (Read 871 times)

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jcricket

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Highland Park B12 rebuild, suggestions please
« on: May 24, 2023, 10:36:13 AM »

Hey Folks,
This is my second post. am newer to lapidary. I will have a faceting machine, Ultra-tecI,  very soon. It is promised for Jun9.
I also want to try cabbing. The other day I found a Highland Park B10 machine, complete with 8" saw. I am going to tear the machine apart and  rebuild it. This will mean cleaning and polishing shafts, cleaning and painting the housings, and replacing anything it needs like bearings and motors. I have a fair amount of experience in these areas so I think I am good to go there.

What I do need help, with is what wheels and grits I should put on the machine. Currently, the machine has a3" expandable drum, two grinding wheels(unknown grit size), a polishing buffing wheel(I think), and an 8" leather polishing disc on the end. I also have 3-4 additional polishing pad wheels for the machine. It appears the machine could easily handle a third grinding wheel. I have seen a few pictures online showing the machine with that configuration.

Through my years I have found that the quality and  completeness  of your tools makes all the difference in the world. It affects you  the finally quality of your job. As such I try to buy only very good or better tools. When I do buy them I generally go through them and rebuild them back to new or better condition and functionality. This brings me to the B10 I have.

I do not know cabbing. I would love some feed back on what grit wheels I should get. Theoretically, I could have five wheels. and expandable drum, and the polishing pad on the end. Would this be the preferred or effective set up? What is the cloth buffing/polishing wheel for. What grits should I get for the drum? I have been watching you tube videos to get an idea of the function of each station. This is where I need your help. If this was your machine, how would you set it up? How many grinding wheels, what kinds, what grits? 

I know this is a bit of an expensive hobby. I paid just over $200 for the B10. I plan on investing some money into the wheels. Sintered diamond is not out of my consideration.  My budget for a premium overhaul, wheels etc, is just a bit under $1400. Pics to follow  soon.


So, thoughts and recommendations please!

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lithicbeads

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Re: Highland Park B12 rebuild, suggestions please
« Reply #1 on: May 24, 2023, 02:20:38 PM »

A sintered 8 inch wheel is about ten pounds and may be problematic for your machine. They are a great bargain  however. Nova wheels can cost as much as you paid for your machine . I like 80 grit hard and 220 hard then 60 grit nova . You could get  diamond belts belts  for an expando for the rest , 220 ,600, 1200, 3000, 14,000.
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jcricket

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Re: Highland Park B12 rebuild, suggestions please
« Reply #2 on: May 24, 2023, 02:31:09 PM »

Thanks for the  reply. Why is the weight problematic?

What is the difference between the 80 grit "HARD" and  the 60 grit "nova"? I'll  google it too and see if I can  get a good read on it.
 Is nova the brand name?
Also what is the difference, if any between then high-tech and the heirloom sintered wheels?
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lithicbeads

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Re: Highland Park B12 rebuild, suggestions please
« Reply #3 on: May 24, 2023, 05:25:59 PM »

Nova is the name of the best soft sanding wheel while hard wheel means metal . The average hard wheel is a few pounds and sanding wheels less. Machines are made for the prevailing wheels  which are far far lighter than sintered wheels. An imbalance  of wheel weights could cause  bearing issues and most machines have noticibly slower start ups with a sintered wheel on it. I have only used heirloom and it is fine.
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R.U. Sirius

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Re: Highland Park B12 rebuild, suggestions please
« Reply #4 on: May 25, 2023, 12:31:09 AM »

Conventional approach (and it certainly works well for most jaspers, agates, feldspars, obsidian, etc) is to use two hard (diamond in metal) wheels (80-120 range, and 180-220 range), followed by series of soft wheels (changeable silicon carbide or diamond belts on expanding drums, or permanent soft wheels such as Nova). Example soft-wheel series would be 240, 600, 1200, 3000.

The mechanics of abrasive action are quite different between the hard and soft wheels, so it turns out that stepping back to rougher grit (100-180 range) on the first soft wheel after rough shaping on the second hard wheel often saves time, especially for harder stones.

While it's fun to learn and compare Mohs scale hardness values for various minerals, such "scratch hardness" of large, single crystals is not always related to the more important and practical grinding hardness of lapidary materials. You will quickly learn that one kind of jasper may wear down at double the rate of another kind. This is due to different microstructure of crystal grains, trace impurities, etc.

When you get to polishing, you will find online charts suggesting best combination of the disc material (felt, leather, canvas, synthetics) and polishing compounds (alumina, cerium oxide, diamond, chromium oxide, tin oxide) for a given stone. Unfortunately, these charts omit other, equally important, details such as pressure and time, and how wet the disc is... Old books and magazines, and forums like this one, are full of sometimes contradicting advice about polishing techniques. Use them as a starting point, but the key is to experiment and to keep your notes.

Be mindful of cross-contamination. Water mist generated by the wheels carries rock dust with it. Do not keep that polishing disc on the shaft - only put it on when you are ready to polish, and store it in its bag or box when not in use.

Also, be mindful of the danger of silicosis. Freshly fractured crystalline silica is quite reactive, and fine, invisible dust can travel deep into lungs where it leads to chronic inflammation. Always grind wet. Water keeps the dust down, but some research also suggests that it may help neutralize some of the surface reactivity of quartz. Still, an appropriate respirator or a mask, rated for water mist and sub-micron particles, is a good idea.

Good lighting is important when grinding/polishing, but also when inspecting the stone between the grit steps.
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jcricket

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Re: Highland Park B12 rebuild, suggestions please
« Reply #5 on: May 25, 2023, 05:51:19 AM »

Excellent information folks!!!

I have a question. The machine has two grinder wheels. The trough or housing for these is 13" wide. How many wheels would be a good  or acceptable amount?
I think 4 would be a reasonable amount. I see the heirloom wheels come in 80, 140, 220 and 325. The nova wheels come in 60, 140, 280, 600, ........ Would an 80 and 220 diamond wheel, coupled with a 140 and 280 nova wheel be a good combination? Then the drum would be maybe 325 and 600?

I doubled checked and I have 5 of the 8" buffing pad/wheels. I plan on replacing the leather covers as I have no way of know about what grit or contamination exists with each pad. I suppose I should replace the polishing wheel for the same reason.

decision, decision.c :smiley:
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nrcamo

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Re: Highland Park B12 rebuild, suggestions please
« Reply #6 on: May 25, 2023, 08:16:14 AM »

Excellent questions and especially the answers. Even helped me out. Thanks.
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kent

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Re: Highland Park B12 rebuild, suggestions please
« Reply #7 on: May 26, 2023, 07:54:21 AM »

I have the B 12 my father purchase perhaps in the 60's ?  I rebuilt it and have some breakdown photos that would be of interest to you. I made a plexiglass hood for the saw with a opening at he right side for my arm and a small hinged lid on the top for visual access. It helps contain the mist. I use water with an additive I purchased from Covington which works tremendously ! Easy clean up and no rusting. The B 12's location in my shop was such that I could not easily use the end leather buffing disc so I removed it, installed a 3" expando wheel and built a housing over the expando to feed water to it and contain and drain the water. IMG_4550.jpg
*IMG_4550.jpg (80.79 kB . 600x450 - viewed 127 times)

IMG_4552.jpg
*IMG_4552.jpg (72.58 kB . 450x600 - viewed 119 times)

I make pendants and sometimes re-bolster folding Buck knives so I like to have a wide surface to work on to help me with getting my material "fair". So my expando gets a lot of attention. I have a second older Raytec machine that will hold two wheels so I use it for 80 and 220 hard diamond wheels and also a 10,000 grit soft polishing wheel. The nice thing about the Raytec is that the wheels can easily be interchanged fairly quickly. I have two 80 grit hard diamond wheels. The sintered one is a work horse for fast removal but can create a rough edge on some material so it gets removed and the other metal 80 grit wheel takes its place.

In some cases the hard wheels are just too aggressive so I use 80 grit on the expando and continue using the expando down to 1000 grit.Then to a couple of Nova wheels which are permanent on the B 12. I replaced my polishing buff with a 2" wide felt wheel which I use with cerium oxide which handles the polishing tasks of most of the stones I work with.  Because I make pendants I am directly holding the piece I am working with and need room to move. I could not work with four wheels side by side on the B 12.
I can email you my break down photos if you like or see my back posts somewhere around 12-2018.

Cheers,

Kent


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kent

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Re: Highland Park B12 rebuild, suggestions please
« Reply #8 on: May 26, 2023, 08:13:02 AM »

Hears a few shots of the saw plexi housing when it was new.
Rock saw reberth 003.jpg
*Rock saw reberth 003.jpg (69.7 kB . 600x450 - viewed 123 times)
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bilquest

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Re: Highland Park B12 rebuild, suggestions please
« Reply #9 on: May 26, 2023, 12:28:43 PM »

Congrats on getting such a smokin' deal!  200 for a vintage HP cabber is truly remarkable.  IMHO, HP built the best cabbing machines and should last several lifetimes.  I own an E-12 that I've modified over the years to be my perfect cabber.  I modified the main basin to hold 3 wheels, including 1 sintered, and have had no problems.  I have never replaced the bearings or motor after about 8 years of use.  Someday I suspect I'll need to replace the bearings, but they appear to be standard pillow block.  As for wheel suggestions, start with the fundamentals (100, 220 diamond, to 600 SC) and see where that takes you.  Have fun!
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lithicbeads

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Re: Highland Park B12 rebuild, suggestions please
« Reply #10 on: May 26, 2023, 03:22:57 PM »

The most important sanding sequence is 600-1200-3000 in diamond , they are the priority. You only need a sintered 60 or 80 hard any good hard 220 of normal weight will be fine as it does not do an extensive amount of work.In the many  years I cut professionally I came to love a metal 600 grit wheel and a 1200 and 600  grit pads on a flat lap for fixing  mistakes.
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jcricket

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Re: Highland Park B12 rebuild, suggestions please
« Reply #11 on: May 27, 2023, 05:26:17 AM »

Hears a few shots of the saw plexi housing when it was new.
 [ Invalid Attachment ]

WOW!!!   :notworthy: :drool:

Nice job!!!  My shop is very full. I decided to put my machine on a stand with casters. I can pull it out in a second and use it. Then put it away and get my space back. The stand is a 1950's craftsman tool stand and the top is a 2" butcher block. I'll see how this works when I am done, hopefully very well.
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jcricket

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Re: Highland Park B12 rebuild, suggestions please
« Reply #12 on: May 27, 2023, 08:32:15 AM »

bilqest and lithicbeads thanks for the info and suggestions.

With what I have been reading, an 80, 220, and 600 hard cutting wheels? Then a 600, 1200, 3000, pre-polish wheels or pads?
On the HP b12 I have, I think I might set up  the "cutting" section with three wheels, the 80, 220, and 600. Maybe the  drum can then be the 1200 and 3000? I also have a polishing wheel. I think I might set 600 pre-polish wheel there. I do have the 5 additional 8" polishing pads that could be charged with various grits and polishes. Even so, I think a final polish buffing wheel separate form everything might be good. This would obviously be outside the scope of this machine.

Does this sound reasonable?
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bilquest

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Re: Highland Park B12 rebuild, suggestions please
« Reply #13 on: May 27, 2023, 01:02:00 PM »

I originally had something close to what you are proposing... mine was 100, 220, 600 hard diamond wheels.  What I learned from that was that I was spending way too much time on the 100 wheel.  I wanted something more aggressive for initial shaping.  I also learned that the 600 hard wheel was difficult to get rid of flat spots on.  So, I bought a 60 grit Sachi diamond wheel (8x2) mounted left, shifted my 100 to the center and moved the 220 to the right.  One of the modifications on my E-12 was to convert the right pad to 8x3 expando which I put a 600 SC belt on.  The 60 wheel eats anything in short order, and the 600 expando does a nice job of finishing the shaping and prepping for further sanding and polish.  For further sanding I have a Poly arbor with 2 8x3 expando's that I use diamond resin belts on, and finally I have a homemade bull wheel for cerium polish.  I have been very satisfied with this setup for several years now and have cut a wide range of material.  I don't think there are any absolutes in cabbing as everyone seems to arrive at their preferred setup over time.  Even though my methods/equipment have evolved, I don't regret any purchases, and have enjoyed every step of the journey.
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55fossil

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Re: Highland Park B12 rebuild, suggestions please
« Reply #14 on: May 27, 2023, 02:30:11 PM »

    No arguments with earlier posts, some great input there. I just switched from a 6 inch Genie to an 8 inch CabKing as it is easier for my arthritic hands.. But I truly love having a dual 8 inch expando wet sander with silicon carbide wheels. I always start out cutting on the a hard diamond wheel but go to the 220 SC drum to get my cabochon shaped up and remove any flat spots. Then I go to my soft starting with 220 grit wheels.
    I find it so much easier getting my final shape on my cabochon with expando drums. The wide surface and slower cutting allow me to glide across my pre-form cab, remove flat spots and get a uniform domes top. Even with my new 8 inch unit I still love the ease of those big 8 inch wet expando wheels. This realy shortens my time per cabochon and I get a better finish without any hidden scratches that show up during polishing.
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