Harold Hall's precision grinding table
- Thread starter xo18thfa
- Start date
Help Support Home Model Engine Machinist Forum:
Thanks guys. I like this table a lot. It did a great job on the practice drill bit. It will do a good job on end mills too, especially 2 flute. That will be a future attachment.
The wheel guard that came with the grinder interfered with the table too much, so it got left off. I will either modify it or make a new one. But yes, it needs a guard.
Looking forward to building Mr Hall's dividing head. It is the basic design using lathe change gears. It will make all the divisions I will ever need.
While building this table, my machining buddies gave me a ration of "bollocks" because Hall is Brit. I don't care. It's a good design. All his stuff is. Australian stuff is good too. If the "damn Yanks" come up with anything good, I'll build that too.
Thanks again.
The wheel guard that came with the grinder interfered with the table too much, so it got left off. I will either modify it or make a new one. But yes, it needs a guard.
Looking forward to building Mr Hall's dividing head. It is the basic design using lathe change gears. It will make all the divisions I will ever need.
While building this table, my machining buddies gave me a ration of "bollocks" because Hall is Brit. I don't care. It's a good design. All his stuff is. Australian stuff is good too. If the "damn Yanks" come up with anything good, I'll build that too.
Thanks again.
Gedeon Spilett
Well-Known Member
Hi
great job with this T&C grinder.
I'm gathering stuff to make one.
How come the slots of the table are square ended, it is not that useful but look super!
Zephyrin
great job with this T&C grinder.
I'm gathering stuff to make one.
How come the slots of the table are square ended, it is not that useful but look super!
Zephyrin
xo18thfa said:
Good to hear about the guard......I know too well what can happen omitting a safety guard on a power tool, I still have the scars...
As for the dividing head, that was one of the first major projects I undertook with my mill and lathe....I'm pleased with the outcome, although it did take me three attempts at making the main block...I'd suggest you read and re-read the text before you embark...Let me know if I can help if you have any questions about it (not that I'm an expert...)
Don't want to be picky,Bob,but isn't grinding on the side of the wheel a big no-no?
I know,I've done it myself,but it always makes me feel a bit uneasy.
I have one of the "potts" style copy jigs for grinding drill bits.but it's got so much play in various joints,it's worse than useless.
You did a nice job on it,and I'm very impressed by your glowing report
I have that book in my library,so I'll have to start gathering material,methinks.
I know,I've done it myself,but it always makes me feel a bit uneasy.
I have one of the "potts" style copy jigs for grinding drill bits.but it's got so much play in various joints,it's worse than useless.
You did a nice job on it,and I'm very impressed by your glowing report
I have that book in my library,so I'll have to start gathering material,methinks.
tel
Well-Known Member
- Joined
- Feb 8, 2008
- Messages
- 3,293
- Reaction score
- 44
You will find it well worth the effort - I use mine quite a lot and it does an excellent job.
I, too have made a start on the grinding rest - the basic rest is just about done and I've started on the accessories, looks to have a lot of promise, if I can just find a bit of space in this rat's nest to set it up.
Gedeon Spilett said:
Zephyrin: There is a fence attachment that drops in the slots on the table. The fence is in use with the drill jig. The fence has a key along the bottom that fits in the slot. So, it was either square the corners of the table or round over the key ends.
Bob
Hi Vic. The drill bit jig works great. I sharpened that old 1/2" drill as a test and it rips thru everything now. Identical chips coming off both edges of the bit. Could not ask for anything better. Highly recommended.
Thanks, Bob
Thanks, Bob
bentprop said:Don't want to be picky,Bob,but isn't grinding on the side of the wheel a big no-no?
I know,I've done it myself,but it always makes me feel a bit uneasy.
I have one of the "potts" style copy jigs for grinding drill bits.but it's got so much play in various joints,it's worse than useless.
You did a nice job on it,and I'm very impressed by your glowing report
I have that book in my library,so I'll have to start gathering material,methinks.
I have a copy of the book (not on hand at the moment) and looked for the answer to this little issue in detail after reading some posts on this and other forums about the dangers of grinding on the side of the wheel. There is a small section in the text recommending that the grinding table or rest (I cant recall which) be set at a slight angle to the wheel so that the tools being sharpened are effectively only contacting the outside corner of the wheel as they slide along. This means that the surfaces made by the wheel will be ever so slightly concave but this was not regarded as an issue.
Edit..... The text describing this is page 102 in milling a complete course and page 31 of tool and cutter sharpening.
Great job on the build... I should get my act together and build one.
Nickle. The first time I use the table it was digging into the wheel the closer to center. The table has a pivot that locks with a set screw. After a small turn of the table, it was cutting more on the edge and worked much better.
Vic: Yes. The attachments simply slide on the table, up against the fence. The adjustment knobs are very accurate. Feed about 0.001" for each pass against the grinding wheel. Have a soft brush handy to clean off the table and attachment every few passes.
Vic: Yes. The attachments simply slide on the table, up against the fence. The adjustment knobs are very accurate. Feed about 0.001" for each pass against the grinding wheel. Have a soft brush handy to clean off the table and attachment every few passes.
The grinding table project is done. Changed out the regular grinding wheel with a cone type wheel. Put the wheel guard back on and modified it to fit the cone wheel. Drilled and tapped more holes for the base bracket since the cone is much smaller then the regular wheel.
Here's the set up.
The drill bit attachment works great. Did this 9/32" bit in about 10 minutes
This is a must have in the metal shop. There is no excuse for dull lathe tools and drill bits now. The next attachment will be the endmill sharpener. I think this table is well capable of sharpening endmills. Also want to make an attachment to hollow grind wood chisels.
Here's the set up.
The drill bit attachment works great. Did this 9/32" bit in about 10 minutes
This is a must have in the metal shop. There is no excuse for dull lathe tools and drill bits now. The next attachment will be the endmill sharpener. I think this table is well capable of sharpening endmills. Also want to make an attachment to hollow grind wood chisels.
tel said:
Hi Tel and Dave: That is exactly what I plan to do too. I ordered a set of MT2 collets for the dividing head. Great minds think alike. If the drill bit attachment is any indication, sharpening endmills should be "do-able"
Very Nice Bob. Thanks for re-posting the pictures. The one I am attempting to build is Harold Hall's Simple Table, as shown in his book about sharpening.
Thanks for taking the time and documenting this tool.
Tel,
Do you have any pictures of your build or finished table and accessories? I sure would like to see your take on his design.
Ronald
Thanks for taking the time and documenting this tool.
Tel,
Do you have any pictures of your build or finished table and accessories? I sure would like to see your take on his design.
Ronald
