A
Alan H.
Forum Guest
Register Today
Ted, I received the book today and the drawings are NOT in inches but are still metric (mm). Not sure how the book was updated for the American market but anyway we have our answer.
-
Welcome back Guest! Did you know you can mentor other members here at H-M? If not, please check out our Relaunch of Hobby Machinist Mentoring Program!
Harold Hall simple grinding rest
- Thread starter Technical Ted
- Start date
- Joined
- Dec 8, 2015
- Messages
- 127
Ted
Geat job on your tool rest. I am in the process of drawing up Harold Hall's Simple Grinding Rest in SolidWorks and coverting the prints to Imperial dimensions. I am just curious as what thread you used for the crossfeed and infeed screws 12-28?, 10-32? Did you pin threaded rod into the shaft ends or were you succesful in turning and threading the rods to size. Anythings you would do different?
Jim
- Joined
- Dec 3, 2014
- Messages
- 778
I got my new updated book a few weeks ago, metric, what a bummer. Still good for the photos though.
- Joined
- Nov 5, 2016
- Messages
- 1,420
I used #10-24 for those. Worked out well. I did single point them on my lathe and then pinned them to the knurled knobs with small split roll pins.
As far and doing anything different, I don't think so... This is a good size for 1/2" and smaller tools. Maybe down the road I might make the advance rest, but make it larger to handle maybe up to 1" tools (i.e. end mills, etc) and then make a set of the associated holders/fixtures larger as well. It would be nice to have both sizes since a larger one wouldn't be as nice for the smaller tools and vice versa...
I haven't updated this thread, but I have finished the round and square holders Harold had in the book. I'm currently working on the end mill side fixture. I drew it up in Fusion 360 and have only finished the base and the two bearing supports. I assembled them and then line bored for the bearings which are next on my list to make. I did locate a piece of cast iron for them. I modified the spindle it to use 2 MT collets instead of having to make them since I have a full set for my Bridgeport M head. I also will make the spindle a little longer since a lot of my end mills are longer.
With winter coming, I have to take a break from this project and get ready for the winter weather and snow! So, it will be a week or two before I can get back to work on the fixture.
Ted
- Joined
- Dec 8, 2015
- Messages
- 127
Thanks for the direction. . I felt this was a great project to get some practice on my "new to me" milling machine.
I am leery about trying to cut and thread the slender shafts. (No follower rest). I may try - but may end up using threaded rod.
Please continue to post updates - this is a great project.
Jim
- Joined
- Nov 5, 2016
- Messages
- 1,420
I turned the shafts and threaded them without a follower. Just take light cuts and make sure your tools are nice and sharp, especially the threading tool. I use HSS tools. Negative carbide tools might give you a little trouble since they would push the shaft away more. Depending on the size of your tail stock center, you might have to turn the end down a short distance just under the minor diameter of the thread and center drill it. Remove this when the shaft is complete. This will give room for your threading tool at the start of the thread. Also, especially on small diameters, I don't cut a relief at the end of the threads. I use my hockey puck indicator, running the lathe at a slow speed, and just quickly withdraw the tool when I get to the end. You can progressively withdraw it a little sooner as you go. I think this might lend itself to a stronger shaft rather than having a relief cut into the shaft giving it a stress point to flex/break. Either way, I think it looks better!
This is proving to be a very nice project and what I feel will be a very useful implement. I've made/sharpened my own cutting tools free hand for years, but as I get older I'm sure I won't be as steady as I was and this will be handy. Being able to sharpen end mills will be
a huge plus!Good luck and have fun!
Ted
- Joined
- Nov 5, 2016
- Messages
- 1,420
Update: Had some time this morning and finally finished up the parts for the end mill side grinding fixture! Now, just finial cleaning, fitting, assembly and lapping the spindle in more after final bearing assembly. Of course this will have to wait a few days now since I have family plans for Thanksgiving and the weekend!
Happy Thanksgiving everyone!
Ted
Happy Thanksgiving everyone!
Ted
- Joined
- Nov 5, 2016
- Messages
- 1,420
All assembled, lapped and tested out. Works great! The operator needs more practice, but the fixture works very well. As with anything, a little experience using a new tool goes a long ways. My initial test was with an end mill I found in the scrap bucket at work years ago that was broken right in half. I figured shorter would be easier for the sides to start with and I had nothing to lose if I made a mistake since it was scrap in the first place. Cut just fine after sharpening even with the grinder's original undressed wheels!
Now, to make the larger flanges for my better grinding wheels (cup and saucer type) and make up some angle cards as suggested by Harold as they will make the angle adjustments/setups much easier. For the first test I used a protractor and eye balled the setups. Then, sharpen a few cutters and use it for a little while before the final mounting of the grinder and steel plates and a few other finishing touches.
It's been a fun project!
Ted
Now, to make the larger flanges for my better grinding wheels (cup and saucer type) and make up some angle cards as suggested by Harold as they will make the angle adjustments/setups much easier. For the first test I used a protractor and eye balled the setups. Then, sharpen a few cutters and use it for a little while before the final mounting of the grinder and steel plates and a few other finishing touches.
It's been a fun project!
Ted
- Joined
- Dec 22, 2015
- Messages
- 561
Very nice work!!
I see you made the spindle longer than the plans called for. Wish I had done that too. Mine works using the stock dimensions but there isn't much to get hold of at the back end. I think Harold must use smaller and shorter end mills than me. I had to make a second, longer, indexing support at the front end, to run along the end mill flutes. The stock one was too short to work with my end mills.
I see you made the spindle longer than the plans called for. Wish I had done that too. Mine works using the stock dimensions but there isn't much to get hold of at the back end. I think Harold must use smaller and shorter end mills than me. I had to make a second, longer, indexing support at the front end, to run along the end mill flutes. The stock one was too short to work with my end mills.