grinding a .098 grove tool

[deere_x475guy]

Well I needed to come up with a .098 wide grove tool today for the fins I need to machine on my next engine. My parting tool is .058 and I probably could have gotten away with using that but I have a surface grinder and plenty of HHS blanks so set out this morning to grind up a tool that was as close to .098 as I could get it.

Here you see that I have blocked in the HHS bit so that it doesn't move. It's always a good idea to use bigger blocks of steel to try to stop the little parts from moving around. If you don't there is always a chance it could move or worse yet go flying across the room.

oops.....I am .0003 under....oh well it's going to have to work...

And I guess I am showing to tools on this thread. I built that micrometer stand probably a year ago or so...heck everything to me is a year ago a so anymore.....dang memory...

 

[AllThumbs]

Did you include any relief in the sides of the tool?

 

[deere_x475guy]

That's a good question Allthumbs. I didn't thinking that since I am only going in .1875 I could get away with it. I will let you know in a about an hour because those fins are my next step. We have today off as a holiday so it gave me an extra day to work in the shop. I get very little time to get into the shop during the week.

UPDATE:
After AllThumbs questioned if I had provided side clearance I realised I hadn't provided top rake either. So I added both.....All was going pretty well, I had finished cutting all the fins (even took a video I will post). I stood back admiring my work spending a few moments of feeling great satisfaction when I realized there we two things wrong.

1st, I didn't cut the first fin far enough from where the head bolts to the cylinder. I was suppose to leave .250 before cutting the first fine. I though...well ok I can maybe work around that.

2nd I didn't cut the fins deep enough. DUH....so..still not a big deal, I can just go back and cut them to full depth....right???? WRONG!!!...on the first re-cut about .030 into the cut BANG~~~....crap....broke the cutting tool and now the part is running out about .015.

I haven't gone back to check out what is bent or broken....

I think I will just sit here a bit...drink some coffee....and reflect on how things can go sideways so easily....

I usually bore pretty easy....I have been machining for about 5 years now....it's always a challenge and I guess that's why I am sooo into it...

 

[BobWarfield]

More mic stand photos please? Or maybe someone will start a mic stand thread. I saw Dickeybird's.

I need to make one. Tired of trying to grow a third hand.

Best,

BW

 

[DICKEYBIRD]

I finally found the site where the seed was planted for mine some time ago. Much better than sticking the poor mike in a vise like I used to do before I made a decent stand for it.

http://www.modelenginenews.org/
Resources>Model Engineering>A Bench Micrometer Stand for the UPT

That's a great site too if you guys haven't visited before.

 

[Lew Hartswick]

Here is another way to grind the bits on a surface grinder. including clearance
angles. I also have one with a variable angle if anyone wants to see it. Not sure
if I have a pix here at home but will take a few tomorrow and another few bits
of some modifications of one of Marvs ideas.

...lew...

 

[deere_x475guy]

Here is another way to grind the bits on a surface grinder. including clearance
angles. I also have one with a variable angle if anyone wants to see it. Not sure
if I have a pix here at home but will take a few tomorrow and another few bits
of some modifications of one of Marvs ideas.

...lew...

Thanks Lew....another bit I need to build..))))..yes please post pics.

 

[Swede]

DeereGuy, your story rings true with me. Deep, even fins on a cylinder or head are deceptively tricky. In fact, they are downright DIFFICULT to execute well. On my 9-cylinder radial, I was faced with hundreds of the little buggers. I started with 14 beautifully turned and lapped steel cylinders, all within 0.0003" of 1.0000", and I killed 4 of them, leaving me with the nine I needed, and 1 spare. I think I broke 3 HSS hand-ground blades. Ouch. :-X