Models for grinding HSS Lathe Tools

[mikey]

I rec'd a piece of 3/8" HSS in todays post which I will set aside, and my son is picking me up some key stock this afternoon.
I'll use the info from this thread and see what I can come up with even though a have not a clue what I am doing.
I have a Sears 1/3HP bench top grinder and a Jet 4" belt sander so I think I am good to go in that dept.

However the most I can do for now, assuming I can grind a reasonable facsimile, is set it on the mill table and look at it!! Electrician still has not returned. I suspect he is being kept up at night fixing corn driers!!
If the offer is still open for the models, please include me.

PM @Z2V to have some models sent to you. That's what I would recommend. Then duplicate them and then stick with keystock to learn how to grind them consistently. All too many of us get too anxious and jump to HSS too early. It is better to be able to control your grinds so your tool geometry is accurate. When you can easily do this with keystock, THEN move to HSS and do the same thing. I promise you that the time spend grinding keystock will pay off.

Please keep us posted and show off your tools if you like - we like looking at that kind of stuff.

 

[WobblyHand]

Never saw this grinder before but it looks good to me. The chassis is stamped steel but heavy, which is good. The right side of the belt is open once the cover is off and nothing is in the way that would impede grinding rake angles on a tool so that is a very good thing. The platen is removable, I think; if so, you can replace it with a good platen with a glass liner on it. And it's got 3/4hp, more than enough to grind tools and for general shop use.

Looks good to me!

Astoundingly, this Dayton belt grinder showed up on my doorstep this evening. That's less than 24 hours! I'm not sure it's fit for the task, although it's a sturdy beast. 3/4 HP motor, with thick metal to hold everything together. Unfortunately the platen is also part of the frame as it is cast. It's thick about 10.6mm. I could grind away the platen on the right hand side, but not the left. Can't add neoceram to the platen as the geometry of the wheel and platen surface are fixed.

Have a look at a few pictures. Could I modify this enough to be ok? Or should I attempt to send it back?
Integral platen 10.6mm thick. Totally non-adjustable.

Almost all the blue you see is one casting, except for the little bit of sheet metal on the bottom right. Platen extends about 1/4" on both sides, give or take.


Is this salvageable? By that I mean, by grinding off the RHS of the platen, can it be useful for tool grinding?

From the parts diagram, item #28 (the platen) is all one piece. I'll check to see if I can get a cost estimate for that part. It is 9628668.01.


Should I send it back? If I grind the right hand side of the platen to gain access to the right side of the belt, will this be sufficient? Just don't have the funds to do the full 2x78 knife grinder, or for that matter, even the Jet.

 

[ttabbal]

Can you get the belt to ride on the edge of the platen? I bet you could make it work good enough for tools.

The knife maker 2x72s don't have to be super expensive. Here's one place to start.

BG-272 DIY 2 x 72" Belt Grinder

DIY 2" x 72" Belt Grinder Project Like almost every newbie knifemaker owning a decent belt grinder is dream. When I realized the price of...

dcknives.blogspot.com

 

[WobblyHand]

@ttabbal At the moment, I don't see how, short of physically grinding part of the platen on the right hand side. The platen is 1/4" nominally wider than the belt on both sides. So if I ground off 1/4" on the right hand side and I modified the belt cover to come in 1/4" maybe. The belt is 1/8" away from the edge of the pulley, so I can't see pushing it much further. Actually I don't know how well the belt tracks just yet as I've yet to plug it in. I don't have a place to tie it down yet. It was delivered in a day, and I wasn't expecting that!

If I did grind the platen on one side and alter the cover to allow the tool to be tilted 15-20 degrees backward, would that be sufficient? Or should I return this grinder? Seriously, the grinder seems like it's built quite well, like a tank, but it's not a blade builder's delight. I just don't have the experience with grinding these tools to make a good evaluation. So that's why I'm asking for guidance and or advice.

I read through that link earlier in my research. It seems like a fun project. At the moment, I want to actually be able to use my lathe, not take on a whole mess of extra projects. Someday I'd like to try building the big 2x78. Right now, I can't take it on.

 

[brino]

Should I send it back? If I grind the right hand side of the platen to gain access to the right side of the belt, will this be sufficient?

WobblyHand,

It all depends on what you're after.

Cutting out the entire platen of this machine to build in a special ceramic one is probably more work than building new grinder around a new platen.

However, if it is simple access to one edge of the belt that you are after then perhaps you can modify it much like I did to mine here:
https://www.hobby-machinist.com/thr...-sander-to-access-the-edge-of-the-belt.63436/

I did mine so I could grind lathe tools as outlined in this thread.
A small slot in that thick casting at the right of the belt should do it.
If you decide to modify it then add the slot where you can have a small support table too.

Your sander looks much more robust than mine!

-brino

 

[WobblyHand]

Brino,

I agree. This grinder is not worth modifying to put in a neoceram platen. Too much machine work. I don't have the machines to do it, and wouldn't want to pay someone for it. It would be cheaper to buy a fancy blade grinder!

What I'm asking is: Is it sufficient (for the purpose of grinding lathe tool bits) to add access to one side for this grinder?
If so, I think I could grind out a chunk of the platen on the right hand side with out any problem. Maybe 1" high by 1/4" deep. That should be good enough to handle my 3/8" tooling. I'd have to alter the belt cover door a little as well.

The grinder has a pretty heavy support table included. It mounts to the left side of the grinder. I just didn't assemble that part - so it wasn't in the picture. One last change I'd have to do is to add a small support for the tool on the right side. Guess I'd just make a plate that bolted on top of the existing support table.

Hmm, this is sounding better! I think I'll keep it!

WH

 

[mikey]

It's disappointing that the platen is part of the body of the grinder. I think we've seen this construction before but I forgot about the possibility. Sorry about that.

Before you go modifying your platen, let's think this through. Once you cut a piece out of it, the grinder will become usable for tool grinding but it also makes it less usable for grinding other stuff because you'll have a part of the belt without any support under it.

Thinking this through, I know how important a glass platen is. That steel platen will not last long and you'll wear a divot into it in short order. I would send it back and build a 2x72 myself.

 

[ttabbal]

I have to defer to Mike on the existing grinder. I have only used my 2x72. If you have a welder or know someone who does, it's not a difficult or time consuming build. You can even get the metal cut to length for you at most suppliers.

If it's really about the desire to make chips on the lathe, would it help if I grind you a square tool to start with? I have some 3/8 bits here... I hate to see you work harder on a less useful (for this anyway) tool than you would on a better grinder.

 

[WobblyHand]

If I just cut out a 1" H x 1/4"W piece of the platen on the right, why wouldn't it be ok for grinding other stuff?

I hear you on the steel platen. This one is not modifiable to glass. And since it's a relatively big and complex piece, it's bound to be an expensive replacement part. How long do you think the platen would last? A month of moderate use? More? Less?

 

[WobblyHand]

@ttabbal I've got loads of welders! Seriously, welding isn't a problem. It's that I priced things out and it seems like the piece parts are in excess of $500. Right now, I can't swing that. I can't fab/cut/hog out the pieces simply because I don't have the tools to do it. I can weld the pieces together. A 2x72 would be great, but I just don't need that project right now. Maybe in the summer, but not now. A guy just has to know when to fold his hand. So I'm folding the 2x72 hand - at least for now.

I do want to make chips. Actually I want to make something, not just make chips. My carbide bits just aren't giving me the finish I want with my little mini-lathe. I don't have any HSS yet, (probably be here by New Years) but I do have 5 pieces of 5% cobalt in 3/8".

I'm still mulling over this grinder. Not quite sure what to do.