Grinding the tight curves on blanks.

[Will Batayte]

So now that I've finished my shop and am actually making knives I'm realizing some of the limitations of my tools. Mostly as the tital says grinding/cutting out small curves on my blanks. I have the hf band saw and I do the best I can to get the curve in the as much as possible using relief cuts. But then to grind those areas smooth I the kmg is kinda limited since I didn't get a super small contact wheel. I use my dremmel to take care of it. But honestly thats slow going. What do you guys use for this. I was thinking of some type of vertical drum set up. Cutting out blanks has been my slowest least fun part of the process. Trying to become more efficient. Thanks

 

[Tom Lewis]

A picture of the small curves you want would be helpful. If you have a kmg, use a contact wheel, and adjust the belt so it is over the edge of the wheel. You can grind some small curves that way.
As far as cutting out blanks, grind them out on your contact wheel using worn 36 grit belts.

 

[Will Batayte]

Yeah that's kinda what I've been doing is using the edge of the belt and having it bend over. Really what I'm speaking about is the finger choil under the guard. it's nothing to pronounced maybe a 1/4 circle of aproximately one inch diameter. Iwas just thinking a small drum on the drill press would be so much easier. Aside from them wearing out quick.

 

[Jeremy Barnard]

The sanding drums are slow as well and wear out fast. I'd recommend the small wheel attachment.

 

[thijsco19]

You can always use a file .

I think that, besides a small contact wheel, the sanding drums on the drill press is the best solution.

 

[Bob Ohlemann]

Profiling blanks is the fastest, easiest part of a project for me. I select a bar that is no wider than I need for my knife profile. I then cut the bar off on my horizontal bandsaw and trace the pattern onto it. From there, a 50grit Blaze belt running about 3600 SFPM is all I need to finish the profile in a couple minutes. I mostly profile on the flat platen but occasionally if there is a tight radius, I may flip my grinder to horizontal (custom GIB build) and use a small wheel. I've used drums on the drill press and on the Dremel and the small wheel with a ceramic belt blows the others away. I only have the 3/4" small wheel and I've not needed anything smaller for my profiles.

Bob

 

[tryppyr]

I use files for the small inside work.

 

[M forge]

+1 on the small wheel attachment. I just got one a while back for my KMG and it was money well spent. I currently only have the 3/4" wheel, but it is great for neck knives and such.

 

[james terrio]

I usually try to get as close as I can with the edge of the belt/platen/contact wheel, and smooth things out with round files and/or a rotary tool. Sanding drums are definitely not meant for serious stock removal.

If you can swing a small-diameter contact wheel like the other fellows are talking about, go for it. You can use the power of your grinder and the durability/versatility of good belts to make short work of inside curves. :thumbup:

When really small areas are shaped properly but need to be polished, I use a little split mandrel like this in my Foredom; you just chuck it up, put a strip of sandpaper in the slot, wrap it around and get to work. Works very well.

 

[Kieran Klein]

Dremels work well for tight spots aswell if you are careful.

 

[tryppyr]

Dremels suck for grinding. They are okay if you are trying to create a specific unique shape, but for grinding they are simply awful. Too prone to creating uneven depths, no matter HOW careful you are.

 

[i4Marc]

Small wheels are the way to go if you can get one the size you need in the type of spindle that works with your tool arm. I also use an oscillating spindle sander but the drums wear out very fast. Sanding drums in a drill press is not the best solution. If all else failed I would use files and sandpaper.

 

[redd1981]

+1 different size round and half round files.

 

[Kieran Klein]

Dremels suck for grinding. They are okay if you are trying to create a specific unique shape, but for grinding they are simply awful. Too prone to creating uneven depths, no matter HOW careful you are.

I guess I must be Super careful since they work well for me

 

[cigardoghd]

I've been using sanding drums mounted in the drill press. One of the things I've noticed is that less pressure against a drum the better it cuts and the longer they last.

 

[tryppyr]

Retracted. I misunderstood the O.P.'s original question.

Apologies.

 

[Horsewright]

I have done D all of the above. Drop the $ and get the small wheels. By far the best, easiest and quickest too. I have the 1" and 1/2" small wheels and should of got em years ago. They do everything I need.

 

[Will Batayte]

Profiling blanks is the fastest, easiest part of a project for me. I select a bar that is no wider than I need for my knife profile. I then cut the bar off on my horizontal bandsaw and trace the pattern onto it. From there, a 50grit Blaze belt running about 3600 SFPM is all I need to finish the profile in a couple minutes. I mostly profile on the flat platen but occasionally if there is a tight radius, I may flip my grinder to horizontal (custom GIB build) and use a small wheel. I've used drums on the drill press and on the Dremel and the small wheel with a ceramic belt blows the others away. I only have the 3/4" small wheel and I've not needed anything smaller for my profiles.

Bob

I saw a grinder like that on a you tube video and thought damn that'd come in handy! I've been cutting out the profile on the 4x6 in vertical mode. I too am trying to minimize the amount I'm removing by selecting the right stock for the design. The band saw is just kinda slow and it makes me want to press too hard. I do have a good blade on there though. I gotta get some real rough grit belts. I've been doing most of my grinding on 60 grit AO and at about 50% power since I'm just starting out. I think im gonna end up getting a small contact wheel. I'll just have to switch over from working one knife from start to finish to doing all my blanks, then all my grinds so im not switching set ups all the time.

 

[jtdesigns]

For me it starts in the design. Since I use autocad, Most of my designs have no sharp corners and I keep my radius' within the confines of my small wheels (5/8", 3/4", etc). When I built my KMG clone, I also built an EF-48 clone. After profiling with an 8" contact wheel, i final grind all including the radius on the horizontal grinder with small wheels.

 

[Omega Leather Works]

I know you're talking about grinding and not finishing, but I saw a cool tool today for that job. The guy took a 1/4" bolt/pipe/rod/whatever of steel, then covered it with a length of air hose. With sandpaper wrapped around it it looked pretty useful.

For very light stock removal I use the drum in Dremel, but it does suck. I'll be getting a drum for the drill press since that way I can at least mostly be assured of a square grind.