New very large belt grinder for production.

S

Stevenj369

Joined
Dec 21, 2013
Messages
42
I have been searching for a large heavyduty belt grinder to use for production grinding. I had just aboutgiven up and was starting a design in CAD to build a very large 6in x???? when I found a Porter Cable G8 Wet-Dry 5hp 8in x 108in grinderon craigslist for a great deal ($340 delivered!!!!) I am going todesign a fixture with linear guides and stops that will attach to thework rest to do flat grinding. This will be my main way to remove thebulk of steel before going to my 2x72 to finish and refine thebevels. Once done it will be a fully water cooled and running at 8000SFPM. At least that is the plan right now. A long term goal will beto design a CNC setup that I can program to help remove any usererror and streamline my process even better.


I'm currently doing testing ofdifferent belts to optimize costs and time. I have found that mostceramic belts cut great new but start glazing over after one chefknife. The curious thing about this is that most of the belts lookbrand new even after this happens. It seams like the compound thatholds the ceramic grit doesn't break up the same way on a flat platenthat it does when grinding on a wheel (which makes sense). I went totru-grit and bought a bunch of belts of different grits and makeups.I'm going to do a Time/Temp/Cutting/Life testing process and get asmuch information before I buy belts for this grinder. When belts costalmost $100 each and have a 10-20 minimum buy (depending onmanufacture) I really want to make sure they are the perfect belt forthe job. I am currently using VSM 50 grit on my 2x72 to do this job.I have done similar testing for my 2x72 and found VSM to be the bestat cost to use. I get 1.5 – 2 chef knives per belt right now.


I will get more picture of the grinderand the process of getting it ready as time allows. It is going to bea long build process since I have to keep up on our currentproduction. If anyone is interested I will post my results on thebelt testing and any other information that comes from this project.


 
Is the advantage of a wider belt that you can grind the bevels faster?

That thing looks like a beast!
 
Thanks guys, I have a feeling I will need some luck with this thing. The main advantage of the wider belt is the faster cutting and less chance of the bevel not being flat. This will be used almost exclusively for 8in chef knives which really needs to be flat because I go to a zero edge before sharpening.

As for the end of day mess I'm not sure what to do yet. Was thinking of some type of vac system, but have a feeling that I will just have to scoop it out everyday.

Question on VFD's
Anyone have any feed back on these cheap china ebay models in the higher output??? I have been looking at http://www.ebay.com/itm/7-5KW-VARIA...-NEW-10HP-220V-SPEED-CONTROL-US-/181797515771
 
Last year I turned down a free 7.5Hp industrial grinder with full dust collection system. It was just 20 miles from my house. It was a Wilton dual belt 3X120 wet/dry grinder with big contact wheels and flat platens. It was fully enclosed in a giant 4X6 foot cabinet. A minor problem was it was 3Ph, ..... major problem was it weighed a ton...literally. The dust collector took up about 15sq.ft., was 6 feet tall, and was probably 1000 pounds.

It had to be removed from a shop that was bought by a friend of a friend of a friend, ASAP, and I had no way to move it and no place to store it. Big grinders like this often sell for far less than a small 2X72.


EBay, Craig's list, and Govt. auctions sell these type big grinders for scrap weight.




Off the subject slightly, but recently I discovered that Northern Tool has discounted the Wilton grinder, but now carries the Jet version of the 2X72 Wilton Square Wheel grinder, and also carries a 4HP version of the Burr King 3X79" industrial grinder.
 
The problem with most ceramic belts glazing is that they're designed for extremely high pressure grinding. i.e. the part is forced against the belt with a lever, or they're used on a machine with physical feeds.


There are some belts that are designed more for "off-hand" grinding, and break down faster. Some belts are designed for certain alloys, etc. It's never as simple as "buy the most expensive belt, and it's the best".

Steel, speed, whether the material is hardened, what hardness, etc. all matter in find a belt that works great. For instance, 3m 977s (yellow ceramic) have a reputation as the best among many older makers (for good reason) that grind mostly hard, alloy steels. 984Fs Cubitron II's are IMHO the absolute best belt for titanium, and quite good for hard or soft carbon, but mostly overpriced for soft carbon.

3m has a new belt that's also a Cubitron II, model 947A, that's designed for lower pressure grinding (i.e. hand pressures), and lower speeds. Breaks down faster, works good for carbon steel, both soft and hard, but I don't like it at all for hard stainless.


Everybody has their favorites, and will tell you "X" is best. The reality is, you'll have to figure it out for yourself, based on your method, materials, and other variables. Personally I stopped buying ceramics over 120 grit, because I found they simply weren't worth it and didn't last longer than AO's, the big exception being structured abrasives, like the Ceramic Trizact and Norax belts, which are wonderful.

Your selection is going to be pretty limited in the size you need for this grinder also, and you'll have to have belts made for any specialty abrasives.
 
That a big honkin' grinder!!!!!!! it will be interesting to see how it works of you. Are you gong try to use some kind of drip or spray water cooling system?
 
looks sweet, but please put some type of guard on that drive belt. It makes me scared just looking at it. Especially since it's at waist level....
 
Thanks everyone for the interest in the project. I took a couple of picture of different parts of the grinder. I am going to start cleaning and getting ready for water cooling (sealing and rust proofing) this weekend.








The motor is going to a local re-builder to get checked out and fixed if needed. Hoping everything is good with the motor since the replacement is in the $700 range!!!!
 
coudl work wewll for you if it was me and i was getting a monster grinder it woudl be a big wheel guy but it all depends what work you do
 
butcher_block said:
coudl work wewll for you if it was me and i was getting a monster grinder it woudl be a big wheel guy but it all depends what work you do
Click to expand...

I have been thinking of making a radius platen for it. I am mostly using it to have one of my guys do the bulk of the steel removal.
 
Looks like a big woodworking sander. A nice add-on for the shop for sure, but i'm not sure it will be the best go-to for grinding blades as it offers not much knucles cleareance.
Blade bevels are hardly true flats, more of an elicoidal shape indeed. If they were true flats the blades would be all triangular shapes.
 
You must log in or register to reply here.
Back
Top