# Sander/Grinder Plans - Ideas Needed



## rayjay (Aug 10, 2017)

I'm going to build a 2x72 belt sander. What are some good sites with plans or builds ?

Thanks !!


----------



## rayjay (Aug 10, 2017)

Here is a pic of the riding mower frame. I hope to use the front half after cutting off the steering mast. I will mount my idlers at the 2 front corners with the motor at the rear.

I just dug the angle grinder out of the shed and it runs fine. Quite noisy though, definitely need ear muffs. One thing I need to check out is the motor rpm in relation to belt speed. This grinder is rated at 4600 rpm. I guess I would compensate by using a smaller drive wheel.


----------



## godogs57 (Aug 12, 2017)

The internet has many do-it-yourself plans. Plus, many grinder manufacturers will sell a frame and you provide the motor...After its all over, I'll bet you will opt for that. Much easier and less headaches. 

Strongly suggest a 1750 rpm motor! Variable speed would be nice but $$$ for you. 

Best of luck


----------



## rayjay (Aug 12, 2017)

godogs57 said:


> After its all over, I'll bet you will opt for that. Much easier and less headaches.
> Best of luck



You do not know me .  I'm probably 1/3 done modifying my Wall RBG 2110P lawnmower blade grinder into a vertical 2x72 belt grinder sort of like what Grizzly sells. I need a contact wheel next. Got to decide between a cheaper 8" plastic covered caster wheel or a 10" Grizzly dedicated rubber covered contact wheel or an Ebay 8" or 10" contact wheel. $40, $95, or $130+.  I have some 2" stock for the upper wheel.


----------



## Anvil Head (Aug 13, 2017)

While I commend your desire and inventiveness, driving big wheels (yes a 72 inch belt grinder is a relatively big wheel esp. in relation to an angle grinder) with a small high speed intermittent use motor = short life for motor, excessive heat and less than satisfactory operation and results. Get a real work horse continuous duty motor, 1 hp or larger that runs at lower speed but has more torque. You are just burning time, effort, and $$ you can't get back. 
**Trust me, I did not read this in a book or on the net.**


----------



## rayjay (Aug 13, 2017)

This  is where I am at. I removed the front bell of the motor and turned the OD so that in the future if needed I could make a concentric ring to clamp to this OD . I also squared up the front face. Then I put the bell in the milling machine table and D&T'ed four holes for mounting the upright. The upright is shown in the second pic. 

I have to go buy a hole saw so I can poke a hole in the channel so it can slide over the motor shaft. Then locate and drill the 4 holes. I will weld a plate to the lower section of the frame so that the lower edge of the upright can be bolted to this new plate for more rigid mounting. When I had the front bell off I occurred to me that since the end bells are only held on by 4 small long fasteners that maybe it wouldn't be smart to mount the entire weight of the upright to the motor end bell.


----------



## rayjay (Aug 13, 2017)

This is the basic layout I am basing my design on. I may go with two wheels at the top so that the overall height is less.  With one idler up top the upper idler ends up at the very top of the flat plate that is welded to the channel section. With two idlers I should be able cut off the flat section and just use the channel. This will reduce the weight and improve rigidity.

http://www.grizzly.com/products/Knife-Belt-Sander-Buffer/G1015


----------



## rayjay (Aug 13, 2017)

My motor is 1725 rpm but only 1/2 hp.


----------



## Anvil Head (Aug 14, 2017)

My bad, when you said angle grinder, I was envisioning a handheld side grinder. Still you are going to be a good bit "underpowered" with a 1/2. Once you put pressure on the belt things load up fast. You will probably not be able to hog any big pieces down efficiently. Looks like you might be able to upgrade later to a bigger motor.
I do suspect the existing mount will have some vibration issues, hopefully minor, that might make you finishing grinds a little rough. You'll have to learn to dance around that.


----------



## northgeorgiasportsman (Aug 14, 2017)

If you're one a budget, get you one of these for your motor.

https://www.harborfreight.com/1-hp-agricultural-farm-duty-motor-68288.html


----------



## rayjay (Aug 14, 2017)

I dug around and found a 6" steel or cast iron caster wheel. I was worried about the SFPM so I found a calculator and came up with 2709. Then I surfed around for appropriate numbers for aluminum and it turns out I am right in the ball park. My main use for the moment will be trimming down alum buttplates to the scribed line. My 12" disc sander does OK on some shapes but not others and it's definitely overkill.

When I was out picking up the hole saw I also bought a pack of 1x42 belts. I may make this thing accept both. The small belt could probably get by with only one upper idler but I think the 2x72 will need two idlers to shorten the overall height or else the thing may no go out the garage door !!


----------



## rayjay (Aug 14, 2017)

Pics are being rotated. hmm


----------



## rayjay (Aug 14, 2017)

I guess it's the aspect ratio. You will just have to twist your neck 

If I decide to make it dual belt compatible I will have to make 2 platens and maybe 2 work surfaces. 

I have a whole 'nother section of that frame rail so I could easily cut and splice it but I think 2 upper idlers will work better. This motor has a switch that allows it to run either direction so that could be interesting for working on the other side of the machine.


----------



## rayjay (Aug 15, 2017)

Today I drilled the 4 holes in the upright so I can bolt it to the front bell of the motor. I also order a nylon drive wheel and a couple of tracking wheels from oregonblademaker on ebay. The drive wheel is only 5" OD so I loose about 450 sfpm down to about 2300. The caster wheel I have is just too heavy. There is no keyway on the motor shaft so it's just a friction fit and a tight nut .  The nylon tracking wheels are only $15 ea which is probably just as cheap as skateboard wheels and these tracking wheels will have much larger bearings.


----------



## tsharp (Aug 16, 2017)

rayjay coming along nicely.


----------



## rayjay (Aug 19, 2017)

So my wheels came in yesterday and last night I went to Lowes and bought two each 4", 5" and 6"  1/2" bolts. I went to HD first but their long bolts were fully threaded and my inner engineer finds that totally unacceptable. Lowes carries bolts with appropriate lengths of unthreaded shank so the bearings on the idlers are properly supported.

Speaking of bearings, these nylon wheels don't have crush sleeves between the bearings and that inner engineer guy can't accept that either. Lowes had some 1/2" id sleeves that just needed shortening by .030" to work perfect and allow for proper tightening of the bolts and nuts instead of funky extra nuts/ double nutting/ plastic washers or other jury rigged setups.

This morning I got out early while it was cool and made an arbor for the drive wheel so I could narrow up the hub by about .350" so that I would have more threads showing. I need to find a nice nylock 5/8x18 flanged nut instead of the 1/2 height jam nut I currently have. While the lathe was nasty I turned off the .030" off the crush sleeves and put the idler wheels back together.

In the JD junk pile was a U shaped piece that already had holes in the right places including a 1/2" hole for the fixed idler so I bolted it onto the upright and figured out how much spacer I needed to line it up with the drive wheel. 

After much cogitating I came up with a functional and fairly simple design for the tensioner / tracking wheel. I already knew I was going to use a heavy duty hinge I had on hand for the tracking adjustment. I had some 1/2" thick x 2" wide alum stock and drilled the back end to accept a 7/16" bolt for the pivot. There was an existing hole already on the upright that just needed a bit of work with a mechanic's reamer to be a tight fit on the shank of the bolt I dug up. With the alum stock bolted to the upright I was ready for the first trial assy.

I bolted together the front idler onto the newly drilled 1/2" hole in the hinge and used a C-clamp to temporarily fit the hinge to the alum stock. I fitted up the belt and used a piece of round stock to prop the tensioner assy up so the at the belt was snug. I stuck some weak springs in between the hinge and alum stock to keep some tension on the front wheel.

With a bit of fiddling with wheel alignment I was able to get the belt to stay on while turning the drive wheel by hand so I said what the heck and turned on the motor. It worked !!! I was able to make the belt move back and forth in tiny increments by varying pressure on the tracking hinge with my thumb. 

I already have a good idea on how I am going to do the platen and the work surface. I have some 1/2" thick x 4" wide aluminum that I will attach to the upright and use this to bolt the other parts to.

So here is a question. How much , if any , does the back of the belt rub against the platen. Just a tiny bit I would think. In the current mock up the upper wheel is just a bit behind the lower wheel so the belt is leaned back to the right about 1/2" at the top. I think this might work good if the belt is supposed to be rubbing the platen when no work is being done.


----------



## rayjay (Aug 23, 2017)

Did some work on the platen and work surface mounting arrangement. I need a finer belt than 240. MSC will sell me one 320 but to get a 400 grit I have to buy 10 = $27 + shipping.


----------



## rayjay (Aug 23, 2017)

I still need to make the actual platen and finish up all the d&t work.


----------



## Anvil Head (Aug 24, 2017)

Pop's Knife Supply - better selection, better quality, better prices since you don't have to buy bulk. He has all ranges of several different mfgr. brands.


----------



## rayjay (Aug 26, 2017)

The upper half is basically done. Just need to detail some of the parts and do some work on the mounting of the rear wheel. I have all the parts for the platen, platen mounting bracket and the work surface. Just need time and energy .

I had a chuckle when working out the tensioner spring. There just happened to be a perfectly located notch to accept the fixed end of the spring .


----------



## rayjay (Aug 29, 2017)

Work table mounting. I think I will leave to the very last the drilling of the hole to bolt that piece of angle iron to the alum plate. I will probably slot the hole so there is some adjustment available. The work table can be rotated around it's single mounting point to align it with the platen.


----------



## StriperrHunterr (Jan 4, 2018)

Anvil Head said:


> My bad, when you said angle grinder, I was envisioning a handheld side grinder. Still you are going to be a good bit "underpowered" with a 1/2. Once you put pressure on the belt things load up fast. You will probably not be able to hog any big pieces down efficiently. Looks like you might be able to upgrade later to a bigger motor.
> I do suspect the existing mount will have some vibration issues, hopefully minor, that might make you finishing grinds a little rough. You'll have to learn to dance around that.



Would the underpowered motor, thus longer grinding time, have a play in ruining heat treats/tempers (excuse me if I'm not using the right term), on already treated blades being that it would be exposed to the heat for longer? 

Or at the very least cause you to really slow down your grinding so as to not overexpose it?


----------



## Anvil Head (Jan 4, 2018)

Although speed control is an important "player" in the grinding game, it is secondary to quality abrasives and paying attention to heat build up. Always use good sharp belts when grinding after heattreat. This reduces the "time" factor and will give you a cleaner finish with reduced pressure against the belt. Most of us have learned to grind barehanded so we can be more sensitive to friction generated heat. We also keep a slack bucket in close proximity to the grinding operation, usually right under the wheel or platen. Allows for a quick cooling dip if things get warm. Simply put if the blade is getting too hot to hold then it is getting to hot.
These things are "practiced-learned", more you do the better you get. 
Speed will get you there faster but also allows you to make mistakes faster. You will have to find that "just right" speed for you and your grinder.
One rule of thumb that will save you some grief, always get all the scratch marks from the previous grit out before moving to the next finer grit. Trying to get the scratches from two grits back with a finer grit is just asking for trouble with overheating the blade.
Hope this is helpful.
Also sending you a pm about a reasonably local maker that can show you a few things about grinding.


----------



## StriperrHunterr (Jan 4, 2018)

Anvil Head said:


> Although speed control is an important "player" in the grinding game, it is secondary to quality abrasives and paying attention to heat build up. Always use good sharp belts when grinding after heattreat. This reduces the "time" factor and will give you a cleaner finish with reduced pressure against the belt. Most of us have learned to grind barehanded so we can be more sensitive to friction generated heat. We also keep a slack bucket in close proximity to the grinding operation, usually right under the wheel or platen. Allows for a quick cooling dip if things get warm. Simply put if the blade is getting too hot to hold then it is getting to hot.
> These things are "practiced-learned", more you do the better you get.
> Speed will get you there faster but also allows you to make mistakes faster. You will have to find that "just right" speed for you and your grinder.
> One rule of thumb that will save you some grief, always get all the scratch marks from the previous grit out before moving to the next finer grit. Trying to get the scratches from two grits back with a finer grit is just asking for trouble with overheating the blade.
> ...



Thanks for the info and the leads. I'm counting down to trackrock and being able to use the gift cert my wife got me for my birthday with Goat n' Hammer.


----------



## rayjay (Feb 23, 2018)

Here is a belated update. I've used the grinder a good bit. Had to upgrade to a much stiffer spring right off the bat. I had a base from a dead grille that I had been saving with this project in mind and I finally got around to putting it all together. Works out great as I have a perfect small spot against the wall that it will go in right at the garage door. I always roll it outside to save making a mess in the shop.

I used it to sharpen our steak knives about an hour ago. Also deburr parts when fabbing stuff .  All in all I am very happy with it.


----------



## rayjay (Feb 23, 2018)

Well, for some reason the pics are side ways......


----------



## rayjay (Feb 23, 2018)

More pics.


----------



## WayneB (Feb 23, 2018)

I wonder if a piece of delrin or similar plastic behind the belt would be beneficial? Looks to me like pressure against the belt will abrade the backing and part the belt.

I love me some home enginerded tools.


----------



## rayjay (Feb 23, 2018)

I don't know. I am a bit concerned but I think that's sop for the platen to be bare steel. Somebody correct me if I am wrong. I will never do any hogging on this machine. Just deburring, polishing and knife sharpening.


----------



## Anvil Head (Feb 24, 2018)

Steel platen is what is most common and supplied by most mfgrs. However, they do wear and round off from extended use, so most knifemakers install a tempered slab of glass or ceramic to slow the wear down considerably. Trick is to get alignment right on the platen so that the belt rides smooth and flat across/along it's length and width. Good belts will wear just fine when using a platen, just avoid those with lapped joints as they bump and can mess up your work.


----------



## rayjay (Feb 24, 2018)

You can see some of the lapped joints in the pics. They definitely go bump bump bump .


----------



## Dr. Strangelove (Feb 24, 2018)

Great job! Looks like a giant Worksharp!


----------



## Artfuldodger (Feb 24, 2018)

I made one when I was getting into knife making. I only made a couple of knives and developed other interests. I had a perfect blade shaped and melted the tip off in the furnace. Oh well, maybe one day I might give it another try. Doing the handles was fun.

Yours in the OP looks better than mine. I didn't have a platen on mine, I just shaped things between the wheels. I wanted one with the contact wheel such as a KMG made by Beaumont Metal Works. 

I looked at different designs of the homemade variety. Mine used a hinge as well for tracking. I used some stainless steel rollers that I found. They were about 2" x 2". The bearings would get pretty hot. It was good for light shaping and sharpening.
It kinda looked like the No Weld Grinder/Sander;

http://usaknifemaker.com/plans-for-the-no-weld-grinder-sander-nearly-50-pages.html

It would be nice have one where you could have a platen attachment that could be removed and replace with a 6" contact wheel.
I wonder what is the most common contact wheel size is?
Maybe the makers use two or three different wheel sizes.

Mine did not have a work rest either. Mine didn't use a standard 72" belt. At the time I had some other sanding options on a Shopsmith that I had. I was trying to clean my shop out to work on some old cars and got rid of some woodworking tools. 

I've never been able to get my shop cleaned out though. It just keeps filling up with junk. Here is a shop I remember looking at back when I was looking at grinder options;

http://www.burgessknives.com/8201/index.html

I got a lot of good advice from makers on this forum.

Yep Ray yours should serve you well.


----------



## Artfuldodger (Feb 24, 2018)

Isn't there a guy in Georgia that sells grinder belts? What are some good sources for belts that don't have lapped joints?


----------



## Anvil Head (Feb 25, 2018)

Pop's Knife Supplies in Washington 
There are also a lot of other suppliers around, but Pop (James Poplin) will treat you right. He's also an exceptional knifemaker and can give you solid advice on what belt works best for any application.
Do need to get away from the lap joints if you plan to do any finesse work.....they'll make you nuts.

Most mfgr grinders come standard with 8" contact wheels, but you always wind up wanting a 10" or larger and small ones for doing radius work. (Wants never end!)


----------

