2x72 Tilt Grinder Project (pics)

[HallHandmade]

I assume your 10" contact wheel is the one from Grizzly. Let us know how it works out once you add the bearings. I am in the midst of my own grinder build (not nearly as nice- based on the No Weld Grinder), and while I expect to do most of my work on the platen, for about $80 and a little work, I may want to try the same.

Yeah, I'm trying to make this grinder on a budget which is ballooning day by day. The boss just shakes her head and scowls at me now when she walks through the garage on her days off. I hope the pink and black G10 camping knife I plan to make for her will smooth things over. Luckily I bagged a good one, she loves guns and knives

Anyways, sorry for the little segway... I was going to bore the wheel out on the lathe, but as soon as I started to set it up I decided to hold off. I didn't like the degree of precision I was getting on that chuck, and I didn't have a four-jaw big enough (a four-jaw is a chuck with four separately movable jaws to allow odd or misshapen parts to be centered and held without need for shims or special fixtures).

I decided to abort, and come back another day to do it on the CNC mill. I'm gonna mount it flat to the bed and use the probe to center the bore, plus it's a lot easier to shim than lathe chuck jaws, if the mill is out of tram at all (head tilt). I feel I'll be happier with the results, plus it's cake to dial in the bearing seat diameter. If I had some real guts, I'd machine some holes in the solid hub to lighten it a little, but I'm 100% chicken when it comes to balancing. I don't want to have to mess with it if I throw it off.


Once more, I'm much farther behind than I'd hoped, but I figured I'd post what I had done anyways, just to keep things interesting.

As promised, I took a couple pics of the idler wheel turning process. This isn't a superior method, it requires a lot of attention and fiddling if you don't have the right machine and/or fixture. In this case, I would have greatly preferred having at least machined some soft jaws, but I didn't have the jaws or the time. I watched the video on Beaumont's site, and that's the "right" way to do it, as opposed to my "barely good enough" way. Things like this really need the proper fixture to get a superb result every time, and not require tweaking at the end.

First, I face off the billet on the "big" lathe at my old work.

Next, I pre-drill the 3/4" clearance bore for the shaft, this was skimmed to size after the bearing seats and counterbore were machined. It allows me to double check my center from the other end once I flip the part. I thought I got a picture of the boring bar setup, but it didn't come through for some reason. Just imagine a long round black metal bar w/flat, using the same triangular insert and tool holder as in picture one.

After this, I bored the counterbore (for grabbing the wheel from the inside when flipped and when cutting the crown), as well as the bearing seat. Then the wheel was flipped and grabbed from the inside of the counterbore. This was one of the fiddly parts I was talking about. It would have been much easier to get the flipside centered if I'd had some soft jaws for the chuck or on an expanding collet. I had to do some shimming and fiddling to get it within reason.

I decided once I got home that I wasn't quite happy with the result, so I set it up on my small lathe to dial in. I chucked up and centered a stub of the bearing shaft, then placed one of the bearings over the stub (the bearings were already press fitted into the seats). Then I used the dead center to hold the other bearing and slightly load it. The wheel is then driven by the nose of the chuck jaws but centered on the bearings themselves. After re-turning the crown, it runs impressively true. That little machine has surprised me more than once.

The finished product. According to my measurements, it's true to within .001", which is as good as I'd hoped for. I already ordered the drive wheel though, for just over $60 shipped it just isn't worth the trouble I went through on this one, plus that bore is best done with a reamer, and I don't feel like scraping the keyway since I don't have a keyseat broach and arbor.

I also got the stand painted, and the wheels mounted. I did a mockup with one of the side panels to give an idea of how everything sits.

When tilted:

 

[PT Doc]

Sweet.

 

[AVigil]

That looks great. You might find though when you really put pressure while grinding it might move with those small wheels. I use to put my wheels in the groove between the garage floor and the driveway to keep it from moving.

Then I just got rid of the wheels altogether.

 

[12345678910]

That looks great. You might find though when you really put pressure while grinding it might move with those small wheels. I use to put my wheels in the groove between the garage floor and the driveway to keep it from moving.

Then I just got rid of the wheels altogether.

You could put a couple or three toggle clamps push pull on the base to put it up off the wheels.

 

[HallHandmade]

That looks great. You might find though when you really put pressure while grinding it might move with those small wheels. I use to put my wheels in the groove between the garage floor and the driveway to keep it from moving.

Then I just got rid of the wheels altogether.

I'm hoping my overbuilding of the stand might buy me a little stability. I already had the wheels; I got a whole box of them for free and slapped them on everything in my shop. I'm pretty space limited, and wheels are the only way I can pull it off.

They've worked nicely for my grinder and buffer, my 6x48+9 sander, band saw, and table saw, but I'm not sure if I'll be so lucky on this one. On my grinders I have to stand on a leg if I really need it still. I was worried about the need to push toward the back on this 2x72 machine. The good thing is that they do lock reasonably well for cheap crappy casters, so as long as I'm not pushing hard enough to tip, I might squeak by (probably not though).

You could put a couple or three toggle clamps push pull on the base to put it up off the wheels.

That's a good idea... I've used those plunger style clamps for fixturing before but didn't think about using them for lifts.

They make some really neat stomp style lift stops that have a spring loaded plunger with rubber foot, but they're $$$$. Once upon a time I thought about trying to design a smaller, lower cost version for small shop guys such as myself.

I suppose I could pull the booties on those toggle clamps and weld on some small plates with a toe hook, and they'd probably work great without having to bend down.

 

[zippin44]

I was curious how did you do that hinge? Was it a purchased item that you welded on the rectangular tube? Where did you get it?

 

[Atlas Knife Company]

I hate to say this, but it looks horribly out of balance. When vertical, the platen, wheels, and belt are trying to offset the motor and shelf. When horizontal, it looks like 100% of the grinder is to the left side of the hinge. You'll have a heck of a time getting the grinder back to vertical, not to mention the likelihood of falling over. You're going to need a rather hefty lock to keep this design vertical.

The best horizontal/vertical tilt grinders I've seen have had the motor partially over the hinge for balance. On this grinder, you can see the mounting holes that didn't work. Half an inch to the left and the grinder wanted to tilt on it's own. I love the simplicity of this grinder. Very little wasted metal, no giant curved pieces just to make it look pretty, and it was rock solid when tilted. Most of all, it's welded. Why on earth would you want to drill and tap dozens of holes instead of welding?

 

[JamesBrauer]

a budget which is ballooning day by day

I feel ya on that one. Even sourcing scrap and spares for the main frame, my numbers keep adding up. But you are making what looks like a fine machine.

And you are a brave soul turning that idler pulley, I couldn't do it . I have a little CNC mill, and a HF 3-in1 lathe-mill, but I just didn't think I could pull off the precision. I could likely get the crown, center drill, and recess for the bearing. But when it came time to flip it around, and re-chuck for the opposite side, I just didn't see it ending well for a piece of expensive stock.

I see what you mean about a "tilt grinder" now. Wonder if a strategic counterweight would help the balance. When I made a base for mine, I rolled the finished machine over a piece of round stock to find where it balanced, then located the legs equidistant from the center of mass.

- James B

 

[HallHandmade]

I was curious how did you do that hinge? Was it a purchased item that you welded on the rectangular tube? Where did you get it?

The hinge came from McMaster-Carr. That particular hinge is raw steel, with 1/8" thick leaves and 1/4" pin. It came blank, and I drilled out both leaves to match the hole pattern on the grinder stand, and on the grinder body. It was only $6, one of the few items that came in under budget on this build.

I hate to say this, but it looks horribly out of balance. When vertical, the platen, wheels, and belt are trying to offset the motor and shelf. When horizontal, it looks like 100% of the grinder is to the left side of the hinge. You'll have a heck of a time getting the grinder back to vertical, not to mention the likelihood of falling over. You're going to need a rather hefty lock to keep this design vertical.

The best horizontal/vertical tilt grinders I've seen have had the motor partially over the hinge for balance. On this grinder, you can see the mounting holes that didn't work. Half an inch to the left and the grinder wanted to tilt on it's own. I love the simplicity of this grinder. Very little wasted metal, no giant curved pieces just to make it look pretty, and it was rock solid when tilted. Most of all, it's welded. Why on earth would you want to drill and tap dozens of holes instead of welding?

The design you posted is a good simple design.

I was working under a list of constraints. I wanted the grinder to be easily mountable on any bench or stand, which had bearing on the way I designed the bottom section of the frame and the floating motor mount. The lower crosspiece (.75"x1.5" steel bar) can easily be attached to a table with two lag or machine screws, and then the grinder attached to it, for a very clean (and easy to clean around) look. I plan to mount it on a tilt-through fixed bench, with the motor mounted underneath its current position, when I have a real shop. It will be nearly perfectly balanced in its final configuration. For now, I just need it on wheels, even if it's a pain at times. It's also why I designed the motor mount to be removable, because it may eventually get trash-canned for the under-table mount.

Many of the popular production grinders use at least a combination of bolt through construction and welding, but many are essentially no-weld. I'm not saying that is the right or wrong way to do it, it's just a way. In my case, I wanted to be able to make changes if necessary, and re-use parts. I'm a professional welder. I really enjoy welding and it has been a large part of my career, and I like to use it whenever possible as opposed to machining operations/bolted assemblies. That said, welding is a fickle, fickle beast. Even when you know what you're doing, stuff moves around, if not slipping in the fixture as it expands, from warping in the heat affected zone.

If I were to manufacture a grinder, then I would probably be using much more welding in the design, but it also would be a significantly simplified design with more custom made parts, and by design, less overall flexibility to change.

A piece of info that is missing is that the latches I've selected are load rated, and also made to automatically snap in place once the grinder is lifted into position. They're spring loaded and will apply active tensioning force to the joint when the grinder is vertical. When horizontal, the grinder will rest on a simple rubber stop. I may make a handlebar to allow easier lifting, but I don't think it will be excessively difficult to switch positions. I have already selected an air spring to assist/dampen the up and down motion if necessary. Since I plan on using a pneumatic tensioner anyways, and the grinder will have full time air, I may actually fully automate the tilt mechanism, I have some large long stroke air cylinders here on the shelf that would be perfect. I don't know exactly how much more work I will put into it before I am able to mount it on a true stand though.

As far as wasted metal goes, the small sacrifice for improved aesthetics was well worth it for me, plus a bit of extra mass isn't even a bad thing in this case. I enjoy a fine looking shop. If you see the side panels and parts in person, there is very little room to cut anything but the smallest scraps from the design. I struck a balance between design economy, performance, and aesthetics.

I feel ya on that one. Even sourcing scrap and spares for the main frame, my numbers keep adding up. But you are making what looks like a fine machine.

And you are a brave soul turning that idler pulley, I couldn't do it . I have a little CNC mill, and a HF 3-in1 lathe-mill, but I just didn't think I could pull off the precision. I could likely get the crown, center drill, and recess for the bearing. But when it came time to flip it around, and re-chuck for the opposite side, I just didn't see it ending well for a piece of expensive stock.

I see what you mean about a "tilt grinder" now. Wonder if a strategic counterweight would help the balance. When I made a base for mine, I rolled the finished machine over a piece of round stock to find where it balanced, then located the legs equidistant from the center of mass.

- James B

I got most of my steel from the remnant pile at the steel yard, one piece came from the dumpster pile at my old work, and a couple from my pile. Scouring for parts is almost enjoyable, but more as a sport, and not when because of a forced budget.

The idler pulley was an ordeal, but "luckily" I got to learn on well worn and very grumpy machines, so I can usually squeeze decent quality work out of fussy equipment. I had a couple moments where I almost went paperweight status on it, but luckily I managed to pull it off decently. Finally deciding to swallow my pride and just order the drive wheel was a huge relief.

You're also quite right... the flipping is where it hits the fan, so to speak.

 

[BallewBlade]

Looking good so far!:thumbup:

 

[Jeremy Barnard]

Looks like you're doing a great job. Nice thread.

 

[co556guy]

I'm interested in seeing where this goes.

 

[Willie71]

I will be working on my grinder this week. To keep the cost and time down initially, I am using longboard wheels as idler wheels. I will upgrade as needed and when resources permit. I didn't think of this, but saw it posted in another thread 6 months ago.

 

[lunar4772]

Vintagefan I have used the same 10" grizzly wheel on my kmg clone build and it has worked very well. It runs nice and true and seems to hold up well. I have not ground many blades with it yet just a couple. So far I am quite pleased with it. I am working on a small wheel attachment and rest assy for it to really take advantage of the horizontal feature. ( profiling etc) I used 2 fire door hinges on mine and a dc motor with a variable transformer for speed control.
Frank

 

[HallHandmade]

I will be working on my grinder this week. To keep the cost and time down initially, I am using longboard wheels as idler wheels. I will upgrade as needed and when resources permit. I didn't think of this, but saw it posted in another thread 6 months ago.

That actually would work quite well. They're definitely suited to dealing with heat and abrasion, and the bearings are usually fairly decent.

Vintagefan I have used the same 10" grizzly wheel on my kmg clone build and it has worked very well. It runs nice and true and seems to hold up well. I have not ground many blades with it yet just a couple. So far I am quite pleased with it. I am working on a small wheel attachment and rest assy for it to really take advantage of the horizontal feature. ( profiling etc) I used 2 fire door hinges on mine and a dc motor with a variable transformer for speed control.
Frank

I'm really happy with mine, I can't believe how true it runs actually. I was really afraid after all of the people saying they had balance issues, but perhaps they just underestimated the amount of care and precision required to properly center on a bore? I'm not trying to implicate anyone, or say that there aren't duds out there, but even as a fairly veteran machinist, it's still an operation that gets my nerves going.




Been a few days, been busy on the grinder and other projects. I just finished working on the grinder for tonight, was gonna try and pull an all nighter getting it done, but then decided to be more intelligent and get some rest.

Setting up the 10" contact wheel on the CNC, using my precious, the 3D dial indicator. This thing is awesome for prototyping. Many of the same advantages as an automatic probe, but much easier for quick one-off jobs and especially modifications/ rework. I was able to quickly and easily verify the original bore dimensions and location as well as properly locate the part for the program to run.

Milling out the bearing seat and relief using a 3/8" HSS endmill.

The finished product. The wheel runs even truer than I hoped for. It will work very nicely for a budget rubber contact wheel, I'm happy I took a chance on it.

I used a fly cutter to shave down the 1.75" steel bar I got to 1.515" for the arm sockets. Eventually I realized I was wasting too much time (the small mill just can't take meaningful cuts with a fly cutter), so I switched to a really nice 1/2" TiN coated cobalt steel roughing end mill I had been saving for a while.

In this picture I'm skimming down the other side of the already completed tension/alignment arm socket crosspieces, I originally went with 1.525" for the contact arm socket width, but ended up tightening it up to 1.515".

Here I'm "hogging" (for my machine at least) about .25" off the tooling arm socket crosspieces. The roughing mill ended up being WAY faster than the fly cutter for this task.

Drilling out the bottom crosspiece, which is backing for the hinge bolts and may double as a rigid table mount if I build a dedicated horizontal grinder.

I also swooped a really nice machine switch from pop's stash, along with a metal box and plate. I milled a little square opening out of the cover plate to let me flush mount the switch. I sprayed it black satin to match the motor and motor mount. You can see the finished product in the last photo.

Here's the current state of the grinder. It actually is extremely stable, even with the smaller stand and cheaper casters. I can't even really budge it when pushing on the contact wheel, it just sits dead still. I tested the drivetrain and it runs smooth and quiet, even with the cheapo pulleys. The tilt works fine, but will definitely get a redesign if I keep the stand. It's safe and manageable, but heavy. I would have built a more balanced mechanism to start, but I was all over the place with my ideas when I started this build, and I was trying to cover all of my bases, which probably diluted the final product a bit more than I'm comfortable with.

To be honest, I like the stand setup so much, that I may scrap the table idea and just redesign an integral tilt mechanism with a new motor bracket. The only reason I was eventually planning on the table was solidity, but this stand is significantly more solid than I expected.

This shows the other side, with the newly mounted switch box and power cord. I stuck the work rest on with a magnet just to show how it will look. I have a little handle I'm going to use for it so it can be easily adjusted for height and angle. I made the rest out of a chunk of an old bed frame. It worked out quite nicely, it even has a couple slots in the front to mount stops or a soft rest. I'm also very happy with the switch, not bad for a random parts bin find.

Tomorrow I will be finishing the idler/alignment wheel mount, and the work rest mount. That's pretty much it and I'm ready to run. Then comes the parade of attachments.

 

[PT Doc]

very nice work.

 

[NickWheeler]

VERY COOL thread... I love your attention to detail! :thumbup:

The adjustable height idler wheel is a really interesting idea. It's certainly something I hadn't thought of before.

***Why not weld it???***--- I couldn't have worded a better response than what you posted about welding this versus bolting. Very well said! I 100% agree with what you posted.

The stand does look to be on the light side, but without actually using the machine I sure don't know that. It's obvious you have spent a lot of time in front of an array of fab equipment, so when you say the stand is solid, I'm a lot more likely to believe that it is.

I would recommend you replace the plastic "star" knobs with ratcheting handle bolts (I have 3/8-16 units on stuff all over my shop). I just love how much you can torque them down and then move the handle out of the way.

That tool rest giz-wizz you found is awfully light... the work surface on most of my tool rests are made from 3/8" plate. That should get you started though, so you can figure out what works for you. I highly recommend you notch it out a bit though, so that it actually straddles the contact wheel & platen. I don't have a tool rest that has less than a 3/8 deep notch, and a couple of them are over an inch deep.

I'm not meaning to come off critical of your build! This is an excellent thread! You have a very clear presentation with great photos, all while building a quality tool. I'm just pointing out a couple things that jump out at me from grinding on these things for the last 17 years.... from one stickler for details, to another.

Awesome work!

 

[HallHandmade]

very nice work.

Thank you very much. Everyone's comments are helping me greatly with motivation.

VERY COOL thread... I love your attention to detail! :thumbup:

The adjustable height idler wheel is a really interesting idea. It's certainly something I hadn't thought of before.

I actually was thinking of a way to be able to change the idler mechanism easily if I didn't like how it behaved, and it grew from that. Once I had it drawn in, I realized that it also added a lot of flexibility. You can swap the idler arm with the tooling or work rest arms, and come up with all kinds of funky upright or quasi-upright designs, so I'm not limited to "plain ol' KMG" horizontal form factor.

I think I need another round of design work though, this is the kind of thing I'll usually hit on the head on pass two or pass three. I'm already thinking about completely redesigning certain parts of it, but I have to be careful or else the boss will kick me out of bed for a week. I just finished this thing and managed to keep her happy the whole way, so I have to be very careful now

***Why not weld it???***--- I couldn't have worded a better response than what you posted about welding this versus bolting. Very well said! I 100% agree with what you posted.

Love/Hate is the very definition of my relationship with welding. I probably love it a bit more than I hate it, but darn is it irritating sometimes.

The stand does look to be on the light side, but without actually using the machine I sure don't know that. It's obvious you have spent a lot of time in front of an array of fab equipment, so when you say the stand is solid, I'm a lot more likely to believe that it is.

It might be a bit hard to tell its actual size, I was just looking at the pics and it does look really top-heavy. It's not so bad in person. I think my camera has a slight fisheye thing going on. To be honest, even though I can see it in person, I'm as surprised as anyone that it is so solid.

Just so you have some reference measurements, the lower crosspiece is made out of 5" wide x 1/2" thick flat bar. It looks really flimsy in the photo but it's actually a pretty big beefy piece of steel. Everything on the stand is either heavy wall or medium wall tubing. The upright tube and socket are hitch/receiver tubing, which is 1/4" wall and 2"/2.5"sq respectively. I'd say the total footprint of the stand is around 2'x2'. It's a lot heavier than it looks in the photos for sure. I'm a decent sized guy, and I had a bit of trouble moving it before wheels.

I would recommend you replace the plastic "star" knobs with ratcheting handle bolts (I have 3/8-16 units on stuff all over my shop). I just love how much you can torque them down and then move the handle out of the way.

That tool rest giz-wizz you found is awfully light... the work surface on most of my tool rests are made from 3/8" plate. That should get you started though, so you can figure out what works for you. I highly recommend you notch it out a bit though, so that it actually straddles the contact wheel & platen. I don't have a tool rest that has less than a 3/8 deep notch, and a couple of them are over an inch deep.

Haha, I knew I should have gone with those, now you're going to get me all self conscious of my little plastic knobs. I'm a 3/8"-16 man myself.

The tool rest is definitely on the light side, it reminds me of one of those cheap import bench grinders. It's actually 1/8" plate though, must have been a pretty nice bedframe back in the day. I think I might make a similar part but with some 3/8" or 1/2" x 4" angle. I was going to notch this guy also, I saw a lot of grinders like that, but I wasn't really sure if I should. I'll take your advice on that one.

I'm not meaning to come off critical of your build! This is an excellent thread! You have a very clear presentation with great photos, all while building a quality tool. I'm just pointing out a couple things that jump out at me from grinding on these things for the last 17 years.... from one stickler for details, to another.

Awesome work!

Thanks!

I love any criticism that people are willing to give. I thrive from it, it gives me new ideas and viewpoints of my own ideas. I appreciate you taking the time to reply with your observations.

 

[Drew Riley]

I love grinder build threads.....

 

[HallHandmade]

The very last part I had to make was the spacer for the alignment wheel, here I am drilling out a scrap of the 5/8" shaft to make the spacer.

Parting off with a 3/32" parting blade.

My big project this weekend was the alignment mechanism, I had all these different ideas, but finally decided to just freehand it and get it done. Too much think, not enough work.

I got all fancy and squared the head of an 18-8 carriage bolt that I found, then paired it with a locknut. Not quite the bling factor of shoulder screws and oilite bearings, but still passable.

It does pretty well with 3/8"-16 for the adjustment screw. Eventually I'd like to go to a finer thread, but this is more than sufficient. It would only be for fine tuning really.

I also finished the work rest. I made a 1" diameter steel standoff with reliefs on both ends, so it sits dead flat, and then paired it with a 3/8" carriage bolt and heavy washer. When everything is cranked down, this rest is actually very sturdy. It doesn't ring/vibrate hardly at all, even when hogging on the highest belt speed.

I can't seem to get a shot that captures the true form factor of the grinder, every picture makes it look really top heavy. Maybe later once the sun is down I can shoot from farther away in my garage and at a lower angle.

Either way, this thing is a wrap, besides some fine tuning here and there. I still plan on making a flat platen attachment, so that will probably be my next project. I've run the machine on all the speeds with heavy belts, light belts, and scotch-brite belts, and it is dead stable. The belt doesn't walk or slip/stall at all once it's set, even when I really lay into it. One of the two trash pulleys is not bored true, so this thing will literally whisper once I have real cast iron pulleys on it.