[deker]

So, I took the plunge over the weekend and started in on my homebrew KMG clone. As promised I'm trying to document everything to share with folks.

A little background on me first...I'm a computer geek by trade...never even took shop class in school. I am starting as a blacksmith/bladesmith and decided that until I have my new workshop up (around spring) I'd work on smaller stuff that will go into the shop. I could have bought a KMG and been working on knives, but some silly voice in my head told me that I could save money and learn stuff by building one...so here we go...

I'll try my best to break this down into the steps I'm taking (mistakes included!) so that people can see what I'm doing and NOT do some of the stuff I've done if they decide to do something like this themselves. Oh, and I decided to see if I could do it without a welder because....well, my welding isn't so good, and my little wire welder won't weld this big stuff anyways...it's all drill & tap...


1) Study pictures of the KMG and try to guess at the sizes of everything.


For me, this yielded the following list:

- 1 - 12" x 18" x 1/2" plate (for the base)
- 2 - 1/2" x 3" x 12" flat bar (for the top and bottom of the tooling arm box)
- 2 - 3/4" x 1-1/2" x 12" flat bar (for the sides of the tooling arm box. More on this later...)
- 1 - 1-1/2" x 20" solid square bar (the tooling arm. I used Rob's advertised measurements for this to determine much of the size of the rest of the pieces)
- 1 - 6" x 6" x 1" plate (for the front vertical support)
- 1 - 6" x 8" x 1" plate (for the rear vertical support)
- 2 - 5" x 5" x 1" plates (for the drive shaft supports)
- 2 - 2" x 1" x 6" flat bar (for the idler pulley support setup)
- 1 - 2" x 1/2" x 10 flat bar (to support the work table)
- 1 - 6" x 6" x 1/2" plate (for the work table)





2) Buy lots of tools and stuff you don't already have

I needed a bunch of stuff I didn't have. Thankfully my wife got me a drill press for Christmas, so I was set there, but a trip to the local Fastenal was needed to secure a bunch of stuff.

- 1 box 3/8-16 1-1/2" countersunk socket drive screws
- 1 box 3/8-16 2" countersunk socket drive screws
- 1 countersink to match the screws (forget the dimensions)
- 2 3/8-16 taps (I figured I'd break one somehow )
- 2 3/8-16 bottom taps (same reason...)
- 1 can of Dykem layout fluid
- 1 can Rapid Tap cutting fluid
- 2 5/16" HSS drill bits
- 1 Tap wrench (OK..this was from Sears. Fastenal was out of them.)




More in following posts.....

This post has been edited by deker: 01 April 2010 - 07:47 PM

[Mike Routen]

Deker,

I'm really interested in this thread, as I am about to embark on a similar journey. I was thinking of going with the welding route since I'm not experienced at all in layout and machining. However, if your descriptions are good enough, I might just give this a go too!

Thanks in advance for all of the work it takes to put something like this together, and for being open enough to let us watch the process!

- Mike

[deker]

3) Decide on a plan and start building!

Everything should have a PLAN right?
I decided to do the tooling arm box bit first as it's the majority of the work and kind of sets the dimensions and placement of everything else. After that the vertical supports for the tooling arm setup, then the motor mounts, then idler setup, then mount to the base. Once the structure is built we get to the fun part of pulleys, etc. That will be a fun section as one of the guys from my blacksmith giuld has invited me to his shop to cast some pulleys from aluminum and them clean them up, crown them ,etc on his lathe...Hey, I said I was building this thing right?!

I have some drawings done to scale (forgot to get pics. I'll try and get them later) so I had an idea of how I wanted things laid out. All that was left to do was figure out exact positioning of holes and start drilling.

4) Layout the Top & Bottom of the tooling arm box

I slightly polished up the surface of the top plate and sprayed it with DyKem. Then using my trusty machinists square I scribed lines for everything and used a punch to set my hole positions. I set the holes 3/8" from the edge with the end holes 1/2" from the ends and the two middle being 4" from the ends.

.


5) Cut the top plate holes

Always remember to clamp your work piece to the table boys and girls!



6) Layout the sides of the tooling arm box to match the top holes



7) Drill the top holes in the sides

I decided at the beginning of this that there is no such thing as too much cutting lube. It keeps your tools in good shape and makes the work go faster. When I either saw too much smoke from the cutting lube (it's burning off) or when the bit stopped cutting curls of metal and started throwing chips, I'd back out and drip more cutting lube in the hole.

Also, make sure that you use the appropriate speed of the drill press for the hole size you're cutting. My press has a little table inside the pulley cover that tells you this information. For 5/16" holes, I was cutting at 1100 RPM.



I used the depth stop of my drill press for this. I set the height of the table so that when the bit contacted the work piece, we were at zero on the depth gauge. I then set the stop to 1-1/4" so that my holes would be deep enough for the screws, but not poke through the bottom of the side supports. If you don't have a depth stop on your press, you can get little depth stops that clamp onto the drill bit, or just put a piece of tape at the proper depth on the bit as a marker of when to stop.

This post has been edited by deker: 17 January 2006 - 09:47 PM

[deker]

Mike Routen, on Jan 17 2006, 11:14 AM, said:

Deker,

I'm really interested in this thread, as I am about to embark on a similar journey.  I was thinking of going with the welding route since I'm not experienced at all in layout and machining.  However, if your descriptions are good enough, I might just give this a go too!

Thanks in advance for all of the work it takes to put something like this together, and for being open enough to let us watch the process!

Mike,

I should add that I know NOTHING about proper layout and machining (as you'll see in a future installment). I'm purely using my common sense and some foggy memories about layout that I read someplace once. We'll see in the end if I'd do it the same way again or weld. Like I said, I don't have a beefy enough welder, nor would I trust my welds anyways. Who knows, I just may end up welding the next one

As for letting you folks watch, I'm hoping that somebody else can learn from my mistakes (which I expect to be numerous!), and that you folks may be able to help me if I run into any problems.

Let's see how it goes!

-d

This post has been edited by deker: 17 January 2006 - 10:58 AM

[Bob Ouellette]

Rob - Looks like a nice start. I'll have to see it sometime in the spring when I'm back from school. Are you using Walt's sliding motor mount idea? Just curious. I hope everything works well for you.

[deker]

Bob Ouellette, on Jan 17 2006, 12:37 PM, said:

Rob - Looks like a nice start.  I'll have to see it sometime in the spring when I'm back from school.  Are you using Walt's sliding motor mount idea?  Just curious.  I hope everything works well for you.

The sliding mount isn't in the plan. The drive will be set up identically to a KMG. I should be able to get the same effect that Walt gets by adjusting the tooling arm. I think he mostly built his that way so he could run different belt lengths which was already considered in the KMG design.

The one open question is if I'll use the 1HP motor I already have (that needs to have a shaft built for it due to it's odd output shaft config) or if I'll buy a variable speed setup. That's partly based on how much more stuff I screw up and have to re-buy...

-d

[Bob Ouellette]

So it would seem about the tooling arm thing. Just make sure that you don't cut corners. I know how much that can hurt you in the long run (remember my anvil stand? )

[deker]

Bob Ouellette, on Jan 17 2006, 02:24 PM, said:

So it would seem about the tooling arm thing.  Just make sure that you don't cut corners.  I know how much that can hurt you in the long run (remember my anvil stand? )

The only corners I'm cutting are the sharp ones...They hurt I actually meant to mention that early on.

MAKE SURE YOU BREAK ALL THE SHARP CORNERS ON YOUR STEEL BEFORE YOU START!

I know that when *I* entered blacksmithing I was taught to dress all corners of cut stock so that the next guy to grab that piece doesn't cut himself. This doesn't really apply to the guys at your local welding supply it would seem. I made sure to dress all edges before I did anything else to ensure that I wouldn't slice myself open and put an abrupt end to a work day...

-d

[deker]

8) Layout the bottom plate and the bottom holes for the side plates

Note the different arrangement of holes here on the bottom plate. I had to make sure of two things:


- The holes weren't in the same place as the ones on top (since the screws would meet up and cause trouble with each other)
- That I had holes at the ends to attach the bottom plate to the vertical supports

This put holes on the bottom plate at 1/2" in from the ends and 1/2" in from the sides at the 4 corners (for the attachment to the vertical supports) and the others at 1-1/2" and 4-1/2" in from each end. (Note here that I didn't specify how far from the edge...this comes back to bite me in the behind later...)

For the side plates I just drilled the holes at 1-1/2" and 4-1/2" from each end, offset 3/8" from the outside edge.



9) Drill the holes in the bottom of the side plates (remember, these are at 5/16" so they can be tapped 3/8-16)



10) Drill the holes in the bottom plate (missed a pic of this, but you get the idea by now...these are at 3/8" so that the screws pass through)

11) Start tapping holes in the sideplates

I made sure that when I mounted anything in the vise for tapping that I levelled it first. I have enough variables flying around here that I didn't want to have to worry about starting a tap crooked.



The start tapping. Get a big tap wrench. It makes cutting the threads EASY. I don't want to imagine doing this with one of those little wimpy tap wrenches...

Also note that after I tapped each hole (with a lot of tapping fluid) that I removed the tap, cleared the chips from it, and then re-lubed it and chased the threads with the tap. I then loaded up a bottom tap and repeated the same for each hole. So, for those keeping count, each hole had a tap run down it 4 times. After I was all done I blew the chips and cutting lube out with carb cleaner (it's what I had handy...also note that you don't need to buy the DyKem cleanup fluid. Carb cleaner takes the DyKem off just fine.)

This post has been edited by deker: 17 January 2006 - 08:47 PM

[deker]

12) Countersink the top and bottom plate holes

I came around to the idea of using the contersunk socket drive screws while chatting with a coworker who used to be an airframe mechanic. I knew I needed something countersunk to attach the bottom plate to the vertical supports (so that bolt heads wouldn't be sticking up blocking the side plates and tooling arm), but he pointed me to the socket drive. Good call John! Thanks! Make especially sure that any screw heads that might interfere with something are sunk all the way below the surface of the piece they pass through.


Also note that on the bottom plate I countersunk the holes for attachment to the vertical supports from the top, and the remainder from the bottom...Otherwise it would have been all backwards
This is another place I should point out the use of cutting lubricant. Anything that cuts metal gets lubed well. It makes the cutting nicer and prolongs the life of your tools. I did notice that the countersink liked a little less lube than the drill bits. I guess because of the different cutting surface it needs a bit more friction to get the job done. Also, remember to keep an eye on the countersink and stop to clean out chips once it fills up. It quits cutting when it gets clogged. I also want to point out that I ran the countersink like a big, slow drill bit at 300RPM. (for folks who have been keeping track, go re-read the edited posts about drilling...I forgot some key bits before...)



13) Try to assemble everything....

How fitting that this is step 13...This is where I realized that even the best laid plans of mice and men often go awry. The top plate to side plate attachment only had 5 screw holes line up right, and the bottom was ALL screwed up (remember that comment about "how far from the edge" those holes should go? I followed the line I scribed at 1/2" for the end holes...it SHOULD have been at 3/8"). I don't have pics of this stuff yet. I got fed up and it was late Saturday night when I got to this point. I packed it in and had a beer. I'll try and get the "what NOT to do" pics tomorrow.

As promised, here's a pic of what happened here. I should point out that it was greatly due to my lack of attention to detail and laying out holes on the bottom plate incorrectly. However, not having stuff bolted together as I proceeded through the layout process messed things up as well.



The next round of screw ups was similar, but the holes on only one side to attach the bottom plate were off left-to-right rather than top-to-bottom as in the picture above.

14) Return to the welding supply for replacement steel

On the drive into town I realized that I should have used 5/8" thick stock for the side plates so that I would have some clearance for the tooling arm to slide. I also figured a little more height on the sideplates would serve the same purpose. Since they don't make 5/8" x 1-5/8" flat (that I'm aware of) I went with 5/8" x 1-1/2" and got some 5/8" x 1/8" flat as a shim. I also had to get a new bottom plate since it was drilled in such a way as to make using it with 5/8" side plates impossible. This was a $13 mistake. Not the end of the world, but it woke me up a little.

15) Re-mark and recut everything (missing some pics, more to come later)

This is where the concept of the transfer punch comes into play. The idea here is that you cut all of the holes on your plates, pick one to start with on the sides, drill and tap it, and then put it together and mark the remaining holes based on the first one. GREAT idea! Why didn't I think of it sooner? (answer: I trusted in math and measurement...they're important, but there's no replacement for sheer practicality). Mind you that I could not for the life of me find a set of transfer punches in town. I settled for using a 3/8" drill bit in a hand drill to mark my starting point through the 3/8" holes in the top plate. I did this because I had Monday off and wanted to get a full day's work in. It caused a LITTLE heartache later when a couple of holes were a LITTLE bit off (just enough to bind the screws up trying to assemble). I solved this by making the plate hole SLIGHTLY oblong in one direction to account for the error. In most cases it was only off by about 1/32". I HIGHLY recommend getting a set of transfer punches. I'll be picking one up tomorrow at lunch from Harbor Freight.

So, I marked one hole on the end of the new side support, drilled it, tapped it, and bolted it to the top plate. Then I dimpled the side plate through the holes in the top plate to mark where to put the rest of the holes. I should point out that I started at one end, did the opposing end completely (drilled, tapped, assembled, etc) and THEN marked the two center holes. This made sure to account for any slight bends in the side plates, etc.

I also remade the bottom plate and redid all of its countersinking. This whole mess wasted the better part of a day.

16) Assemble all the new parts...

...and realize you screwed up again...

I had started with the top plate to sideplate fit as in step 15. Then I did the same for the bottom. One side came out fine, but the other had holes drill out of place again! HOW THE F^!$ DID THAT HAPPEN?!?!?!

The short version is that I should have had everything assembled to the top plate when I set the holes for the bottom plate. They weren't QUITE right longitudinally, and this cause things to not fit again... (pics of this upcoming as well)

17) Slink back to the welding supply just before closing time...

So, I walk into the local welding supply and the guy I've been dealing with comes around the corner after finishing with another customer and just kind of looks at me...

Me: Somewhere my Grandfather is looking down at me and yelling "MEASURE TWICE! CUT ONCE!"
Guy: So, you did bad things again? (with a smirk)
Me: Yeah...only half as many this time though. I only need ONE piece of 5/8" x 1-1/2" At this rate this should be the last one!

He proceeds to cut the steel I need and carry it from the bandsaw to me. He hands it to me and tells me that since this is "like the 20th one" this one is free. you know you've screwed it up when the welding supply guy takes pity on you in the form of free steel since you keep messing everything up...

18) Go back and do it right.

By now you should be able to figure out how I fixed my errors...If not, go re-read this post....

19) Mark and drill the vertical supports

I very simply marked these by standing them up and laying the bottom plate on them. I marked one hole, drilled, tapped, assembled, marked second hole, etc for each end.

Again, make sure you level things. In the case of these supports, since they are long AND tall, make sure you level along the two axes it can tip while standing in the vice. This picture shows one leveling. turn the level 90 degrees and level from front to back as well.



Same goes for tapping...



20) Assemble eveything!

Didn't get pics...Will try tomorrow AM. I was too tired after a whole day of screwing up...

-d

This post has been edited by deker: 19 January 2006 - 01:46 PM

[Andrew Recher]

I hate to jump into the middle of your tutorial, but I found a link to this group the other day and since it's applicable, I thought I should share. I don't know where I found it or if it's been posted here previously or not? It's got lots of Lot's of pics.

http://groups.msn.co...hopmadeGrinders

And thanks for sharing your experiences and info.

Andy

[deker]

Andrew Recher, on Jan 17 2006, 10:55 PM, said:

I hate to jump into the middle of your tutorial, but I found a link to this group the other day and since it's applicable, I thought I should share.  I don't know where I found it or if it's been posted here previously or not?  It's got lots of Lot's of pics.

http://groups.msn.co...hopmadeGrinders

And thanks for sharing your experiences and info.

Andy

No worries at all. I've looked at a lot of the stuff over there in preparation for this project. There's a lot of good info there. Actually, your post reminds me that I should go back and gather up other links that were helpful to me and post them. I'll try to remember to do that shortly.

Thanks!

-d

[Guy Thomas]

Great project and thanks for the progress sequence! I'm planning on building a press soon and it requires heavy plate in various sizes as well, how expensive was it for you to order the plate pre-cut in various dimensions?

[deker]

Guy Thomas, on Jan 19 2006, 11:19 AM, said:

Great project and thanks for the progress sequence! I'm planning on building a press soon and it requires heavy plate in various sizes as well, how expensive was it for you to order the plate pre-cut in various dimensions?

Guy,

I don't have the specific numbers per piece, but the whole 115lbs or so of steel was $125. Thick plate gets expensive, but I think that the welding supply guy saved me $$ by using big 1"x8" flat for the plate sections (original quote had the total of the 1" plate being near $100 by itself). The total I paid ended up being $75 less than the original expectation. If you have a method to cut it you can probably find 1" plate at a scrap yard a lot cheaper from those big plates they use to cover holes in the road.

Also, check and see if your local steel supplier will let you pick around in the scrap bin. Usually they'll sell you scrap bits really cheap and they may have had cutoiffs from a big project that will suit your needs.

-d

[deker]

This isn't a post with more steps as much as it is a "current status" and "new parts" post. After getting the tooling arm box together and attaching it to it's vertical supports, we have the following: (Yes, I know the top could use better countersinking, I'll be fixing that. And the one bottom bolt sticking out was a bit tight so I figured I'd deal with it later since I have to disassemble it all again anyways...I also think that my dimensions for the vertical supports were a bit long, I'll probably trim some excess from them with the bandsaw before this is all over.)










I also meant to point out before that I marked pieces to make sure they matched up repeateably in assembly, since I'd have to take things apart and re-assemble a bunch while working on the tooling arm box. This picture is kind of blurry, but you can see how I marked the front of one side plate to match up to specific corners of the top and bottom plates. This ensured I didn't incorrectly assemble something and then drill holes based on that.



I also got some more parts in the mail the other day...

Here is the Grizzly 10" contact wheel. It has a 3/4" bore designed to attach directly to the output shaft of a motor. I plan to either have it mounted to a live shaft or to modify the hub slightly and press bearings into it.





I also got my bearings in. Here are the flange-mounted pillow block bearings that will hold the drive shaft that the belt drive pulley will be mounted on. They have a 3/4" bore.



I got these pillow blocks in case I needed to make a live shaft for the contact wheel. I figure that if I don't use them here I can use them to make a buffing setup later. These are also 3/4" bore.




More to come after my next work session....

-d

[P.Abrera]

Cool thread! Been mulling over a build-or-buy grinder solution myself for a while now. Keen to see the finished product. Have an estimate for how much do you think you'll be spending in total for completion?

[Hurl Vreeland]

That is a very ambitious project. You have more courage than I did and I have complete access to a full machine shop. I was going to copy the KMG fully and Rob was kind enough to post pictures on how the tracking wheels were made or at least the parts thereof. I decided in the end I would just buy one, I got a flat grinder though. Go with 2 hp if you can, 3200 rpm.

Are you going to put a locking arm on the wheel support?

Looks good so far. I do alot of fabrication where I work and layout is no sweat as long as everything is square in your cut and measurement. A sliding square and a long "T" square is a big help. Always use a center punch and start your first hole with your smallest bit and work up from there. Be careful with your taps its really gonna suck if you break one in a hole. Get 3 flute taps whenever you can, the 4 flute break real easy.

Good luck and measure twice!!!!

[deker]

Hurl Vreeland, on Jan 19 2006, 08:50 PM, said:

That is a very ambitious project.  You have more courage than I did and I have complete access to a full machine shop.  I was going to copy the KMG fully and Rob was kind enough to post pictures on how the tracking wheels were made or at least the parts thereof.  I decided in the end I would just buy one, I got a flat grinder though.  Go with 2 hp if you can, 3200 rpm.

I don't know if it's courage really. I'll attribute it to me not knowing that it should be hard...or something...

I've been trying to find any pictures of the KMG tracking mechanism and have come up empty. Do you have a pointer to the pics someplace?

Quote

Are you going to put a locking arm on the wheel support?

Do you mean the tooling arm? If so, yup. I plan to put a threaded hole in one of the side plates and add a locking handle. If not, what do you mean by wheel support?

Quote

Looks good so far.  I do alot of fabrication where I work and layout is no sweat as long as everything is square in your cut and measurement.  A sliding square and a long "T" square is a big help.  Always use a center punch and start your first hole with your smallest bit and work up from there.  Be careful with your taps its really gonna suck if you break one in a hole.  Get 3 flute taps whenever you can, the 4 flute break real easy.

Good luck and measure twice!!!!

I haven't been step drilling...maybe I should start I've also had pretty good luck with my taps so far. The only 4 fluted ones are the bottom taps and they're doing a lot less work so hopefully they'll be OK.

Thanks for the words of encouragement. From one minute to the next I never know if I'm actually in over my head or not

-d

[deker]

P.Abrera, on Jan 19 2006, 08:25 PM, said:

Cool thread! Been mulling over a build-or-buy grinder solution myself for a while now. Keen to see the finished product. Have an estimate for how much do you think you'll be spending in total for completion?

Well, the total depends on how much more stuff I screw up

So far here's the rough numbers:

Steel: $125 (+ $13 for stuff I screwed up. A few pieces were a bit too big so it could have been a few bucks cheaper)
Bearings: $38
Contact Wheel: $80 (including shipping, tax, etc)
Bolts/taps/drill bits/etc from Fastenal: $122
Tap wrench from Sears: $17
1HP 1725RPM motor: $50 shipped off of Ebay

The pulleys should cost me pretty much nothing since we'll be casting them from scrap transmission cases, etc. I figure I've probably got a little more to spend as I need driveshafts , pulley bearings, and step pulleys . I also need to have a special drive shaft made up for the motor I have if I use it since it just has a short threaded shaft.

I may spring for a variable speed setup though if I can find a good deal. Assuming I don't do that I'll be under $500.

-d

[Bob Ouellette]

Glad everything is finally comming together for you. I like that selection of wood in one of your pictures (have you managed to cut up any of that apple yet?).