Building a GIB

Daniel Macina

Well-Known Member
#1
I am starting to build a GIB (Grinder in a box.) from Polar Bear Forge. Just curious from those of you that have built them, what issues have you run into? What are the parts that can be really tricky? Just trying to gather as much info as I can before jumping in. As always Pics are awesome! It is going to be a long process because I am buying parts very slowly but I will post pics as I go.
 

EdCaffreyMS

Forum Owner - Moderator
#4
I'm assuming the one you have is the version 2?

I've built a number of these machines for others..... the two areas that caused issues, and I had to modify are..... the pivot/joint where the idler arm bolts to the frame/upright. Using a common bolt there allows for "slop", and allows the idler arm to move slightly side to side. On a couple of the machines I installed a "yoke" on the frame/upright with close tolerances that prevented the side to side movement. On a couple of others I bored out the pivot hole in the idler arm and bushed it, then used a precision shoulder bolt to eliminate the side play. Any bolt with threads at that location needs a nylock nut on it.

Although a lot of folks think using one of the "spring cylinders" for belt tension is the cat's meow, I simply don't care for them....particularly on the GIB type machines.

Spring cylinders don't care what belt you have on the machine, nor how hard or soft you're pressing against it...... it applies the same force no matter what....which in the case of varying belt types isn't always a good thing. That being said, I do have a spring cylinder on one of my grinders, but that because that machine never runs anything other than an X weight belt on a 10" wheel for profiling. If I put anything lighter than a X weight belt on it, the belt jumps all over the place when grinding. On all those machines I've built for others, I deleted the spring cylinder and replaced it with a coil spring.

The variable rate that a simple coil spring provides keeps the tracking constant, no matter what belt you're using, or the amount of pressure you're putting on the belt. In my experience, with the spring cylinder, Y and X weight belts run fine, and J or finer tend to jump around. With a coil spring, all belts track the same on these type machines, without any jumping around.
 

Daniel Macina

Well-Known Member
#5
Thank you sir. Yes it is a version 2. I am putting lock nuts and thread lock on everything. overkill probably. Does it take any large modifications to do a coil spring instead of the gas cylinder? Thanks this is exactly the info I needed.
 

EdCaffreyMS

Forum Owner - Moderator
#6
I guess it depends on the equipment you have available...... I machined out a "carrier" for the bottom of the spring.... basically around chunk of steel, about 1 1/2" long, with 1" of it turned down so the spring ID would fit over it. It has a centered hole, threaded for 1/2"-13 threads.... I also drilled/tapped the same size hole in the tooling arm socket/frame. The carrier sits on a piece of 1/2-13 threaded rod, and is adjustable up and down..... that was the only way I could figure out to do it since there is so much room between the idler arm and the frame on these machines.
 

One Armed

Well-Known Member
#11
I was almost set on going with the GIB from Polar Bear. Came across them several years ago and fell in love with it! But when I finally had the funds, I knew I was able to just build my own, the way I wanted it! But I still believe the GIB is a great machine! With my full DIY build(and it would seem with the GIB as well), the most challenging was drilling the tracking wheel hinge pieces. Making sure the holes are aligned perfectly.

I'm always available to help as well!
 

Daniel Macina

Well-Known Member
#12
I was almost set on going with the GIB from Polar Bear. Came across them several years ago and fell in love with it! But when I finally had the funds, I knew I was able to just build my own, the way I wanted it! But I still believe the GIB is a great machine! With my full DIY build(and it would seem with the GIB as well), the most challenging was drilling the tracking wheel hinge pieces. Making sure the holes are aligned perfectly.

I'm always available to help as well!

Yes that's what I'm most worried about

Thanks buddy!
 

One Armed

Well-Known Member
#14
Take your time. Measure, measure again...., then go get a drink and measure it one more time! LOL. I've had a saying I've used for sometime. I taught it to my son for everything we would work on. I would tell him, "triple check your double check!"

Do you have a drill press and a mill/drill vice? I am fortunate enough to have a mill, but I could have done with my HF drill press and I only have a cheap vice.
 

Daniel Macina

Well-Known Member
#15
Take your time. Measure, measure again...., then go get a drink and measure it one more time! LOL. I've had a saying I've used for sometime. I taught it to my son for everything we would work on. I would tell him, "triple check your double check!"

Do you have a drill press and a mill/drill vice? I am fortunate enough to have a mill, but I could have done with my HF drill press and I only have a cheap vice.

Sorry for the delayed response. I have a HF drill press that I got to run fairly true. I should probably get a drill press vise. Currently I'm just using clamps. I would absolutely love to have a mill.
 

One Armed

Well-Known Member
#16
You'll do ok with the drill press and as long as your clamps are really heavy duty. But if you can, I would recommend getting a cheap mill vice like I have. Cost $15 or $20 on Amazon.

I'll tell you this, save up for a mill. You WON'T regret it! I have absolutely enjoyed mine to the fullest! But I did make good use of my cheap HF 1/3HP drill press. I even milled out the slots for the magnets in my magnetic chuck with it!
 

Daniel Macina

Well-Known Member
#17
OK. Kind of a dumb question. What holes HAVE to be tapped on the GIB? Obviously the idler block and the holes on the base Plate. I want to tap as few holes as possible just so I don't run the risk of not tapping a hole straight or something dumb like that. Or do all the holes need to be tapped. Or is just a lock nut good enough on some holes?
 

One Armed

Well-Known Member
#18
Off the top of my head I'm not sure all the holes that will need tapped. But it will be very obvious. I bet a majority of the hardware is 1/4-20 thread. (That's what 75% of my grinder uses). Any hole which needs tapped will be drilled with a #7 for 1/4"-20. A "through" hole will be slightly larger than the size of the bolt. I.E., 1/4" bolt will be slightly over .250" in diameter.

When you get it and are doing the build, feel free to contact several of us here. I'll give you my email and/or phone number as well when you are ready. Easy for me because I am disabled, and I don't drive. So I'm ALWAYS home! But when it comes to building things, I do ok. Several members here will attest to that. And I am always willing to help a fellow knifemaker.
 
Top