Single speed GIB owners, question

[medicevans]

Do you feel limited running only single speed? I doubt I'll have the extra $200-400 for a VFD anytime soon, and really am feeling the itch to upgrade to a better grinder. My craftsman is great, but I'd like something a bit slower and with a better platen so I can really get my lines down.

Do you have a 4" or 6" wheel? 1750 or 3600 rpm motor?

I just don't want to box myself in and regret it later. I doubt I would, but I still wonder.

[javand]

Without trying to placate you, I'll say simply: Find the money for a VFD, buy a cheaper Teco VFD and build a box to house it in if you have to. Also, seriously consider the Wilmont LB grinder kit as an alternative to the gib. The hardware+drive and tracking wheels kit will save you money.

[medicevans]

I wondered if someone would say that.

I will look into the Wilmont grinders. I already have a GIB/EERF kit that a buddy laser cut for me for free.

[AVigil]

You have to decide on your motor and VFD at the same time. You will need a 3 phase motor to use a VFD. If you buy a single phase motor to use on your GIB as a single speed you will need to buy another motor when you go to add VFD.

[jawilder]

Just run it with step pulleys. That's what I did. I think it cost me $60 for the cheap pulleys, shaft, and pillow block bearings. they can be bought at different times to space out the extra cost if need be. I'm very happy with mine.

[Justin King]

I ran mine single speed with a 3600 rpm motor and 4" drive wheel for a couple of years and made a lot of blades on it. There is some pucker factor when grinding hardened blades at this speed as it will heat the workpiece up pretty quickly, it eats finishing belts like a hungry dog, and it is harder to fine-tune your grinds.

I have it set up VS now with a 1750 rpm motor and 6" drive, and my grinds are improving faster than they ever have, with less time spent hand-sanding.

The moral: you can work with single speed, but VS will allow you to work at a whole other level and is worth every penny, the moment you can afford it.

[tryppyr]

I run single speed with a 1725 RMP motor, and I like it. I am using the 6" drive wheel, so the effective SFPM is higher.

On the whole, I'd say a VFD would be a very useful addition... but not one I was willing to fund at my skill level. Since I don't sell anything, there's no way this will ever pay for itself, so I'm keeping expenses relatively low.

Of course, I say that and then invariably spend money on knifemaking supplies, such as my cabinet full of stabilized wood blocks and ivory. Oh well... doesn't have to make sense to anyone but me.

[Don Hanson III]

I'll never run a single speed grinder again! Ever!

[medicevans]

JAW, where did you find step pulleys that cheap!?

Also, I have though about buying a cheap VFD from the 'bay and making an enclosure and running a remote control, but I just don't know.

I keep kicking it all around. I just wanna make knives, but the 4100 sfpm of the Craftsman is killing my grinds and my fingers!

[tattooedfreak]

I have a coote with a 10" wheel 1750 rpm 1hp motor with a 2"/3" step pulley. It works great, I run it on the 3" most of the time for slow speed but occasionally put it on the 2. You can by 2 or 3 speed step pulleys a just about any hardware store for under 25$.

[jawilder]

I got mine from ace hardware. They aren't balanced like the expensive ones but work just fine.

[medicevans]

Thanks guys. I've seen plenty of step pulleys at Ace and Rural King here, I just wasn't sure how an unbalanced set would work. I'm sure I can find a decent used single phase motor locally.

All told, I have sourced a 1.5 hp motor and NEMA 12 VFD for $300. That seems decent.

VFD gives a lot more functionality, but I will have to see if I can find a single phase motor very cheap around here.

[jawilder]

Did you find the VFD locally or online? I might be upgrading mine in a few months and that seems to be a good price

[medicevans]

Why are you upgrading? I'll email you a link. Don't want to get in trouble for deal spotting.

[jawilder]

My motor is 2hp 3600 rpm and even on the slowest settings, it still runs a bit too fast for some handle work. And, my motor is a pool pump, which I'm sure will go out eventually (it was free). So I will either need to upgrade to 1400 rmp motor or just go with vfd. Not sure yet which I will do. I do like having the 2hp.

Thanks for the link.

[polarbearforge]

I run most of mine at 3450 with a 4" wheel. I have one finisher that I use a 4" wheel at 1725. It was more cost effective for me (especially the my prototypes of the GIB) to build multiple grinders than go with VFD. I have used variable speed before, but I know me, I'd probably set it at one speed and leave it.

Jamie

[medicevans]

So, what you're saying is that you are using a 1750 rpm motor for post heat treat?

[polarbearforge]

Except for shaping the guard, the handle, and setting the initial edge, I don't do any post heat treat grinding. All of my finishing post heat treat is hand sanding(I use salt pots).

Jamie

[medicevans]

Yeah, salt's the way to go I think.

So, what speed do you grind at predominantly?

[polarbearforge]

The 3450 rpm machine(s) with a 4 inch wheel are used probably 98% of the time.

Jamie