Belt Grinder from Poland

P

Polish_Grinders

Joined
Dec 4, 2018
Messages
10
Hello!

I'm knifemaking enthusiast, but building machines always were greater fun for me than later using it ;)


I would like to introduce my grinder to you.

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3.jpg


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It uses 50x2000mm belts, but 2x72 inches belts can be used too. (It's adjustable)
Motor: 1,5kW 3 phase motor (But I'm also mounts 1,5kW 230V 1 phase motors)
Belt speed - 24m/s with 160mm drive wheel or 30m/s when I'm using 200mm drive wheel
Weight about 60kg.

It's prototype, but as we can see on this video - it works nice and smooth ;)


(Sorry for bad quality of video)

Best regards:
Maciej
 
Cool looking rig, but correct me if im wrong - dont u need to be a paying member if you are adverting a sale?
 
In fact - I'm not selling that - I just wanted to share with you my latest project, it's prototype and I'm very glad that works. That's all ;)
 
Polish_grinders,

Two things come to my mind when I see that grinder:
1 - You go all the way to getting the pieces cut (plasma? laser? waterjet?), bent (CNC?) and then you cheap out on the base! That grinder (even if a prototipe) deserves a proper stand.
2 - And this a serious one (from my point of view!). I don't think it is a good idea to support the WHOLE grinder (60kg minus the weight of the motor itself, your words) only by the motor. Unless I am mistaken, the grinder structure is attached to the motor itself, which, in turn, is bolted to the base. The motor legs are usually (in small motors like this) cast aluminum of some sort and the bolts that attach the legs to the motor carcass are the smallest in your grinder setup. Also you have to take into consideration not only the weight of the contraption, but the leverage you are going to make on those bolts when you lean on the platen to, say, cut the bevels of a knife.

I think it would be much more robust to have the grinder structure self-standing (welded/bolted to the base) and then attaching the motor to it.

Other than that, sure it runs smooth!
 
Mikel_24
I've ordered stand from 8mm steel - it's weight will be 10-15kg, motor weight it's 15kg so the rest of construction weights -30kg (60kg it's weight after adding bigger stand).

I've already built a grinder that weighs 120kg. Now there was a need for something portable, easy to dismantle and hide in a toolbox if needed. I do not think that motor legs will withstand such a load. However, I can do a simple test in the future - to hang 100kg anvil on 1m 40x40 square in place of platen. Will it be authoritative for you?

Using the motor in this way is also something new for me - but if we do not check it in practice - we will never know its capabilities;)
 
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Polish_Grinders said:
Hello!

I'm knifemaking enthusiast, but building machines always were greater fun for me than later using it ;)


I would like to introduce my grinder to you.

1.jpg

3.jpg


1bb.jpg


It uses 50x2000mm belts, but 2x72 inches belts can be used too. (It's adjustable)
Motor: 1,5kW 3 phase motor (But I'm also mounts 1,5kW 230V 1 phase motors)
Belt speed - 24m/s with 160mm drive wheel or 30m/s when I'm using 200mm drive wheel
Weight about 60kg.

It's prototype, but as we can see on this video - it works nice and smooth ;)


(Sorry for bad quality of video)

Best regards:
Maciej
Click to expand...
Nice video !!
Now confess. You used superglue on that coin.. Right ??
 
I agree about having the entire grinder supported by the motor. All it would take is a couple piece of steel or a piece of 6”x6” angle iron. You could bolt it to the frame(once you get it) and then to the base. But think that could cause a serious problem down the road. I mean, what happens if that fails? I wouldn’t want to be standing near it when it happens. Sure you may be able to hang an anvil off it now, but what about after it has 50hrs on it? It’d be super easy to rig up another support beam.
 
I'll change that in next projects I think, but I still don't know why you're thinking that 4 M8 screws for frame, 4 M10 screws for baseplate and aluminium (even, if it's casted) cannot take 30-40kg of construction and pressure of grinded material. Why it should brake? Where? And when? During normal grinding?

I can understand your point of view, Gentlemen, but in my opinion your fears are a bit exaggerated. I do not believe in situations when suddenly all 4 screws that fasten the frame or base break, or cast in which they are screwed.


By combining the base with the body I wanted to come up with something new, interesting, going beyond the standard form;) Do not treat my posts as an attack, but rather a substantive discussion.
 
Smooth grinder and well put together.well done
But I'd agree with the above posts about it being bolted together this way
I'm all for trying something different and something new but most importantly it would have to be something better and I can't see how this improves a grinder
 
I don't see a problem with a motor frame like that supporting the grinder. If it was a normal 56 frame c-face with a 12 gauge frame and spot welded base, that would be much more problematic.

If I were to level any critique for the design it would be the length of the tool arm and the distance necessitated by it to the clamp and tension arm, and the lack of clearance on the tool arm side of the platen.
 
Thank you Gentlemen.

I always try to improve my machines if I find the possibility;)
Below I am posting another video from the "coin test".

Best regards,
Maciej


 
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Nice work on that Grinder.

"Polish Grinders" sounds like a delicious sandwich lol

Here in the USA "Grinder" is a type of sandwich also called Submarine, Hero and Hoagie :)
 
I'd say to add a second mount for other accessories. Look at northridge tool grinder for example
 
The machine is a light version that can be sent within Europe in one courier package or to US in two packages (but without motor and drive wheel).
I can add a second socket on order, however this base version can also be used successfully with a contact wheel, small wheel attachment, even surface grinder - and does it for 1/3 price of northridge's one.

Best regards,
Maciej
 
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It may just be me but the last few posts sound an awful lot like a sales thread which I believe you need a paid membership for, it’s not fair to those that do pay for the membership privileges. Maybe a moderator
could jump in and clarify things.
 
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