Project: Long road to a belt grinder

[Cenedd]

Alright. I've been persuaded to start this by VPT since he said he'd enjoy reading it.

Well, the story is this. I have had belt grinder envy for a while. I want to build something decent and, having asked people's thought on it, I'm looking at a 2HP 3-phase TEFC motor with a VFD. This will probably be to Jeremy Schmidt's design but that's not set in stone. I've not ordered the motor yet as I've spend the budget on a (necessary) portaband Currently I have the aluminium to make the wheels and the bearings....but not much else.

Apart from cash-flow, there's another tiny bump in the roadmap for this project: not enough space! In order to do this - and to maintain my sanity - I'm going to have to expand my workshop from tiny to merely small. I currently have half the room and the rest is storage - partly of tools etc but also of things like half-cans of paint and the like that could live somewhere less convenient like the loft....which is another project in itself. I should, at this point, warn that this project is likely to be glacially slow. Doing anything relies on first doing something else....which in turn relies on doing something else. You know how it goes, right?

So, my thought is to get rid of the wooden bench I have (that isn't rigid enough and also split - varnish and pressure-treated wood turn out to disagree with each other) and replace everything with one long bench made of square-section steel tubing. I've been working on a plan - for a change - so I can see if everything is likely to fit. I'd appreciate any comments on design, materials, layout...anything constructive at all. Especially about the jib-crane I've added. I've no experience here but it would be nice to be able to lift things onto and around the bench if necessary - we're not talking tons here, just the likes of the 120kg for the lathe or 70kg for the mill.

This is the plan so far (click for larger version or download the over-size Sketchup file):

SketchUp Model 23MB

• The wall at the back is drywall on a stud partition - office space behind.
• The red RSJ holds the weight of the flat roof - although there are wooden joists running at right angles. The RSJ seems to be merely sitting on the top of the medium density block piers with a splat of mortar to keep it in place - so I figure it would take load directly hanging down from it but not so much torsional load without some sort of bracing.
• The big grey/blue block on the ceiling is the current position of the ladder - it could be moved a little but the jib needs to clear this.
• All the models of the machinery are approximations - similar items stretched to about the right dimensions. The mill's table isn't that long, it's representative of the total travel. The transparent part of the lathe door is to ensure enough space to swing open the change-gear door.
• Boxes piled up under the bench are mainly tool cases.
• The floor isn't totally flat like it is in this model - it's not horrible but it's neither flat nor level by any stretch of the definition.
• I've modeled the framework of the bench to be modular - each section would bolt to the next by means of a flange. This is so it can be built in sections (in the garden) and assembled in situ and also so it won't be too heavy to handle for painting.
• At the moment I've put the belt grinder (that I want to build) at the far left with the bench grinder on a pull-out shelf below it. The theory was to at least have all the grinding down at one end and the door shouldn't hit the belt grinder's table that end. Mill and lathe could be swapped around or moved down - currently they are one section to the right.
• The wall currently has dado trunking carrying electrical outlets on the right hand half. This shouldn't be hard to extend. It also has peg boards, storage bins and the like screwed to it so this isn't wasted space like it appears.
• Once I've got a little spare space (one section of bench) it could be used to weld on for parts of the grinder build. This is assuming that it's safe to put the ground clamp on the same bench that the mill and lathe are sitting on?! Or do I need an electrically isolated section if I want to do that?
• The compressor shown in the model is a place-holder. I'd like shop air but don't currently have the room.

[vpt]

I look forward to the belt grinder build and rebuild of your shop!

I like the idea of pull out work surfaces! However it is nice, when working at a bench, to be able to put your feet under the bench (stand close to the bench). The drawers on the bottom wouldn't allow that.

One trick I've seen is a work bench that can be raised (to the ceiling) and lowered to be out of the way when you don't need it. The ones I seen used cable winches. Just an idea.

[Cenedd]

Thanks Andy. Hadn't considered needing to have my feet under the bench - was just trying to fill what would have been wasted space. Currently my bar stock is unceremoniously shoved under the bench in that space but it is possible to put your feet under. Will have to check and see if it's anything I do or if the lack of depth to the worksurface means I don't need to.

I like the idea of winching the workbench up to the ceiling to get it out the way but I don't think I've got enough height to make it work usefully. Even making the legs fold away to the wall is going to fail unless the bottom storage part is empty. I'll at least be thinking of the possibility of going up when I'm thinking of things now though.

The pull-out worksurfaces are mainly because I don't currently have enough space to put things down and find them again - I'm just not cut out to be tidy enough to avoid this problem. I think I'll have to drop the surfaces down a bit though as I can see that what will end up happening is me pulling it out, putting the tools I'm using on it and then needing to slide it back in to get past. You know, solution and cause of further problems, all rolled into one

[J Tiers]

Put that belt grinder FAR AWAY from everything else. You will have more dust than you can think of, and you do not want that on the other tools.

Distance helps. Doors (which mean walls) in between help more. Open but smaller doorways (no door in it) help a bit, just because they mean there is a wall between to discourage dust flow..

What I have found is that 2 feet of space from grinder or belt to other machines is nothing, you will get pretty good dust accumulations. 6 or 8 feet cuts the big stuff. 15 feet does little more than 8, at that point you need a wall or curtain. Clear across a basement does OK, I cannot prove where any remaining dust came from.

That may vary with what your heating or A'C is. Forced air will spread the dust all over anyhow.

[Cenedd]

Hmmm. Unless I can build it light enough to move and set up outside, I'm stuck with what I have. I could move mill and lathe to the far right, leaving the empty section (work space) next to the grinder but that's three feet at most. 8 feet would be out of the building! Unless I build it all aluminium, it's likely to be too heavy to conveniently move (no space for rolling carts and also door step to get over) and I would assume that aluminium would be much less rigid and probably more expensive. I think I'll have to rely on just covering everything else and not removing it (where possible) until the dust settles.
No AC to stir things up. Only heating is a 120W tube heater and that's enough for the space even in winter.

[noah katz]

I agree with Andy about the low drawers.

But just insetting them a few inches should solve the toe-stubbing issue.

Unless I can build it light enough to move and set up outside, I'm stuck with what I have.

Not sure what you're referring to, but steel is 3X stiffer and 3X denser than aluminum.

Re dust, consider adding a dust port to attach a shop vac to, and/or a shop air filter to catch the floating fines before they get to where you don't want them.

There are some simple dust control solutions here

https://www.google.com/search?safe=active&ei=gKCSXNmEBIqksAXsuqzQDA&q=belt+grinder+dust+control&oq=belt+grinder+dust+control&gs_l=psy-ab.3...3404.5238..6054...0.0..0.110.750.6j2......0....1..gws-wiz.......0i71j0i13i5i30j0i8i13i30j33i10.yDOIXoVTHrE

I've designed a 4x72 belt grinder with dust control, but it's gotten so complicated (though it is feature-rich) that I'm almost embarrassed to show it.

[Bob Engelhardt]

When I built my grinder, keeping it small was the 1st criterion. Especially that it not take floor space. Basically, I made it to take about the same space as a bench grinder. I did not need it to take off large amounts of stock, as in knife making. Mostly deburring & small scale shaping. KISS!

It uses 2x42 belts, is driven by a treadmill motor, is small enough to be bolted to a shelf, and has been everything that I needed and wanted in a grinder.

[Cenedd]

I agree with Andy about the low drawers.
But just insetting them a few inches should solve the toe-stubbing issue.

Cool. I'll look into it and maybe inset them. I suspect they'll be one of those 'afterwards, when I get around to it' things anyway.

Not sure what you're referring to, but steel is 3X stiffer and 3X denser than aluminum.

I meant that making it out of aluminium would make it lighter (desirable) so that it might be conveniently liftable....but doing so would increase the cost (undesirable) and reduce the rigidity (also undesirable) and I'm not sure it would be light enough anyway.

Re dust, consider adding a dust port to attach a shop vac to, and/or a shop air filter to catch the floating fines before they get to where you don't want them. There are some simple dust control solutions here

I was definitely thinking of doing something in terms of guarding so hopefully adding a nozzle for the shop vac (with cyclone and possibly an extra box rated for hot stuff) to that shouldn't be too tricky....he said naively!

I've designed a 4x72 belt grinder with dust control, but it's gotten so complicated (though it is feature-rich) that I'm almost embarrassed to show it.

It'd be interesting to see it even if just for interest's sake. Inspiration would be a bonus, of course.

When I built my grinder, keeping it small was the 1st criterion. Especially that it not take floor space. Basically, I made it to take about the same space as a bench grinder. I did not need it to take off large amounts of stock, as in knife making.

That's a nice looking build Bob. I like the idea of keeping it simple and small but unfortunately I do want to be able to take off larger amounts. In some way I want to be compensating for the inadequacies of my mill - there's a lot of things that can, with the right jig, be done much faster with a sufficiently powerful belt than they can on the mill. Even just rounding the corners off a plate I'm working on at the moment; it's possible with a corner-rounding endmill and a rotary table....but it's no fun when you're taking maybe ten passes to get a full depth radius. I may well resort to hand filing it for speed over perfection! ....and I'll go to vast lengths to avoid doing things by hand even if it does actually take more effort

[mattthemuppet]

dang Bob, that is really cool. I've been mulling something similar (2x42, treadmill motor) for ages and that's given me a lot of fresh ideas. Very simple and pretty much all I'd need too. The tensioner looks very neat - do you have any ability to adjust tracking or did you get it straight first shot?

[Cenedd]

do you have any ability to adjust tracking or did you get it straight first shot?

Looks like the motor pivots on the top mount with a screw for tracking.

[mattthemuppet]

oh yeah, well spotted. Well, that makes it even cooler That's gotten me several steps closer to getting off my ar$e and making one!

[noah katz]

Very nice, Bob!


Cenedd, re the drawer, you could just put it on small casters instead of fussing with slides, and it would have unlimited extension

[Cenedd]

Cenedd, re the drawer, you could just put it on small casters instead of fussing with slides, and it would have unlimited extension

I was thinking something along those lines - although typically over-complicating it as some sort of captive roller set...like a pallet truck but massively scaled down. Would stop it wandering (fixed steering) but is probably totally unnecessary! Make them a bit shorter than total depth and we have adjustable inset on demand too
I need to look at making them out of wood rather than metal as-modeled too....just for cost reasons!

[Bob Engelhardt]

Looks like the motor pivots on the top mount with a screw for tracking.

Exactly right.

[noah katz]

Cebedd,

Re drawers again, I made a bunch for small parts bins by welding pairs of metal shelves edge to edge and turning them upside down.

You could add plywood sides if you need them taller.