Belt grinder

[dikman]

I just love looking at things that folks have cobbled together! Fortunately I'll only be generating a fraction of the dust that Brian does so controlling it shouldn't be too much of an issue. You may have noticed that my grinder is mounted right next to the doorway, I did that deliberately when I installed my first grinder, and if I'm likely to be doing a bit of work on it I use a floor fan blowing out the doorway.

[RockyAussie]

11 minutes ago, dikman said:

I just love looking at things that folks have cobbled together! Fortunately I'll only be generating a fraction of the dust that Brian does so controlling it shouldn't be too much of an issue. You may have noticed that my grinder is mounted right next to the doorway, I did that deliberately when I installed my first grinder, and if I'm likely to be doing a bit of work on it I use a floor fan blowing out the doorway.

I have to say that as much as I LOVE the versatility of this machine it does look as though it would be a considerable challenge to adapt some form of suction that would work with it in an attached sort of way. I have now seen the other video and all of the attachments and am even MORE impressed. I am starting to think about making a less versatile version for leather work with an extractor set up in mind. 

[Spyros]

2 hours ago, RockyAussie said:

Thank you for that info @Spyros I will have to get myself one of those metres. Sanding many thousands of belts over the years has not done my lungs much good along with a filthy smoking habit on top.

Happy to help if I can.  I'm the same although I vape instead of smoking these days.

But yeah one of the reasons I got into leather, other than that I love it of course, is to get out of the shed a little and still satisfy my making/crafting needs without breathing sawdust all the time.  

Your set up there with the shroud and the DC machine outside looks perfectly adequate, I bet you don't have a problem there.  But stick the meter close to the sander at head/nose level and note down some readings before and after sanding, with the DC on and off, different positions of your fan etc until you find the best setup.  Like i said don't expect too much accuracy with those cheap units (a professional dust meter runs in the thousands) however if you look at the reading directionally and proportionately it still gives you a really good idea of dust levels.  With sanding it doubles/triples straight away.

Shipping from China is pretty terrible these days because of COVID, if you want I can send you mine for a while, let me know.  You don't need it all the time, only to take readings when you change something to make sure dust levels haven't change much.    

Edited June 5, 2020 by Spyros

[Bert51]

Having the ability to change layout of the pulley's makes me think you will need to think carefully about what you want before building an extraction system for it, maybe an adjustable suction funnel like under the rest might be the go.

Bert.

[dikman]

Bert, that's what I'm working on. A quick mockup showed that it should work and I was going well today until I got a call that my wife had fainted at the bank, so had to rush over there. She was ok, she had given blood earlier that day and the bank was hot and stuffy and that combined with a long wait got the better of her but the medics still insisted on carting her off to hospital. Couldn't do any more on the dust collector 'cos I had to walk back to get the car and then hang around by the phone.

[Bert51]

Wow, I thought she may have seen the account balance after buying the new toy

Sadly I am unable to give blood or donate my organs, I wish I could but I hope other people do.

I'm pleased she is okay, that's the main thing.

You can start on it again tomorrow.

Bert.

[dikman]

Actually, she saw it on the credit card account and said perhaps I should have it as a combined birthday/christmas present.

Here's the "finished" product, a cheap (because I used whatever I had in the sheds) and rough-as-guts (well, I did give the wood a rough sand to remove most of the splinters) dust catcher! I routed a slot in the rear piece so it can be adjusted for height, a few assorted plumbing fittings, a spare hose from an old vacuum cleaner and a cheap shop vac. Works well for leather and wood (no good for metal, of course), but even with the vac outside it's still noisy!!!

Now I think I need to buy one of those digital tachometers off ebay so I can measure the speed and mark my adjustment dial.

 

Edited June 6, 2020 by dikman

[Bert51]

Looking at the video of the grinder being used, I think that will do what you need it to do, not much will get missed.

Bert.

[RockyAussie]

Now that is looking promising - well done. I should also ask you to thank your wife for giving as she has done and I hope that she does not ever get such a bad result again. I wish her well.

On 6/5/2020 at 11:12 AM, Spyros said:

Shipping from China is pretty terrible these days because of COVID, if you want I can send you mine for a while, let me know.  You don't need it all the time, only to take readings when you change something to make sure dust levels haven't change much. 

@Spyros I would like to take you up on your offer as I have been asked to do a little consulting and training on the croc belt making by the end of this month. Getting one out a China that quick is unlikely at present. I would be happy to buy yours for $100 for now if you would like to go that way please pm me you details. They have a sanding machine set up for this but from what I have seen I know they need a lot better and I am thinking about making them up something way more heavy duty and as they are a BIG company the dust extraction will be an important thing to be clued up on. I will appreciate it a lot if you can help me with this one.

Brian

[RockyAussie]

On 6/2/2020 at 5:37 PM, dikman said:

I have a belt grinder which I use a lot - metal, wood, plastic, nylon and yes, leather. The problem is it's too fast and burns the leather and wood if I'm not very careful. So I bit the boolit, so to speak, and treated myself to a new grinder, something I've wanted for years. This one is designed primarily for knifemakers and runs 48" belts, and I went the whole hog and bought a 3-phase motor with it and a separate VFD. It took a while to figure out how to programme the VFD but now I can run the grinder from almost nothing to flat out! No more burning leather.

I'm so impressed with the VFD/3-phase motor setup that I'm thinking of fitting one to my lathe.

@dikman Can I ask what hp that motor has? I am also thinking of running a similar arrangement and could use a little help on what and where I may be able to get a hold of some of it along with any kind tips you may have to offer. I do like how you have the control knob box separated and keeping the main VFD nicely away from the messy stuff - also well done.

[dikman]

Brian, it's a 1.1 kw (1.5 hp) motor, it's the size they recommend for this grinder. As it's designed for hogging out metal I don't think I'd want anything less, but if it's only used for leather/wood you could possibly get away with 1 hp, but the price difference between the motors isn't much. I bought the motor from Artisansupplies only because it was convenient but there's a place on ebay called Conon Motors, in Vic, and they have a good range at what appears to be good prices (unless you can find one locally maybe). If I go ahead with modding my lathe I'll get the motor from them. I bought the VFD from them ($200) but there are others on ebay for around $100 and I've found good reports on them. I think if I buy another I'll try one of the cheaper ones. Putting the VFD in a separate case is a good idea, as you say it protects it and once it's set up you don't really need to access it, all you do is fit remote  start/stop and speed controls, all done by programming.

My background is in electronics but the programming had me scratching my head for a while as the terminology was a bit new to me. I watched a few vids on youtube where guys had fitted them to lathes and that helped me understand the basic ideas. Most of the settings don't need to be changed for our needs, basically just add the motor parameters (volts, phase, current, hp etc, all of which is on the motor nameplate) and that's it. Depending on the VFD type it may be necessary to set the voltage input, I didn't have to on mine. The trickiest part was working out the settings for the remote controls, but like a lot of things it was fairly obvious afterwards!

Anything you want to know just ask.

[Matt S]

My little 1x30 grinder suddenly feels very inadequate. I'm jealous. Looks like a real workhorse!

If I can figure out a place to place it I might just have to upgrade...

[dikman]

Matt, a 1x30 can be very useful (bigger isn't always better ). I've had the other one for over 30 years and I've found that I actually use a belt grinder quite a bit, but the main reason for lashing out on this is to get the variable speed, as there's no easy way to vary the speed of a single phase grinder.

[RockyAussie]

14 hours ago, dikman said:

Putting the VFD in a separate case is a good idea, as you say it protects it and once it's set up you don't really need to access it, all you do is fit remote  start/stop and speed controls, all done by programming. 

  Electronics is definitely not one of my strong points. I have to ask where I would get one of them remote start stop speed control things and exactly what I should ask for when ordering it? Thank you again for the above information. I am sorry to admit that I think I will be back with some more questions on this as I get some it together.

[dikman]

Unfortunately you don't just buy a remote unit made up (at least not from the store). It consists of a potentiometer (I used 10 kohms), a knob, a switch and a box to mount it in, all of which are available from Jaycar, if they're handy, or online. Some of the VFD's have a removable control panel but I don't think it's a good idea to try and mount it remotely. I used a 3-way switch to give me forward and reverse but after wiring it up it struck me as pretty pointless having the grinding belt going backwards!! I'll probably replace it with a simple on-off switch. Pity we don't live closer, instead of 3,000 kms or so, but I'm happy to help in any way I can. If you get stuck with the remote bit I can make you one and send it up.

I've been looking at the cheaper VFD's on ebay and all of them that I looked at had 220v input and 318v for the 3-phase, and while they obviously work we use 240v and 415v for 3-phase - which the one I bought from Conon is rated for. I'm thinking that I should buy another one of those for the lathe (I'm undecided). I noticed that the lathe motor has a squeak, which is not good.

 

[RockyAussie]

Thanks mate I will get back to you once I round up a few of these things and have them in hand. I do have some sort of a fancy VFD out in my project shed I bought a while ago but one look at it blew my head apart right at the get go. I will dig it out and see what I can make of it firstly. I think I may be needing a 2hp motor as it may be needed to run a polishing wheel as well and they do drag a fair bit of power when polishing with a large finishing brush on them. This is one of the reasons I am thinking of using a VFD as sometimes the brushes dont polish well if going too fast and the same can be said about the sanding as well.

Having one on the lathe sounds like a good idea not having to change them cogs about so much.

[RockyAussie]

Thanks mate I will get back to you once I round up a few of these things and have them in hand. I do have some sort of a fancy VFD out in my project shed I bought a while ago but one look at it blew my head apart right at the get go. I will dig it out and see what I can make of it firstly. I think I may be needing a 2hp motor as it may be needed to run a polishing wheel as well and they do drag a fair bit of power when polishing with a large finishing brush on them. This is one of the reasons I am thinking of using a VFD as sometimes the brushes dont polish well if going too fast and the same can be said about the sanding as well.

Having one on the lathe sounds like a good idea not having to change them cogs about so much. Or are we talking about a wood lathe?

[Spyros]

@RockyAussie

 

@dikman

Hey guys let me introduce you to Bob Loss, the closest thing I know to a dust expert.  He's an academic from Curtin Uni who has done a lot of research on creating clean workplaces and he's also a woodworker and a member on the the Australian wooworkforums.com.  In that forum he has helped countless people, including me, otherwise I wouldn't have a clue about dust meters or ventilators or even how dangerous dust is.  I can't remember how many times he has personally inspected people's photos, diagrams of their shed, and budgets, and helped them design a much better system even in those cases where it seemed pretty much impossible (like my case).     This is where to find him:

https://www.woodworkforums.com/f200/dust-extraction-presentation-235255#post2192616

Go ask him, honestly, if anything just watch the video.  You're not gonna find another guy like that, most other people in the dust extraction world will want to sell you something.

[RockyAussie]

Thanks for the thought @Spyros I will get into having a look at his Video sometime today and a bit more on that subject he has done and report back. Funny thing is I am originally a wood machinist by trade.