KMG Grinder build in progress

Hi Tedinatl

Glad you like it, if you are thinking of building one, then take a look at the URL's I listed in my first post of this thread - they have far more detail than this post. The KMG one is a complete - step by step guide to making a KMG grinder, from the sizes of all the steel pieces to the bearings, bolts etc, and a step by step construction of a KMG grinder. I printed out that link, and a bunch of other info I found on the KMG grinder and bound it all into a book and it has been my workshop guide to building this one, even though I have built it by drilling and tapping rather than welding, which has required some changes to some of the parts and the layout / design to suit the drill/tap construction method.

It has been great fun to build, and a lot of work, but It will be worth it in the end!!

Rick
 
Hi Everyone

I have now completed the tracking arm tension spring, I can't believe my luck spotting the gate closer at the local hardware store. It worked perfectly, i just had to drill and tap the spring platforms, and then shorten the spring to fit. (I also discovered how to flatten the coil spring ends so the shortened spring fitted the spring platforms properly.) See the pics below

I beveled all of the corners on the tracking spring mount and tracking pivot mount, as they all had sharp corners, and I have lost some skin scraping past them while tightning bolts etc. I think I will also shamfer / bevel the corners of the tracking pivot mount - like I did with the toolbox legs & bearing support mounts, to remove the sharp corners.

I did some searching around various suppliers in Cape Town yesterday but was not able to find the tracking arm adjustment knob or the locknut for the toolarm. (I went to RS Components - the supplier mentioned in the KMG link, however RS have no local stock and would have to order out of the UK and I would have to buy a minimum of 10 each, so it looks like I will have to make another plan.

Next up is figuring out how to drill the drive shaft / bearing holes! IDEAS ??

KMG - tracking spring 1.jpgKMG Tracking Spring 4.jpgKMG Tracking Spring 2.jpgKMG Tracking Spring 3.jpg
 
Hi Keith

I am about ready to see it finished myself - but it will still take a bit more work yet.

Thanks
God Bless you too
Rick
 
Hi Pieter

Thanks for that - I will probably order from KMTS if I can't find them here.

I made some more progress yesterday and managed to drill the bearing mounts with my small drill press - 10mm mounting holes and a 22mm hole saw for the drive shaft. - Even though the spindle speed was a bit higher than recommended 515rpm vs 450, I took it slow, used lots of cutting lubricant (old motor oil) and it cut perfectly. I clamped the two bearing carriers together, so the bearing mounts and drive shaft holes are perfectly aligned (I may need to open the drive shaft holes up slightly for drive shaft alignment) - if this is neccessary I will enlarge the hole with a dremel and drum sanding attachment.

I'm quite chuffed, it's really starting to come together now. I think the next thing to be done, besides getting the motor and VFD nad the drive wheel, contact wheels etc is to construct the flat platten tool arm, and a work rest.

Thanks for all the feedback so far
Rick
 

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Hi Everyone

Sorry for not updating the WIP recently, I just came back from a business trip for 10 days in Italy so have not had time to do any more work on the grinder.

I may have struck it lucky with a VFD - one of the guys at our knife club mentioned on Saturday that he knows someone who is selling one. He has previously bought three or four VFD's from the same chap and they have all been in perfect condition and available for a fraction of the price of a new unit. I am holding thumbs !!!

Question - For all the guys with grinders - what would you recommend as a good diameter contact wheel to start with? I realise the wheel diameter to use is dependant on the width and thickness of your steel blank, but I cannot afford to go out and buy multiple contact wheels from the start - so I need an idea of which would be a good diameter to start with 8", 10" 12" ??? I am leaning toward a 10" wheel

I hope to be able to make some progress and put up some pics this weekend.

Bye all
Rick

I am
 
Hey Rick,
I started out with an 8" contact wheel for my NWGS, and while I'm still quite happy with it, I think I am leaning towards wishing I had a 10" wheel. Both have their own advantages of course, but I think 10" would be a good starting point.
 
Hi AR

Thanks for the advice, I think I will go with the 10" wheel.
I found out today that I can get the VFD (1.1KW) for 1/3 of the price of a new one - and it is in virtually new condition - excellent news. I might be able to get the contact wheel, drive and tracking wheels and the motor next week as a colleague is travelling to Johannesburg for a few days, if he can bring them back with him, it will save a lot on shipping costs.
 
Hi Everyone

After a couple of weeks of work related traveling I was finally able to get back into the shop and get some more done on the KMG today, I fitted the drive shaft, chamfered the corners of the pivot arm mount and finished off the pivot mount itself, I also stared work on the flat platten by marking the steel.

As mentioned in my last post, the club secretary at my knife club managed to find me a 1.1KW VFD for 1/3 price of a new one, so now I need the 3phase motor and the various wheels to complete the grinder - Drive wheel, Tracking wheel, 10" contact wheel and the rollers for the flat platten.

Cheers Rick

KMG-drivshaft3.jpgKMG-driveshaft1.jpgKMG-driveshaft.jpgKMG-driveshaft4.jpg
 
Great job Rick, I think you have a knack for all of this.

Looking forward to seeing the finished product.

Rick O'Shea (Scott L)
 
Hi Rick (Scott)

Thanks - I'm really enjoying myself, it's inspiring creating things!!
I look forward to finishing it, hopefully it will not be too much longer!!

Rick
 
Looks great!
Question though, so you make the whole thing out of aluminum? Are you concerned with vibration? Anyone else out there made one from aluminum? I am looking at making one also, hope it looks as good as yours Rick!

Chris
 
Hi Chris

My grinder is actually mostly made out of steel (10mm & 15mm bright mild steel) the only part of the grinder that is aluminium is the toolarm (since I couldn't find the correct size mild steel square bar), and now also the base plate. I changed the two "Feet" for a square aluminium plate to facilitate mounting the motor (450mm x 450mm x 8mm). I don't think making it out of aluminium would be a problem if you used thick enough aluminium, and construct it accurately and solidly.
The plans I referenced in my first posting (not the KMG one, the other one) utilises aluminium plate construction (16mm thick) throughout. It should be lighter than mine since the mild steel is heavy compared to aluminium.

I have made a bit of progress in the past two weeks, including changing the grinder base (as described above), purchasing the 1.1Kw (1.5Hp 3 phase motor) and the 1.1Kw VFD, as well as obtaining a couple of Castors, one for use as the drive wheel, and the other for use as a 10" contact wheel. The castors were pretty rough castings, but one of my knife club friends helped me out by machining them true on a lathe, and then balancing them, he also machined the tracking wheel for me out of 85mm dia Aluminium rod. I have also all but completed the flat platten & toolarm and the toolarm for the 10" wheel. I still need to make the work rests for the toolarms. With a bit of luck the grinder should be complete within the next week or so.

I will upload some picture this weekend, unfortunately I have been travelling on business again and haven't had a chance to upload anything in the past week or two.

Good luck with yours Chris, I think you will enjoy making one, it is a fun project and you will most likely learn a few things along the way.

Cheers
Rick
 
Grinder update

Hi Everyone

I just realised that I have some recent pictures from last weekend of the grinder on my Blackberry, and since I have a couple of hours to kill at the airport, I did a couple of quick edits and uploaded them. See below for grinder progress as of last weekend.

I hope to be able to finish it off within the next week or so. I still need to find a NEMA sealed enclosure for the VFD since it is not a sealed unit, and would not last long in an environment surrounded by steel dust. I need to find one with a clear front panel to be able to see the speed readout etc on the VFD.

I can't wait to be able to use the grinder!!!

Bye for now
RickCastor - Contact wheel.jpgKMG + motor.jpgKMG Flat Platten.jpgKMG - new baseplate.jpg
 
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