How to build KMG type belt sander

KMG 2”x72” belt sander for knife making. Construction Instruction for beginner. Part 1.

General thought and material list.

The belt sander is the number one most important tool for making saleable knives. It is by no mean to say that you can’t build very high quality knives using only hand tools. I did that for many years. And by know exactly what I put into the blade in regards of heat treating. I can positively said that my blade are very good.

Alas, saying that, there is one big drawback for using hand tools only. Most of the people that showing interest in the knives subjects, purchasing knives for collecting purpose and not as working tool. That is fine, but as they buy it for display, the knife need to be of higher visual quality. I am not saying that connoisseur out there are not looking for other quality, thing like materials, construction method, heat treatment method and alike. But I think the majority of knives enthusiastic (at least where I live in, the UK) are looking first of all for good visual appearance knife.

So by using hand tools only, you can never (or at least it will take you forever producing a knife) build knife that is one hundred percent symmetrical and look immaculate and shiny with crisp lines. Also you will find that to make the knife ricasso area completely flat is very and I mean very difficult, and this is on crucial area of the knife.

You can never make it viable operation, selling knives that is, without Belt Sander.

I decided to get one. I been looking on the internet to buy one, but in the UK it is very difficult item to find, and if you do find it, it’s very expensive ( I bet it is the case everywhere).

So I went about build my own. I did a lot of internet searching and find few plans to build a belt sander. The KMG come along to be one of the simple model. Although its simple, it is very nice entry level belt sander. It is versatile enough to accommodate several attachment head and it is not too much sophisticated to complicated the construction of it.

I did not find however good blue print for construction, so I draw my own ones. It is base on instruction I found on one of the British knives forums.

I have now got it in DWG and PDF format and I will be happy to share it, and In the next few post I will go about how I built my KGM belt sander.

Here is what you need:

I decided to cut all the part using laser cutting service. It is by far more accurate and fast then what you can achieved cutting it yourself.

If you send it for laser cutting, asked them to hatched the exact location of all the halls you will have, it will save you hell of a lot of time. Also I recommend to asked them to make all the halls that you need to thread, especially those for the pulleys, as they need to be dead striate.

You will also need:

Drive wheels. 100mm diameter x 55 wide with 20mm bore.

2x Platen rollers. Billet aluminium, 50mm diameter x 55mm wide, fitted with 10m ID bearings.

Tracking Pulleys. Billet aluminium, 50mm diameter x 55mm wide, crowned and fitted with 10mm ID bearings.

20mm Shaft. In suitable length. See assembly drawings in next post.

2x UCFL.204 bearing. UCFL.204 metric bolt oval cast iron flange housing with 20mm bore insert. Make sure the total width of the bearing can fit in between parts F.

2x V Pulley. 100mm dia.

V belt. To match the pulley. See (or wait for) post part 6.

2x Taper bush. One to fit 20mm shaft and one to fit the motor shaft (presumably 24mm).

One pulley bush lock. For locking the pulley in to the shaft.

Electric motor. 2-3 hp electric motor, three phase, dull voltage, 2 pole foot mounted. Three phase to control the speed of the motor. Make sure it is a frame size 90, to fit in the No. (Parts F) brackets.

Phase convertor. Phase convertor to enable using three phase motor on domestic electric net, and to enable the motor to change the direction of it rotation. You will also need box for it and two electric batten, one for on/off and direction and one for controlling the speed. It is rather beyond my understanding so you better asked electronic engineer for advice.

Main tension spring. Wire dia 3.5 or 4mm. Free length 127mm or there about.

 Spring platform. It proved to be difficult thing to find. However it need to be in size to match the diameter of the spring. You need to one for the top and one for the bottom. I add to improvised the all kit (see in next post) and it worked. I used M8 High Knurled Nut.

2x Tracking adjustment knob. I used M8 Five Lobe Grips with External Thread. One is for the tracking idler and one for adjusting the platen.

Clamp lever. M10 clamping lever for locking the main tool arm.

M8 Cylindrical revolving grip handle. For the tracking arm.

Nuts and bolt that you need:

Length is approximate and not absolute

For the bearings. 2x M10 Hexagon Head Setscrews 96mm + 4x Hex Nuts, + 4x Washers, 4x Spring Washers.

For the tracking hinge arm. 1x M10 Hexagon Head Setscrews 60mm + 4x Washers, + 1x Hex Nyloc Nut.

For the tracking hinge. 2x M6 Hexagon Head Setscrews bolt 28mm + 2x Washers.

For the tension spring. 1x M8 55mm Threaded Rod + 1x Washer, + 1x Hex Nut. 1x M8 Hexagon Head Setscrews bolt 60mm + 1x Washer, + 1x Hex Nut.

For the platen. 1x M12 Hexagon Head Setscrews bolt 72mm + 1x Washer, + 1x Hex Nut. 2x M10 Hexagon Head Setscrews 90mm + 2x Hex Nyloc Nuts, + 4x Hex Nuts, + 6x Washers, 2x Spring Washers. + 6x M6 Socket Head Countersunk Screws 25mm.

For the platen rollers and the idler. 3x M10 Metric Socket Head Cap / Allen Screws 90mm.

For the rest table. 2x M6 Socket Head Countersunk Screws 20mm. 2x M8 Hexagon Head Setscrews 30mm + 2x Washers, + 2x Spring Washers.

For the motor. 1x M10 65mm Threaded Rod + 2x Washer, + 3x Hex Nut. 1x 12mm dia axle rod, both end threaded 245mm, + 2x Washer, + 2x Hex Nut. 4x Hexagon Head Setscrews 96mm + 4x Hex Nuts, + 4x Washers, 4x Spring Washers, to suit the motor base.

In the next few posts I will talk about the construction and commissioning the belt sander. So if interested, do follow by subscribing to my blog.

For people in the UK I will publish the name of company that can source all of the above in future posts.

Have fun.

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How to built KMG type belt grinder

Hallow there

This post is about how I built KMG type belt grinder, belt size: 72” x 2”.

KMG clone belt grinder
KMG clone belt grinder

After spending around fifteen years making knifes, I realised that belt grinder is the most important tool that you can get. For sure you can build high quality knife without any electric tools. What make the knife high quality are the blade materials, the handle materials, and the heat treatment you give the blade. For constructing and finishing my knifes, I use mainly files, sand papers and drill press.  I use mainly scrap metal. For it I use small gas forge, shaping the blade up to around eighty present of its final shape. As I use only steel and not stainless steel, I can do all my heat treatment. So I know exactly what the inner quality of the blades is.

Problem with that method of building a knife is the finishing. The knife is good as any ABS master smith knife (I know, because I did test my knife), but the finish is less the perfect. It is very difficult to keep the knife shape symmetrical and it takes forever to build it.

Most of the knife collectors go by the look of the knife and by the name of the maker. It is hard to make them buy my type of knifes, and I can’t blame them for that.

So the solution for all of the above is: a Belt Grinder. It will significantly reduce construction time and the finish can be perfect.

The image sketch is taken from one of the British knife making forums. Several years back a guy publishes series of posts about how to make that type of belt grinder. I can’t remember his name, but I will be more than happy to give him the duly deserved credit, if someone will email me his name.

Probably you can find his instruction posts on the web’ and use it, it is what I did.

However, like all the instructions out there, part of it was clear to me and some not. I thought that in my article I will add more details to the ‘how to’.

I will not get into the exact construction, but I will go to lengthy details about the materials, dimensions, brand name and supplier in England and will supply CAD drawings.

KMG Drawing

Hope it will help you in your belt grinder project.



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