Kennet tool & cutter grinder

Hi there.

I've just bought myself a Kennet grinder and am struggling to find out a couple of details about consumables.

Would anyone who owns one of these machines let me know the diameter of the drive belt, please? I know it's a round (polycord?) belt, and how to determine a length, just not sure about cross-section.It's got the standard 1/6th HP motor, so Iassuming that the pulleys are also standard.

The other thing is...where can I get grinding cups to fit! I've found the sizes shared by John Baguley in a post, but cannot locate any. John's were labeled as Consort products, the remains that arrived with my machine are branded Universal. Both appear to focus solely on diamond abrasives nowadays, and gave me no pointers. Any suggestions?

Any advise would be much appreciated.

Thanks,

Jerry.

Universal abrasives are one of the largest suppliers of grinding wheels, all sorts of grinding wheels, not just diamond. I have just searched for 3 inch cup wheels and dozens have come up, same for taper cups, I suggest you search the internet.

Hi Jerry,

Welcome to the Kennet club. As this is built from kit may find all sorts of things have been tailored to suit the makers requirements. I use 5mm dia. Belting I have the texture variety but I don’t thinks there’s much to choose between that & the smooth. I bought a 100mm cup wheel from Midland’s off flea bay. Do be prepared for a lot of run out on the wheel I had to dress a lot off to get it running in better balance. It wasn’t a case of the wheel not being mounted wheel the wheel itself wasn’t round. I have spent a fair bit of time creating dust shields and aprons to reduce the amount of grit entering the slides and the tilt & rise and fall mechanisms as it was driving me nuts. If you haven’t got an Er collet holder for it Er25 is a worthwhile addition.

Tony

Thanks Tony, I’ll see where 5mm gets me. If it doesn’t fit, I can always make myself a catapult to keep the pigeons off the veg. patch…

As for cups, 100x40 mm looks to fit within the existing guard. It’ll need reducing - 12.7mm bore will fit the spindles.

Then all I’ve got to do is learn how to grind tools properly 😁. Will be spending a lot of time with Harold Hall’s books!

Hi Jeremy, I had wheels from midland Abrasives and like tony found them to be WAY out of balance. Balance of a wheel is very important in any tool and cutter grinder. If you can make mountings for your wheels then you need to incorparate a means of balancing. Then you need to make(or buy) a set of balancing ways. Noel.

I also bought a Tyrolit cup wheel - it was no better. In terms of concern ntrcity or balance. The Chinese diamond wheels are better but aren’t the best choice for HSS.

That would make an interesting article about how to pre balance a grinding wheel before fitting it to a grinder.

Once the wheel is fitted to the grinder it should be dressed but it shouldn't be too out of balance or need too much dressing.

The safety issue of course is fitting a wheel that is out of balance direct from the manufacturer straight onto the grinder with the risk of it causing too much vibration and possibly bursting.

So it's a chicken and egg situation, how do you know if it's out of balance before you fit it to the grinder, which brings me round to the first sentence in my post...!

For initial balancing, you could spend £3.56 on one of these:

https://www.ebay.co.uk/itm/275570011508

It should also be noted that a wheel can be in balance but out of round.. There is no point in balancing  a wheel that is out of round it needs to be trued first and this will also improve balance.  Unless there is a balance weight arrangement the wheel will need to be drilled to remove imbalance, that’s not something I have tried and it makes me nervous thinking about it, although the wheels I have are pretty thick at the  base of the cup where the drilling would take place. Rotating the mounted wheel by hand with a reference pointer will show how far out of round it is before firing it up to dress. I heavily dressed the cutting face to get that true and the first  20mm or so of the outside cup and a bit on the inside to improve matters. I had to be  creative to come up with a way of doing this with a bit of square bar with a single point diamond dresser at 90 degrees slid along a fence mounted to the table guard removed. Imbalance will cause bearing wear over time and will shake the setup but I believe that the risk of a ring tested new wheel exploding during this initial balancing and truing is low and should not cause bearing damage. I use a 1 thou DTI on a mag base to measure carriage movement and when balance is bad it’s unreadable due to needle movement.

The other thing to mention is the two cup wheels I bought are both 6mm or so deeper than the wheel guard which I think is a Quorn item.

Edited By Tony Ray on 29/07/2023 08:19:57

Crikey, there’s a lot more to getting started than meets the eye! Thanks for all the advice guys, I’ll get hold of some wheels and see what they are like. I will be stripping the whole thing down to give it a good clean and check over, so I’ll be able to give the bearings the once over. It feels like it hasn’t been used for quite a while - it will be interesting to see what state it’s in inside.

Jeremy,

Hemingway kits sell an aluminium oxide cup wheel which is used on their Worden grinder. I built one and didn't experience any balance issues with it at all. It may require a custom flange to mount on a Kennet, however.

John

Hi Jeremy,

The belt that came with the kit is 5mm dia. The wheels also came with the kit.

I ended up balancing the two large cup wheels by gluing pieces of lead onto the inside surface of the wheels.They were pretty round so truing them would not have helped the balance a great deal.

John.

Presumably they also sell the various wheels for the Quorn which they now have sole rights to.

Rod

Rod,

I suspect so. The wording on the Hemingway web site certainly suggests that is the case.

John

Methods of balancing mentioned in this thread include drilling holes in, (how?), or gluing lead weights to the abrasive wheels wheels.

I would suggest that either method is highly inadvisable. The wheels would be locally stressed and/or the weights could become detached.

I agree with Clive both ideas may lead to accident or injury ! There are numerous ways to balance a wheel but use a wheel carrier. The Brierley uses a dovetailed groove round one of the flanges into which little threaded cones sit with a grub screw to set them. Adding, removing or repositioning them sets the balance. Obviously one is going to need a set of balancing ways. Noel.

To be clear I never said anything about drilling holes in the wheel. Drilling results in a series of dimples. It is well explained on YouTube by respected machinists. I agree that a balancing hub would be preferable, if anyone has a design for the Kennet or Quorn I’d be interested to see it.