"Tormek 47" revived ?

[Ken S]

Rich Colvin posted a topic hoping to continue to use his worn  250mm wheels on a 200mm T4. At the time, I saw no practical answer. The situation may have changed.

The minimum diameter constrait is caused by the water trough. In order to fit over the 250mm wheel, the side of the trough must be lowered. As a result, a much reduced wheel sits above the water line.

The newT8 features a newly redesigned water trough with a lift. At the lowest point, the wheel is completely out of the water. What I do not know is how small (diameter) wheel is still emersed enough to be usable when the trough is in the full up position. This might possibly provide a practical solution to Rich's dilemma. I will not be able to measure this until my T8 arrives. Perhaps Stig could provide the answer for us.

Ken

[Herman Trivilino]

My guess is that it's designed to give you an adequate water depth at the minimum diameter recommended by Tormek, whatever that is.

Perhaps a person could stretch things beyond the recommendations. That's the usual case with manufacturer recommendations.

[jeffs55]

Nope, the smaller the wheel the greater the curve. Take the earth for instance, it is a sort of round planet large enough so that its curvature is not visible from anywhere on the planet. You can gain enough elevation to make it apparent but not while on terra firma. Reduce said planet to the size of a basketball and the curvature is readily apparent. So it is also with Tormek wheels, you can grind until you reach the drive shaft but your resultant edge will not be efficient or pretty. There is a point of diminishing returns. You reach sharp nirvana for a fraction of a second, until you actually try to cut something and then your edge folds over. Are we going to rehash this ad nauseum?

[Ken S]

Jeff,

I happen to agree with you. However, Rich asked the question, and there is precedent. The mounting instructions for the BGM-100 state that it is recommended for six through ten inch grinders. Personally, I would be reluctant to use Tormek jigs with a six inch grinding wheel, which is probably less than six inches. However, I would not presume to question Sweden.

Ken

[Stickan]

Hi,
Using our 250 stones on a T-4 will not work, as they are 10 mm wider. It will not fit the watertray and also, not enough treads to lock it on the shorter shaft on the T-7.

We recommend to not use the stones under 180 mm on the T-7 and the same recommendation will be on the T-8.
In principle you can use it as long as you have water on it which is about 150 mm.

Best,
Stig

[Ken S]

Thanks, Stig.

I think we have a situation where we must decide if possible is desirable.

Ken

[Inuwashi]

Hello,
Just as Stickan sad. Water tray and the length of the main shaft won't allow to use the 250mm stone on T-3/T-4.
However I know someone who has a T-7 for years and recently he bought a T-4. He is into DIY solutions and made it possible to use the worn out SG-250 stones on this T-4.
He changed the washer behind the stone with a smaller in thickness and using the metal ezylock from the T-7 instead of the composite. It works just fine. Water tray and length of the shaft is not a problem any more. However i don't think this is recommended by Tormek.

[Ken S]

Clever observation.

When my T4 first arrived, I noticed the smaller wheel would work on my T7 if I added the washer from the T4 as a spacer. Therefore, it seems possible to me that using the thicker SG-250 wheel without the washer, or a thin washer, would work with the T4.

However, since the T4 costs four hundred US dollars, and the T8 costs seven hundred dollars and includes a new, full diameter SG-250 grinding wheel (which would cost one hundred eighty four dollars); the new SE-77 square edge jig; and a TT-50 truing tool; to say nothing of the improved water trough, larger diameter grinding wheel, and the other improvements, I think the T8 is a more cost effective way to go.

Being possible does not make an option the most logical choice. Actually, the lowest cost option is to just replace the grinding wheel. A Tormeker who has worn down several grinding wheels has probably derived income from the process.

Ken

ps I went down to my workshop and took a closer look at the T4 and water troughs. As is, the T7 water troughs will not fit in the area of the T4. The constraint is the angle braces for he frame. I strongly do not recommend removing the braces! The alternative would be shortening the T7 water trough, preferably the older model. This seems very iffy at best.

As the Car Talk guys say, "It is the stingy man who pays the most". Just buy a new grinding wheel or a T8. (DIYers might try placing spacera under the trough to raise it.)