yulan
New Member
Hi thanks for looking hope I can help
Posts: 11
|
Post by yulan on Mar 19, 2024 12:43:04 GMT
Hi All.
I just got a RS Pro Edge.
I went for this system because it advertises a "Flat Grind". But found it does not, always a bump in the middle of the grind.
I spoke with RS Customer care. They said they are aware of this, & for me to buy a new back plate. I did still the same. RS did say if it still the same to send it in for them to have a look. That would be about £25 posting ither way.
I noted on the old back plate it was flush at the side of the frame. Which meant there was a gap between the belt & back plate about 1mm. I adjusted it moving the back plate towards the belt as far as it will go. Now no gap between belt & backplate. it's better but still slight bump to the middle of the grind.
Has only one solved this
|
|
|
|
Post by Bumble Bee on Mar 19, 2024 13:44:49 GMT
I've experienced the same, and decided the "bump" is from the splice in the belt. I can't fix that, as all belts have a splice. Mine is for sale.
Bumble Bee
|
|
|
|
Post by Pete on Mar 20, 2024 17:12:08 GMT
Hi Yulan
What tools are you sharpening and with which jig? I only sharpen woodturning tools on mine and have not found "a bump" the pressure needed to achieve a sharp tool is very little (not even the weight of an arm) but even so the back plate can wear over time (replacements are under £10 so not a big deal)
As I said first I need to know what tools you are sharpening and with which jig.
Also a picture of your backplate with a straight edge over it would be helpful, I know it's been replaced but a picture will still be helpful.
Finally and much harder... how much pressure are you putting on the tool against the belt? I tend towards a single finger on my left hand pushing down while my right hand just controls the tool handle weight and movement.
|
|
yulan
New Member
Hi thanks for looking hope I can help
Posts: 11
|
Post by yulan on Mar 20, 2024 21:06:53 GMT
Hi Yulan What tools are you sharpening and with which jig? I only sharpen woodturning tools on mine and have not found "a bump" the pressure needed to achieve a sharp tool is very little (not even the weight of an arm) but even so the back plate can wear over time (replacements are under £10 so not a big deal) As I said first I need to know what tools you are sharpening and with which jig. Also a picture of your backplate with a straight edge over it would be helpful, I know it's been replaced but a picture will still be helpful. Finally and much harder... how much pressure are you putting on the tool against the belt? I tend towards a single finger on my left hand pushing down while my right hand just controls the tool handle weight and movement. HI. I am grinding lathe tools & wood chisels. I notes it when I sharpened a wood chisel. I am a retired joiner so been Grinding/sharpening gear for the past 50 year, I understand about light pressure Mainly to keep the tool from heating up ie on 2 seconds off few seconds. I have also tried moving the tool across the belt. Just the same. I also tried a bit more pressure on & off, This was a bit better but the chisel got warm faster "It is an old chisel". I examined the back plate & yes slight in-cave, I also put a straight edge from top wheel to bottom wheel left side, Then same right side. there was a different measurement of almost 1mm. IE plate is not parallel. So I buy new one £12.93 eBay. Fitted new back plate measurement was better. Only difference this time back plate is as far forward as it will go, I think this will stop any slag in the belt, But fear it may help towards heating the back plate faster. have you put a straight edge across the grind to see it flat. |
|
|
|
Post by Pete on Mar 20, 2024 22:40:42 GMT
Yes literally today after I wrote my reply, I made myself curious. Very slight concave only visible when I put a torch behind the square I was using as a straight edge. I bought my replacement one from Yandles for £9.99 but I go there quite often so picked it up it would probably have been about the same price with postage.
Bench chisels I only put on the course belt to repair damage, and I did it when I bought a new set a few years back I flattened the backs of them then took to 25° but I finish and maintain them on a stone as they only get used occasionally. I do know professional flat workers who use the Proedge for bench chisels as they need to get them all sharp fast for next week, but mine get used once a month so the stone suits me.
I forgot to ask what belt/s you are using. I use the Ceramic belts or the diamond belt, I own the Trizac ones but never really used them.
Also if you click the "Reply" button on the right hand end of the screen you get the more advanced editor which allows you to post pictures, which may help in getting to the bottom of this problem.
If you are in the UK then it will only cost you £2.99 to return the backplate to Sorby customer service (2nd class small package under 2kg)
|
|
yulan
New Member
Hi thanks for looking hope I can help
Posts: 11
|
Post by yulan on Mar 21, 2024 9:56:29 GMT
its the blue belts Think 60 & 100
Yes that very slight bump alters the gringding angle a lot. So if you grind @ 30% with the bump it's 45% approx. which makes a big difference when finding the bevel at the start of a cut. when you are used to 30% concave angle.
I was using a 8" wet stone. Got used to the concave effect with the wheel, @ the mo I'm thinking the wet grind is much better.
When I first grind on the pro, I did notes a difference on finding the bevel @ the start of a cut. At first I thought now its straight that's the difference. wasn't until I was "sharpening" my 1" flat chisel on my Trend is highlighted the bump.
On your backplate.
Is it flush with the side frame that you screw the plate to it.
Or is there a protrusion, If there is a protrusion how much. Mine now protrudes about 1.1/2mm.
I found when first got the pro it was flush with the side frame, Hence about 1mm gap between the backplate & back of the belt.
Now I have moved the plate as far forward as I can the belt rides on the backplate. I think this will give limited bend in the belt.
Im wondering if we can alter the tension on the wheels ie more or less.
|
|
yulan
New Member
Hi thanks for looking hope I can help
Posts: 11
|
Post by yulan on Mar 21, 2024 12:11:20 GMT
I've experienced the same, and decided the "bump" is from the splice in the belt. I can't fix that, as all belts have a splice. Mine is for sale. Bumble Bee Hi. Is your back plate flush with the left side & have you checked if they are tight |
|
|
|
Post by Pete on Mar 21, 2024 14:32:40 GMT
Mine is flush with the frame so the belt is only touching the backplate when I am sharpening and putting a little pressure on the belt.
Many knife sharpening linishers work on belt tension alone with no back plate.
30° to 45° is a massive difference. I am not even sure how you achieve that discrepancy, I may get 1° or so difference depending on how I present the tool but without changing the jig no way could I be 15° out.
Where in the UK are you? If you happen to be near Bristol then I could come and see the problem first hand, but of course that is unlikely.
|
|
yulan
New Member
Hi thanks for looking hope I can help
Posts: 11
|
Post by yulan on Mar 21, 2024 17:36:12 GMT
Mine is flush with the frame so the belt is only touching the backplate when I am sharpening and putting a little pressure on the belt. Many knife sharpening linishers work on belt tension alone with no back plate. 30° to 45° is a massive difference. I am not even sure how you achieve that discrepancy, I may get 1° or so difference depending on how I present the tool but without changing the jig no way could I be 15° out. Where in the UK are you? If you happen to be near Bristol then I could come and see the problem first hand, but of course that is unlikely. That's interesting. Flush with the frame. There must then be about 1mm between belt & backplate. Mine was like that & I did wonder if that's how they made it to stop over heating on belt & backplate. But my point here is the belt will bend until it hits the backplate, Must do mine did have Wear on the plate. This I thought will give a slight round/bend & did. When I moved the backplate closer as far as it will go, This did reduce the bump. Haven't Dunn much grinding as yet did feel the back plate best I could without taking the side off. Could not feel heat or sizzling LoL. If I get time to work out the discrepancy I will, I only used the fingers as speech not as accurate numbers, But would not surprise me if not far out. Im in Hull Humberside. Just managed to do a measurement on My 1" Skew ground at 30 deg. The cutting edge is around 27mm longe. measure hale way that's the bump/hill, Best I can measure is bump now about 1/2mm higher than the heal & point. When I protractor it, it comes out, That's from the tip of Skew to bump, It comes out 36Deg. when I first saw the bump best I can remember it was about 1mm maybe a bit smaller, Measure the same this came out 40Deg. So may not be as far as I thought at first. But must admit it makes it out by a significant distance. On a gouge think it will be smaller Degree, As from cutting edge to heal is smaller. But as you are trying to find your grind on the lathe you first hit the heal & now the bump then start cutting. So what ever you do your grind at the bump alters it significantly, So giving you a smaller riding point. if you want a 30Deg grind, You will have to set it at 36Degrees As what I'm used to & now think its better is a concave grind from wet & dry wheel, This gives you only to points. The heal then the cut. |
|
