Nathan the Machinist
KnifeMaker / Machinist / Evil Genius
Moderator
Knifemaker / Craftsman / Service Provider
- Joined
- Feb 13, 2007
- Messages
- 17,740
These are 9" grinding disks made of hardened alloy steel (4130 HRC 44), turned in a way to minimize runout and then balanced. They were made by request in response for a need for industrial quality grinding disks made for professional use.
I have 5 taper with the 5/8" bore ready and 1 flat and 1 taper with the 3/4" bore today.
The 3/4" bore disks are not broached, they're a plain bore to mount on a Thompson shaft. I will broach them on request before shipping, no problem, but it will be a reduced depth key so as not to cut too deep in the wall of the stub. You'll need grind your key to fit.
This is just about the last of a batch of 100 disks. When this is finally finished there will be no more of these.
The last thing I do is spin it up on an unmounted motor and let it coast down. The motor is unrestrained so any vibration or other troubles would have an opportunity to show up here. Video if you're curious:
[video=youtube_share;-b_h7NaZxKg]http://youtu.be/-b_h7NaZxKg[/video]
The manufacturing of these disks was documented on this WIP thread:
http://www.bladeforums.com/forums/showthread.php/1088181
These disks are 8.875" in diameter and mount to a 5/8" shaft. Setscrews are included as is some keystock. The key stock may require some slight fitting etc (you're a knife maker right?)
It is important you tighten the two setscrews properly. This disk weighs over 7 pounds, you want it to stay on the shaft. The setscrews are high quality Holo Krome brand fasteners of domestic origin, the sockets will not easily strip. You should use a hex insert in a screw driver rather than a dinky wire Allen Key, and if in doubt use a drop of blue loctite. The thread is 10-32 if you want to change to different screw type.
In this sale I have five 5/8" bore disks with a 1 degree taper on the face, and I have one each with 3/4" bores. If you order a 3/4" and want it broached you need to let me know. They are $160 each and shipping is $10 in the USA via USPS priority mail. Be aware that if you're more of a casual user, Beaumont Metal Works has an aluminum disk for half this price.
Please keep sales in the sale threads to help me keep up with it. Those of you who have bought platens and chillers know how these sales work, but here is how to order a disk:
I need you to please follow these instructions to help me keep up with everything (otherwise folks will fall through the cracks).
1: State your claim in this thread.
2: send me an email (not a private message) carothersknives at gmail dought com
The email should include what you are buying, your BladeForums handle (i.e.: "Nathan the Machinist"), your actual name, your shipping address and your paypal email address.
I will send a PayPal invoice to that email.
3. Pay the paypal invoice. Once it is paid, I will ship your order to the name and address you gave in your order email.
If you don't want to use paypal, we can arrange to send a check.
If there are shortages it will be based upon first come first serve who posts in this thread. I have to do it this way to keep things sane.
Thoughts about "runout":
The manufacturing approach I'm using virtually eliminates runout in the disk because the OD, working face and the internal diameter of the bore are all single point turned in the same setup on a CNC turning center. Unlike drilling and reaming, which can create an off center hole, single point boring creates an accurate hole without risk of bias or walking. Cutting the face at the same time sets the working surface perfectly perpendicular to that bore and cutting the OD at the same time also sets that feature perfectly concentric to that bore. Observable runout on the actual disk is almost physically impossible. That said, you could have the most perfect disk in the world, but if it isn't mounted to your spindle properly or if your spindle itself has runout it is still going to wobble. Electric motors are not ultra high precision spindles, they're simply designed to turn pulleys etc without a lot of fuss. Some even have bushings instead of bearings. If you get a disk and it wobbles I can almost certainly guaranty the problem isn't the disk, but I will still gladly refund your money if you will return the disk in perfect condition.
Thanks,
Nathan
I have 5 taper with the 5/8" bore ready and 1 flat and 1 taper with the 3/4" bore today.
The 3/4" bore disks are not broached, they're a plain bore to mount on a Thompson shaft. I will broach them on request before shipping, no problem, but it will be a reduced depth key so as not to cut too deep in the wall of the stub. You'll need grind your key to fit.
This is just about the last of a batch of 100 disks. When this is finally finished there will be no more of these.
The last thing I do is spin it up on an unmounted motor and let it coast down. The motor is unrestrained so any vibration or other troubles would have an opportunity to show up here. Video if you're curious:
[video=youtube_share;-b_h7NaZxKg]http://youtu.be/-b_h7NaZxKg[/video]
The manufacturing of these disks was documented on this WIP thread:
http://www.bladeforums.com/forums/showthread.php/1088181
These disks are 8.875" in diameter and mount to a 5/8" shaft. Setscrews are included as is some keystock. The key stock may require some slight fitting etc (you're a knife maker right?)
It is important you tighten the two setscrews properly. This disk weighs over 7 pounds, you want it to stay on the shaft. The setscrews are high quality Holo Krome brand fasteners of domestic origin, the sockets will not easily strip. You should use a hex insert in a screw driver rather than a dinky wire Allen Key, and if in doubt use a drop of blue loctite. The thread is 10-32 if you want to change to different screw type.
In this sale I have five 5/8" bore disks with a 1 degree taper on the face, and I have one each with 3/4" bores. If you order a 3/4" and want it broached you need to let me know. They are $160 each and shipping is $10 in the USA via USPS priority mail. Be aware that if you're more of a casual user, Beaumont Metal Works has an aluminum disk for half this price.
Please keep sales in the sale threads to help me keep up with it. Those of you who have bought platens and chillers know how these sales work, but here is how to order a disk:
I need you to please follow these instructions to help me keep up with everything (otherwise folks will fall through the cracks).
1: State your claim in this thread.
2: send me an email (not a private message) carothersknives at gmail dought com
The email should include what you are buying, your BladeForums handle (i.e.: "Nathan the Machinist"), your actual name, your shipping address and your paypal email address.
I will send a PayPal invoice to that email.
3. Pay the paypal invoice. Once it is paid, I will ship your order to the name and address you gave in your order email.
If you don't want to use paypal, we can arrange to send a check.
If there are shortages it will be based upon first come first serve who posts in this thread. I have to do it this way to keep things sane.
Thoughts about "runout":
The manufacturing approach I'm using virtually eliminates runout in the disk because the OD, working face and the internal diameter of the bore are all single point turned in the same setup on a CNC turning center. Unlike drilling and reaming, which can create an off center hole, single point boring creates an accurate hole without risk of bias or walking. Cutting the face at the same time sets the working surface perfectly perpendicular to that bore and cutting the OD at the same time also sets that feature perfectly concentric to that bore. Observable runout on the actual disk is almost physically impossible. That said, you could have the most perfect disk in the world, but if it isn't mounted to your spindle properly or if your spindle itself has runout it is still going to wobble. Electric motors are not ultra high precision spindles, they're simply designed to turn pulleys etc without a lot of fuss. Some even have bushings instead of bearings. If you get a disk and it wobbles I can almost certainly guaranty the problem isn't the disk, but I will still gladly refund your money if you will return the disk in perfect condition.
Thanks,
Nathan
:thumbup:
