Needs Pictures: 0
Results 1 to 15 of 51
Thread: Home built toolpost grinders
-
23rd Jul 2020, 06:25 PM #1Most Valued Member
- Join Date
- Sep 2010
- Location
- Lebrina
- Posts
- 1,910
Home built toolpost grinders
I have been pondering the subject of home built toolpost grinders lately, so I did the usual Youtube research and discovered that there are quite a few that have made toolpost grinding setups and these range from being very well executed https://youtu.be/znTTiDv02GM to useless deathtraps https://youtu.be/ExOk3vxIqEM
My curiosity revolves around why nobody seems to be building larger toolpost grinders with the build quality of Stefan Gotteswinter's as shown in the first youtube link. It seems to me that it shouldn't be that difficult to build a machine with an induction motor somewhere from 1/4 to 3/4 Hp that would utilise either a 4-8" wheel or a smaller stone for internal work.
I would imagine that bearings with the appropriate tolerance shouldn't be an issue and the machining seems pretty basic for anyone with a lathe and a mill.
What am I missing?
-
23rd Jul 2020, 07:28 PM #2Most Valued Member
- Join Date
- Nov 2017
- Location
- Geelong, Australia
- Age
- 57
- Posts
- 2,651
I think the difference is that there aren’t really any small ones available so people build their own. Larger ones, for the work involved it’s better value for most people to just buy a used commercial one for a few hundred dollars.
Steve
-
23rd Jul 2020, 07:29 PM #3
Not missing anything. I'm building one using a 2Hp 30,000 rpm max brushless DC motor running on 18V. It's less than 50mm diameter and 85mm long.
Trying it out with standard bearings to start with but expect to have to go to angular contact bearings to make it good....
Cheers
JoeCheers, Joe
retired - less energy, more time to contemplate projects and more shed time....
-
23rd Jul 2020, 08:50 PM #4Most Valued Member
- Join Date
- Jun 2012
- Location
- SA
- Posts
- 1,649
The problem with standard sized TPG's is that they really only suit a lathe larger than 10" swing to allow accurate centre line alignment on the toolpost top slide.
So smaller home made TPGs are much more useful for smaller lathes. I have a Waldown 01, a 775 DC powered much smaller home made TPG, a tool post mounted electric die grinder, and a tool post mounted air pencil die grinder.
The small 775 DC powered TPG gets most use as it is the most easily mounted and useful of the lot on my 10" swing lathe, for mainly model making work. It can also cross and radial drill as it has Jacobs chuck mounts.
If you have a larger lathe and do larger jobs, then go larger if you want, but be aware tool post mount centre line issues may be a problem the larger you go.
Cheers RobThe worst that can happen is you will fail.
But at least you tried.
-
23rd Jul 2020, 08:51 PM #5
Hi Karl,
Have a look at my "Brooks TCG" posts in projects. I'm currently on my third attempt to build one. Having had some issues with the four jaw chuck, and discovering just how difficult it is to get both end of the body truly in line. But like all things there is a learning curve.
I'm currently making the end caps to screw in. Turning them to size is the easy bit.Best Regards:
Baron J.
-
23rd Jul 2020, 10:01 PM #6Most Valued Member
- Join Date
- Sep 2010
- Location
- Lebrina
- Posts
- 1,910
Admittedly, I haven't looked too hard or for too long, but I have only seen one for sale in Australia and that was on this forum. As always there are plenty in the US via Evilbay, but they are typically 115V and freight is often greater than the grinder price.
I can understand the issues around center height, but my new lathe is a 20" swing, so I've covered that issue at least.
Based upon the unit that sold via this forum for $400 or thereabouts I think, you would definitely be better off buying rather than building, but my luck is usually to find the bargains just after someone else has.
-
23rd Jul 2020, 10:10 PM #7Most Valued Member
- Join Date
- Nov 2007
- Location
- melbourne australia
- Posts
- 3,228
-
23rd Jul 2020, 10:14 PM #8Member
- Join Date
- Oct 2012
- Location
- Mullaloo WA
- Posts
- 80
Toolpost Grinder
Checkout of YouTube a presenter Clough42 made one for smaller lathe.
Col
-
24th Jul 2020, 09:54 AM #9
Not sure where your located but here is one
https://www.gumtree.com.au/s-ad/mona...oid_VIP_stickyUsing Tapatalk
-
24th Jul 2020, 11:04 AM #10Most Valued Member
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 2,129
Karl you can get a very good surface finish using good quality standard brgs and a suitable shaft diameter on a tool post grinder.
Making it rigid and getting the wheel close to the tool póst is important to not get chatter.
When internal grinding depth of bore is limited to shaft and extension mandrel diameter, small dia shafts and grinding wheels chatter very easily
so you can only do very short bores, when you get chatter if you are close to your target you will over shoot and throw the part over the fence.
-
24th Jul 2020, 07:09 PM #11Most Valued Member
- Join Date
- Jun 2012
- Location
- SA
- Posts
- 1,649
The worst that can happen is you will fail.
But at least you tried.
-
24th Jul 2020, 07:58 PM #12Most Valued Member
- Join Date
- Apr 2012
- Location
- Healesville
- Posts
- 2,129
Rob, if this https://www.youtube.com/watch?v=nHqHPGfgjuI is the extent of your internal measuring equipment then I doubt very much that you would know when you are getting chatter.
-
24th Jul 2020, 08:04 PM #13Most Valued Member
- Join Date
- Jun 2012
- Location
- SA
- Posts
- 1,649
What the hell has that got to do with chatter ? Get real. You would see it in the grinding pattern first up and secondly it should NEVER happen given the very light pressures involved. LOL How much grinding have you actually done ?
Just so we are quite clear on this, today I ground some 3 mm diameter shafts with my TPG. Try that with any sort of chatter.The worst that can happen is you will fail.
But at least you tried.
-
24th Jul 2020, 08:30 PM #14
Yes, the speed controller is suitable for 80A.
I'm going to run it off an 18V battery.
Just because it can draw that current, I doubt that grinding wheels in this application are able to absorb that sort of power. I'm also hoping to use it with burrs and small milling cutters. They won't use that sort of power either I suspect.
I'll post pictures and more descriptive info when I've got it finished and tried it out.
Cheers
JoeCheers, Joe
retired - less energy, more time to contemplate projects and more shed time....
-
24th Jul 2020, 08:32 PM #15Golden Member
- Join Date
- Aug 2015
- Location
- Melbourne, Australia
- Posts
- 843
Karl, I was pretty keen on building one - I even starting sourcing various parts - then a waldown c0 cropped up at a good price. done. ) I even picked up some small 11000rpm motors (as a lot of two) that might suit but they turned out to be 110v!
Similar Threads
-
Home built fly cutter
By steamloco1954 in forum METALWORK GENERALReplies: 2Last Post: 2nd Mar 2020, 11:06 PM -
What have you built with your welder.
By R W in forum WELDINGReplies: 23Last Post: 24th Apr 2016, 03:44 PM -
Anyone built a car hoist
By simso in forum METALWORK GENERALReplies: 16Last Post: 4th Jan 2011, 09:20 AM -
has anyone built a trailer from a ute
By ROB313 in forum TRAILERS & OTHER FABRICATED STUFFReplies: 13Last Post: 7th May 2009, 11:33 PM