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Blood Sweat Tears and Grease => Wheels Tires and Brakes => Topic started by: doc_rot on Jan 24, 2018, 01:31:32

Title: question for machinists
Post by: doc_rot on Jan 24, 2018, 01:31:32
I need to bore this needle bearing inner race from 16 to 17mm. A carbide boring bar wouldn't cut it at all. I'm thinking about making a tool holder for a dremel and putting a sanding drum on it. what should i do?
Title: Re: question for machinists
Post by: Tim on Jan 24, 2018, 02:19:15
Buy a replacement bearing with the right dimension race?
Title: Re: question for machinists
Post by: doc_rot on Jan 24, 2018, 02:32:56
I looked but its a weird size. The needle bearings are 25x32x30 and the inner race needs to be 17x25x35 or could be 17x25x30
Title: Re: question for machinists
Post by: J-Rod10 on Jan 24, 2018, 08:44:56
What is that made of that carbide wouldn't touch?
Title: Re: question for machinists
Post by: irk miller on Jan 24, 2018, 09:36:19
Adamantium
Title: Re: question for machinists
Post by: SONIC. on Jan 24, 2018, 09:50:48
Adamantium

Beat me to it you bastard.
Title: Re: question for machinists
Post by: J-Rod10 on Jan 24, 2018, 11:30:50
Probably give ceramic a go on the Wolverine claw bushing.
Title: Re: question for machinists
Post by: Pete12 on Jan 24, 2018, 18:52:34
I need to bore this needle bearing inner race from 16 to 17mm. A carbide boring bar wouldn't cut it at all. I'm thinking about making a tool holder for a dremel and putting a sanding drum on it. what should i do?

I made a tool post holder for a die grinder with a cylindrical stone to grind my chuck jaws. I angled it very slightly to cut on the leading edge and it worked perfectly.
Title: Re: question for machinists
Post by: J-Rod10 on Jan 24, 2018, 20:02:51
I made a tool post holder for a die grinder with a cylindrical stone to grind my chuck jaws. I angled it very slightly to cut on the leading edge and it worked perfectly.
Poor mans tool post grinder. Well done.

*Not calling you poor, just far cheaper than a tool post grinder.
Title: Re: question for machinists
Post by: Pete12 on Jan 24, 2018, 20:40:03
Poor mans tool post grinder. Well done.

*Not calling you poor, just far cheaper than a tool post grinder.

Haha, no problem. As much as I'd like a tool post grinder it would be very hard to justify for the amount of times I'd use it.
Title: Re: question for machinists
Post by: crazypj on Jan 25, 2018, 12:05:57
I made a tool post holder for a die grinder with a cylindrical stone to grind my chuck jaws. I angled it very slightly to cut on the leading edge and it worked perfectly.

+1
Thats the best way to do it.
 Carbide tooling would work but only if you have a big heavy machine to use it or it will bounce and flex chipping or shattering tool
You could try making a bushhing first to support boring bar and prevent it bending away cutting area
Grinding gives a better surface finish than running carbide at wrong settings though
I've also made holders to put angle grinder on tool post, real handy for 'attacking' the hardened Yamaha XS 650 flywheels or anything else you need to grind on OD
Title: Re: question for machinists
Post by: c.h.stoltz.1 on Jan 26, 2018, 15:17:58
Hi guys I have a Suzuki GSX1100 RR I have redone the wiring but it looks like I missed something. I have electrical power ( constant 12v ) up to the coil packs but no spark. I have changed the cdi and everything exept the signal generator and the coil packs. Do any body know what can be the problem ?

Sent from my SM-G935F using Tapatalk

Title: Re: question for machinists
Post by: J-Rod10 on Jan 26, 2018, 16:30:30
Hi guys I have a Suzuki GSX1100 RR I have redone the wiring but it looks like I missed something. I have electrical power ( constant 12v ) up to the coil packs but no spark. I have changed the cdi and everything exept the signal generator and the coil packs. Do any body know what can be the problem ?

Sent from my SM-G935F using Tapatalk

May want to start a thread in the electrical section.
Title: Re: question for machinists
Post by: Oldmanonasuzi on Jan 28, 2018, 17:24:31
You can buy shaft material that has a nice hard outer surface but is soft enough on the inside to machine.
As an example https://www1.mcmaster.com/#1482K42
Title: Re: question for machinists
Post by: doc_rot on Jan 31, 2018, 15:01:52
I got it done. Rather inelegant, but it worked great. https://youtube.com/watch?v=iFUMuCnJDCU&feature=youtu.be
Title: Re: question for machinists
Post by: Oldmanonasuzi on Jan 31, 2018, 15:33:37
Nice,
I have an air grinder that chucks up well in my lathe. Can't say I am happy with the surface finish but I can hit the dimensions I need as you did. It might be the Dremel you have may have better bearings than my setup as well.
Title: Re: question for machinists
Post by: Hurco550 on Jan 31, 2018, 15:42:28
I have a dumore tool post grinder for my south bend 9, and its often so cumbersome to use that a setup like your little dremel there would be much easier to work around.
Title: Re: question for machinists
Post by: doc_rot on Jan 31, 2018, 16:02:42
The problem I ran into is as the cut progresses the grinding stone wore down producing a slight taper in the bore. It was a little tricky but I got a pretty good fit.  If I was going to do this more frequently I would make something like this https://m.ebay.com/itm/The-ORIGINAL-Dremel-tool-holder-frame-metal-lathe-1-2-in-sq-shank-/361520655374?nav=SEARCH


Title: Re: question for machinists
Post by: irk miller on Jan 31, 2018, 17:19:43
The problem I ran into is as the cut progresses the grinding stone wore down producing a slight taper in the bore. It was a little tricky but I got a pretty good fit.  If I was going to do this more frequently I would make something like this https://m.ebay.com/itm/The-ORIGINAL-Dremel-tool-holder-frame-metal-lathe-1-2-in-sq-shank-/361520655374?nav=SEARCH
Everyone should have a flex shaft anyway. They fit conveniently in a holder, or get the right size boring bar holder...

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Title: Re: question for machinists
Post by: doc_rot on Jan 31, 2018, 22:38:17
Everyone should have a flex shaft anyway. They fit conveniently in a holder, or get the right size boring bar holder...




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I have the right size boring bar, but even a fresh carbide insert wouldn't cut these bushings. They are the inner race for a needle bearing so they are probably 58-64 HRC
Title: Re: question for machinists
Post by: J-Rod10 on Jan 31, 2018, 23:02:19
Coated, or uncoated?
Title: Re: question for machinists
Post by: doc_rot on Feb 01, 2018, 00:16:36
coated with a 1/2" boring bar. I was watching the tool deflect and just polish the inside.
Title: Re: question for machinists
Post by: Pete12 on Feb 01, 2018, 04:25:40
coated with a 1/2" boring bar. I was watching the tool deflect and just polish the inside.

Good result with the grinding doc.
Just had a look at that holder you tagged, never thought about cutting bolts down like it shows, great idea.
Title: Re: question for machinists
Post by: crazypj on Feb 02, 2018, 19:40:19
The problem I ran into is as the cut progresses the grinding stone wore down producing a slight taper in the bore. It was a little tricky but I got a pretty good fit.  If I was going to do this more frequently I would make something like this https://m.ebay.com/itm/The-ORIGINAL-Dremel-tool-holder-frame-metal-lathe-1-2-in-sq-shank-/361520655374?nav=SEARCH (https://m.ebay.com/itm/The-ORIGINAL-Dremel-tool-holder-frame-metal-lathe-1-2-in-sq-shank-/361520655374?nav=SEARCH)

Should have had a couple more stones on hand and just roughed out close to size first then changed stone to get better finish and parallel. It stones wore too fast due to depth of hole, just go so far ten finish with new stone.

Good result with the grinding doc.
Just had a look at that holder you tagged, never thought about cutting bolts down like it shows, great idea.

It's real handy for 'parting off' tough / hard materials
Put a cheap 4"~4.5"Chinese diamond wheel on angle grinder to 'do' Titanium  or HSS  ;)
You only need a piece of heavy duty angle iron with some holes to hold angle grinder (and a bunch of washers / spacers to get it on centre)