Demon V8 Slow Build

[Maxine]

I was just now looking at what GWizard suggests for speeds and feeds. It came up with 4000 RPM and 5.5 IPM for a #43 bit. Maybe I was being too tentative and feeding too slow? Also I will try your suggestion and drop the peck depth down to 0.06 or so but I am still not sure what to do with the feed rate. If I plug a 0.05" bit into GWizard just to compare it with your experience it says 4000 RPM (max on my machine) and 2.8 IPM when your experience says you can feed almost twice that rate. Maybe I just can push the feed rates more than I thought? These bits are so small I was afraid to push too hard. Anyone else have any suggestions or real world experience to share on these small bits?

Thanks for the help Steve. I appreciate the help, after working a ton of hours I was all excited to take a day off and get back at this project ... until those bits broke

Maxi

 

[mu38&Bg#]

Yes, too small a feed. I was reading a thread on a production machining forum and a lot of people feed their drills much too slow it seems. Drilling with too small a feed creates too much heat and the chips weld to the drill. Uncoated drills also work better in aluminum than TiN. From the OSG catalog it looks like you want to be feeding .001 IPR minimum in aluminum, maybe as high as .002 IPR. I recently drilled a few .129" holes on my CNC mill and was surprised at how well it went at ~5k and 10IPM or so(.002IPR). Some of the high performance drills could go .005-.007IPR in aluminum in this diameter range, probably carbide with thru coolant.

Greg

For some crazy drilling performance try this.

[youtube=425,350]http://www.youtube.com/watch?v=e0yM5fHjxqc[/youtube]

[ame=http://www.youtube.com/watch?v=e0yM5fHjxqc]http://www.youtube.com/watch?v=e0yM5fHjxqc[/ame]

Edit: Fixed youtube link. Don

 

[Maxine]

OK thank you for the help. I picked up four #43 and two #50 jobber bits at the local hardware store today and I will go over to my shop tonight and try a variety of higher feed rates in a piece of scrap aluminum to see how it goes. Maybe between 0.001 and 0.002 IPR like you suggest. Wish me luck. At least this will be in scrap and the bulk jobber bits are only a buck a piece. If the holes go well I guess I will try tapping them as well to make sure I have this all down right before I try anything on the block again.

Maxi

 

[Maxine]

Well it has been quite a while since I have been able to be in my shop. I was able to get there today and make the cylinder liners for the V8. Now I just need to debur them and then hone the ID. Later this week I hope to finish up drilling and tapping the block. It is good to be able to work on this project again!

 

[Maxine]

It sure is nice to be able to be out in the shop again...

 

[stevehuckss396]

It sure is nice to be able to be out in the shop again...

Enjoy it. I can't remember the last chance I had to get out and make something.

 

[Maxine]

A little more progress today...

 

[Maxine]

I had a bunch of 1/4" 6061 aluminum scrap in the shop so I made the main bearing caps and a bunch of connecting rods today. Later I'll put them in a fixture and face them down to the proper thickness and then ream the bores.

 

[jerryc]

It sure is nice to be able to be out in the shop again...

I was a Tool&Die maker 1958-2009 My brother was an Insurance man and made projects like this in his basement in spare time. Brother thought I was the luckiest guy in the world to get to do this AND get paid for it.
Now that I'm retired I see what he meant. I'm shopping for a Bridgeport and a small lathe. Glad I found this site.

 

[Maxine]

Welcome Jerry! It sounds like you have tons of skills and advice to offer to those of us who are self taught hobby types. I enjoy this because it challenges my skills and I am learning something new every day. As you say, if I was paid for it I would be really happy. Good luck finding your new shop equipment.

 

[Maxine]

I made some rings today just to test out the method since I have never done that before. They came out fine but when fitting them to a piston I found that the ring groves in the pistons I made aren't the right width. They are about 15 thou instead of the required 20 thou. I originally bought a mini grooving tool from Little Machine shop but they didn't have 20 thou blades ... they only had 15 thou blades for it. So I used the 15 thou ones and plunged in twice with a 5 thou step over between plunges. The blade must have deflected into the existing groove (from the first plunge) on the second plunge leaving me with a slightly tapered groove only about 15 or 16 thou wide as I said.

Today I tried grinding my own blade for a cut off tool holder that I have but I had a lot of trouble getting down to 20 thou accurately. I tried three times but couldn't get satisfactory results so I set it aside for the day.

Long story for a simple question. What tools or methods would the experts here suggest for cutting (or recutting) these narrow ring groves? Any help or advise would be appreciated.

Maxi

 

[stevehuckss396]

KBC tool has .019 inserts for there Nikcole holders. I plunged in, moved over and then came back out. If you cant get them you could make the grooves and rings wider for there .027 or .032 inserts.

http://www.niko-nikcole.com/standar_grooving_inserts.htm

 

[GailInNM]

Maxi,
It is difficult to grind thin grooving tools offhand on a grinder. For narrow shallow grooves I have used various high carbon steel blades in improvised holders. Keep the unsupported projecting part of the blade as short as possible.

An Xacto #10 or 11 blade is 0.020 wide. Utility knife blades vary a bit by brand but are about 0.025.My single edge razor blades are 0.009 wide. Some people have used hacksaw blades.

All will have to be ground to shape and sharpened. This will be a bit slow as it is easy to get the blade too hot and remove the temper from the blade.

Gail in NM

 

[Maxine]

Thanks for the help gents. I am ordering some of the Nikcole 0.019" inserts but in the meantime I rummaged around and found a #10 Xacto blade as suggested. I ground just the very tip into a grooving shape and gave it a try just for grins. Now don't laugh at my rinky dink set up. To try it out I just tightened the blade up really tight, clamped the whole Xacto knife into a spare cheapo boring bar holder that I had sitting in a drawer and gave it a shot. It actually worked fine. The rings fit just fine now on that test piston. I think that I will wait for the proper inserts to come to finish regrooving the rest of the pistons though.

Some pictures are attached that show the piston before and after regrooving.

Again thanks for the advice.

Maxi

 

[Maxine]

I made a fixture to cut the ring grooves today. I didn't want to do them one at a time. It consists of a mandrel that the ring ID just fit over, two spacers so I can capture the stack of rings tight, and a cap that is a slip fit over the OD of the rings to hold them in place. The cap also compresses the spacers slightly so the stack of rings is held firm while milling. Then a slot of the proper width was milled. It worked out good, a nice pile of rings with identical grooves is the result.

 

[Maxine]

Drilled and tapped the 4-40 and 2-56 holes in the block today as well as milling a few other details on the block.

http://www.youtube.com/watch?v=YapBzFL86Uc&feature=youtu.be

 

[Maxine]

This is an operation that I had been holding off on for a while. It's not so complex for seasoned machinists maybe but reaching down inside the cylinder bores with a 5/8" diameter cutter that had little clearance to mill out the internal water jackets was bugging me. I didn't want to mess it up. I worked up my nerve and got it done today and it worked out just fine.

[ame]http://www.youtube.com/watch?v=Wp_3y-WKiQs&feature=plcp[/ame]

 

[stevehuckss396]

Very cool! I did mine manually. I like your way better.

 

[student_Machinist]

Very cool! I did mine manually. I like your way better.

Ive just started the block, im not at that stage yet but ive been trying to work out how to cut the water jackets. the only way i can think of at the moment with out cnc is to center each cylinder bore on a rotary table and spin the hole block around, is this how you did it?

 

[stevehuckss396]

pm me your email address and i'll send you a pdf