TheSamba.com :: View topic

Tue Aug 30, 2022 11:33 pm

Last year, I finally got a milling machine of my own. Over the winter I rebuilt the head and cleaned up the rest of the machine. I went hunting for a good thread to add some content to, but no existing thread seemed quite what I had in mind. So, I thought TheSamba could use a thread for people to post up their machine work, tools, techniques, etc. Anything from the humble home gamer with a few basic tools to professionals with full shops, no matter how basic or complex the operation.

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Figured I may as well start it off with a Type 4 case I am boring out for 103mm pistons/cylinders. I finished up the 1/2 side of the case, but need a little welding done on the 3/4 side yet before going any farther with that side. More on that to come in the future.

Although I have a fair amount of machining experience from my work in engineering and the automation industry, this was the first VW case I did on my own machine in my home shop.

I have bored holes for bearings and bushings before, and figured one hole is really no different than the other, so how hard could it be to open up a case? Someday my attitude of “how bad could it be?” and “what could go wrong?” will catch up with me, but I am happy with how this turned out.

Sure, there are more efficient and specialized tools for opening up cases for big bore cylinders, but I worked with what I had on hand which was just an old school boring head.

Part 1 of 3 - Preliminary discussion on case prep. If rambling bores you, skip to video two or three.

Part 2 of 3 - Fixturing, indicating, boring head tool, and mill setup.

Part 3 of 3 - Boring the case and measuring

Wed Aug 31, 2022 4:11 am

I am interested!

I bought a small milling machine a few years back with hopes of learning to use it in retirement. If I ever get the kitchen renovation done....

Wed Aug 31, 2022 4:22 am

time for a cnc conversion :wink:

Wed Aug 31, 2022 9:00 am

oprn wrote: I am interested!

I bought a small milling machine a few years back with hopes of learning to use it in retirement. If I ever get the kitchen renovation done....

Is it one of the bench top mini mills, like the Sieg models everyone rebrands?

Wed Aug 31, 2022 10:03 am

Bench top model. I bought it from the widow of a friend of mine. Unfortunately she sold his lathe and gave the new owner all the tooling for the mill to so I will be starting from scratch on the tooling. It may not be big enough for a VW head.

Wed Aug 31, 2022 10:43 am

So in canada... Rong fu 31 is called busybee?
Did you get that at princess auto? :P

Still very useful if you know what it can do
I tried to buy one years ago but everybody wanted 1500$+
I got a bridgeport II special for a few dollars less

Wed Aug 31, 2022 11:16 am

It would be cool to have a simple tutorial on common milling practices, terms, uses and what not. Fixtures, application, how to's for all the tool junkies, like me :D

Wed Aug 31, 2022 12:42 pm

How about a tutorial on cutter geometry?
Better as a separate thread tho, but we can put links from here to there as needed.

Wed Aug 31, 2022 1:21 pm

No idea where he bought it. I did get an indexing head with it though...

Yes any tutorial would be excellent. I'm in!

Wed Aug 31, 2022 1:35 pm

oprn wrote: Bench top model. I bought it from the widow of a friend of mine. Unfortunately she sold his lathe and gave the new owner all the tooling for the mill to so I will be starting from scratch on the tooling. It may not be big enough for a VW head.

Good idea for a new topic, "what vw machine work can you do on a bench mill". Many dont have the space for a full size mill, and need to make do with what they can fit in their garage or workspace. It can be nerve racking sending unique/rare vw parts, and worth it to do it at home.

You can get a 3 axis DRO and adapt it to the bench mill for $200 lately.

I have the same mill as the busy bee. I made a internal frame for the stand out of 1 inch thick wall box tubing.

Wed Aug 31, 2022 2:27 pm

I've a similar mill , in Aus they are a Hafco HM30 , I also recently invested in a Hafco 320 lathe . 320mm swing . The mill was second hand $1000 aud with some tooling , it would have paid for itself if I've had to pay for the work I've done on it , even at "Mates Rates" . The Lathe is new . finding a good second hand lathe around here for a good price is very hard .

I did the same as Dirk with opening up a case for bigger cylinders ,only all manual feed . took a while but I was learning as I went .I don't have a DRO and was not perfect in the machining but the end result has proven to be reliable .
I also have converted a pair of Arctic Cat ITB's to fit IDF manifolds . made new shafts , air filter base ,fuel rails etc

Latest thing was a trigger wheel from 8mm plate .
I think this is a great thread , sharing ideas and knowledge . tool geometry or the correct insert type for the required job , plus cutting speeds etc .

Wed Aug 31, 2022 4:55 pm

My lathe is an old belt drive South Bend with a drawer full of gears for threading. It’s well used and could use some work but I wouldn’t be without it!

Fri Sep 02, 2022 9:47 am

No pics but I machined out a bad case saver on my CNC mill and fly cut the cylinder head valve cover rails for perfect sealing. Rtv'd the cork to a really clean cover and never has a leak yet. Only took around 0.010 off of the heads.

Fri Sep 02, 2022 12:01 pm

So - machinetools porn? :lol:

People here might think some of you's are elitists. I thought we had a thread w/ 'My machinetool is bigger than yours' -thread.

We just had one on machining heads - guides and things.

i will post some of mine - they are all in my gallery. I need to get my Gleason crank welder going. I am stickly w/ machines. I want to detail them first and make sure all the wirings are ship-shape before I re-fire them up. But of course, I see them running when I buy them.

Getting some headway on my GoPower dynamometer is my project this time.

Fri Sep 02, 2022 12:29 pm

Wreck wrote: Latest thing was a trigger wheel from 8mm plate .
I think this is a great thread , sharing ideas and knowledge . tool geometry or the correct insert type for the required job , plus cutting speeds etc .

How did you index your trigger wheel to cut the slots? Rotary table?

I have been considering making 35 shallow (~4mm) pockets spaced around the back side of the flywheel and using an inductive sensor for crank position. The T4 engine already has a hole in the case that could easily be made to hold a crank sensor. Picking up on the flywheel would eliminate the need for a separate trigger wheel. Basically make a 36 missing tooth trigger wheel out of the flywheel.

Fri Sep 02, 2022 2:41 pm

nsracing wrote: So - machinetools porn? :lol:

Edit- Could be. There is a thread for some of that sort of thing already. I had in mind a place for people to discuss, ask questions, or show what and how they do things with machine tools.

nsracing wrote: People here might think some of you's are elitists.

I don’t want it to turn into another bragging about superior tools or capabilities type of deal. I’m hoping that anyone can contribute. Even if it doing something as simple as asking how to, or showing how they extract a snapped off stud. Someone with basic skills may be quite proud of their successful stud extraction. Everyone has to start somewhere. I don’t want them to feel left out.

In other words…

Vanapplebomb wrote: Anything from the humble home gamer with a few basic tools to professionals with full shops, no matter how basic or complex the operation.

Most people are far more capable than they may think. A large chunk of people hear could easy install case savers. Unfortunately, I see way to many threads devolve into “send it to a machine shop” when clearly the poster has the skills or tools… they just had questions.

nsracing wrote: I thought we had a thread w/ 'My machinetool is bigger than yours' -thread.

We just had one on machining heads - guides and things.

Yes, also a thread specific to breaking in a Bridgeport. Came across that when looking for a suitable thread to post in.

Fri Sep 02, 2022 4:16 pm

Ok, Here is a machining question/tooling question. How can someone with a drill press, small X & Y table, dremel, files, welder, saws, etc make something to do a simple 30 degree backcut on 4 intake valves? The width of the cut needs to be about .025” My mind draws a blank

I watched a guy on you tube hand hold a dewalt against a small bench sander to do it, and although, it wasn’t bad, no way would I try that

Yeah I can send the valves out or find a local head shop, but I like to experiment when possible.

Fri Sep 02, 2022 4:20 pm

Vanapplebomb wrote: Wreck wrote: Latest thing was a trigger wheel from 8mm plate .
I think this is a great thread , sharing ideas and knowledge . tool geometry or the correct insert type for the required job , plus cutting speeds etc .

How did you index your trigger wheel to cut the slots? Rotary table?

I have been considering making 35 shallow (~4mm) pockets spaced around the back side of the flywheel and using an inductive sensor for crank position. The T4 engine already has a hole in the case that could easily be made to hold a crank sensor. Picking up on the flywheel would eliminate the need for a separate trigger wheel. Basically make a 36 missing tooth trigger wheel out of the flywheel.

I'd like a rotary table , next on the purchase list , I just use the lathe to scribe a line 12mm from the outer edge , then worked out the spacing for 24 holes , scribed them with a vernier (took a few goes) then careful centre punched and drilled the 10mm holes , finally spun the outside down to break into the holes and manually filed the rest .

Fri Sep 02, 2022 6:54 pm

You did a really good job with that. I’m super impressed how nice that came out for such a manual operation. 8)

Fri Sep 02, 2022 8:21 pm

Motor skills like that are very rare these days!