45 replies to this topic

[Bill from NH]

I don't know what materials Sherline uses, but Injecta Machine in Switzerland has been making high precision woodworking machines of aluminum using the Inca brand name starting in the 1920's. They are not machines that need constant fiddling with to keep accurate. I don't own one, but I've had my hands on their bench saws, jointers/planers, & band saws. The Inca line is still available, now owned by Multico in France.

[Isaac S.]

Made some inserts out of Cox wheels. Worked super well. 

 

[Phil Hackett]

Cast iron is superior to aluminum and steel. It is far stiffer and dense (absorbs  induced vibrations). Steel's advantage over cast iron (the ability too bend without fracturing) is it's disadvantage in machine tools.

 

Even in the big industrial mills and lathes having box/dovetail ways is better than machines having linear guideways for heavy machining. Now, you might wonder why this might matter with machining small things like slot car/model car parts: the forces being delevoped by cutting isn't really that much less than, say, a 12" lathe. In fact, small parts often require stiffer heavier machines than you'd think. Look at Swiss-style lathes and see how their constructed. They need stiffness and the ability to cancel out any harmonics for the parts they make.

 

You don't see Levin lathes made from aluminum, do you? I'd take a cast iron machine over aluminum *anytime*.

[Isaac S.]

Tried it out again. This time I wanted a black-ish look to the inserts. I picked some really corroded ones and when I cut it down to the right size I scrubbed it with a wire brush and then cut it off. Works well. Also, yes that is my new fancy display case that I got from Goodwill at the end of my shift. That 20% off came in handy.

[Pablo]

Side note, Isaac if you ever need EJ's #15 rubber front tires, I have lots of them

[Isaac S.]

Here is what I did last weekend, I was bringing out my artistic side. Machined down the step on a pair of Riggens, machined the back and finished both off with steel wool. Then glued and trimmed a pair of NOS Cox donuts. These will be used on the next suitable build.

[dc-65x]

Nice job Isaac.  

[Horsepower]

Nice job! I wish I could do that.

[Bill from NH]

Looks good Isaac! Did you have gray dust everywhere to clean up, or did you grind the tires outside or some other inconspicuous space? What diameter & width did they end up as? If you ever find a diamond comm cutting bit reasonably priced, pick one up. They're a good all-around bit to use with a Unimat. 

[Isaac S.]

Sorry, I didnt see this till now. And I even got an email about it! The dust wasnt everywhere just around my table where I can clean it up. It ended up a touch more than 1/2 inch wide and I think around 7/8 diameter.

[Isaac S.]

Wanted to turn down the stack on a 26D arm but I knew my cheap C2 carbide bits were not going to work. Looking at all the options McMaster Carr had, I decided to go with the micrograin carbide so that I could cut not only steel but tougher materials like stainless steel, cast iron and gummy aluminum alloys. 

 

After advancig the timing a little I epoxyed the windings, ground down the stack and did a static balance. Turned out well.

 

Afterwards I decided to mess around a little and see what the new bit could do. Here's the aftermath-

Overall, pretty great. An added bonus is that it is super fun. 

[Bill from NH]

Tap Magic has a cutting fluid for aluminum too. It works well when turning.

[Don Wedding]

I have the Green Unimat  and would consider a trade for the Book :  The 60's of Slot racing by Oliver K Bryant  798 pages . Pm me and I can send pics. 

[Martin]

Issac, how are you supporting the armature, at both ends ?

[dc-65x]

For a 1/8" shaft armature like this RAM a true running wheel in a live center that's free to spin supported the arm great for light turning:

 

[Eddie Fleming]

The tool being used in the photo above looks to have three usable points on a plate mounted on a bar. It seems to be rather popular.

 

What is it called and what is it good for and anything else you would care to share about it.

[dc-65x]

Hi Eddie,

 

The lathe tool is one of a set like this one from Little Machine Shop:

 

 

Here's a link with the info:

 

Turning Tools, 1/4" Indexable, Triangle Inserts 

[Isaac S.]

Martin, I just have the end spinning in a just slightly loose drill chuck in the tailstock. I also add plenty of oil. Actually supports it really well. For axles I put a ball bearing in the chuck and this works well. This didn't work well with the armatures for some reason.  

 

Eddie, the indexable tools are very useful. Just make sure to get a varying grade of inserts tat can cut from aluminum to steel. 

[Martin]

Here's an idea. if you put a small piece of bronze or Delrin held in the tail stock chuck. You could then put your straightest drill bit in the main chuck.

Run the tail stock with the material in it into the drill bit to make a cone shape to support the motor or axle shaft you plan to cut on.

 

Its a quick fix, but really you need a custom live center with a bearing.  You could make one on the lathe with a axle bearing plus holder.

It would be held in the tail stock chuck.

[Bill from NH]

You could also hold a proper size bushing or bearing in the Jacob chuck for shaft support.

[Martin]

Thats true Bill but a live cone shape lets you put a small amount of pressure on the shaft to best support it for cutting.

 

And a cone will fit a range of shaft sizes

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