Making Molds On a POS Manual Mini Mill

I sold my first injection molds made on a tiny Taig CNC milling machine. Compared to a half million dollar Haas mold maker it too was a POS.

In the spirit of paying it forward I am working on a video series making "useful" molds on a PIECE Of Shi.. Er Sweet Potato Mini Manual Milling Machine. Most of these "molds" will not be commercial resale grade, but if anybody wants to buy one... The goal is to give people who couldn't afford anything better than a Seig X2 in one of its many variations or variations on paint scheme to do something fun and possibly useful.

I have no use for it. I already have a South Bend Knee Mill that is very nice for my manual milling needs. At first I thought about using that for the project. That would be cheating. Its as much better than an X2 clone as a half million dollar Haas mold cutter is to a Taig. It would be perceived as disingenuous to use a $24000 machine to demonstrate what you "can do" on a $1000 machine. It would be perceived that way because it would be true. It would be blatantly dishonest to say "because I can do it on a 2 ton 5 HP knee mill with DROs and power feeds that you can do it on a 130 lb .3 horsepower Piece of Shi... Err Sweet Potato."

In spite of my belief in spending money to make money and spending money to save time because time is money... I am still inherently frugal. Finally I decided to my integrity was worth than that. I bought one. There are cheaper mills, but they are so small ass to not be practical for this experiment. I did buy the absolute cheapest one I could find. It was not the one from Harbor Freight. Harbor Freight had the cheapest sticker price I could find, but it was online only. After tax and shipping it was about 6 dollars more expensive than the one I bought.

The first video will be an introduction covering this and maybe with a fast motion overview of the first mold. It will be a concept introduction video.

Before Episode One which will probably be about making a lead casting mold of some kind there will be some beginner videos.

A. Machine over view and deficiencies. B. Work holding and Work Holding on a budget. C Tool Selection and tool holding with a focus on the initial project videos. D. Minimum tooling and best cost benefit for part location, and machine tram and alignment.

That may be put into just two videos and anybody who already knows how they will do those things will be encouraged to skip them and wait for Episode One.

Reply to
Bob La Londe
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I sold my first injection molds made on a tiny Taig CNC milling machine. Compared to a half million dollar Haas mold maker it too was a POS.

In the spirit of paying it forward I am working on a video series making "useful" molds on a PIECE Of Shi.. Er Sweet Potato Mini Manual Milling Machine. Most of these "molds" will not be commercial resale grade, but if anybody wants to buy one... The goal is to give people who couldn't afford anything better than a Seig X2 in one of its many variations or variations on paint scheme to do something fun and possibly useful. ....

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Thank you. You are very generous to donate your time to help beginners.

I've tried to find the line between purely hobby mills and those that are adequate for serious work, for an inventor or mold maker perhaps. My Clausing would serve nicely if it was still in production, and especially if it took R8 collets.

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The generous spacing between 0.001" divisions allows finer positioning.
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I haven't used a machine in the Sieg X2 class. The work envelope seems close to the Clausing's. Power is lower but the Clausing's power and rigidity aren't outstanding either.

I tried and pretty much gave up on an RF-31 due to its poor accuracy, 0.005" was possible with effort, 0.001" wasn't for too many uncorrectable reasons. I though a 2-dimensional workspace would be adequate for electronics, drilling control panels etc, but it wasn't when I need to make a precision part for handling machinery. That job went to the Clausing.

The other candidate I had a chance to use was the Enco variant of this: (short URL)

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offers one for $2500. (long URL) The reviews from experienced machinists are mostly good.

It appeared to be an updated version of the Clausing, with the same head tilt and swivel (but not extend) and an R8 spindle. The major components of the Enco were decently machined but the small parts looked like someone made them by hand at home. I could improve their fit with a file. The engineer who ordered it was Swiss and had adapted it for ER collets, which consumed most of the vertical working space.

I think a well-made version of it would be fine for someone who needs precision more than large working envelope. For milling small parts I prefer the Clausing's ergonomics to a Bridgeport's.

Reply to
Jim Wilkins

That first picture looks like a combination of a radial drill press and a mill. Interesting machine. I am guessing yours is more like the second picture.

That is a failing on many mini machine tools. Worse some have divisions of .002. I don't know yet about my new mini mill. Its still in the crate

Roughly 1/3 hp if the specs are to believed. You can do a lot with 1/3 HP (that's what the Taig has), but... I'll leave that to the overview and deficencies video. My fear is that its like some other import motor specs where they rated it at close to the stall current.

I had an RF30 from Harbor Freight from back when Harbor Freight had more than two mills. I felt it was not great, but it also spent 30 years on a guy's back porch work shop. When I sold it I had to take a sudden cut in price because the motor failed to turn on when I went to show it to the buyer. It had been running fine, and was still covered in chips from its last job. Oh, well. Interestingly from what I can garner most prints are considered to be 0 to +.005 unless there is a call out. I do have another smaller round column mill drill, but it has no fine feed on Z making it just an XY drill press. Its sad because it actually has a better spindle than the RF30. I used it once in a while for rough milling work by using the depth stop and gage blocks to set semi accurate depth. I got it cheaper than a drill press because one of the gibb adjusting screws was missing. I made a short video about replacing he quill lock handle with a shop made shoulder bolt I could use a vise wrench on. I may have posted it here in the past.

Those middle weight bed mills can be ok. I can't speak to Enco. I always thought those Enco machines were like Harbor Freight machines of the same era. Just so you know. MSC still has a few Enco machines left over after the buy out. I see them on the website from time to time when I am looking for other things. I had an RF 45 and it was ok, but head nod and tram were always a struggle. I had to shim the column below the base, and shim the head between the pivot. Mine was a badly implemented CNC conversion, and eventually the seller gave me a Syil X4 and let me keep the main carcass of the machine in exchange for sending back all the control board. I still have pieces of that machine here and there. The Taiwan assembled machines from Precision Mathews seem to be the bang for the buck machines today. Matt sells Chinese machines, and machines made in Taiwan. My 14 x 40 lathe is one of his Chinese made machines, and I am pretty happy with it for the price I paid. ($5K at the time. Its more now.) Dave (Dale?) Clements (aka ArizonaVideo99) in Phoenix has a thriving business in making CNC conversion kits for Precision Mathews milling machines.

I don't think so. Last I looked Harbor freight only offers two mills now. The X2 or X2 clone, and a miniature knee mill that needs to set on a stand to be at a comfortable work height. They have cut out 95% of the "industrial" machines they used to sell. Maybe I confused the Clausing you were talking about (which looks similar) and the bed mill you were talking about.

I am under no illusions abut the X2 clone I bought. Its got lots of deficiencies. I am already aware of some of them. Some I may discover when I take it out of the crate. Others may not become known until I start cutting parts. I expect no particular degree of accuracy, and I imagine of lot of the videos will contain elements of "good enough" vs tolerance stacking. Its a challenge more than anything else. I'm NOT a manual machinist. I just do a little manual machining when its faster and easier than doing it on the CNC mill or when the CNC mills are all busy.

There are version with R8 spindles and versions with Morse taper spindles. I'll talk about that when I get to tool selection and tool holding.

Reply to
Bob La Londe

[rambling trimmed]

Are the Taig machines as goofy as they look? How usable at they in manual mode?

I briefly looked at them before going with a Sherline. No regrets- the Sherline stuff is small, but works great within those limitations. The variable speed motor isn't revolutionary, but Taig didn't offer that at the time. The whole single speed fan motor design just seemed stupid and lazy.

Reply to
Cydrome Leader

Tangent trimmed.

Reply to
Bob La Londe

IF... you hadn't dismissed the whole purpose of my post as irrelevant rambling I might have answered your questions. Even while I was deciding not to answer I had answers running through my mind. I did use the Taig for a long time, tore it apart several times for both good and bad reasons, and made a few of changes. I'm very familiar with it.

Reply to
Bob La Londe

That first picture looks like a combination of a radial drill press and a mill. Interesting machine. I am guessing yours is more like the second picture.

---------- Nope, I have a slightly different earlier version of the one that's drilling angled holes. I think the second photo shows a Clausing base with a Bridgeport M head. One clamp locks both head tilt and ram slide and they are are best left alone after positioning the spindle relative to the rear vise jaw and tramming the tilt. Despite its slim appearance it's a real live precision steel-cutting milling machine as long as you aren't in a urry. -jsw

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Those middle weight bed mills can be ok. I can't speak to Enco. I always thought those Enco machines were like Harbor Freight machines of the same era. Just so you know.

--------- I certainly do know. Enco had a nearby store where I could inspect a machine before buying it to see if I could cure its flaws. The RF-31 I mentioned came from MSC but may have been an Enco. Even the worst machine I bought, a used 30" CM shear/brake/roll, could be patched and tweaked to work well enough although the previous owner had given up fighting it. He may not have understood how to make the adjustments it still needed. I made it shear paper. -jsw

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I don't think so. Last I looked Harbor freight only offers two mills now. The X2 or X2 clone, and a miniature knee mill that needs to set on a stand to be at a comfortable work height. They have cut out 95% of the "industrial" machines they used to sell.

--------- I found a shorter URL this time:

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looks like the Enco which was the same compact size as my Clausing, with an R8 spindle, 26" x 6.5" table and more power. I made a log splitter, sawmill and a bucket loader for my garden tractor on a mill that size. At ~650 Lbs it isn't "miniature", the original M head Bridgeport wasn't that much larger, though considerably heavier at 1500#.
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I am under no illusions abut the X2 clone I bought. Its got lots of deficiencies. I am already aware of some of them. Some I may discover when I take it out of the crate. Others may not become known until I start cutting parts. I expect no particular degree of accuracy, and I imagine of lot of the videos will contain elements of "good enough" vs tolerance stacking. Its a challenge more than anything else. I'm NOT a manual machinist. I just do a little manual machining when its faster and easier than doing it on the CNC mill or when the CNC mills are all busy.

-------------- Without trying one, the Sieg X2 appears on paper to be a good balance of price and performance and a good candidate for your effort. I hope it lives up to its promise and doesn't waste your time. I presented the HF compact knee mill as a possible next step up from the X2. The size is good, if not the implementation. Every metal part I designed at Mitre or milled on Segway's Bridgeport could have been done on my Clausing or its quivalent. -jsw

Reply to
Jim Wilkins

Well, not interested in the video of a person that rambles on and on about who knows what. They'll no doubt be really long and have no point.

Have fun with them though.

Reply to
Cydrome Leader

Have fun being superior in your own mind all by yourself.

Reply to
Bob La Londe

I'm ok with it falling on its face (figuratively). One of its KNOWN deficiencies would already drive me crazy if I didn't have a plan for that after its first ore second basic project.

Reply to
Bob La Londe

I'm ok with it falling on its face (figuratively). One of its KNOWN deficiencies would already drive me crazy if I didn't have a plan for that after its first ore second basic project.

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What was your second choice?

Reply to
Jim Wilkins

The difficult question for a beginner is what to buy, how much do you really need and want to to spend. I can answer that the size of my machines has proven adequate to make my own designs since I can adjust them to the machines' capacity, and they are small enough to fit easily into a house, unlike a Bridgeport. They are probably too small for general commercial or serious automotive work. They are old American iron that's scarce and likely worn, thus I looked for current equivalents.

Size-wise the most demanding use for them has been making modifications and repairs to homeowner lawn and garden equipment. I'm ahead if a $1000 machine tool can salvage a $2000 garden tractor, so in that respect they have paid for themselves. I used them to demonstrate that I could do more than my job description suggested, and advanced at work. Perhaps they could be used to take in repairs, except for the zoning and liability concerns and the need for heat-treating the sort of parts that wear out.

I use them pretty much as I think was intended, to make custom tooling and lab demos and experiments. They are larger than necessary for model engines. Besides the Clausing I have a 10" lathe, plus other stuff but those two are the essentials. I've talked to repair shop owners who had a mill-drill instead of a knee mill and were satisfied with it. I might manage with a mill-drill of better quality than the one I tried, but I definitely need

0.001" accuracy on the Z axis.

As for CNC, I don't even have a DRO. I usually make only one of a part and refine its design as I go, or trim it to fit another part that may be worn out of size. For that manual graduated dials and cut-to-fit are good enough. I learned paper and pencil drafting in the 50's when most machines had only dials and that won WW2 and got us to the moon. I've done plenty of CAD/CNC design for aerospace and learned to translate a paper drawing into G code but I don't have to depend on it.

For example last evening I used the lathe to press-fit a 5/32" tube into the

4mm drain opening of my car's radiator, so I could cleanly drain and re-use the low mileage coolant when replacing the thermostat. It was a purely cut-and-try operation. I've found the CNC control panel on a Bridgeport to be a hindrance when I was trimming a casting to a scribed line.

That's my two cents worth. I can't recommend any particular currently available machine. Does anyone have one they really like?

-jsw

Reply to
Jim Wilkins

That is a very difficult question, however there are a group of newbies who buy a machine because its affordable and don't really know what to do with it. I sort of started that way. My first "real" machine tool was a 7x10 mini lathe from Harbor Freight. My wife gave it to me for Christmas. I piddled with it a bit mostly turning metal into chips. I had little knowledge or skill about turning. I think the first real useful real world project I made also came from my wife. She suggested a bracket to mount on the back of a piece of medical equipment that would facilitate holding the consumable's dispensers without having to drill more holes in a wall and mount it separately. I turned a couple dozen tiny little nail head shoulder bolts as part of the project and it worked very well. The dispenser looked just like it belong instead of looking tacked up. I'm not trying to SELL a machine. Maybe if somebody had given me one for this project I might highlight its unique features if any over some other machines, but nobody did. I paid full retail for one of the most sold (I think) small machines for non-machinists. What I am trying to do is help people do something with the machine they have.

There is also the tinkerer who buys this machine because they can afford it, but plan to improve it a little bit at a time because its not as much cash out of pocket all at once. There may be some of that in this series, but there are plenty of guys who have posted a video titled, "Look at What I Did to Make My Machine Less of a POS."

I expect I will recommend against buying any machine in this class with the caveat that "if you already have it or its all you can afford these are some things you may be able to do with it." I am open to changing my mind by the end of the series, but I do have a clear prejudice against this machine starting out.

Reply to
Bob La Londe

For this particular endeavor this was my first choice.

If I was getting a small machine just to have, could afford it, and it wasn't to small for goal oriented choices I'd consider something in the BF20 or BFR20L class. I think the Grizzly G0704 is very close to the same machine. In addition to being an "okay" small machine there is a huge base of serious users sharing information on these. Mods, upgrades, & fixes.

However if I wanted the MOST flexibility for my dollar a small Bridgeport or Bridgeport clone would be the choice to make. A larger import bed mill might be more rigid (once its tweaked out) but its hard to beat an articulating head knee mill for a huge range of possibility. Like your Clausing.

When I decided I needed a manual mill for "everything else," in my shop I bought one of the larger knee mills I could find that had all the features I wanted. It was a toss up between the South Bend and Vectrax. The Vectrax had #40 taper which is more rigid than R8, but I felt I could buy R8 tooling cheaper in the long run. I knew I wouldn't always have a pocket full of money when I needed a tool for a job. I could have bought a smaller brand new Bridgeport cheaper, but I wanted a beast. I find myself using it for second ops a lot more than I thought I would too. Not just one off parts, tools, and repairs. I even used it last year in some production parts. I sold 100 identical lead casting molds to one company. I was able to keep the CNC machines doing the primary work, and do all the hinge pins and handles on the Knee mill. I've even started using it for making fixture plates for the smaller CNC machines.

Reply to
Bob La Londe

If I was getting a small machine just to have, could afford it, and it wasn't to small for goal oriented choices I'd consider something in the BF20 or BFR20L class. I think the Grizzly G0704 is very close to the same machine. In addition to being an "okay" small machine there is a huge base of serious users sharing information on these. Mods, upgrades, & fixes.

However if I wanted the MOST flexibility for my dollar a small Bridgeport or Bridgeport clone would be the choice to make. A larger import bed mill might be more rigid (once its tweaked out) but its hard to beat an articulating head knee mill for a huge range of possibility. Like your Clausing.

----------------- I've had exactly one job that might justify a Bridgeport, drilling parallel pivot holes 4' apart in the two lift arms for my bucket loader. The Clausing handled it by clamping the two together and match-drilling the ends. I did the bigger job of drilling 3/8" x 6" bolt holes for the center splice in the assembled 16' gantry hoist beam with a Portalign.

In my opinion the Clausing and perhaps the newer versions are (and always were?) too small and slow for a time-is-money production shop, unless they want it for the occasional special tool/fixture, keyway or hole pattern for which they lack a CAD drawing. It vibrates and chatters if I push it when roughing out steel. It's fine for me because I'm not in a hurry. The 10" South Bend is in the same class, their ad recommends it for short production, tool-room and maintenance.

Reply to
Jim Wilkins

You're right. To be superior I'd need some old timer story about buying a "motor drill" and then upgrading to a fancier model. I've never though about upgrading tools or anything like that before. Maybe you can make a seven part video series about how this works.

Reply to
Cydrome Leader

I knew when I bought the Logan (PowrKraft) 10 x 31" lathe that it was going to do the kind of stuff I'm interested in - though there are times when I wish it had a bigger hole through the spindle . Same with the RF45 clone bench-top mill . I did do a lot of research about the various mill-drill machines , almost bought a RF31 ... But I knew that one day I'd need to move the head in the middle of a job . And neither machine has ever disappointed me . And neither machine has ever needed "improvements" to do their job . Unless you count adding a DRO to the mill .

Reply to
Snag

Bob La Londe snipped-for-privacy@none.com wrote: ...

You're right. To be superior I'd need some old timer story about buying a "motor drill" and then upgrading to a fancier model. I've never though about upgrading tools or anything like that before. Maybe you can make a seven part video series about how this works.

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I also started by modifying a cheap drill press for X-Y milling. It was good enough to machine the plastic electrical connector housings I needed for my homebrew computer. Then I bought a crappy worn mini lathe and made a milling attachment for it in night school.

Objectively the drill press and AA lathe were wastes of time and money but those projects taught me a feel for speeds and feeds and the forces of cutting metal, and that I liked doing it enough to invest in decent machinery, my $1200 SB lathe and $800 Clausing mill.

Bob isn't pounding his chest to proclaim he's bigger and better than you, he earned what he has and now generously shares it. Free yourself from the zero-sum delusion that you can rise only by pulling down others. That's for losers and communists.

Reply to
Jim Wilkins

I knew when I bought the Logan (PowrKraft) 10 x 31" lathe that it was going to do the kind of stuff I'm interested in - though there are times when I wish it had a bigger hole through the spindle . Same with the RF45 clone bench-top mill . I did do a lot of research about the various mill-drill machines , almost bought a RF31 ... But I knew that one day I'd need to move the head in the middle of a job . And neither machine has ever disappointed me . And neither machine has ever needed "improvements" to do their job . Unless you count adding a DRO to the mill .

---------- How accurately can you cut to height (Z axis) on the RF-45? The Z axis was the RF-31's worst failing. I could set it to 0.001" but tightening the spindle clamp shifted it inconsistently.

Reply to
Jim Wilkins

It cuts quite accurately . The clamp system puts no vertical force on the spindle . I have more problems with the spindle "climbing" if I try a cut without locking it . I have watched the Z readout on the DRO as I tighten the clamp and it doesn't move at all .

Reply to
Snag

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