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MachinistBlog.com

Plans, projects and how-to's for home machinists

I Bought a LONG Shop Vacuum Hose

I just bought a 20-foot hose for my shop vacuum and I wish I’d done it decades ago.  I never realized it before, but my shop vacuum is probably the tool that I spend the most time using and a longer hose makes it much easier to use. 

The hoses and electrical cords that came with my shop vacuums aren’t unreasonable short, but over the years I’ve spent many hours moving my shop vacuum from one electrical outlet to another in order to reach every corner of my workshop.  I’ve also pulled the hose out of it or tipped the vacuum over innumerous times while trying to move it by pulling on the hose.

With the new hose, I can leave the vacuum in one location and still reach every corner of my garage workshop.  It will also let me vacuum the interiors of two cars without having to first plug my shop vacuum into an extension cord and then move it around the cars four or five times.  

Buying a shop vacuum hose can be difficult and a little risky because there are a variety of different hose diameters and the ends come in different sizes.  I purchased a 20-foot Cen-Tec Systems 92707 Premium Shop Vacuum Extension Hose from Amazon for $34.86 and I’m very pleased with it.  It is what I recommend you buy if your shop vacuum accessories fit a 1-1/4 inch diameter hose. 

The intake end fits the intakes of my Shop-Vac brand vacuum, two Sears shop vacuums and a Ridgid shop vacuum, even though these vacs came with hoses ranging from 1-1/4 to 2 inches in diameter.  The accessory end fits all the 1-1/4 inch extension tubes and accessories that I’ve acquired over the years. 

I was surprised to find that the ends on this, and many other long hoses, screw on and off; and that there is wide variety different size ends and adapters that you can buy to fit your equipment.  The problem is that the size descriptions for fittings and adapters are not always clear.  Fittings also come in both US and metric sizes, and sometimes the sizes are close enough to work because of the taper.  For example, a 32 mm inside diameter fits on the ends of my 1-1/4 inch hoses.

Hoses restrict air flow and so the the longer the hose is the less suction you’ll get.  This can be offset by using a larger diameter hose.  My new hose has plenty of suction, but I do wish I’d thought of this and checked to see if I could have bought a 1-1/2 inch hose with the same size ends as this one.  I’m sure they’re available and they probably don’t cost much more.

I’d never thought about buying a longer shop vacuum hose because I thought that shop vacuum accessories were/are obscenely overpriced.  But I needed a long hose to reach the dust shoe of my new CNC router.  This hose works great with it but I did have to design and 3D print an  adapter for it.  I will be sharing the .STL and Fusion 360 files for that in a later post. 

Review – $40 QCTP for 7x Mini-Lathes

This is a review of a very inexpensive Quick Change Tool Post (QCTP) set for 7x mini-lathes that can be purchased on Ebay for about $38 (including shipping).  It is considerably less expensive than similar size QCTPs that you can find on LittleMachineShop.com and Amazon that cost about $135 to $155 plus shipping.

I purchased it because the cut-off blade holder for my 10-year old A2Z CNC QCTP had broken and I needed another one ASAP.  I didn’t have time to fix it and I couldn’t buy a replacement because the company has gone out of business.  My set was on loan to the SparX 1126 FIRST Robotics Team, where I am a mentor, and it was getting heavy use because we were in the middle of the build season.

So, when I came across this cheap QCTP set on eBay I decided to take a chance and buy it for the team.  The same set is sold by many eBay vendors and I chose this one and paid a higher price, $45, because they were promising delivery sooner than most other vendors and the seller has a high rating.  It was delivered six days after I ordered it.

It’s manufactured in China and it comes with four tool holders – two identical holders for turning and facing bits, a ⅜-inch boring bar holder and a holder for ½-inch cut-off blades.  The tool post is made almost entirely from hard anodized aluminum and the tool holders are made of steel.  In comparison, the $135 QCTP that Little Machine Shop sells for 7x lathes is made entirely of steel and it includes an additional holder that can knurl in addition to hold another tool bit. Continue reading Review – $40 QCTP for 7x Mini-Lathes

My Lulzbot Mini

My Lulzbot Mini with LED strip lights that I added. The object on the bed is half of an exhaust adapter for a laser cutter.

I started the Rochester Makerspace more than 2-1/2 years ago. It’s a non-profit (501c3) community workshop and art studio in Rochester New York that provides low cost access to sophisticated tools, teaches classes, organizes events, and hosts school field trips.  The makerspace has many very hard working volunteers but it’s still a nearly full-time job for me.  It’s also unpaid one so I also have a very demanding full-time day job.  That’s why this website has been so dormant.

Ironically, I don’t get a chance to make anything anymore because I’m so busy all the time.  That was really starting to bother me so last spring so I bought a Lulzbot Mini 3D printer.  It conveniently sits in my home office so I can make something once in awhile.  It’s a great machine and I want to to tell you about it in case you’re looking for a really good “hobby-class” 3D printer.

The Lulzbot Mini costs $1350, which makes it one of the more expensive 3D printers in its class.  But I think it’s worth the extra cost.

  • To get a high quality 3D print your bed needs to be perfectly level and your nozzle has to start at the proper height about the bed.  Most current machines (all?) require you to make those adjustments manually and you have to periodically redo them.  The Lulzbot eliminates that chore because it has a self-leveling bed.  It measures the height of the four corners of the bed before every print and then automatically compensates if it’s not level. I won’t try to describe exactly how it does that but trust me, it works great.
  • Most printers also have a problem with getting ABS plastic to adhere to the bed consistently.  So their owners resort to all kinds of tricks, like using hairspray, glue sticks, large skirts, or a mixture of acetone and plastic. Many people avoid the problem completely by only printing with PLA on a layer of blue painter’s tape.  The Lulzbot Mini doesn’t have this problem because its heated bed has a layer of PEI. It’s a plastic that ABS sticks very well to when it’s hot and comes off of fairly easily when the bed cools down.  As a result I print almost everything with ABS because of its extra strength and durability and because it’s just so easy with the Lulzbot.
  • I also bought the Lulzbot because I wanted to be able to print with Nylon, which is something most 3D printers can’t do.  The Mini can do it because it has an all metal extruder that can reach the necessary temperature.
  • The Mini also produces very high quality prints.  I’m not sure I remember correctly, but I think it came in second in Make magazine’s latest 3D printer tests.  It’s also super easy to use.

I also think the Mini is very well designed and durable.  It’s also an open source design and you could download all the files and information you need to build one from scratch.

There are a couple of things that I don’t like about the Lulzbot.  It’s too noisy when it’s running.  The Rochester Makerspace has a couple of Soldoodle 3D printers and a Rostock Delta we built ourselves and they are almost as quiet as a whisper.  I also think the cost of some of the Mini’s replacement parts are too high.  The two parts you’re most likely to need to replace someday are the cooling fan on the extruder and the PEI on the bed.

The Mini comes with a one-year warranty and I know first hand and from others that the company provides very good customer support.  The PEI on my bed was badly damaged by someone who used a screwdriver to pry a print off of it when I wasn’t looking.  I needed to fix it within 2 days for a demonstration and the company very nicely agreed to ship a replacement overnight at no extra cost.

If you don’t know what you can make with a 3D printer then check out Thingiverse.

I’m not sure when I’ll be able to contribute something else this to this website.  The Makerspace is getting closer to being able to hire some staff members, which will make my life easier.  I may actually be able to do some machining again.

I want to thank Mikey and Roger for continuing to help visitors to this website who have questions or need advice.

Wrench/Hammer Combination Tool for Mini Mill

By Roger Leete

This tool was made for my Grizzly G8689, but it can be adapted to almost any mill.  Just choose the right sized socket for your particular drawbar.  Note that I did not come up with this idea, but found it on the web.  I made the parts based mostly on the materials at hand.  Dimensions are mostly made up on the spot, and measurements were all made with a scale.  In other words, this project requires no careful measurements or has any critical dimensions.

Socket

First step is to find a deep well socket that fits the drawbar.  For my mill, that means 17mm.  I bought sockets at Harbor Freight, but just about any cheap deep well socket will do.  HF has them for about 2 bucks.  As you can see from the pictures below, I cut about 1/2-inch off the drive end, simply parting it off at the line on the socket.  (Some sockets have a different appearance, so roughly 2-3/8-inch long) This dimension is by no means critical.  I was worried that the sockets may be hardened, but a standard HSS parting blade cut it cleanly and easily.  This operation was done on a 7×12 mini lathe, so it’s not like you need an expensive machine to part off.  When you break through to the square bore it will be an interrupted cut, so take it slow at that point, or finish with a hacksaw.   Tip: get or make a carriage lock for your lathe.  It makes parting so much easier.

Next operation was to bore out the square drive hole.  Once again, this was done on the lathe.  The square hole makes for an interrupted cut, so take it slow and easy until you get it round to avoid too much impact on the tool bit.  Drilling first may be easier, to remove the bulk of the material.  You want to bore it out enough for the inner filler piece, but leave enough wall thickness for strength.  My bore is about 5/8-inch diameter, but this is not critical either.  I purposely made the bore tapered slightly.  I’ll explain why in the next step.  Set your compound over a degree or two, and bore it out to size.  The socket machining is done for now.

As purchased on the left, machined on the right

Next piece is the inner filler.  I made mine out of brass for weight, and because that is what I had on hand.  Steel would also work, but I’d not recommend aluminum as you want more mass.  This piece is slightly tapered the same as the bore.  The reason for this is to have it jam up into the socket to facilitate tightening of the hammer head.  Once turned to size, drill and tap for the hammer head screw.  I used 3/8-16, but 1/4-20 would work just as well.  You want enough thread to hold securely, but if you go too deep, you’ll be tapping into the side of the screw when you make the handle.  Using a hacksaw, cut a screwdriver slot in the opposite end. Continue reading Wrench/Hammer Combination Tool for Mini Mill

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No such thing as spare time
No such thing as free time
No such thing as down time
All you got is life time
Go!

— Henry Rollins – Shine Lyrics