I was curious how far we can go to create a minimum budget DIY lathe that can still produce decent work. I already had the Dremel tool. Almost everything was designed around materials on hand; mostly scrap.

This is the method I devised for my DIY routing table to hold the Dremel tool. It clamps in a track so the height can be adjusted.
 Not pretty, but it is functional..
The model 400 XPR which does not have a round body like earlier models, so it required more creativity to mount it firmly. The shiny black band is metal banding strap used for shipping heavy items (bricks, rebar), with a carriage bolt through two holes in it. A wing nut under the wood base pulls it snug. The bottom of the base has a hole big enough for me to get my fingers in to tighten the nut. A square of Masonite is screwed and glued over the hole for the wing nut to pull against. Note the jam nut on the carriage bolt to prevent it from turning in the banding strap. The Dremel was mounted this way to make the speed control (blue wheel at the rear) readily accessible.  

The Masonite tabletop worked well on the routing table, so that will used for my lathe bed instead of the steel plate in the original fonly. It would be wonderful to have beautiful wood and steel parts, but I priced steel plate at ACE and decided I did not want to invest that much.

Now, take a look at the clamping method for the guide bar on the router table... The square part of the carriage bolt heads clamp securely to the edge of the Masonite tabletop. I will use this method to position and clamp things that will slide along the bed,  for example a center rest, or filing rest. This means that looking from the end the bed will look like this:

Lathe bed end view



Here it is set up for aligning the "headstock" using a long drill bit. Use a piece of 1/8" cold rolled rod if you wish. The rear piece is sanded to the proper height to make the drill bit parallel first, the it is glued and moved side to side to make sure it is aligned the full bed length.

Not wanting to invest in some great looking hardwood like the original 'fonly, I used at-hand materials. The base is inch and a quarter angle iron from a discarded bed frame. I checked it with a straight edge first. The part that clamps the Dremel nose is plywood with a 3/16 bolt held in with J-B Weld. A wing nut is on the other side of the photo. The hole was drilled 5/8" then the 1/2" sanding drum used to make the Demel nose snug. The table saw was used to make the slot so the bolt can clamp it.

The bed is 5" x 11" Masonite with a 4 1/2" x 11"  piece under it. This gives it a lip for clamping. Later I will double check the bed for flatness. Paper shims can be used under the bed it it is not flat. It will be finished with floor wax. The white paint is epoxy spray meant for appliances.

1-4-09 First job
Before I even made any bed accessories, I made a 3mm center and center drill.

An abrasive cutoff wheel was used to slice an old 1/8" drill bit like this. 1/8", or 3mm is standard for jewelers lathes.

Each piece was chucked in the 1/8" collet and rotated at medium speed. The abrasive wheel was mounted in a regular electric hand drill and held against the rotating drill blank. A 60° paper template taped to the lathe bed is handy for getting the proper angle. The same was done for the other piece with the flutes. That one a lot faster since there is less metal to remove. It was finished by cutting the relief with the Dremel cut-off tool by hand.

There is a minor problem doing it this way rather than buying a (rather expensive) ready made center drill... An extra step is required because it can't drill the pilot hole. The work is marked and center punched as usual, but a small drill bit is used to make the pilot hole before the 60° center drill can be used. Anyhow, I saved a lot of money by making it myself.


Controls
The original 'fonly has the cutting depth adjustment on the rear of the bed. I made my bed longer and want a wider bar.

The original 'fonly plans suggest using 1mm screw pitch so that the adjusting knob can be calibrated. If you wanted English graduations, 1/4 x 20 screws could be used.


1-11-09 Face plate
   Holes not drilled yet to drive the dog.
The blank was made from two layers of Masonite laminated with polyurethane glue. The nut is for the flex tool. It was annealed and drilled so that a dead center can be counted with a collet. The disc was drilled 3/8 then filed hex and polyurethane glue used. Tapping on the nut with a hammer makes shiny marks in the hole that show you where to file. Just before the glue is dry, it can be mounted on the spindle and alignment corrections made. Course sandpaper was held against the rotating disc to make it round and true. UPDATE  Once the lathe got to a point where it can start making its own tools, I made a light facing cut across the faceplate and checked it with a straight edge to make sure it is flat. The sanding disc will get the same treatment.



Tailstock drill fixture


The oak block that mounts the chuck is glued to its base. When dry, (I am spending a LOT of time waiting for glue to dry) glue is applied the the bottom of the block pedestal, a screw driven in, and final alignment made.



Tool holder thoughts...
Long ago, before square lathe bits were the industry standard, round bits were common. These are making a comeback at least in the area of automotive brake disk turning. The claim is they cut smoother and 25% faster.
A tool holder might look like this for my fonly:

A drill the size of the bit is chucked in the headstock and a hole drilled through a wood block. The round bits could be bargain bin drill bits from Big Lots or a number of auto supply stores really cheap. Grinding half-way through the end of the bit automatically makes the cutting edge the right height. To switch from right-hand cutting to left hand, all you have to do is turn the holder around. There is no reason a number of blocks could be easily made to accommodate a variety of bits including square ones. The bits will be epoxied in.

The base is two layers of Masonite laminated together. A carriage bolt and wing nut serve as a tool post adjustable clamp. Here is where there is a major difference in construction from the original 'fonly... The square part of the carriage bolt head can't be pressed into Masonite. It will crack or chip. A three cornered file must be used to make the square hole in the Masonite. 

My thinking now is a rectangular bar for the "cross slide" adjustment. It would be epoxied to the metal bar the tool post slides against. This should give a slightly lower profile for the bar
.


1-19-09  Sawing/sanding table

I use 5" self-sticking sanding disks on the drill motor. It seems a shame when I replace them, because the centers are always in good shape. But now I have a use for them. Simply stick it to the smaller 'fonly sanding disc and trim the edges. Nothing complicated about this table design. It measures 5" x 8", two layers of Masonite with a gap for the saw guide in the center. The two upper pieces were glued with polyurethane glue and attached with screws. The back side has the aluminum angle, and the front is attached with a single carriage bolt and wing nut. The bolt head becomes sort of a J clamp.

1-20-09 Sanding disc

The sanding disc measures 3", and can be used with or without the saw table. Laying on the bed is the index blank. The hole in the center is large enough for clearance using the 1/4" chuck. It only took two tries to print the index pattern the right size. Water soluble glue was used, but I sprayed it with clear plastic to keep it clean. It will be drilled with two sets of index holes. I want it to index to 20 for making graduated knobs for 1/4-20 thread screws, such as the cross feed. 20 increments equals .0025". This mean that one graduation will remove .005" when turning in the lathe.



The crossfeed is laid out. The knob seemed to nag me, but I had all these little plugs from cutting out holes. Two plugs will be the graduated scale, and two more for the knob part. I made a stainless steel (because I did not have brass that size) bushing out of 5/16 stock with a 1/4" hole to keep the threaded rod from chewing into the aluminum. A polyethylene coffee can lid provided a smooth working washer.

1-25-09 Handwheel
Index attachment is put to work.
The graduations are scribed on the inner part of the handwheel. It is is held on a 1/4" rubber mandrill (1/8" shank) for small sanding drums, then chucked in the collet behind the faceplate. Lines are scribed in the white epoxy paint by moving a scriber held in a small vice. A block of wood with a sharpened nail would have worked just as well. The tubing will be cut off of course.

Here is where I found that the backing plate for the index interferes with loosening the nut that clamps the nose of the Dremel. It will get cut to a rectangular shape. It would be better if I can remove the Dremel without disturbing the index plate.

After the outer (larger diameter) part of the knob had been glued and set, the excess tubing sliced off, placed on a sheet of poly plastic to prevent sticking, and the hole packed with J-B Weld Kwik. The threaded rod inserted and allowed to dry with checks often to make sure it is vertical.


Rather than make something complicated, or a bottom cover that would collect chips to keep the leadscrew nut in alignment, I settled on a simple pin epoxied in the nut holder that fits in the rear of the T bar. The pin just slides in the hole.


Except for making it a bit prettier, the cross side is done. The two angles on each side of the T bar stem are for fine tuning the T bar for squareness. You may be wondering why this came last. It is to make sure the cross slide would  not interfere with any bed accessories. I used a magic marker to make a blue dot and a red dot on the graduations for reference at 10 divisions each. Saves tedious counting.

So how do we make sure it is square? By mounting a scrap bar between centers (or the chuck and the live center). Using a tool that is near on-height with the centers, make a light cut. If the diameter is the same at each end, the T bar is square with the work.

1-27-09
First real tests were a little disappointing because of wobble in the Dremel tool spindle. I can make the modifications spelled out on the first page. From the beginning I wondered how the flex shaft would work as a lathe. More thought is required, and a little more investigating.

Here is a Dremel 225 T2 flex shaft being used on a large lathe in the tool post. Diameter of the handpiece is 1/2".
NOT my lathe.

I disassembled my flex tool hand piece and found that it lacks the rubber bushing that the 400 XPR has. This explains why it has less wobble under a side load. 

2-23-09 What I have learned so far...
1. While making the bed from Masonite was expedient and cheap, I will likely invest in steel now that the project has gone so well, because the Masonite scratches as the tool post is slid along the bed from the inevitable metal chips. 

2.  The more I think about using either the 225 or 225 T2 flex shaft for the headstock makes sense. For one thing, it would free up the Dremel 400 for vertical operation. Something I would like. Lets say we want to drill accurate radial holes; perhaps a wheel hub for a model something-or-other. A drill attachment using the 400 could be mounted on the bed, and the workpiece indexed on the headstock.

3.  The live center is wonderful. No changes there.

4.  Tail stock drill attachment seems okay, but somehow I have the feeling I could do better.

5.  The index plate is fine, BUT it should have been painted white first because gluing it to bare Masonite makes the white in the printed paper gray. Also, heavy clear packing tape will be used to protect the printing instead of the acrylic spray.

6.  The headstock clamps will be of hardwood. I had to re-glue the plywood twice where it delaminated.

7.  The guide rod for the saw table was made from scrap aluminum left from making the modified angles to make bed accessories. I proved too rubbery. Use steel flat stock.

Continued with a rebuilt to incorporate these changes here

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