Quickie Junior

Something that is not a tool! (just for a change)

Inspired by the original Quickie I decided to try my hand at a quick and simple loco. Simple, yes, quick, not for me so far (-:

I've based my design on both the Quickie and on an industrial loco local to me, shown below, and have later added input from the FRED plans that appeared in Model Engineer 15 April 1994.

(Thursday 26 Feb 2004)
So far I have completed the axles (after finding bearings in my scrap box) and have started on the wheels. I've also done some CAD work to make sure I know where I'm going. I'll be doing a flexible outside frame that carries the wheels. The superstructure will fit to that on springs.

I'm having a lot of fancy ideas for controlling it. Some sort of radio maybe? I'd like to have it drivable by the target audience, kids, but I'd also like to have a measure of safety embodied in a remote control unit that at least gives 'emergency stop' capability and prevents instant reversing. We'll see what can be found. At the least I can have a tether and a 'go' button that a kid can press for forward motion.

Sunday 29 Feb 2004
Got 2 wheels made this weekend! Unable to get valve springs from my friend who fixes lawn mowers >-: He moved his workshop over Christmas and threw away all his old springs. Now looking at some springs from electric staplers salvaged from a printer works.
Monday 28 Jun 2004
As you can see below the main drive axle is complete. The second axle is very nearly done, Just awaiting the bolts to hold the sprocket on (there I was. blithely tapping M4 holes only to discover I had no more M4x20 bolts to go into them!) and then I can fit the 2nd wheel with a bit locktite.
the inbetween time
Current status of this project is 'stalled'. Sadly, this thing needs springs, AND the worm driven motor just won't work. During testing, the acceleration and deceleration forces were clearly large enough to strip those gears under load (testing was loco + battery only). So, plan B involves purchasing some radiator cooling fan motors, and fitting springs. Fitting 2 motors means redoing all the sprockets too, which means getting at least one wheel off the axle.
So, the motor will be repurposed for a power hacksaw, and springs will be found... hopefully this 2006 summer season.
05/05/2008 10:26
Some progress has been made! A good friend sent me a huge motor (thanks Peter) and another friend gave me a welded frame plus the plans for 'Fred' an electric loco featured in the ME magazine April 1994 (thanks Richard). However, the frame is the wrong width (someone read 5 5/8" off the drawing instead of 6 5/8" so I have cut it in half and will be welding in some spacers. Pictures coming soon.)
Also needed is a change to the drive sprockets but I believe I have a plan that does not involve removing a wheel...
27 June 2008
Happy to say work has resumed. I have cut the frame in 2 and welded it back together with 16mm spacers to make it fit my existing axles. (that was last week). This is still narrower than the plans size, however, I think it will better align the bearings like this.

Today I started on the bearing holders. I purchased some selfaligning bearings that are 22mm OD and 8MM ID and 7mm thick (expensive items!). These will fit into 28x28x21mm blocks that attach to 4mm plates that ride on the springs. The original used castings but while I hope to get set up for aluminum casting, I am nowhere near doing that yet. Since I have 4 springs, enough for one axle, the other axle will get rubber blocks, effectively giving a 3 point suspension. I have no idea how much resilience is needed in the rubber, but I can choose between some hard blocks that normally fit into car springs, or rubber gas pipe, or something else not yet found in my pile of junk.

With regard to springing for this type of loco (ie not steam) I have wondered about those nice coil over shock units used on bicycles. Obviously those springs are pretty strong to support a cyclist (and normally configured such that the spring is at a disadvantage). However, what if the axle boxes were levered onto a spring unit mounted between frames? One can then configure the advantage ratios, and have a damped spring of adjustable strength. The levers taking the axle box movement to the spring will also provide for side to side differential, thus providing for '3 point' type suspension.

up till 13 July 2008
Have completed the bearing blocks and 2 of the plates that support them. Have not decided yet whether to attach the blocks to the plates using bolts or silver solder (having never silver soldered before, this amy be a fun way to learn to do it.)

Had a rather intersting experience with a negative rake tool. In setting up to face off the 4mm plates after hacksawing I chose a tool ground for general turning, but set it on its side for facing. Thus the cutting edge has negative rake. Using this to face a 75mm long plate edge, 4mm wide, resulted in very hot chips, and a very smooth finish, but it did need some cutting fluid to prevent chipping out the trailing edges. I use chicken fat for this, and will be having roast chicken tomorrow to replenish stocks. I find the oil is better, but when that runs out the fatty solids deposits also work well on all grades of steel.

up till 8 Sept 2008
Not much going on in recent weeks. I did get one bearing block completed before getting distracted into making a camera quick release mounting. The plan is to try to get the chassis rolling by 20 Sept. I'll be on leave for the week after that, with the plan to get the loco running by 27th Sept, which is a public running day.

Wish me luck... those bearing plates take a lot of drilling


A quick render of the basic layout. It it about 600mm long and 360mm wide. The battery (standard car battery type 628) is supposed to fit in the cab. I will balance more weight onto the front axle by means of big lumps of lead. The original Quickie was 7.25"" gauge and could fit 2 batteries on board.

Note that I now have published plans for a loco named Fred (April 1994 ME). Its size is 750mm long and 294mm wide,which is close enough to what I was planning anyway, so I'll leave it that size.

Last edited February 20 2013 09:54:48.

The local diesel hydraulic Funkey I am sort of copying for my loco. This loco is about 5 meters long and 3 wide, and runs on 3'6" track. That would scale to 595x357mm at a true scale of 1:8.4. The frame I am using is 750x294mm, thus a bit longer and thinner.

Well, now that I have plans to hand, I'm not copying this loco at all except maybe in rough outline, and possibly paint job.

Last edited February 20 2013 09:54:48.

Sunday 29 Feb 2004

Wheel 2 on the faceplate prior to turning the tread and boring the axle hole. It is fastened to the faceplate by 4 M6 bolts tapped into the back. It is spaced away from the faceplate by 2 pieces of ground HSS about 3mm thick with a single layer of laser printer paper wrapped around them. When I was roughing in the first wheel I found it shifting despite the 4 bolts, just not enough friction on the smooth HSS.

Last edited February 20 2013 09:54:49.

A collection of parts. This is wheel 1 plus it's axle and bearings. The bearings are 6000z's but although all the references I found to type codes specify that 'z' means a shield on one side, these have shields on both sides.

I'll have to turn the ends of the axles down to fit the 7mm ID self aligning bearings I am now using. I can do this between centers with the wheels in place.

Last edited February 20 2013 09:54:50.

The wheel inspector checks for smooth running on my short test track. The first wheel is a tight slip fit (I thought it would be tighter) and wheel 2 turned out to be a slip fit. I'll buy some Loctite 603 this week and fit them with that, and think about pinning them too.

Of course, I also need to think about fitting whatever sprockets etc I need for the drive chains before fixing the wheels.

Last edited February 20 2013 09:54:51.

One of the 4 bearing mount blocks. Machined from 12x50 hot rolled bar. Hole is 26mm diameter to take a ball bearing. These will be bolted to the frame, relying on the frame to flex for 'suspension'. (which never worked)

This system has been scrapped in favour of having at least one axle sprung.

Last edited February 20 2013 09:54:52.

The 7 tooth drive sprocket on the axle, with the wheel in the background. I made this sprocket by drilling the holes at the bottom of the teeth, then anglegrinding the teeth to rough shape following a glued on paper pattern. The material was 4mm thick. After boring it to fit the axle, then fastening it to the axle with Loctite 603, I reduced the tooth thickness to match the chain (ordinary bicycle chain) then took a bit off the tips until all teeth had flat spots. I then checked the tooth shape with the chain under tension. A little bit of filing fixed the few that were a bit 'fat'.

Last edited February 20 2013 09:54:53.

Here is the almost completed main driver axle. 7 tooth sprocket on the left, and 18 tooth sprocket on the right. This sprocket just needs 3 bolts to hold it to the wheel. A similar 18 tooth sprocket will go on the other axle to give all wheel drive. The sprockets came off small bicycles that the kids grew out of.

The 7 tooth won't be needed now that I am driving the axles via a layshaft. I'll just leave it on there

Last edited February 20 2013 09:54:53.

The frame for Fred as it arrived. The studs are the spring guides. As it stands here it is too narrow, the wheels do not fit between the frame members and they should. The pillow blocks are for the intermediate drive shaft that acts as a gear reduction from the motor, and splits the drive to the 2 axles.

Last edited February 20 2013 09:54:55.

I cut the bearing blocks from my stock of 60x60mm BMS bar. The cuts shown here were done on a friends bandsaw, except for the 3rd cut which I did by hand due to difficulties holding the smaller blocks in the bandsaws vice.

These blocks will trimmed to 28x28x21 and bored to fit the bearings.

Last edited February 20 2013 09:54:56.

An overview of the loco from the magazine article. Two batteries, motor in the middle, chain drive, fit your choice of body over the top. Cannot really be simpler!

Last edited February 20 2013 09:54:58.

I had to cut the frame in half so I could widen it. The drawings I have are a copy several generations old and the poor quality lead to reading the width incorrectly. I resized it according to my wheels.

Last edited February 20 2013 09:54:59.

Welded back together with 16mm spacers. The frame was welded together from a collection of flat bars, hence the groovy look. I intend to fill the grooves with spot putty before painting.

Last edited February 20 2013 09:55:00.

Inside the frame is not so pretty. So far I cannot see a reason to grind it clean so I'll leave it. It will all get a coat of anti-rust and then enamel paint. Also planning to fill the grooves on the outside of the buffers with spot putty.

Last edited February 20 2013 09:55:00.

3 of the bearing blocks. 28x28x21mm, bored 22mm dia 14mm deep for the self aligning bearings. They will get a bit of 4mm plate attached on one side which will ride on the guides and press against the springs. Not sure yet whether to bolt them together or try my hand at silversoldering.

Last edited February 20 2013 09:55:01.

I ground up a new boring tool for this job. I normally use a rather small one ground many times over from a 6mm square bar of HSS. That tool has had various forms over the years, and is getting shorter....

This one is 8mm square bar ground to a sort of 1/4 round profile, freehand, and run upside down against the far side of the bore. I find this provides a good view of the work, and easier knob movements (and calculations) for infeeds.

Last edited February 20 2013 09:55:03.

Closeup of the tool. All these fotos are taken from the back side of the lathe.

Last edited February 20 2013 09:55:03.

Attempting to the show the 1/4 round shape of the tool. Sadly the business end is out of focus, but you get the idea. All freehand ground on my bench grinder.

Last edited February 20 2013 09:55:04.

Playing with Google Sketchup produced this isometric rendering of the frame. I only did one bearing block as I find copying and pasting into accurate positions in Sketchup to be difficult.

Last edited February 20 2013 09:55:05.

An inside view of the bearing block. A 22x8 self aligning ball race fits in that hole, and springs fit between the frame and the bearing block, guided by the cyan studs.

Last edited February 20 2013 09:55:06.

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Last modified: February 20 2013 07:52:46.