What did you do Today 2018

John, Ian S C describes it correctly, the trailer hitch only allows vertical (up and down) movement of the trailer along with left and right for turning. The geometry of the hitch point to the wheel contact point with the ground provides a level of stability if the weight is kept low down. Bit like towing a wheelbarrow in reverse.

Ian, mine uses a 'step-through' style frame with an extension welded to the steering tube to curve across the back wheel of the towing bike. I wanted to maintain the same wheel size as the towing bike so it gives me a spare tyre, wheel rim and spokes if anything major should happen to one of the bike wheels while out riding. I'll be fitting a basket or panniers of some sort on each side of the frame, as well as several water bottle holders.

I'll post some photos once it's presentable.

Some designs put the hitch on the seat post, just below the seat, I did that for the lad across the road for his paper round. I don't like the common design that has a long sweeping tow bar that connects to the(usually) Lh end of the rear axle. My design is quite happy following behind on the local forest bike track, any where the bike will go the trailer will go.

For heavy weights, two wheels is the only way, mine has 16" wheels. I bought home in a number of loads all the 75 x 50, and 100 x 50 timber to build the partition between the car(Mum's) and my workshop, by fitting a turn table on the trailer, and strapping an extra pair of wheels on the end of the timber. It helps that I live in a small rural town, and also it is fairly flat.

Ian S C

After drilling and tapping the required holes, I did a trial assembly of the 7 5/8" raising block I'm making for the milling machine.

Advantages:-

1. It gives me enough headroom to do two of the jobs I've got lined up for the mill.
2. It allows the full travel of the knee. (what's the point of a table that can be raised to the same height as the spindle nose?)

Disadvantages:-

1. I'm going to need duckboards or steps to change tools and speeds, since the mill is already as much as I'm comfortable reaching up to without the raising block.
2. I don't know yet what, if any, effect there will be on rigidity. That'll be found out when I start to use it.
3. As shown in the first picture, The raising block could have been even taller. There's another 5" of quill travel available!

During the drilling of the holes, I hit a couple of hard spots that needed the drill to be resharpened. I stuck the drill in the Drill Doctor and ended up with variable (usually negative) relief several times. I've been having problems with the Drill Doctor 750X, even when following the instructions religiously, for some time. So the Drill Doctor has been struck off for gross incompetence and a Picador drill grinding jig was mounted on the surface grinder. Perfect results in a fraction of the time . I had. previously, had reasonable results from the DD, but it gradually became unreliable even after replacing some of the wear parts at significant expense. Its now going to the local tip!

The lugs on the side of the raising blocks are to take some arms/brackets to hold the milling vices and the rotary table and its chuck out of the way, but where I don't have to lift them onto the table when I need to change them.

Edited By Mark Rand on 12/12/2018 00:01:59

I took advantage of ian p's advert on here for a Steve Ward Rotary controller to attach to my 4" Sharp rotary table.

I'd really only intended this 3D printed connector as a prototype prior to fabricating something in steel but I think it might be robust enough to be a permanent fixture - we shall see!

It all works really well. Ian, you clearly did a nice job of putting the controller together.

Cheers,

Rod

Well that is a surprise, as I was not aware that I had advertised Steve Webb's controller, or anything else on here.

JS (very much missed!) sold me one of his boards and a programmed ICs which I made up in a casing complete with and old laptop external PSU. The casing front and back were actually the discarded lids off two scrap ABS electrical enclosures (black rectangle on the front panel is the stepper driver heatsink).

I think your printed motor mount is more than man enough for the job and a metal version would not perform any better. Is the slot purpose to give access to the coupling grubscrews?

Ian P

Rod... what material did you extrude on the 3D printer to make the extender/adapter for the stepper motor & rotary table?

John

Whoops, sorry - Ian J not P. Bit of a coincidence though!

The connector housing is PLA - I haven't investigated printing ABS yet. And yes, the slot is to get at the grubscrews on the flexi connector joining the 1/4" stepper shaft to the 3/8" rotary table shaft. The flexi connector was an Ebay purchase, 6.35mm to 8mm which I had to drill out to .375". The handle on the RT controls the worm engagement so I also had to make a collar with a locking screw to fit on the shaft inside the housing. That was the first engineering job in the new workshop .

Rod

If You are getting negative rake with the Drill Doctor, just slightly loosen the collet and turn the drill bit slightly clockwise (I think) and tighten it up and try again. If it's worse then it goes the other way, I don't have My notes here with Me at the moment.

It should be anticlockwise for more relief, assuming the DD instructions about moving the collet clockwise for more relief are correct. Results were still inconsistent. I just got sick of the thing's problems, even though I've used if for five years.

The Picador drill grinding fixture, mounted on the surface grinder really is an order of magnitude faster and more repeatable. I had been looking at Graham Meek's modifications, but most of them aren't needed for the Picador version. I will, probably, build a larger version to cope with MT drills up to 1" diameter.

Well, i've finished the trailer and hooked it up to the bike, but the performance was pretty underwhelming. Very unstable and leaning the opposite way when cornering. Seems like i've messed up the geometry of the tow hitch arrangement with the axis of the left/right pivot leaning the wrong way. Will need to remake the tow hitch, but even then i'm not sure it's going to work too well. I'll give it another shot next week but if it's no better then i'll put it in the 'lessons learnt' box. .

Perko 7, I must get some photos of my hitch, the hitch part on the trailer is 2" long with a 3/4" bore, the part on the bike is in two parts, one at the top, and the other at the bottom, ie double shear. through the three parts is a 3/4" dia pin(tube actually), head at the top, and a R pin through the pin at the bottom or the main pin tends to work it's way out. The set up must be ridged vertically. You should have no stability problems. You could try having the main beam of the trailer an inch or three lower than the axle height. My trailer with 16" wheels has 6 1/2" road clearance.

This is also towable, it is a home built alternator with a 3hp Kawasaki motor, mounted on a home built sack barrow. when hitched up the wheels at the Lh end are removed. Total cost $NZ10 for the motor, $NZ26 for the main wheels.

Ian S C

In between trying to get the Chester mill motor off I have been making up a backsplash guard for the Myford Super 7.

Needs a bit more work to route the DRO cables and provide safe power to the DRO but basically finished it today. Fitted the DRO scales about 12 months ago and this is the first time I have powered them on. The display came of the Myford 7 I recently sold.

I need to fit the DRO modification to put the magnetic scale under the cross-slide but need the mill to do this or get my mate to do it on his Hauser jig borer.

Colin

Well I boxed a 12V 4A transformer and fiutted some connectors to restore our 'fibre optic Christmas Tree' to its former glory, having reached the end of my pine-needle tether.

Then my battery powered lights (lights still working after three Christmases!) had three wires cut through so a bit of experimentation needed.

Finding that with arteritis in my left wrist and numb fingers that pressing the start button getting difficult so I move the stop/start unit it's now a lot better to use

I've had one of these table clamps on my drilling table for some years now and a very useful feature it is for securing jobs whilst drilling.

Sometimes the arm is too short to reach the job that requires holding, so I bought the next size up which has a longer arm. Unfortunately this one is secured to the table with a 12mm stud and the slots in the drill table are only 3/8", nevermind I think I'll make a smaller stud to suit. After more closely examining the way the stud is attached to the clamp assembly I concluded it was a lot easier to cut the stud off and make a new sub base with a smaller stud screwed into it. This is the result of an afternoon's work delving in the scrap boxes, I know it will never win any prizes but it now does what I want and to my mind that's all that matters in this instance.

By the way if anyone is wondering what the ropes are at the back of the table, they are part of a crude and simple counterbalance to offset the weight of the table when raising and lowering it.

Phil

I ordered a Prusa I3 MK3 3D printer at end of October. It turned up early November, but left it to yesterday and today to build when I knew I would have some free time.

Had little unwanted help as you can see.


First two printed items shown. Took couple of goes to get the printhead height correct to get the PLA to stick to bed.

I think they look reasonable. The first go at Benchy did not stick, did one layer then came loose.

Any suggestions for change, I just used the built in defaults. I know Neil is specialist in all this, perhaps I should buy his book.

Colin

That benchy is pretty good - only minor defects on some corners.

I would just go ahead and print some objects and only worry about changes when you find prints not coming out as you expect.

I dunno about changes being needed Colin, that 3D printed cat looks REALLY realistic! ......oh wait......

Just kidding. the boat and sign are a start. Just keep practicing. There are lots of stick-improvement tricks depending on the bed type you have. glue stick, PVA glue, two sided tape, etc. I defer to Neil and others on best technique for your machine. Generally the larger the area of the first layer the better it will stick. Rafts and rims can be used to increase stick area. Speed of nozzle and feedrate of filament can have big effects on adhesion to bed and build quality too.

Merry Christmas to all.

That is impressively attractive. Congrats.

Not today, but 4 days back ... finished this little racer to go with the 3-year-old grandkid's little garage set. It's titanium, brass and delrin, 22mm track by 67 long.