NBA FB to Medieval Madness Conversion

[robm]

Yep, the old pool table is a great resource!

Once the playfield was stripped, i had plenty of hardware bits to start on the new playfield. Also had a massive tangle of wiring from the harnesses. I separated them out into the 4 harnesses, and washed them in the laundry tub with degreaser and nifti. They weren't filthy, but did have a bit of black gunge that was good to get rid of. After washing, i rinsed lots of times, then left outside in the sun to dry properly.  I then stored them away as these will probably be a later job at this stage.

So i had all the T nuts from NBA, and installed them on the MM playfield - the ones on the top side of the playfield were tapped with the hammer to start, then finished using a socket just a bit smaller than the T nut as a drift.

I then installed the timber side rail - cut the NBA one a bit shorter to the correct length, then i put the hinges on underneath the playfield and installed in NBA cabinet. Note that i have also installed the MM roms, so i guess i officially have an NBA Madness now???



I have also started making the backboard. Used 12mm MDF, and got dimensions off Wally who had previously done a conversion - then used the backboard decal to locate the appropriate holes



I've installed the Mantis protectors - this Merlin one is a real pain to install, happy of anyone has any tips? Its sitting a few mm proud of the playfield, and needed to be bent to install, i'm assuming installing from underneath is the best - looks like i will have to bend the front lip down, but haven't worked out the safest way to do that installed without potentially damaging the playfield



Installed the other two Mantis protectors as below - the right larger one was too wide to fit the hole (being a repro playfield) and needed to be bent a fair bit to fit, so it still needs some panel beating to make one side fit a bit more snug - although this will be hidden once the castle is installed.



One thing worth noting now while i remember, is that just going through the process of ordering parts is massive.  I have been through the manual 4 or 5 times now and still realising i have missed parts - many that i thought i would be able to grab off NBA, or might have lying around as spares. The manual does not even have many parts listed. For example, the scoop below is listed nowhere in the game manual!!!


And all the tiny nuts, bearings, rods, gears, coil brackets, springs etc that go in each of the various assemblies, all add up in cost, and are a pain to order.  Since i do not have the luxury of looking at an existing machine, it adds another challenge to all of this. Reference photos from the net, and that others have given me are a great resource to help out. Of course there are still a few parts that are currently not available, so will be making a few of these up.  I should mention at this point that both Wayne and MarkC from Melbourne have been very helpful in purchasing stuff, as well as Tony from pinball shed with a few spares.

[swinks]

nice work Rob

maybe get the mods to move the thread to either the custom section or restoration section so it can found easily later on

[solar value]

Is this an Illinois Pinball repro playfield?

If so you may want to have a look at this video by High End Pins about the various fit corrections needed on these:

[DSB]

Is this an Illinois Pinball repro playfield?

If so you may want to have a look at this video by High End Pins about the various fit corrections needed on these:

Some seriously good info in that clip.

[robm]

Brilliant info thanks solar value...although i'm not that keen to hack into a cleared pf, but looks like i will have to!

[robm]

So when i started looking at a few photos on the net, i realised the black side timber on top of the right side of the playfield had some steps cut out to accommodate the large ball guide.  If i had a MM here to compare it would be easy, but its all part of the fun trying to work this all out. Looking at a few photos from different angles, i estimate where the steps should be cut out, and took the rail over the the neighbour who has a router mounted on the bench. Cut the step out, and painted black, and everything now installed looks pretty right.

Cutting with the router


I then started making some of the hex posts, i had some measurements from a photo on the net, but looking at the parts manual, i think the lengths listed are more accurate in the manuak (also according to a few other people i emailed). Let me just comment that imperial system is soooo painful.  The lengths in the parts manual are listed as decimal imperial....don't know why the yanks cant figure that metric is so much easier!!!  Cut the posts to the correct lenght, then centre punched them, drilled out and tapped the hole to 8-32 size



Someone had sent me a link of high end pins youtube video stating how reproduction playfields need to have some modifications.  One such was the photo below - i cut a thin slot so the protector can line up correctly with the hole



The next nerve racking cuts were made where the gate assembly goes - the slots need to be widened to the right as marked below



Used the dremel to cut a bit wider



One other issue i have just come across is the mantis merlin hole protector actually interferes with the popper that pops the ball out of the merlin hole - happy if anyone has any suggestions to overcome this one?

Then i got all the ball guides. These were laser cut and bent up by a top bloke with a few more metal skills than myself



Start to install the ball guides



Started to install some of the posts, and some of the holes in the playfield were only marked, not drilled. Again, a few nerves and make very sure the drill doesn't slip when doing this stuff!!!



Again - i don't have anything to copy off, so just going off photos of where things go, but things are starting to come together a bit now

[robm]

OK, just to prove this is still ticking along....  I really haven't done anything for a few months, been too busy with other projects and family, but got a bit inspired yesterday to give it a bit more attention.

Stripped pop bumper bodies from NBA FB, cleaned, and put pretty much all new components in them



When i went to install them, the holes in the playfield were a tiny bit too small to fit the pop bases, so after a bit of filing the edges of the hole, they all fitted



Installed the mechanisms



I've also installed the two ball gates, divertor and a few more posts, slingshot assemblies and the like.

Its amazing how you think you have everything ordered/planned but still come across heaps of small things I missed.  When trying to build the catapult assembly, i realised i haven't got the pin that connects the linkages together - things like that really slow everything up.  Also can't find the 10 opto board i put aside somewhere 'safe' for this project!!!

Hope to get a bit more done this week after work

[pinball god]

I hate that when the clear makes the holes too small. I used Dowell and sand paper to make the bumper holes bigger. By doing this I now know how to make fire in the wilderness   

[jennystack]

Very nice
Good luck

[goodolddays]

Good to see you are still ticking along with this project Rob . Quite amazing to think you are doing this without an MM to copy from 

[robm]

This would be so much easier if I had a mm to copy! Things like hex post lengths that are wrong in the manual as well as whole assemblies that are missing from the manual like the damsel scoop can be tricky to work out from pictures.   Also working out which order to install and wire things would be a lot easier. Not to mention just copying a wiring harness rather than working out everything from the switch and lamp matrixs.

Its all part of the challenge though.

[pinball god]

Beyond my scope of expertise and more importantly, patience. I'd be killing people by now with all the frustration you're going through

[robm]

A few more hours spent over the last couple of evenings. Started pulling the old bayonet light holders off the NBA GI harness, then linking them up and installing on the MM playfield. A reasonably slow but easy job.  The GI by the manual states it is top, middle and lower playfield - so i just organised them into groupings split roughly into thirds of the playfield, with almost equal numbers of bulbs in each string.



All done, and i thought it was OK until i starting thinking that the new playfield didn't have any holes drilled for the flipper shafts....until i realised in my haste to install the light holders, i had put one in each of the two flipper holes!  Left side removed, right side in the pic below needs to be removed.



Pulled the old flipper plates and mechanisms apart, someone had got pretty keen wrapping some extra length of spring here



New flipper bushing, coil stop, sleeve, plunger and link, and printed a new wrapper as well

[Homepin]

Bewdiful ! - (said with my best Con the Fruiterer accent).

[robm]

Made up the wire ball guides, these were pretty easy to bend by hand in the vice - although the radius is a little larger than factory. The NBA FB had heaps of these, so just cut and bent them.



One of the challenges was the shafts for the drawbridge assembly are not available. So i bought some 4mm stainless rod, and made up a poor man's lathe with a drill press and dremel to cut the slots for the e-clips



I was pretty happy with the outcome, almost looks factory!!



All this stuff is tricky as the manual is next to useless with no measurements and diagrams very messy. So most of this was made from pictures on the net and from other people.  Once the two shafts were made, it was a matter of installing the gears, then cutting some old post spacers up to align the last gear cluster



Hooked up the motor, and it all works perfectly!! I made a short clip showing the process

Follow this link http://youtu.be/jNroJDgXNNo