[CAM2]

What I'm basically asking is have you ever wondered why there's a square cutaway open window above the inlet seeings the top of the carb is removeable?

Using a tuned airbox instead of an airfilter works even better with those carbs too....


In reply to the slide cutaway question....Those carbs are more comprehensive than you realize....There's a master tuning pack that has assorted slides with different type cutaway n such to fine tune those carbs in addition to inlet reducers needle types and jetting...

 

[CAM2]

EPR: 3D printers can indeed make things simple. It's unusual for me to use it for any kind of part that's for actual final use. Up until now it has almost completely been used for parts development / test fitting only. I had didn't have any plans to sell them as I am short on time and energy as it is but the possibility is there if it's on a low volume. I already have an online store for auto parts and I send at least half of my products out of the country so it would be very quick and easy to make a listing for these.

Cam2: Even after taking my carb apart into pieces and once again thinking about how it all works I still don't follow what you mean. The bottom of the slide is flat so I don't see which cutaway height you are referring to. But I have yet to read up on doing carb tuning so if that will give me the answer then I don't want to trouble you with more of an explanation.

You're quite right Sam..3d printers do make good of the work...

I myself prefer good old wood and clay then cut the final piece on my mini lathe...To me it's a easier process..

 

[MrKitty]

no way the 3d printer is the way to go you just load the cad file into the slicer and hit start I like to keep an eye on it untill layer 3 then I go find something better to do I will check up on it every so often some times my printer will mess up but once you get the hang of setting it up for the most part you just pull the part off and it's ready to use

 

[CAM2]

no way the 3d printer is the way to go you just load the cad file into the slicer and hit start I like to keep an eye on it untill layer 3 then I go find something better to do I will check up on it every so often some times my printer will mess up but once you get the hang of setting it up for the most part you just pull the part off and it's ready to use

I've never seen a program write itself and feed itself measurements in order to bring the part to life and for sure it takes better than an hour

Even with the fastestt 3D printing technology, a part will not take more than a day or two to design, and that couple days, again, is with a massively large part using FDM or FFM technology.

The advantage of 3D printers is that the complexity and types of parts they can build is dramatically higher than that of the parts that can be built on a CNC machine. Which 95% of my designs can be...

 

[MrKitty]

No you're right you have to design the part I use tinkercad but there's tons of other software out there

Here is a folding drone I just printed out it's a work in progress

I think you whould really enjoy 3D printing and you could make some really cool stuff with your past experience...

 

[Sam-Q]

What I'm basically asking is have you ever wondered why there's a square cutaway open window above the inlet seeings the top of the carb is removeable?

I did previously try and work out why there was that cavity above the main 14mm intake hole. After taking the carb apart and seeing that there was no direct path for the air to go from there to anywhere else I figured that it was only there to simplify and save material during the die casting process. Unless you mean the air getting between the small clearances between the housing sides of the slide then I still don't understand how it does anything. I thought you might be referring to the central brass fuel tube but that's closed at the top as well so I am left seriously confused. No matter how much I dislike them I need to do some reading to learn more about carbs. Do I need to match that top opening shape directly to the velocity stack or can I just have a partial cut-out to feed air to that part?

In reply to the slide cutaway question....Those carbs are more comprehensive than you realize....There's a master tuning pack that has assorted slides with different type cutaway n such to fine tune those carbs in addition to inlet reducers needle types and jetting...

That makes sense, thanks for posting the pic. I was wondering how it was that there was only a main jet and a mechanical stopper for the slide closing and nothing else. No wonder I was confused. I currently have the flat bottom / #1.

I've never seen a program write itself and feed itself measurements in order to bring the part to life and for sure it takes better than an hour

I was originally only going to use the 3D printed part as a test fit but otherwise machine it manually. But then I had a think about it and figured it should be fine in the 3D printed PLA material. But it could really use some work with sandpaper to smooth the transition of the air going in.

When I am making something I would normally measure it up and design it for either choice. I may use CAD for both options depending on the part so it would depend on that and the time it would take for machining if I choose that. As for the 3D printing I would need to export the CAD file into my printing program, a few quick settings made, exported to a SD card and then plugged into my 3D printer. From there after choosing the file I can usually leave it alone. So while it did take close to 2 hours to print I was off doing work elsewhere. Printing the part can potentially also have a big bonus in that I can quickly make some changes to the CAD file and then set it to print again, all without taking much of my time. So it comes down to the part and it's application.


I completely agree in the fact that it allows for things that would normally not be practical to machine up. The image below is the 3D model of a part that I designed and printed off for a friend during the week. This one could of been made using a combination of machining and fabrication but it would not of been worth it.

 

[MrKitty]

I made this box for my girl friend for valentines day my printer squirted it out in 6 hrs

 

[Sam-Q]

I made this box for my girl friend for valentines day my printer squirted it out in 6 hrs

Looks good, well done.




UPDATE: Previously I decided to build a second spare engine so as to reduce any possible down-time with my scooter as much as possible. To go about this I had a new case / housing set arrive 2-3 weeks ago that I had ordered from Aliexpress. At the time I quickly noticed that while similar it was made from a different casting mould. Looking closer I discovered what seems to be the insignia from a different company. Unlike my other old cases this has "888" on each housing. In some ways quality is better and in others worse.

The job I did on the weekend is to do some Blueprinting, mods and a little assembly to this new housing. To do the Blueprinting I would align the faces and take the lightest cut possible to clean up and increase the accuracy of the faces. For example making sure were relevant the faces are indeed parallel.



Pic 1+2 - Outer faces: The surfaces of the outer faces were seriously rough with heavy chatter marks. Pictured before and after doing a light surfacing cut. The photos don't show it well due to the reflection of my lighting system.


Pic 3- Intake face: Normally this surface is not at all critical, however I found that unlike my other housings this wasn't parallel to the face of where the barrel bolts on but rather on a small angle to it. This could of caused some complications in trying to clamp each housing for some of my other machining work. To avoid that I did the quick and easy job of re-cutting the face. To make it parallel to the chamber to barrel face I pushed that part of the housings down against some parallel bars.


Pic 4 - Pin alignment: Using my edge finder to check the alignment of the pin holes relative to the center point between both sides of the case. Unlike the last housing I checked it was actually not too bad. If it wasn't right I could of re-aligned the holes by enlarging from 5 to 5.5mm using a milling cutter and reamer to then make some new 5.5mm dowels out of linear rod. If I actually would of been bothered to do so is another question.


Pic 5 - Barrel face: This face where the barrel gasket seals against had a crap finish. I could feel with my finger nail I could feel a small step between two passes of the previous milling. Using the same method as the intake face it was cleaned up with the smallest cut possible. Also visible are two different relief cuts to allow better airflow into the boost port(s).


Pic 6 - Bottom mounts: Predictably these were pretty bad. Pictured half way through the cut to show how far off they where. By fixing these up it guarantees the upright alignment of the engine. Secondly when the engine mounts don't all evenly touch the surface of mounting plate in the frame it causes stress to be put on the housings when the bolts are tightened by due to some feet being pulled down more than others.


Other jobs that I was able to do that aren't pictured:

- Re-cutting the top engine mounting point to make sure it's parallel. This is important as it's what I use to align the engine into my frame.

- I checked the alignment of one end of the crank to the other. They where parallel to each other but one side was 0.3mm off-centre to the other. Even though I know this is bad to have I left that alone because it would be way too much trouble to do anything about it.

- Assembly of the bottom end with these reworked cases, this time without a full circle crank.

 

[EPR]

Nice work, you never know what you are going to get when you buy China stuff.

 

[CAM2]

I made this box for my girl friend for valentines day my printer squirted it out in 6 hrs

Thats pretty neat...6 hours..?

I made these 316 Stainless steel items back in 2000...

They were drawn on a cad board in 26 mins,digitized[smoothed out] on autocad in 45 min,sent over to CNC mainframe in 1 minute..

Setup CNC Laser in 10 minutes and cut out items in 12 minutes........

Popped from sheet and bent into 3d shape...2-3 minutes each.........

What you dont see was I cut 50 of each item too that I gave away to family members and friends......Somewhere I have a picture of the free standing 2 ft tall stainless steel T-Rex skeleton I made too..........

The NY city scene took 30 minutes and the underwater creatures took under 20 minutes..

Looks like I got alot more better quality items from the CNC world for the same amount of time than what you got from that d-limonene machine.......:]

On the postcard in the middle was the park project in Queens that I helped out with called Forest Park...

When I see the commercials with the lady that makes 3d printed prosthetics for animals I think to myself now thats a great machine for such a worthwhile task....

One day when Im too feeble to do things manually Ill break down and buy one....By then theyll have most likely full blown replicators....LOL

 

[MrKitty]

Yes unfortunately my stepper Motors are pretty slow 😞 and it's a homemade machine if I try to run it too fast it shakes and loses resolution but right now I have to focus my money on my engine that I'm rebuilding for my Oldsmobile

 

[CAM2]

Yes unfortunately my stepper Motors are pretty slow 😞 and it's a homemade machine if I try to run it too fast it shakes and loses resolution but right now I have to focus my money on my engine that I'm rebuilding for my Oldsmobile

They have really low mileage engines for sale on the internet with free shipping cheap and come with 3 year warranties,,,,

Its alot faster of a process than youre gonna go through especially if you kicked a rodbearing in that puppy and ran it for any substantial time....The oil filter aint gonna help ya much if thats the case........

Youre in for a full, total and pretty costly rebuild otherwise......

Good Luck

 

[CAM2]

Looks good, well done.




UPDATE: Previously I decided to build a second spare engine so as to reduce any possible down-time with my scooter as much as possible. To go about this I had a new case / housing set arrive 2-3 weeks ago that I had ordered from Aliexpress. At the time I quickly noticed that while similar it was made from a different casting mould. Looking closer I discovered what seems to be the insignia from a different company. Unlike my other old cases this has "888" on each housing. In some ways quality is better and in others worse.

The job I did on the weekend is to do some Blueprinting, mods and a little assembly to this new housing. To do the Blueprinting I would align the faces and take the lightest cut possible to clean up and increase the accuracy of the faces. For example making sure were relevant the faces are indeed parallel.



Pic 1+2 - Outer faces: The surfaces of the outer faces were seriously rough with heavy chatter marks. Pictured before and after doing a light surfacing cut. The photos don't show it well due to the reflection of my lighting system.


Pic 3- Intake face: Normally this surface is not at all critical, however I found that unlike my other housings this wasn't parallel to the face of where the barrel bolts on but rather on a small angle to it. This could of caused some complications in trying to clamp each housing for some of my other machining work. To avoid that I did the quick and easy job of re-cutting the face. To make it parallel to the chamber to barrel face I pushed that part of the housings down against some parallel bars.


Pic 4 - Pin alignment: Using my edge finder to check the alignment of the pin holes relative to the center point between both sides of the case. Unlike the last housing I checked it was actually not too bad. If it wasn't right I could of re-aligned the holes by enlarging from 5 to 5.5mm using a milling cutter and reamer to then make some new 5.5mm dowels out of linear rod. If I actually would of been bothered to do so is another question.


Pic 5 - Barrel face: This face where the barrel gasket seals against had a crap finish. I could feel with my finger nail I could feel a small step between two passes of the previous milling. Using the same method as the intake face it was cleaned up with the smallest cut possible. Also visible are two different relief cuts to allow better airflow into the boost port(s).


Pic 6 - Bottom mounts: Predictably these were pretty bad. Pictured half way through the cut to show how far off they where. By fixing these up it guarantees the upright alignment of the engine. Secondly when the engine mounts don't all evenly touch the surface of mounting plate in the frame it causes stress to be put on the housings when the bolts are tightened by due to some feet being pulled down more than others.


Other jobs that I was able to do that aren't pictured:

- Re-cutting the top engine mounting point to make sure it's parallel. This is important as it's what I use to align the engine into my frame.

- I checked the alignment of one end of the crank to the other. They where parallel to each other but one side was 0.3mm off-centre to the other. Even though I know this is bad to have I left that alone because it would be way too much trouble to do anything about it.

- Assembly of the bottom end with these reworked cases, this time without a full circle crank.

Very nice setup you have going on Sam and good plan to build a back-up...

With almost each and every project build I always build spare engines and sometimes spares for the spare....LOL.......

I cant rememer if it was covered with you but as far as the cases cylinders cranks pistons etc theres many many different manufacturers and stuff built on the very hinky side that still actually functions with similar looks but obvious differences...

Ive even covered breaking down stuff and individually weighing each piece....youll be surprised how much two similar pistons can differ in weights.......wrist pins and even the piston rings too..........

The TM and Sanren stuff is the slightly better quality stuff....Ive never ran across an 888 case and Ive built many many many engines........

Keep up the great work and thanks for posting the pics of the process.........

 

[Sam-Q]

Very nice setup you have going on Sam and good plan to build a back-up...

With almost each and every project build I always build spare engines and sometimes spares for the spare....LOL.......

I cant rememer if it was covered with you but as far as the cases cylinders cranks pistons etc theres many many different manufacturers and stuff built on the very hinky side that still actually functions with similar looks but obvious differences...

Ive even covered breaking down stuff and individually weighing each piece....youll be surprised how much two similar pistons can differ in weights.......wrist pins and even the piston rings too..........

The TM and Sanren stuff is the slightly better quality stuff....Ive never ran across an 888 case and Ive built many many many engines........

Keep up the great work and thanks for posting the pics of the process.........

Thanks for the kind words and the advice like usual.



With the workshop it's taken me many years to set up my small workshop to the state it is now.

I did notice some different variations on parts when I was previously looking so it figures that there are more companies out there making these parts than what I originally thought. One thing that I recently discovered and found interesting is a new type of barrel that I had not seen before. It has the same 4 port transfers like my other recent barrel purchase features a larger square shaped exhaust port opening on the flange face and also the quite sizeable cooling fins. These are available real cheap and I will likely mention something about these in other thread that's for the 2-piece heads. Pictures attached.


I shall keep an eye out for those two brands you mentioned, good to know.



Should I do anything worth mentioning then I shall indeed report back.

 

[CAM2]

Thanks for the kind words and the advice like usual.



With the workshop it's taken me many years to set up my small workshop to the state it is now.

I did notice some different variations on parts when I was previously looking so it figures that there are more companies out there making these parts than what I originally thought. One thing that I recently discovered and found interesting is a new type of barrel that I had not seen before. It has the same 4 port transfers like my other recent barrel purchase features a larger square shaped exhaust port opening on the flange face and also the quite sizeable cooling fins. These are available real cheap and I will likely mention something about these in other thread that's for the 2-piece heads. Pictures attached.


I shall keep an eye out for those two brands you mentioned, good to know.



Should I do anything worth mentioning then I shall indeed report back.

I sure hope you will on all accounts...Ive dealt with them split transferport cylinders...

You can get some really killer torque out of them when theyre setup correctly..........I found that enlarging both channels aswell as shortening the divider with a knife edge yields killer torque aswell as a crispy throttle response........

The forward transfer can be raised an extra 1/16" too.........

Heres an example of what Im saying using my Xtreme XG499 49cc piston ported scooter....

 

[Sam-Q]

I have been meaning to do an update for a while now. I was able to take this for a decent ride for the first time. It was very stable but needed heavier clutch springs. After about 45 minutes it stopped dead. Pulling a torch out of my pocket I discovered that the housing of the carby itself had broken off at the flange. I figure it's the combination of too much engine vibrations from the inbalance and over-tension of the carby mounting bolt. Conveniently the spring loaded tensioner lets me take the chain off quickly and easily so I will able to push it without any drag and I was back at my car after 10 min of pushing.

I was already in the process of building another bottom end but this time (this time without making the mistake of using a full circle crank) and as such it didn't bother me much when I had this breakage. Pulling the engine apart I did a little more work to the barrel and also prepared a second barrel I had available. I was able make some good progress but when I was doing one final reference cut on the bottom flange side of my original barrel the milling cutter grabbed. This pulled it out of the vice and tore a section of flange out where it's meant to bolt down. I was quite irritated with that development. So much for having a spare prepared barrel on hand.

Other work I did were some piston mods in cutting a small amount of material off the crown of the piston. It looks like a lot but is only about 1 gram worth. This changes the shape from a dome to instead a taper for the outer part. I did all my pistons at once while I had the lathe set up. I believe this gives big advantages- the first being that all of my pistons now have the same pin to dome height which will mean my port timing won't change with a piston change. Secondly it optimises the combustion chamber to have gentle taper in the quench zone from the outer edge opening up a little once it reaches the main chamber. Before the shape of the piston and dome was such that it would trap a donut shaped circle of gases around the outer edge of the chamber under compression. If that makes any difference or not I don't know but it does make it a much more accurate process to measure the minimum squish clearance.

The scooter was fully reassembled with a new carby fitted and while it would run it would only do so with some engine starting compound in the intake, so the carby just isn't doing it's job. I have since tried taking it apart to see if I could find anything wrong with it and even changing the jet over from my old broken model but no it does the same thing. I also checked the fuel flow and that the jets were all clear. Next weekend I will aim to put a completely different carby on and see if it makes a difference. If anyone has any tips then I will gladly receive it. Once again I really hate carburettors.

Another update I have is I finished my Blata-rep V-block reed cage adapter and the matching parts to suit. I shall cover that in another post. I am happy with how it turned out. Of note the carby problem I have happens with both my old and new intake system so it's not the issue.

 

[MrKitty]

the del rep carbs do that to a lot of people ...

 

[EPR]

looks typical to me, did you notice the crappy alum casting, nothing like a Honda, lol.

 

[Sam-Q]

MrKitty: I will see if another carb fixes it. I really don't want to make another manifold to suit the original carby model with it's 2 bolt flange.

EPR: Rubbish casting quality but that's hardly a surprise to anyone. I did consider that the current issue I have is due to an air leak inside cause by the exact same questionable quality. I will find out via a process of elimination what the issue is, or at least I hope to.


Now as promised I have some photos of my custom reed intake. As I mentioned earlier I had a V-block reed housing left over from another project long ago. To use it I made up an adapter to go from it to the crankcase. As for the other end I custom machined up a manifold to suit. To make this manifold I used the lathe and mill to do all bar the internal transitions. I couldn't do the inside as that's not a practical option with a manual mill. So I instead milled a shallow step (marked in orange) as a reference and then later used a die grinder to shape it by hand, it should work well enough.

All things considered I think it turned out decent, well visibly at least. As for how well it works that I will find out. It was entertaining to machine up though.

 

[Phillysoul.jf]

This bike was left in the garage of the home I recently just moved into but I don’t know the make and model. All help appreciated. Thanks in advance