Page 6 of 37
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Sun Jul 08, 2012 7:02 pm
by Seabass
Regular Nylon is what we are using. I agree some vent holes are needed but the guy wanted to try without them first. A real quick .0005 pass with a ball nose endmill would probably provide the relief needed. We will see in the next couple weeks
For the size shot we need, I am certain the 20 ton press should fill the mold but then again who knows. The press has the capability to melt the nylon but by nature of plastics, nylon is one of the toughest to push and fill a mold. Only time will tell.
Jake
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Sun Jul 08, 2012 10:59 pm
by ck33
This is a great thread... I commend your ambition. You will need some vent/riser locations (probably several) to get material out. Air has to escape the die as material enters, and you need to make sure the plastic flows at the critical areas so you get the spec material properties. You will also need to worry about ejecting the part after it molds. A production die would have slightly angled/drafted surfaces, and ejector pins. You may be OK with a one shot die. You can pick up any AE or other RC part, and you can find where the ejectors and vents are located. Sounds like the guy you are working with has some experience. As they say, one test is worth 1000 expert opinions. Ever thought about making a mold to replicate rear arm mounts?
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Mon Jul 09, 2012 12:18 am
by Seabass
Thanks for the suggestions. The mold is not going into an automatic machine which I doubt I could design the mold for one of those machines having no experience. I still need to do a bit of work to the molds polishing out the tool marks and also putting a slight taper on the part edges so I get a decent release.
Lets hope for the best, if it doesn't work out I will go back to the drawing board on this one.
Jake
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Wed Jul 11, 2012 12:29 am
by tiger1
Love the kydex mock up and the mold machine work
Re: 91 Masami Stealth replica (30 Degree CF panel arrived)
Posted: Wed Jul 11, 2012 4:31 pm
by slotcarrod
bigjeepzz wrote:Got a ton of work done last week. As I stated earlier the chassis and top brace was cut from 1/8 kydex so I could have something to build the car as I go. I also drew up the front shock tower and cut it from the kydex as well.
I started machining the molds for the arms and ran into several problems. I eventually figured it out and was able to get the molds done. I am very experienced with casting but injection molding is a bit new to me. I still need to polish the inside of the molds but I should have them ready to send out in the next few days. The guy doing the molding for me is using a 20 ton press to inject the arms and we are still not sure his machine can handle the volume of nylon 6 I need, we will see. I did not put any vents in the mold and the guy told me he wants to try it without the vents first. If that does not work he is going to machine the vents in the mold for me.
I am placing another material order today so I can machine the front bulkhead and rear castor blocks. From there it will be putting the car together and making changes to the final drawings, then cutting the material for the final car.
As I get more done, I will be sure to take pics.
Jake
Uhmm!.... Maybe I should talk to my doctor about this, but is it ok to be sporting wood after seeing these images????
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Thu Jul 12, 2012 10:16 am
by fredswain
Is your injection molding technique using hot melted nylon or are you using a "cold" material that approximates the characteristics of nylon? If it is going to be hot, did you enlarge the molds a few percent to account for the material shrinking as it cools?
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Mon Jul 23, 2012 8:51 am
by fredswain
Updates, updates, must have updates!!!
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Mon Jul 23, 2012 7:30 pm
by Seabass
Sorry no updates on this one yet. Polishing the molds is a very tedious process.
To answer your questions about the mold, yes these are being molded with melted nylon pellets. I have done quite a bit of research and I know about the shrinkage on molding. I did not machine the parts ony larger and this is probably going to be more of a true test of can it be done.
I am experienced in mold making but not injection molds. This is my first go with injection molding and I totally expect utter failure. If it turns out ok, it is a bonus. The only thing holding me up right now is getting rid of the tooling marks.
As soon as I get some new progress I will be sure to post.
Jake
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Wed Sep 26, 2012 5:37 pm
by tommy911t
Looking forward to updates! Hopefully you're all done and secretly testing all of these parts on unaware local racers!
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Fri Feb 22, 2013 8:50 am
by Seabass
Guys this project stalled once again due to me being in Korea. I will pick it back up when I get back to the states. I purchased a CNC so I won't have to travel to my dads house to cut the parts.
I was unable to get my molds sent out because I was having issues polishing out the tooling marks. I got the rear arm mold ready but the front mold has some really tight corners I could not get into. It is going to be critical that i get the molds smooth, or we may not be able to get the parts out.
This car is going to happen, I am just on the same timeline as Scr8p right now...
Jake
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Fri Feb 22, 2013 9:05 am
by scr8p
Seabass wrote:I am just on the same timeline as Scr8p right now...
somewhere around 2017 then.........
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Fri Feb 22, 2013 9:09 am
by Lonestar
Don't worry Jake - we won't let you off the hook
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Fri Feb 22, 2013 12:35 pm
by askbob
Just make it back here safe man!
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Fri Apr 19, 2013 9:19 am
by Showcase1186
I'm very interested in this project. I think I have a good alternative to molding the arms, but I need the cad files. PM sent.
Re: 91 Masami Stealth replica (Arm injection molds ready)
Posted: Fri Apr 19, 2013 6:55 pm
by Phin
Was just browsing through an RCCA scan and spotted this pic of Cliff Lett showing off the Stealth car and thought it would be ironic to post it in this replica thread since he's was pointing to a No Copies decal.
I also thought it was pretty interesting that the body on the Stealth car is not sporting a Masami paint job.