Mobile Driving/Flying Cockpit with Motion and Tactile ( Build )

[RCHeliguy]

The mold set for about 14 hours. It asked for 12.

The blank came out pretty easily.

Because the Delrin released as easily as it did, I decided to go ahead and pour the epoxy with the black mica powder on my first try. I spent a couple minutes flicking the sides of the mold with my finger to try to release any bubbles. The top looks pretty smooth now.

The package says 36 to 72 hours to cure depending on the pour size. Since it allows for up to 2 inch thick pours and this is only 3/4" thick, I may see how it does in 48 hours. If it looks good, I'll pour a second copy immediately and start testing the first for durability. Epoxy typically gets stronger for a few days after it sets. I'll need to sand the back flat which is the open side of this mold.

 

[RCHeliguy]

Also trying different grit polishes out to see what I can do with aluminum on my new 3/4 hp polishing machine.
Making progress, but this was my first attempt. I mostly focused on the aluminum edge.

 

[Atak_Kat]

What a great journey. So many great tips and ideas along the way (the UHMW tape is possibly my favourite, need to find that stuff). The time you've put into your rig with all the enhancements and reconfigurations is impressive. Perhaps more impressive is the level you've gone to document, photograph, and talk through all the different items and share it here. So, thanks for that.

 

[RCHeliguy]

he molding process works.
The part released well.
The bolt hole is perfectly perpendicular and the bolt fits perfectly.

However I did expect the finish to have some issues since I saw bubbles on the underside of the mold which is the face you will see. I have a degassing chamber ordered to get the air bubbles out of the silicon for the next mold I make.

I'm also glad I ordered the jet black dye. The black mica finish might be OK, but I think black will be best.

 

[RCHeliguy]

I started testing the part with 48 hours of cure time.
So far so good and the charcoal actually looks pretty good once mounted.

However I need to rethink how I made the mold while I'm waiting for the degassing vacuum chamber to arrive. Currently I have to flatten the back of the mold and that will take too much time.

 

[Atak_Kat]

Sounds like a 2 part mold is an idea? I might try to make some Fanatec ones on my mini-lathe....

 

[Deleted member 197115]

Any benefit of molding over 3D printed model?

Simucube 2 QR mount by Uros76

This is my first 3D print design. I couldn't find such mount out there so I created one. If you have a steering wheel with Simucube 2 SQR system this is a mount design for your simracing rig. I was feed up leaving wheels around the room. With this mount you can simply hook the wheel on the rig...

www.thingiverse.com

 

[RCHeliguy]

Any benefit of molding over 3D printed model?

I've passed that link around repeatedly. Uros approached me after I posted my initial Delrin solution asking me for an STL file. After I said I didn't have one, I gave him the critical angles and suggested he use them to create a 3D printed version which he did and then shared.

There is nothing wrong with 3D printed parts for this application. I think my design is a bit more elegant and a bit more versatile using a single bolt, but as long as it isn't exposed to lots of heat where the PLA will fail, it should be fine given enough infill. Since most rigs are indoors, I don't see an issue.

Cosmetically once I get my vacuum degasser, the molded parts will have a much prettier finish with perfectly smooth edges. In fact based on what I saw from my first molded part, minus mold bubbles, they will look quite a bit better than my original Delrin parts. So I'm intending to replace both of my delrin parts with molded parts and keep the original Delrin parts for use as mold blanks.

Granted I have filed, sanded and polished my chosen Delrin blank quite a bit now, so that took a bit of effort.

While I have a 3D printer on the way, I see 3D printers as much more of a prototyping tool. In many instances I would expect to print a part and then either sand it or skin it with bondo and prime that part to use as a mold either for silicone molding or for aluminum casting in the future.

I have seen good results out of 3D printers, but I wouldn't be going through the effort I am right now if I didn't think the solid molded parts were better.

From a production standpoint if I can make a number of molds, I can pour them all at once and just pop them out when they are cured and pour another batch and all the while have my 3D printer available for me to work on the other things I want to prototype. So there is that as well. I want my 3D printer available to me and not tied up in production.

Sometime next week, I should have a good looking part. I'll take detailed pictures of it. You will be able to see it's finish, but not feel it's silky finish. Still at that point you can decide for yourself if it was worth it.

 

[RCHeliguy]

Sounds like a 2 part mold is an idea? I might try to make some Fanatec ones on my mini-lathe....

I just sold my two aluminum Fanatec mounts. You can find them on Etsy for $29 each delivered.

 

[RCHeliguy]

The vacuum degasser arrived today. The initial test looked good. It quickly drew down to nearly -1 bar or -30 inches of Hg according to the gauge.

The idea is that I put the silicone in there let the vacuum run and then open the intake if it foams up too much and risks overflowing. Then cycle like this until all the air is out. The same thing with epoxy, but it doesn't foam up like silicone does.

The vacuum pump comes nearly dry, so it's important to fill it before starting the pump. I also washed the dust and debris off the lid seal.

I think I purchased enough pump oil to last me as long as I pump lasts.

Will make 1 or 2 new molds this weekend.

 

[RCHeliguy]

Much better. This should give much better results. There are no bubbles in the mold.

 

[RCHeliguy]

Preparing to cut this mold differently than the last time and decided to take my ancient X-Acto blades and run them through my diamond stones.

At first I just didn't like the rust on them, but then I ended up going Course, Fine, Extra Fine and then Extra Extra Fine (8,000 grit) 3 micron diamond stone for the blades I planed to use 2 or 3 of them. But once I started, I just kept going until they were all sharp and ready to go. A couple that I plan to use are quite a but sharper than stock out of the bag blades come.

I'm also wearing a band aid right now. A few of them are crazy sharp now.

Compare the stock finish on the wide flat blade below and the thin flat blade in my smaller blade holder. You can see the grain on the wide blade and the small blade is mirror smooth and counter beveled at the end.

I keep all my hand plane honing stones and Veritas blade holders in the is old Brookstone wooden box that used to hold a wine cork tool that broke.

Going to come in sideways and detach the small end of the bolt hole.
Then I'll cut a wavy pattern on the large side of the mold and finally meet up with the mold.
I'm going to leave the large side of the mold attached to the wood with anchoring screws and bolt hole support screw in place and cut the wood backing down to size.

Then I should be able to slightly over fill the mold and press the top down. I may need a small relief area, but I'll see how this goes. It should release much easier from this side. Fingers crossed.

 

[RCHeliguy]

This will work. The molded part is on the left and lightly sanded to remove flashing. After polishing it should look very good.

When I flipped the mold, there was a bit of air in the mold.
Since the mold is sealing well, I'm going to mold a straw into the next mold and pour from the back and just tilt the mold to make sure that it the high point. I'll have little nub to sand off, but otherwise it should be perfect at that point.

 

[RCHeliguy]

This has been trial and error. The 3rd mold is now what I was aiming for except that it needs a larger pour hole.

1. Zero bubbles
2. Wavy joint cut all around cut so both halves will register exactly
3. Pour hole cut into the bottom of the back of the piece.
4. The mold size is now exactly 10oz of silicone.

Still I've ordered some 3000,5000,7000 grit wet sand paper to get a final finish. I've also ordered some small funnels.

The molds are at a slight angle to try to make sure all the air ends up at the top and I'll slightly over fill the mold and then trim off the pour hole. Hopefully zero bubbles in the parts this time.

This thick pour epoxy has a VERY long cure time and seems to take 20+ minutes to clear the bubbles from it in the vacuum chamber.

Bleeding the vacuum slowly especially starting from full pressure reduces the amount of vacuum pump oil that escapes in the exhaust. My wife commented that the oil smell was like asparagus pee and that when I bled the vacuum slowly she said it didn't smell nearly as bad.

What I found out this morning is that my pour holes are too small. I spent too much time burping the molds and they took forever to fill. So after these parts come out in a couple of days, I'm going to make the pour holes larger. Meanwhile now that I have the molding process down I'm going to make another mold or two.

 

[RCHeliguy]

I'm seriously debating cutting bait on this endeavor. So far they are too time consuming and I have to wet sand them after they come out of the mold now because of flashing from the mold halves and now pour and vent holes.

At this point I would be just as fast cutting them out of solid Delrin in my shop, which I had already written off as way too time intensive.

I've added vent holes to the molds below, but now I'm not liking the ones coming out of the 2nd mold as well as the 3rd mold.

I'm at the point of only wanting to keep the last mold out of the three molds so far. I need to make at least a 3 or 4 more to make the batches work. While I think I've got the mold making process down now, I've very much lost interest in making more molds, never mind all the degassing, pouring, wet sanding etc.. I'm remembering how much I hate production of any kind. Once I've got a part designed and have what I need personally, that is when I need to stop.

So at this point I think even the chance that I try to create a small production run is very minimal. I've got too much billable work that this is conflicting with.

 

[RCHeliguy]

This is not related to my rig, so I'm going to stop posting about these wheel hangars after this post.

I ended up doing a complete 180 on this and just ordered a bunch of 3/4" thick black Delrin. I'm going to make up some tooling to make a single batch of 50 perfect precise pieces in an assembly line in my shop.

Started the tooling and ordered some 500lb hold down clamps to make the jigs work properly. They are over rated so the arms are longer and they will require less effort to engage/disengage and I liked the design better.

They fit perfectly, but I'm making modifications to it.
1. The hole sits a tiny bit lower so it can not be seen if a wheel is in place.
2. More complex bevels on the bottom. It should add a bit more eye candy to the design. I'll be experimenting with that.

Below is still a primitive shape, but it is easier to drill holes before the finishing touches go on.

I think have 5 total fixtures with two being used twice on my router and one on my shooting board.

My current plan is to make a circular cut with a 1/8" spiral down cutting bit on both the top and bottom of the part and then come back with a chamfer bit using the same two fixtures.

Then one more fixture to hold the parts on my shooting board in both orientations to cut remaining sharp edges off. That should go reasonably quickly with my #6 hand plan.

That should get me all the way to final finish where I'm expecting my new 3/4 Hp 8" polisher will buff these to a shine.

 

[RCHeliguy]

I'm pretty happy with my tooling for this and wanted to show off a bit.
CRAZY sharp bits!!!!

Cutting both ends in two passes, straight cut and then chamfer.

It still needs polish, but I like how it came out. I think it is very clean looking.

I've got the Router bit speed figured out.

BUT, I can't do this in a single pass.

 

[RCHeliguy]

I posted in the Tactile thread about how I noticed while playing with thick pour epoxy that because of it's LONG cure time it can be formed around complex objects a couple days into the curing process while it is still very bendy. I have some ideas on how to improve my seat transducer's mount to my seat using this process.

However the first thing I may do using this process is simply pour a small rectangular slab of epoxy, let it setup for 24 hours, then form it to the exact curve of my HE Spring clutch pedal. Once it has hardened, then I would through drill it and shape it to the curve I want.

 

[RCHeliguy]

As if I didn't have enough on my plate....
I have a lot of ideas for my rig that this 3D printer will help me with, however I'm not sure I'll even have time to crack this box in July or even August.
I am COMPLETELY covered up with work right now working crazy hours and I don't think I'll have time to play with this for quite a while. My rig has been collecting dust for a while now. I'm effectively in work-o-holic mode right now not that I like to be in this mode and it looks like I'll be in this mode for at least 1 maybe 2 or more months.

 

[RCHeliguy]

Couldn't take it anymore, had to start building it!