Tooling costs

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#1

I just did a quick search on RTM molding. I would like to be able to have use of such equipment and tooling but it seems very expensive. The big company that specializes in RTM set ups charges $27,000.00 for one hood mold. The RTM equipment is $87,000. The thing that makes it seem worth it is making one part every 20 minutes.

I almost swallowed my tongue on that 27K mold cost.

What typically do carbon fiber shops charge for making a mold the size of a hood ( two molds there )?

Most times I charge $25hr + materials… but in this economy i have gone even lower than that charging only $10hr if the customer has me make all the parts for them and i get that end of their business.

#2

It depends what type of mold you want. low temp, high temp, carbon mold, glass mold, prepreg mold, autoclave mold. Many variables that would effect the cost of the tool.

Shop rates include all the overhead of the shop, usually $75+/hour. Im sure there cheaper shops out there doing $50ish. I dont see how any company could survive going much under that. I guess it depends what they have for an overhead, and the employee salaries etc… Usually material price is brought up another 50% atleast.

#3

Yeah but once you got the RTM injection system, you can just make molds to offset the costs! Else, go RTM Lite…cheaper!

#4

What do you want, what do you have (plug?), what do you expect.

RTM mould? What kind of RTM? What will your layup be?

The 78.000 dollars on RTM machines seems a lot to me. There are way cheaper solutions. (professional solutions, not a pressure pot with a bucket of resin in it.)

Hell, I just sold a old surplus, non-revised injection machine (Plastech Hypaject) for Euro 1000. I must admit this was an oldie, and looked sh!t, but it worked.
I believe new machines are 10k upwards, but need to check.

Also, with a bit of training or some good instructions, making your own RTM Light moulds is not too difficult. It is a matter of doing things as in the instructions.

#5

What’s the difference with RTM lite? smaller system?

#6

RTM is where 2 rigid moulds are pressed together, with a stack of fibers in between. A vacuum can be applied, but is optional, and resin is pressed in the mould at high pressure. Temperature can be rised, if needed.

One of my customers makes objects with glass and sand this way, heating up the mould to 180 degrees C before infusion at 20 bars.

RTM Light is where there is a rigid mould, and a semi-flexible top mould. Again the mould is loaded, and the top mould is closed. The perimeter of the mould has 2 seals, and a high vacuum is created between them, pressing the mould down. The product space is vacuumed as well, and resin is fed in, at low to moderate pressure (1-4 bars usually). This is slower, but the moulds can be much more simple.

Both systems are very clean to work with, no fumes, no resin contact. If I were to open a shop, these systems would be what I would target for.

#7

[QUOTE=herman;27429]RTM Light is where there is a rigid mould, and a semi-flexible top mould. Again the mould is loaded, and the top mould is closed. The perimeter of the mould has 2 seals, and a high vacuum is created between them, pressing the mould down. The product space is vacuumed as well, and resin is fed in, at low to moderate pressure (1-4 bars usually). This is slower, but the moulds can be much more simple.QUOTE]

does RTM lite sound a lot like infusion to anyone else?

#8

it sounds like vartm. vacuum and then pressure to pump resin.

i like the idea of the “bag”, top mold, being flexible and reusable.

1st Q: With RTM or RTM lite is peel ply or release ply needed or used?

2nd Q: What materials and equipment is needed to make your own flexible top half of the mold?

#9

Rtm is usually done with two solid molds since the resin is injected into the mold with pressure. If the mold halves weren’t solid the flexible side would inflate.

#10

VARTM, RTM Light, it is all a matter of definition. Be careful when talking to eachother, to make sure you are discussing the same process. Making up fancy acronyms seems to be everyones hobby…

Q1: No, RTM Light (lets call it that way) produces products which are smooth on both sides. Of course you could introduce peelply, but it would be sitting against the mould. (can be done in any situation, I once built a boat in a sloppy female mould, and the first layer I laminated was peelply)

Q2: To make your own flexible top mould, there are some small things you need. Basicly it is just laminating a thin part, but with the perimeter heavily reinforced, to create a stiff structure. (usually incorporating a steel structure, which is glued to the laminate.)

When you have your female mould, with flanges, here are the basic steps:

-create your laminate thickness. This used to be done in wax sheet. If you choose to do so, coat the mould with PVA first, or you will have a hard time getting the wax out. Alternatively infuse some Soric in the mould. Soric holds its thickness beautifully. Make it smooth afterwards.
The mould flanges need to be designed. That is a matter of applying some wax sheet, and glueing some silicone rubber profiles to the mould. (they create recesses in the top mould for installing rubber seals, create a resin path around the part, etc)

Then it is a matter of laminating a thin part over the lot, and adding a lot of glass and filler paste to the sides.

After cleaning up some connectors are glued in, for perimeter vacuum, for seal inflation (the inner seal inflates to create a positive seal) and for the resin inlet.

Creating a part is filling the mould with fibers, close the mould, install (push fit) a catch pot, and apply vacuum, connect the resin feed line (there is a nice gadget for that) and connect the solvent line to a waste tank, if it is not sitting on the machine already. Now infuse the part. after infusion, press the flush button, and about 1/4 of a pint (100 ml) of solvent is flushed through the system, al the way up to the resin inlet (through the gadget) and deposited into the waste tank. The resin that was sitting in the line from the mixing head to the resin inlet, and the 100 ml of aceton, is all the consumables that are used. Nothing more.

Here is a video that I feel is not the best, but it does give an idea. [ame=“http://www.youtube.com/watch?v=yTsXKGUdtCE”]YouTube - RTM Light process “The best case” English version Fiberglass[/ame]

The market for this technique is quite big, and there are many small tools and products that really do help, like the gadget to add resin and be able to flush, flange mould release (liquid) that cleans the mould flange as well from any excess resin (some resins leave some deposit when there is only a thin layer), etc etc.

#11

I guess what I mean is if you use one of those silicon reusable bags for infusion, you automatically go from infusion to rtm light?

#12

Sort of, yes. You are slightly more flexible in layup and runner system with silicone, but the price is quite high, and durability, especially with polyester, is limited.

#13

Hi Herman, great link and info!

Can one make their own silicone form-fitted male counter? are there any liquid silicone materials out there that are suitable for such application?

#14

No, it’s not any different than just switching to another type of bagging film. Resin infusion = vartm anyways.

#15

Tooling is often overlooked when estimating the time and cost of producing composite parts. Mostly by hobbyists, but also a lot of companies I’ve worked with. This can easily be the largest expense of any project. These costs obviously have to be amortized over the production run, and are especially important when planning personal projects!

There’s lay-up tooling, secondary bond tooling, trim & drill fixtures, and final assembly fixtures to consider. Regardless of material they’re made from, they will not be cheap. They always need to be of the highest quality possible, whether only 1 part will be made or 1,000.

Here’s an example of tooling for a new project. This large layup tool cost about $250,000 and was designed with the particular manufacturing process in mind. It rotates to allow the techs to apply release agent and layup pre-preg inside, and has removable inserts for raised sections in the final part. The stand was designed to allow for direct loading in the autoclaves without using a separate cart.

#16

Another example where tooling costs will seem insane just to produce relatively simple parts.

There was a need for structural aircraft parts with a “T” profile with all smooth surfaces. In order to accomplish this, it was necessary to have compression tooling made, and cost was easily over $15,000. All for a simple shape that goes inside of a large structure comprised of several sub-assemblies.
During the engineering phase of this tooling, it was necessary to account for final layup thickness of all three legs of the “T”, and how it would be put together after layup without distorting the plies.

#17

this guy has some great vids

[ame=“http://www.youtube.com/watch?v=KJ_xZ7XYYaw&feature=mfu_in_order&list=UL”]YouTube - Explaination and Injection of a Light RTM Mold Part:1[/ame]